The Egyptian Rheumatologist (2014) 36, 93–99

Egyptian Society for Joint Diseases and Arthritis

The Egyptian Rheumatologist

www.rheumatology.eg.netwww.sciencedirect.com

ORIGINAL ARTICLE

Serum BLyS and APRIL as possible indicators

of disease activity in pediatric systemic lupus

erythematosus and juvenile idiopathic arthritis

* Corresponding author. Address: 23 Elrewidy Street (in front of

General Hospital), Berket Elsaba, Minofya, Egypt. Tel.: +20

1222482447.E-mail address: g.olemy@yahoo.com (G.G. Elolemy).

Peer review under responsibility of Egyptian Society for Joint Diseases

and Arthritis.

Production and hosting by Elsevier

1110-1164 � 2013 Production and hosting by Elsevier B.V. on behalf of Egyptian Society for Joint Diseases and Arthritis.

http://dx.doi.org/10.1016/j.ejr.2013.11.001

Gehan Gamal Elolemya,*, Eman Abdelalem Baraka

a, Soha Abdelhady Gendy

b,

Eman Ramadan Abdelgwad c, Abeer Ahmed Aboelazm d

a Department of Rheumatology and Rehabilitation, Faculty of Medicine, Benha University Hospital, Elqalyubia BO 13518, Egyptb Department of Pediatric, Faculty of Medicine, Benha University, Egyptc Department of Clinical Pathology, Faculty of Medicine, Benha University, Egyptd Department of Microbiology and Immunology, Faculty of Medicine, Benha University, Egypt

Received 17 September 2013; accepted 2 November 2013Available online 5 December 2013

KEYWORDS

Pediatric SLE;

SLEDAI;

JIA;

JADAS-27;

BLyS;

APRIL

Abstract Aim of the work: To assess serum levels of B lymphocyte stimulator (BLyS) and a pro-

liferation-inducing ligand (APRIL) to determine their correlations with disease activity in pediatric

systemic lupus erythematosus (pSLE) and juvenile idiopathic arthritis (JIA) patients.

Patients and methods: Twenty-nine pSLE patients and 33 JIA patients were recruited. SLE dis-

ease activity was assessed using the systemic lupus erythematosus disease activity index (SLEDAI),

while the juvenile arthritis 27 joint disease activity score (JADAS-27) was calculated for JIA

patients. Serum samples were assayed for BLyS and APRIL by the enzyme linked immunosorbent

assay (ELISA).

Results: Serum BLyS and APRIL were elevated in both pSLE and JIA patients compared to

controls. Serum BLyS levels correlated with both SLE and JIA disease activity (p= 0.042,

p= 0.019, respectively) whereas serum APRIL levels correlated positively with JADAS-27 and

inversely with SLEDAI (p= 0.001, p= 0.02, respectively). Elevated serum BLyS and APRIL were

significantly associated with a lower incidence of nephritis (p= 0.043, p= 0.016, respectively),

while elevated serum APRIL significantly associated with negative anti-dsDNA in pSLE patients

(p= 0.017). In JIA patients, both serum BLyS and APRIL were significantly associated with the

94 G.G. Elolemy et al.

presence of ANA (p= 0.008, p< 0.001, respectively), while high serum APRIL associated with the

presence of RF (p= 0.035). APRIL and BLYS levels correlated with each other positively in JIA

but inversely in pSLE patients.

Conclusion: Serum BLyS showed elevated levels that correlated significantly with pSLE and JIA

disease activity, accordingly anti-BLyS therapy might be of great benefit to offset disease flare. The

inverse correlations observed between APRIL with both BLyS and disease activity in pSLE patients

raises the possibility of being a down regulator of the disease process.

� 2013 Production and hosting by Elsevier B.V. on behalf of Egyptian Society for Joint Diseases and

Arthritis.

1. Introduction

Emerging data from clinical trials are providing a critical in-sight regarding the role of B cells and autoantibodies in vari-ous autoimmune conditions. Deregulated B-cell function has

been implicated in several autoimmune diseases, including sys-temic lupus erythematosus, rheumatoid arthritis, and multiplesclerosis. B cells contribute to pathological immune responses

through the secretion of cytokines, costimulation of T cells,antigen presentation, and the production of autoantibodies [1].

Given the crucial role of B cells in the pathogenesis of SLEand RA, it stands to reason that factors which promote B cell

survival and/or function are also crucial [2]. B-lymphocytestimulator (BLyS)––also called B cell-activating factor belong-ing to the tumor necrosis factor family (BAFF)––and a prolif-

eration-inducing ligand (APRIL) are members of the tumornecrosis factor (TNF) family and are important regulators ofB-cell maturation, survival, and function [3,4].

They regulate the size and composition of B-cell compart-ment and act as important driving factors for B-cell hyperpla-sia and autoantibody production in autoimmune processes [5].

BLyS and its homolog APRIL are widely expressed bymany cell types, including hematopoietic and stromal cells[6]. There are two forms of BLyS, membrane-bound and solu-ble. The gene expression and the levels of BLyS are regulated

by cytokines, basically interferon-c and to a lesser extent inter-leukin-10 [7].

The binding of BLyS and APRIL to their receptors acti-

vates specific TNF receptor-associated factors (TRAFs), whichregulate signal transduction in B cells [8,9].

Beside their well-known function as antibody secreting

cells, an antibody independent role for B-cells in diseasepathogenesis has been documented by experimental data aswell as the promising results of B-cell depleting therapies in

RA [10–12].Juvenile idiopathic arthritis (JIA) is a heterogeneous condi-

tion gathering distinct forms of chronic arthritides of unknownetiology that begin before the age of sixteen and persist for at

least six weeks [13].SLE is a systemic autoimmune disease characterized by

autoantibody production against self-antigens [14]. The role

of BAFF (BLyS) in the pathogenesis and disease activity inSLE is well-known and the novel noticeable correlation withthe damage index highlights the utility of BAFF as an indica-

tor of disease damage and predictor of poor outcome [15]. Therationale for developing B-lymphocyte (BLyS) inhibitors hasincluded successive investigations. B-cell stimulatory factorsthat can promote the loss of B-cell tolerance and drive autoan-

tibody production are exciting new candidates [14].

This study was designed to assess the relationship of serum

BLyS/APRIL levels to disease activity in pediatric pSLE andJIA patients.

2. Patients and methods

2.1. Study approval

This study was approved by the Ethics Committee of our insti-tution (Benha faculty of medicine). Legal guardians of all sub-jects gave their written informed consent before participation

in this study.

2.2. Participants

This study included 82 children recruited from the inpatientand outpatient clinics of the rheumatology and pediatricdepartments, faculty of medicine, Benha University Hospitals.

Twenty-nine pediatric patients met the American College ofRheumatology (ACR) criteria for SLE classification [16], while33 juvenile patients were diagnosed as juvenile idiopathic

arthritis (JIA) according to the International League AgainstRheumatism (ILAR) classification criteria [17]. Twenty ageand gender matched children served as controls.

The following information was obtained: demographic data

(age, gender, age at disease onset, duration of disease), JIAsubtype, number of active joints, clinical manifestations ofpediatric SLE (pSLE) patients at presentation, laboratory val-

ues and treatment data (biologics, concomitant DMARDs andcorticosteroids including start and stop dates, as well as rea-sons for withdrawal).

pSLE patients were evaluated using the systemic lupuserythematosus disease activity index (SLEDAI) [18] while,nephritis was classified according to the World Health Organi-

zation (WHO) classification based on patients’ previous data[19]. JIA patients were evaluated using the juvenile arthritis27 joints disease activity score (JADAS-27) [20].

2.3. Laboratory investigations

Complete blood cell count (CBC), erythrocyte sedimentationrate (ESR) by the Westergren method, complete urine analysis

for casts and/or proteinuria, IgM rheumatoid factor (RF)done by Rose–Waaler test, antinuclear antibody (ANA) anddouble-stranded DNA antibodies (anti-dsDNA) done by indi-

rect immunofluorescence on Hep-2 cells by Kallestad HEp-2Slides and Kallestad indirect fluorescent antibody (IFA) assays

Serum BLyS and APRIL as possible indicators of disease activity in pediatric systemic lupus 95

for detection of autoantibodies to dsDNA respectively, bothkits were supplied from Biorad.

2.4. Serum BLyS and APRIL determination

Assay of BLyS and APRIL was made by the enzyme linkedimmunosorbent assay (ELISA) technique using the kit sup-

plied from R&D Systems, Inc (USA). Human BAFF/BLyS/TNFSF13B (Catalog Number DBLYS0) Immunoassay wasused for BAFF assay. Intra-Assay Precision (CV) was 3.8%.

Inter-Assay Precision (CV) was 7.8% for Human BAFF/BLyS/TNFSF13B Immunoassay. Human APRIL/TNFSF13Catalog Number: DY884 was used for assay of serum APRIL.

Both assay procedures were followed according to the manu-facturer’s instructions.

Statistical analysis: The collected data were analyzed usingSPSS version 16. Categorical data were presented as number

and percentages while continuous variables were presented asmean and SD if parametric, and median and range if non para-metric. Chi square, Z test, Mann Whitney U test, Kruskal–

Wallis test and Spearman’s correlation coefficient were usedas tests of significance. Two sided p-value <0.05 was consid-ered significant.

3. Results

3.1. Demographic and clinical characteristics of the study groups

The present study comprised 29 pSLE patients (females to

males, 25:4 with median age 14.3 years) and 33 JIA patients (fe-males to males, 23:10 with median age 12.2 years). JIA patientswere further classified into 6 systemic-onset, 12 polyarticularand 15 oligoarticular subtypes. Nephritis was observed in 8

pSLE patients (27.58%), one patient was class II nephritis,2 patients class were III, one was class IV and 3 were class V,while the nephritis class could not be determined in one patient.

The median SLEDAI was 12 (range 6–28), while the medianJADAS-27 of JIA patients was 15.1 (5–37) with no significantdifferences noted among different subtypes (p= 0.16).

Although the pSLE patients had shorter disease durationthan JIA patients, no significant difference was noted betweenthem (p < 0.05). Marked significant differences betweenpSLE and JIA patients were observed regarding certain medi-

cations, with more pSLE patients receiving corticosteroids(p< 0.001), azathioprine (p< 0.001) and cyclophosphamide(p= 0.013), while more JIA patients received methotrexate

(p< 0.001). There were no differences regarding (NSAIDs)(p= 0.57) and hydroxychloroquine (p = 0.86) therapy. Onlyone polyarticular JIA patient was receiving etanercept (anti-tu-

mor necrosis factor treatment). Characteristics of the studiedpatients are shown in Table 1.

3.2. BLyS and APRIL levels in pSLE

The median BLyS serum level was 1.14 ng/ml in pSLE patients(range 0.2–2.13) and 0.58 ng/ml in healthy controls (range 0.04–1.06), p < 0.001. Sera from patients with pSLE also showed a

high median APRIL serum level of 11 ng/ml (range 0.11–205)compared to healthy controls (0.9 ng/ml, range 0.0–23.4),p = 0.046.

Higher serum levels of both BLyS and APRIL were associ-ated with lower incidence of renal involvement (p = 0.043 andp= 0.016, respectively). Meanwhile, higher serum APRIL lev-

els associated absence of anti-dsDNA (p= 0.017), while serumBLyS did not (p= 0.197), (Table 2).

Only serum BLyS was significantly higher in patients

receiving cytotoxic drugs (azathioprine, cyclophosphamide)(p= 0.017). On the other hand, neither high prednisone doses(>1 mg/kg/day) nor gender significantly affect serum BLyS

(p= 0.83, p= 0.23, respectively) or APRIL (p = 0.56,p= 0.25, respectively) levels, Table 2.

Serum BLyS levels correlated positively with disease activ-ity (r= 0.38, p= 0.042). Inverse correlations between serum

APRIL levels and disease activity (r = �0.429, p = 0.02) inpSLE patients were observed, Fig. 1(A and B). There wereno significant correlations between serum BLyS, or APRIL

levels with age, disease duration or blood leukocyte and lym-phocyte counts (p< 0.05).

3.3. BLyS and APRIL levels in JIA disease

Serum BLyS levels were significantly higher in JIA patients(median 1.18 ng/ml, range 0.2–4.21) compared to controls

(median 0.58 ng/ml, range 0.04–1.06), p< 0.001. The medianserum BLyS level was significantly elevated in systemic onset,3.52 ng/ml (range 1.23–4.21) compared to polyarticular onset,1.25 ng/ml (range 0.45–4.12) and oligoarticular onset, 1.04 ng/

ml (range 0.2–2.59) with p = 0.007. The median APRIL Levelwas 35.3 ng/ml (range 0.8–211) in sera of patients with JIA and0.9 ng/ml (range 0.0–23.4) in sera of healthy controls

(p< 0.001). A significantly elevated median APRIL level(p= 0.004) was found in sera of systemic onset patients(184.5 ng/ml, range 33.6–211) compared to polyarticular onset

(41.75 ng/ml, range 3.5–201) and oligoarticular onset (23 ng/ml, range 0.8–100).

Both BLyS and APRIL levels were significantly elevated in

sera of JIA patients with positive ANAs (p = 0.008,p< 0.001, respectively). Only serum BLyS was significantlyhigher in JIA patients with uveitis (p= 0.031) and APRILwas higher in sera of those with a positive RF (p = 0.035).

There was a significant increase of serum BLyS levels in pa-tients receiving DMARDs compared to other patients(p= 0.006). Also, there were no significant differences in ser-

um levels of APRIL between JIA patients receiving and notDMARDs (p < 0.05). BLyS and APRIL levels among seraof JIA patients did not differ significantly with respect to

gender or corticosteroid doses (prednisone P1 mg/kg/d),(p< 0.05), (Table 3).

Both BLyS and APRIL levels significantly correlated withdisease activity (r= 0.497, p= 0.019 and r = 0.549,

p= 0.001, respectively) in sera of JIA patients, Fig. 1 (C andD). Neither BLyS nor APRIL correlated with age, diseaseduration or thrombocyte count (p < 0.05). APRIL and BLyS

serum levels correlated positively to each other in JIA patientsbut inversely in pSLE patients (r= 0.469, p= 0.006 andr= �0.403, p = 0.03, respectively), Fig. 1 (E and F).

4. Discussion

Autoreactive B cells are driven by self-antigens, but the fac-

tors that promote the loss of B cell tolerance and drive

Table 1 Demographic and disease characteristics of pSLE and JIA patients.

Controls

(n= 20)

pSLE patients

(n = 29)

JIA patients

All JIA

(n= 33)

Systemic

(n= 6)

Polyarticular

(n= 12)

Oligoarticular

(n = 15)

Median age (range)/years 12.5(3–15) 14.3 (9.6–16.8) 12.2 (3–16) 10 (3–15) 14.3 (7–16) 11 (4–16)

Female/male (No.) 14/6 25/4 23/10 4/2 7/5 12/3

Disease duration(years)

Median (range) – 4.6 (0.0–7.3) 5.4 (1–11) 5 (1–10) 6(2–11) 5(2–11)

SLEDAI median (range) NA 12 (6–28) – – – –

JADAS-27 median (range) NA – 15.1 (5–37) 16.7(5–25.2) 16.1(9–37) 12.5(5.9–17)

Laboratory findings

–WBCs · 103/mm3 median (range) NA 4.9 (2.5–14.7) 7.2(3.9–14.2) 6.7(4.5–14.2) 7.3(3.9–12.9) 6.9(4.2–13.2)

–Lymphocytes · 103/mm3 median (range) NA o.38 (0.05–0.77) 0.41(0.12–0.7) 0.40(0.15–0.7) 0.41(0.11–0.8) 0.43(0.12–0.7)

–Thrombocytes103/mm3 median (range) NA 170.6(70.5–250) 447(180.6–544.8) 470.5(243–544.8) 346.8(215–490) 319.8(180.6–422)

–ANA, +ve no (%) – 29 (100) 15(39.58) 1(9.09) 5(31.25) 13(61.9)

–Anti-dsDNA, +ve no (%) – 26(89.65) 0(0) 0(0) 0(0) 0(0)

–RF, +ve no (%) – 3(10.34%) 5(10.4) 0(0) 4(25) 1(4.8)

Medications, no (%)

–NSAIDs 12(41.37) 16(48.48) 3 (50) 9(75) 4 (26.66)

–Predisolone < 1 mg/kg/d 25(86.2) 8(24.24) 5(83.33) 2(16.66) 1 (6.66)

–Predisolone P 1 mg/kg/d 3(10.34) 3(9.09) 3(50) 0(0) 0 (0)

–Hydroxychloroquine 26(89.65) 11(33.33) 0(0) 7(58.33) 4 (26.66)

–Methotrexate 1(3.44) 23(69.69) 3(50) 12(100) 8 (53.33)

–Etanercept 0 (0) 0(0) 0 (0) 1(8.33) 0 (0)

–Azathioprine 15(51.72) 0 (0) 0 (0) 0 (0) 0 (0)

–Cyclophosphamide 5(17.24) 0 (0) 0 (0) 0 (0) 0 (0)

pSLE, pediatric systemic lupus erythematosus; JIA, juvenile idiopathic arthritis; SLEDAI, systemic lupus erythematosus disease activity index;

JADAS-27, juvenile arthritis 27 joint disease activity score; WBC, white blood cell; ANA, antinuclear antibody; Anti-dsDNA, anti-double

stranded DNA; RF, rheumatoid factor; NSAIDs, non-steroidal anti-inflammatory drugs; NA, not applicable.

96 G.G. Elolemy et al.

autoantibody production are still unknown [21]. BLyS isconsidered as a fundamental survival factor for transitional

and mature B cells, whereas APRIL mainly affects B1 cellactivity, humoral responses and class switching of immuno-globulins [3].

Whereas many previous studies have evaluated the roleof BLyS in adult populations with various immune baseddiseases [22–29], debated yet little information is available

about serum APRIL levels in adult patients with SLE [29–31] and almost none on pSLE. Important differences do ex-ist between pSLE and adult SLE and between JIA and adultRA [2]. Few studies have involved association of BLyS/

APRIL in pediatric patients with autoimmune diseases[2,32], whereas one study assessed plasma BLyS proteinand blood leukocyte BLyS mRNA in pSLE and JIA pa-

tients [2], another study [32] assessed BLyS/APRIL serumlevels in JIA patients only.

One of the hallmarks of active disease in human SLE is the

increased percentages of activated B cells and plasma cells inperipheral blood [33,34]. Concurring with previous studies,we demonstrated increased serum BLyS levels in pSLE pa-tients compared to healthy controls with a significant correla-

tion to disease activity (p = 0.042) [2].In addition, similar previous findings in a study done on

adult SLE patients reported a significant correlation between

changes in circulating BLyS levels and changes in diseaseactivity [26]. A better correlation of disease activity with bloodleukocyte BLyS mRNA levels than with plasma BLyS protein

levels was documented in another cross-sectional observa-

tional study [25]. Meanwhile, other studies did not find anyassociation between BLyS serum levels and SLE activity in

adult patients [22,23]. These disparities are not surprising asclinical manifestations of SLE are diverse and differences inthe pathogenesis between adult and pSLE may be present.

Elevated APRIL levels were also observed in our pSLE pa-tients compared to healthy controls with a limited inverse cor-relation to disease activity (p= 0.02). Similar results were

obtained in previous studies in adult SLE patients [29–31],whereas a significant correlation between serum APRIL levelsand musculoskeletal manifestations among patients with adultSLE when assessed by the BILAG index was reported in an-

other study [30].On comparing serum BLyS and APRIL levels with differ-

ent clinical parameters, serological markers and management

protocols, there was no association between serum BLyS levelsand anti-dsDNA antibody while contradictory results were ob-tained with serum APRIL levels, whereas lower serum APRIL

levels were found when anti-dsDNA antibody was present.The direct link between anti-DNA antibodies and nephritis

has been demonstrated [35,36], as well as its titers have beenconsidered as a predictor of renal flare [37]. Moreover, Reich-

lin et al. [38] stated that both anti-dsDNA and anti-ribosomalP antibodies were associated with a higher prevalence of renalinvolvement in juvenile SLE.

Since these antibodies are strongly associated with nephritisin SLE this may explain the lower incidence of renalinvolvement in our patients with high serum BLyS and APRIL

levels.

Figure 1 (A and B) Correlation between B lymphocyte stimulator (BLyS) and a proliferation-inducing ligand (APRIL) serum levels, and

systemic lupus erythematosus disease activity index (SLEDAI); (C and D) correlation between BLyS and APRIL serum levels, and

juvenile arthritis disease activity score (JADAS-27); (E and F) correlation between BLyS and APRIL serum levels in pediatric systemic

lupus erythematosus (pSLE) and juvenile idiopathic arthritis (JIA) patients, respectively.

Table 2 Comparison between BLyS and APRIL serum levels in different parameters of pSLE patients.

BLyS (ng/ml) median (range) p APRIL(ng/ml) median (range) p

Gender Females (25) Males (4) 1.13 (0.2–2.13) 1.24 (1.1–2.01) 0.23 10 (0.11–155) 56 (0.5–205) 0.25

Lupus nephritis +ve (8) –ve (21) 1.12 (0.2–1.85) 1.24 (0.7–2.13) 0.043* 5 (0.11–70) 56.5 (0.5–205) 0.016*

Anti-DNA +ve (26) –ve (3) 1.14 (0.2–2.13) 1.39 (1.02–2.11) 0.197 7.5 (0.11–205) 144 (53–155) 0.017*

Cytotoxic agents Yes (21) No (8) 1.21 (0.8–2.13) 0.8 (0.2–1.25). 0.017* 11 (0.11–205) 15 (0.5–100) 0.96

Predisolone P1 mg/kg/d Yes (3) No (26) 1.12 (0.82–2.13) 1.17 (0.2–2.11) 0.83 0.8 (0.8–40) 11.5 (0.11–205) 0.56

Anti-DNA, anti-double stranded DNA; BLyS, B lymphocyte stimulator; APRIL, a proliferation-inducing ligand.

Serum BLyS and APRIL as possible indicators of disease activity in pediatric systemic lupus 97

Davis et al. [39] reported an increased urinary excretion of

BLyS in adult SLE patients, especially among those with clin-ically overt renal involvement. On the other hand, circulatingsoluble APRIL may not be the only form of APRIL relevantto B cell biology and/or B cell based autoimmunity [31].

In concordance with our results, Morel et al. [29], found aninverse correlation between serum APRIL and anti-dsDNAantibody titers, they did not report any correlation between

serum BLyS and anti-dsDNA antibody titers. In other studies,

serum BLyS correlated with anti-dsDNA antibody titers inadult SLE patients [22,40].

Interestingly, serum BLyS levels were higher in pSLE pa-tients receiving cytotoxic drugs. This contradiction could be

attributed to the fact that patients with more active disease re-ceive more cytotoxic drugs. Adult RA or SLE patients treatedwith rituximab demonstrated reductions in B cell loads among

Table 3 Comparison between BLyS and APRIL serum levels in different clinical, laboratory and therapeutic variables of JIA

patients.

BLyS (ng/ml) median (range) p APRIL (ng/ml) median (range) p

Gender Females (23) Males (10) 1.31 (0.2–4.21) 1.11 (0.21–4.11) 0.32 27.5 (0.8–211) 19.5 (0.8–40) 0.27

Uveitis +ve (13) �ve (20) 2.13 (0.2–4.21) 1.09 (0.21–2.59) 0.031* 152 (0.8–211) 24(0.8–142) 0.051

ANA +ve (15) �ve(18) 2.03 (0.2–4.21) 1.03 (0.21–4.11) 0.008* 142 (13.11–211) 21.5 (0.8–40) <0.001*

RF +ve (5) �ve (28) 1.32 (0.89–3.9) 1.18 (0.2–4.21) 0.48 100 (36–211) 29.3(0.8–211) 0.035*

Cytotoxic agents Yes (23) No (10) 1.32 (0.2–4.21) 0.84 (0.21–1.85) 0.006* 47.5(0.8–211) 24.25(0.8–40) 0.07

Prednisolone P1 mg/kg/d Yes (3) No (30) 1.32 (1.21–2.13) 1.18 (0.2–4.21) 0.57 36(13.11–211) 34.46(0.8–211) 0.66

ANA, antinuclear antibody; RF, rheumatoid factor; BLyS, B lymphocyte stimulator; APRIL, a proliferation-inducing ligand.

98 G.G. Elolemy et al.

those under therapy that may have resulted in the elevated cir-culating BLyS protein levels [41]. The data presented heredemonstrate that corticosteroid therapy has no significant role

in BLyS/APRIL serum levels in pSLE patients concurring withprevious results [2].

In our JIA patients, elevated serum levels of both BLyS andAPRIL were observed and significantly correlated with disease

activity (p= 0.019, p = 0.001, respectively). Gheita et al. [32]found increased BAFF (BLyS) and APRIL serum levels in JIApatients associated with disease activity.

In contrast, no correlation has been reported between plas-ma BLyS protein concentration and disease activity, however,the Childhood Health Assessment Questionnaire (CHAQ)

which is a measure of functional disability, was used to evalu-ate disease activity [2].

B-cell pathology plays an important role in early-onset JIA.B-cells function as amplifiers of chronic inflammation in the

disease progress of JIA and might be a target of future thera-pies [42]. A profound decrease in circulating natural killer(NK) cells with coexisting hypergammaglobulinemia in JIA

consistent with B-cell hyperactivity has been reported [43].Thus, BLyS might play a crucial role in early activation of

self-antigen-driven autoimmune B cells with autoimmune T

cells further driving the switch for the production of patho-genic IgG autoantibodies [22].

In agreement with a previous report [32], we demonstrated

elevated serum levels of BLyS and APRIL in systemic onsetJIA patients compared to other types of onset. Furthermore,BLyS levels were significantly higher in JIA patients with uve-itis. A primarily B-cell-infiltrative process of an enucleated eye

globe has been observed in a 12-year-old patient with recurrentoligoarticular JIA [44].

Presence of RF was associated with higher APRIL levels in

JIA. There was no comment in the results on BLYS or APRILlevels in RF positive or negative pSLE patients.

A significant correlation between BLyS and APRIL in ser-

um of JIA patients was found in our study, in agreement witha previous report [32]. Similar to our results, Morel et al. [29]established an inverse correlation between BLyS and APRILin serum of adult SLE patients, suggesting a protective role

of APRIL.In conclusion, serumBLyS showed elevated levels that corre-

lated significantly with pSLE and JIA disease activity, accord-

ingly anti-BLyS therapy might be of great benefit to offsetdisease flare. The inverse correlations observed between APRILwith both BLyS levels and disease activity in pSLE patients raise

the possibility of being a down regulator of the disease process.

Conflict of interest

All the authors responsible for this work declare no conflict ofinterest.

Acknowledgement

We thank Professor Dr. Samia Abdel Moneim for her greateffort in editing the manuscript, it is really appreciated.

References

[1] Bluml S, McKeever K, Ettinger R, Smolen J, Herbst R. B-cell

targeted therapeutics in clinical development. Arthritis Res Ther

2013;15(Suppl. 1):S4. http://dx.doi.org/10.1186/ar3906 [Epub

2013 Apr 4].

[2] Hong SD, Reiff A, Yang HT, Migone TS, Ward CD, Marzan K,

et al. B lymphocyte stimulator expression in pediatric systemic

lupus erythematosus and juvenile idiopathic arthritis patients.

Arthritis Rheum 2009;6:3400–9.

[3] Dillon SR, Gross JA, Ansell SM, Novak AJ. An APRIL to

remember: novel TNF ligands as therapeutic targets. Nat Rev

Drug Discov 2006;5:235–46.

[4] Tangye SG, Bryant VL, Cuss AK, Good KL. BAFF, APRIL and

human B cell disorders. Semin Immunol 2006;18:305–17.

[5] Krivosikova M, Dallos T, Maslinski W, Buc M. B cell activating

factor, its role in autoimmunity, and targeting in autoimmune

diseases. Bratisl Lek Listy 2009;110:137–45.

[6] Davidson A. The rationale for BAFF inhibition in systemic lupus

erythematosus. Curr Rheumatol Rep 2012;14:295–302.

[7] Nardelli B, Belvedere O, Roschke V, Moore PA, Olsen HS,

Migone TS, et al. Synthesis and release of B-lymphocyte stimu-

lator from myeloid cells. Blood 2001;97:198–204.

[8] Miller JP, Stadanlick JE, Cancro MP. Space, selection, and

surveillance: setting boundaries with BLyS. J Immunol

2006;176:6405–10.

[9] Morrison MD, Reiley W, Zhang M, Sun SC. An atypical tumor

necrosis factor (TNF) receptor-associated factor-binding motif of

B cell-activating factor belonging to the TNF family (BAFF)

receptor mediates induction of the noncanonical NF-kappa B

signaling pathway. J Biol Chem 2005;280:10018–24.

[10] Cambridge G, Leandro MJ, Edwards JC, Ehrenstein MR, Salden

M, Bodman-Smith M, et al. Serologic changes following B

lymphocyte depletion therapy for rheumatoid arthritis. Arthritis

Rheum 2003;48:2146–54.

[11] Edwards JC, Szczepanski L, Szechinski J, Filipowicz-Sosnowska

A, Emery P, Close DR, et al. Efficacy of B-cell-targeted therapy

with rituximab in patients with rheumatoid arthritis. N Engl J

Med 2004;350:2572–81.

Serum BLyS and APRIL as possible indicators of disease activity in pediatric systemic lupus 99

[12] Takemura S, Klimiuk PA, Braun A, Goronzy JJ, Weyand CM. T

cell activation in rheumatoid synovium is B cell dependent. J

Immunol 2001;167:4710–8.

[13] Ravelli A, Martini A. Juvenile idiopathic arthritis. Lancet

2007;369:767–78.

[14] Chiche L, Jourde N, Thomas G, Bardin N, Bornet C, Darque A,

et al. New treatment options for lupus – a focus on belimumab.

Ther Clin Risk Manag 2012;8:33–43.

[15] Fawzy SM, Gheita TA, El-Nabarawy E, El-Demellawy HH,

Shaker OG. Serum BAFF level and its correlations with various

disease parameters in patients with systemic sclerosis and systemic

lupus erythematosus. Egypt Rheumatol 2011;33:45–51.

[16] Tan EM, Cohen AS, Fries JF, Masi AT, McShane DJ,

Rothfield NF, et al. The 1982 revised criteria for the classifi-

cation of systemic lupus erythematosus. Arthritis Rheum

1982;25:1271–7.

[17] Petty RE, Southwood TR, Manners P, Baum J, Glass DN,

Goldenberg J, et al. International league of associations for

rheumatology classification of juvenile idiopathic arthritis: second

revision, Edmonton, 2001. J Rheumatol 2004;31:390–2.

[18] Bombardier C, Gladman DD, Urowitz MB, Caron D, Chang CH.

Derivation of the SLEDAI: a disease activity index for lupus

patients. The Committee on Prognosis Studies in SLE. Arthritis

Rheum 1992;35:630–40.

[19] Churg J, Sobin LH. Renal disease: classification and atlas of

glomerular disease. 1st ed. Tokyo, Japan: Igaku-Shoin; 1982, 127–

49.

[20] Consolaro A, Ruperto N, Bazso A, Pistorio A, Magni-Manzoni S,

Filocamo G, et al. Development and validation of a composite

disease activity score for juvenile idiopathic arthritis. Arthritis

Rheum 2009;61:658–66.

[21] Kotzin BL. Systemic lupus erythematosus. Cell 1996;85:303–6.

[22] Zhang J, Roschke V, Baker KP, Wang Z, Alarcon GS, Fessler BJ,

et al. Cutting edge: a role for B lymphocyte stimulator in systemic

lupus erythematosus. J Immunol 2001;166:6–10.

[23] Stohl W, Metyas S, Tan SM, Cheema GS, Oamar B, Xu D, et al.

B lymphocyte stimulator overexpression in patients with systemic

lupus erythematosus: longitudinal observations. Arthritis Rheum

2003;48:3475–86.

[24] Dillon SR, Harder B, Lewis KB, Moore MD, Liu H, Bukowski

TR, et al. B-lymphocyte stimulator/a proliferation-inducing

ligand heterotrimers are elevated in the sera of patients with

autoimmune disease and are neutralized by atacicept and B-cell

maturation antigen-immunoglobulin. Arthritis Res Ther

2010;12:R48.

[25] Collins CE, Gavin AL, Migone TS, Hilbert DM, Nemazee D,

Stohl W. B lymphocyte stimulator (BLyS) isoforms in systemic

lupus erythematosus: disease activity correlates better with blood

leukocyte BLyS mRNA levels than with plasma BLyS protein

levels. Arthritis Res Ther 2006;8:R6.

[26] Petri M, Stohl W, Chatham W, McCune WJ, Chevrier M, Ryel J,

et al. Association of plasma B lymphocyte stimulator levels and

disease activity in systemic lupus erythematosus. Arthritis Rheum

2008;58:2453–9.

[27] Mackay F, Sierro F, Grey ST, Gordon TP. The BAFF/APRIL

system: an important player in systemic rheumatic diseases. Curr

Dir Autoimmun 2005;8:243–65.

[28] Bassyouni IH, Azab NA, El-Dakrony el-HM, Fawzi MM,

Ghanoum R, Bassyouni RH. Elevated serum levels of a prolif-

eration-inducing ligand in patients with systemic sclerosis: possi-

ble association with myositis? Joint Bone Spine 2011;78:56–61.

[29] Morel J, Roubille C, Planelles L, Rocha C, Fernandez L, Lukas

C, et al. Serum levels of tumour necrosis factor family members a

proliferation-inducing ligand (APRIL) and B lymphocyte stimu-

lator (BLyS) are inversely correlated in systemic lupus erythema-

tosus. Ann Rheum Dis 2009;68:997–1002.

[30] Koyama T, Tsukamoto H, Miyagi Y, Himeji D, Otsuka J,

Miyagawa H, et al. Raised serum APRIL levels in patients

with systemic lupus erythematosus. Ann Rheum Dis 2005;64:

1065–7.

[31] Stohl W, Metyas S, Tan SM, Cheema GS, Oamar B, Roschke V,

et al. Inverse association between circulating APRIL levels and

serological and clinical disease activity in patients with systemic

lupus erythematosus. Ann Rheum Dis 2004;63:1096–103.

[32] Gheita TA, Bassyouni IH, Emad Y, Nour El-Din AM, Abdel-

Rasheed E, Hussein H. Elevated BAFF (BLyS) and APRIL in

Juvenile idiopathic arthritis patients: relation to clinical manifes-

tations and disease activity. Joint Bone Spine 2012;79:285–90.

[33] Odendahl M, Jacobi A, Hansen A, Feist E, Hiepe F, Burmester

GR, et al. Disturbed peripheral B lymphocyte homeostasis in

systemic lupus erythematosus. J Immunol 2000;165:5970–9.

[34] Jacobi AM, Odendahl M, Reiter K, Bruns A, Burmester GR,

Radbruch A, et al. Correlation between circulating CD27high

plasma cells and disease activity in patients with systemic lupus

erythematosus. Arthritis Rheum 2003;48:1332–42.

[35] Dang H, Harbeck RJ. The in vivo and in vitro glomerular

deposition of isolated anti-double-stranded-DNA antibodies in

NZB/W mice. Clin Immunopathol 1984;30:265–78.

[36] Koffler D, Schur PH, Kunkel HG. Immunological studies

concerning the nephritis of systemic lupus erythematosus. J Exp

Med 1967;126:607–23.

[37] Cervera R, Font J, Shoenfeld Y. European working party on

systemic lupus erythematosus: a 15-year report. Autoimmun Rev

2006;5:549–53.

[38] Reichlin M, Broyles TF, Hubscher O, James J, Lehman TA,

Palermo R, et al. Prevalence of autoantibodies to ribosomal P

proteins in juvenile-onset systemic lupus erythematosus compared

with the adult disease. Arthritis Rheum 1999;42:69–75.

[39] Davis Jr JC, Gross J, Gescuk B, Harder B, Wofsy D. ZTNF4 and

soluble TACI receptor levels in serum and urine may reflect

disease activity in patients with SLE. Arthritis Rheum

2001;44:S99.

[40] Cheema GS, Roschke V, Hilbert DM, Stohl W. Elevated serum B

lymphocyte stimulator levels in patients with systemic immune-

based rheumatic diseases. Arthritis Rheum 2001;44:1313–9.

[41] Cambridge G, Isenberg DA, Edwards JC, Leandro MJ, Migone

T-S, Teodorescu M, et al. B cell depletion therapy in systemic

lupus erythaematosus: relationships among serum B lymphocyte

stimulator levels, autoantibody profile and clinical response. Ann

Rheum Dis 2008;67:1011–6.

[42] Wiegering V, Girschick HJ, Morbach H. B-cell pathology in

juvenile idiopathic arthritis. Arthritis 2010:759868. http://

dx.doi.org/10.1155/2010/759868 [Epub 2010 Dec 2].

[43] Wouters CH, Ceuppens JL, Stevens EA. Different circulating

lymphocyte profiles in patients with different subtypes of juvenile

idiopathic arthritis. Clin Exp Rheumatol 2002;20:239–48.

[44] Parikh JG, Tawansy KA, Rao NA. Immunohistochemical study

of chronic non granulomatous anterior uveitis in juvenile

idiopathic arthritis. Ophthalmology 2008;115:1833–6.