primaryimmunodeficiencies arpad lanyi phd. immunodeficiencies inherited (primary) loss of function...

PRIMARYIMMUNODEFICIENCIES

ARPAD LANYI PhD

IMMUNODEFICIENCIES

• INHERITED (PRIMARY)• Loss of function

mutation of genes of the immune system• Enhanced susceptibility

to infections• Particular types of

pathogens depending on the gene defect

• Did not show up until 1950 - antibiotics

• ACQUIRED• Due to infectious

diseases • AIDS• Other virus infections• Malnutrition• Artificial

immunosuppression• Drugs• Radioactive irradiation

• Recessive traits• Autosomal genes

• Disease in homozygous children • Heterozygous children are carriers

• X-linked genes• Single gene defect causes disease in males• Single gene defect in females renders the affected

woman carrier

PRIMARY IMMUNODEFICIENCIESMOST ARE RECESSIVE MUTATION OF SINGLE GENES

NUMEROUS IMMUNODEFICIENCY LOCI RESIDE ON THE X CHROMOSOME

CGD: Chronic Granulomatous Disease

WAS: Wiscott-Aldrich Syndrome

SCID: Severe Combined Immunodeficiency

XLA: X-linked Agammaglobulinemia

XLP: X-linked Lymphoproliferative Disease

XLHM: X-linked Hyper-IgM Syndrome

• Recessive traits• Autosomal genes

• Disease in homozygous children • Heterozygous children are carriers

• X-linked genes• Single gene defect causes disease in males• Single gene defect in females renders the affected

woman carrier

• Dominant traits have been eliminated from the population

Disseminated infection by the BCG strain of Mycobacterium used for vaccination

PRIMARY IMMUNODEFICIENCIESMOST ARE RECESSIVE MUTATION OF SINGLE GENES

Mutation in the IFNγ receptor results in binding without intracellular signaling -

dominant

THE IMPACT OF RECESSIVE AND DOMINANT

MUTATIONS IN THE IFN-γ RECEPTOR ONMONOCYTE ACTIVATION

• PHAGOCYTIC SYSTEM• Enhanced susceptibility

to bacterial infections

• LAD1: CD18 (CR3, CR4, LFA1)

• CGD• NADPH oxidase

• G6PD

• Myeloperoxidase

• Vesicular fusion

• COMPLEMENT SYSTEM• Some infections, primarily

with encapsulated organisms and Neisseriae

• Immunocomplex deposition• Soluble and membrane

factors • C1 – C4• Alternative pathway• C3• Terminal components• Complement inhibitors

TYPES OF INHERITED IMMUNODEFICIENCIES

INNATE IMMUNITY

• ANTIBODY DEFICIENCY• Recurrent

sinopulmonary and GI infections beginning after 3-4 mo.• B cell development

• RAG-1, RAG-2

• Artemis

• DNA-PK

• ADA

• XLA

• IgA deficiency

• Hyper IgM

• B – T cell collaborations • CD40 ligand, XLHIM

• T CELL DEFICIENCY• SCID, opportunistic

infections manifest early in infancy • T cell development

• IL-7/Jak3

• RAG-1 RAG-2

• Artemis

• DNA-PK

• ADA

• BLS

ADAPTIVE IMMUNITY

TYPES OF INHERITED IMMUNODEFICIENCIES

IMMUNODEFICIENCIES

AFFECTING INNATE IMMUNITY

DEFECTS IN PHAGOCYTE FUNCTION

ENHANCED SUSCEPTIBILITY TOBACTERIAL INFECTIONS

LEUKOCYTE ADHESION DEFICIENCY (LAD1)CD18 DEFICIENCY (ITGB2;21q22.3)

Common β-subunit of CR3, CR4 and LFA-1.


LEUKOCYTE ADHESION DEFICIENCY (LAD1)CD18 DEFICIENCY (ITGB2;21q22.3)

Common β-subunit of CR3, CR4 and LFA-1. Blocked phagocyte migration from blood to infection site. Inhibited uptake and degradation of opsonized bacteria. Persistant infection with extracellular bacteria, pyogenic infections.

(No opportunistic infections.) Defect in wound healing, omphalitis, pneumonia, gingivitis,

peritonitis. Lethal within the first decade of life without bone marrow

transplantation.


Omphalitis in

LAD I patient

CHRONIC GRANULOMATOUS DISEASE – CGD(1 million in the US)

Mutation of NADPH oxidase – any of the 4 subunits (most common: gp91 – X-linked)

• No superoxid O2- radical antibacterial activity is compromised

• Chronic intracellular bacterial or fungal infections – granuloma formation

• Aspergillus pneumonia, suppurative arthritis, osteomyelitis, superficial skin infections (cellulitis, impetigo).


CHRONIC GRANULOMATOUS DISEASE – CGD

CHRONIC GRANULOMATOUS DISEASE – CGD (1 million in the US)





• IFN-gamma improves resistance. Mechanism??

• Diagnosis: NBT + PMA treatment of neutrophils. Lack of blue colour in CGD.

Healthy

CGD

Carrier


CHRONIC GRANULOMATOUS DISEASE – CGD (1 million in the US)





• IFN-gamma improves resistance. Mechanism??

• Diagnosis: NBT + PMA treatment of neutrophils. Lack of blue colour in CGD.

Defect of glucose-6-phosphate dehydrogenase

• Less severe phenotype

• X-linked

• Reduced NADPH level

• Predisposes to hemolysis

• Malaria

Myeloperoxidase deficiency (Chr 17)

• Less severe phenotype

• Myeloperoxidase produces cytotoxic hypochlorous acid (HOCl) from hydrogen peroxide (H2O2) and chloride anion (Cl−)

• Respiratory burst with a normal nitro blue tetrazolium (NBT) test

• Disseminated candidiasis


CHÉDIAK-HIGASHI SYNDROME

• Affected gene: chs1 (1q42-43)

• Defect in vesicle fusion mechanism. Failure of phagolysosome formation, phagocytosed material is not

delivered to lysosomes. Persistent and recurrent bacterial infections. Infections most commonly involve the skin, the lungs, and the

respiratory tract and are usually due to Staphylococcus aureus, Streptococcus pyogenes, and Pneumococcus species.

Severe immunodeficiency, NK cell, CTL defect, neutropenia Oculocutaneous albinism: hypopigmentation: skin, hair, eyes,

photophobia. Accelerated phase: lymphoma-like syndrome, early childhood, life

threatening


COMPLEMENT DEFINIENCIES

IMPAIRED ANTIBODY EFFECTOR FUNCTIONSACCUMULATION OF IMMUNE COMPLEXES

C5C6C7C8C9

C3

C1C4C2

EARLY COMPONENTSAUTOIMMUNITY

Accumulation of immune complexes

Tissue demage

Inflammation

SLE, RA

INFECTIONS Inadequate humoral response

Decreased production of the opsonin C3b

Sinopulmonary infections

Streptococcus pneumoniae

Haemophilus influenzae

Neisseria meningitidis

C2 deficiency is the most common

(1 in 10,000)

COMPLEMENT DEFICIENCIESCLASSICAL PATHWAY ALTERNATIVE PATHWAY

C3b B

D P

EARLY COMPONENTSFactor B:

No case described

Factor D:

Rare, increased risk of infections

Properdin:

The only X-linked complement protein

Increased susceptibility to bacterial

infections of the Neisseria family

(fulminant meningococcal disease)

TERMINAL COMPONENTSInvasive meningococcal disease

Disseminated gonococcal infection

COMPLEMENT DEFICIENCIES

C5C6C7C8C9

C3

C1C4C2

C3b B

D P

C3: CENTRAL POSITIONDefective synthesis, expression or secretion of C3:

AUTOIMMUNE/INFECTIONS OR BOTHAutoimmune disorders: SLE-like, glomerulonephritis

Recurrent, severe, invasive infections

Gram+/Gram-

S. pneumoniae, S. pyogenes, S. aureus

N. meningitidis, H. influenzae

Impaired responses to immunization

Secondary C3 deficiency: Impairment in the regulatory proteins factor I or factor

H

Uncontrolled amplification of C3 cleavage results in acquired C3-deficiency

Higher susceptibility to S. pneumoniae and N. meningitidis infections

Immune complex deposition-mediated diseases (SLE, glomerulonephritis)

aHUS: atypic hemolytic uremic syndrome: systemic thrombotic microangiopathy, stroke, heart attack, renal failure, and death.

Mutations in factor H and factor I are associated with HUS.

Mutation of membrane co-factor protein CD46 (MCP) is also associated with HUS.

Factor I:

Cleavage of C4b, C3b

Factor H:

C3bBb inhibitor

Co-factor of factor I

COMPLEMENT INHIBITOR DEFICIENCIESDEFICIENCIES OF C3 CONVERTASE INHIBITORS

Acquired clonal mutation of pig-a gene (X-chromosome) in myeloid progenitors

No GPI-enchored proteins in the cell membrane of affected cells (rbc, plt, wbc)

A CD55 (DAF) és CD59 (MIRL) complement regulatory proteins are GPI-enchored proteins

PAROXYSMAL NOCTURNAL HEMOGLOBINURIA (PNH)

COMPLEMENT INHIBITOR DEFICIENCIES

Normal, CD55+CD59+ red blood cells can resist complement-mediated lysis

Doi:10.3324/haematol.2009.017848



Doi:10.3324/haematol.2009.017848

Absence of CD55/CD59 leads to MAC-mediated intravascular hemolysis



INTRAVASCULAR HEMOLYSIS

Release of hemoglobin

Large amounts of Hb deplete haptoglobin

Free Hb irreversibly binds to nitric oxide (NO)

Release of erythrocyte arginase

Conversion of L-arginine, the substrate for NO synthesis, to ornithine

NO SCAVENGING

THROMBOSIS

PLATELET AGGREGATION



Anita Hill et al. Blood 2013;121:4985-4996

Magnetic resonance angiography in a patient with PNH and superior sagittal sinus thrombosis with collateral vessel

formation.

Case of dermal vein thromboses in a patient known to have PNH.

COLOUR OF URINE SAMPLES TAKEN FROM PNH PATIENT AT DIFFERENT

TIMES

TREATMENTGeneral: Blood transfusion

Bone marrow transplantation

Pharmacological: Immunosuppression – Prednisolone Iron supplements Thromboprophylaxis: Anticoagulants (warfarin) Eculizumab



ECULIZUMAB:ANTI-C5 HUMANISED MONOCLONAL ANTIBODY

With C5 blocked, PNH red blood cells are protected from hemolysis, but once opsonized by C3 RBCs become prey to macrophages.

Chronic treatment increases the risk of infections with Neisseria meningitidis.

It does not appear to change the risk of myelodysplastic syndrome, acute myelogenous leukemia, or aplastic anemia.

Doi:10.3324/haematol.2009.017848

HEREDITARY ANGIONEUROTIC EDEMA (HANE)C1 inhibitor deficiency; Autosomal dominant (1 in 30000)

Inhibition by C1INH in many steps

Uncontrolled production of vasoactive peptides

Non-inflammatory swellings of skin and mucosal membranes due to leakage of fluid from blood vessels into connective tissue.

Subcutaneous tissues: face, hands, arms, legs, genitals

Abdominal organs: stomach, intestines, bladder, and urethra; vomiting, diarrhea, serious abdominal spasms

Larynx swelling – suffocation, may cause death

Child with symptoms of HANE

Treatment:

Anabolic steroid (Winstrol)

iv. C1INH, FFP (fresh frozen plasma)

Kallikrein inhibitor

Bradykinin receptor antagonists

C1inh deficiency predisposes to autoimmune diseases (SLE) due to its consumptive effect on complement factors 3, 4.

Enhanced permeability of postcapillar venules

IMMUNODEFICIENCIES

AFFECTINGADAPTIVE IMMUNITY

B-CELLIMMUNODEFICIENCIES

SYMPTOMS OF B-CELL DEFICIENCIES MANIFEST REALTIVELY LATE DUE TO THE PRESENCE OF MATERNAL ANTIBODIES

Approx. 70% of all IDs.Increased sensitivity to: Encapsulated bacteria, Streptococcus pneumoniae, Haemophylus

influenzae, Enteroviruses, parasites

ANTIBODY DEFICIENCY INABILITY TO CLEAR EXTRACELLULAR BACTERIA

Genetic defect:

• Mutation in the Bruton’s tyrosine kinase, essential for B-cell activation and development.

• NO B-CELLS IN THE PERIPHERY – block at pre B-cell stage.

• Male XY HEALTHY – XY DISEASE • Carrier female XX HEALTHY – non-random

inactivation of X in B-cells

X-LINKED AGAMMAGLOBULINEMIA, XLA(Bruton’s agammablobulinemia), 1:200,000

DIAGNOSIS OF THE LACK OF B-CELLS BY FLOW CYTOMETRY

Normal XLA

Symptoms:

• First few months of life is relatively normal (maternal Ig).

• Tonsils are small, lymph nodes are barely palpable.

• Increased susceptibility to bacteria and enteroviruses (likely due to IgA defficiency).

• Encapsulated bacteria resisting ingestion by phagocytes unless they are coated with antibody and complement.

• Recurrent infection of sinuses and of the middle ear. Pneumonia.

• Pyogenic bacteria – permanent tissue demage caused by enzyme release from bacteria and phagocytes – bronchiectasis, chronic lung disease

• Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus

• Oral polio vaccine disseminate and cause poliomyelitis.

• T-cell responses to intracellular bacteria is normal (mycobacteria).



Treatment:

• Monthly injections of Gamma globulin (IVIG OR SC).



µ heavy chain (IGHM)

λ5 (IGLL1) lgα (CD79A) lgß (CD79B)


NON BRUTON’S AGAMMAGLOBULINEMIAAUTOSOMAL

X-LINKED HYPER IgM SYNDROME (XLHIM)Genetic defect:

• Defect of the CD40L gene (Xq26).

Symptoms:• No specific antibody response to T-dependent antigens.

• low IgG, IgA, IgE

• No macrophage/B-cell/DC activation by T-cells – CD40 – CD40L

DIMINISHED ANTIBODY PRODUCTION AS A RESULT OF INHERITED DEFECT OF T-CELL HELP






• No germinal center formation.


LACK OF GERMINAL CENTERS IN LYMPH NODES OF X-LINKED

HYPER-IGM SYNDROME PATIENTS






• No germinal center formation.

• No leukocytosis but neutropenia.

• Susceptibility to pyogenic bacteria/opportunistic infection.• Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus

aureus

• Pneumocystis carnii infection. Not seen in XLA.

Treatment:• Antibiotics

• IVIG

• Injection of GM-CSF (neutropenia)


AUTOSOMAL HYPER IgM SYNDROME• Intrinsic B-cell defect, activation induced deaiminase (AID) deficiency.

Cytidine uridine conversion.• The enyme is involved in affinity maturation and Ig. class switch.• Limphoid hyperplasia.• Lack of opportunistic infections.

doi:10.1038/nri1489

Occurance: 1:160-1:800 (Europe, less in Asia). May be asymptomatic, but often associated with

chronic or recurrent disease of the respiratory system.

Giardia infection with chronic diarrhea is frequent. Higher frequency of allergies. Tenfold risk of coeliac disease. Autoimmune disease, autoimmune cytopenia. 40% of patients develop anti-IgA antibodies.

SELECTIVE IgA DEFICIENCYIgA: protection against infections of the mucous

membranes

Chest radiograph of a 50-year-old man with immunoglobulin A deficiency and

severe bilateral pneumonia

COMMON VARIABLE IMMUNODEFICIENCY,CVID

Symptoms:•Low IgG and IgA/IgM levels.•Frequent respiratory infections. •Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus, •Pure response to vaccination.•Autoimmune manifestations: cytopenia, RA, psoriasis•Lymphocytic infiltration: lymphadenopathy, splenomegaly, hepatomegaly•Granulomas in lung and in the GI system.•GI problems: lactose intolerance, lymphoid hyperplasia/diffuse lymphoid infiltration, loss of villi and infection, especially with Giardia lamblia, diarrhea•Hematological malignancies, Non-Hodgkin's lymphoma

Therapy: IVIG •Only 10 % has a family history.•Only 10% with a known genetic defect.

Transmembrane activator and CAML (calcium modulator and cyclophilin ligand) interactor (TACI)

A GENETICALLY AND CLINICALLY HETEROGENEOUS GROUP OF DISEASES

CHARECTERIZED BY LOW ANTIBODY LEVELS AND RECURRENT INFECTIONS 1:25000

SIGNALING PATHWAYS EMANATING FROM TRANSMEMBRANE

ACTIVATOR AND CAML INTERACTOR (TACI)

DOI:10.1111/j.1749-6632.2011.06266.x

T-CELLIMMUNODEFICIENCIES

• Neither T-cell-dependent antibody response nor cellular immunity are functional.

• Persistent and recurrent infections with a broader range of pathogens than patients with B-cell deficiences.

DEFECT IN T-CELL FUNCTIONST-cells are involved in all aspects of adaptive

immunity

SEVERE COMBINED IMMUNODEFICIENCY,SCID

• The common γ-chain of interleukin receptors is mutated, IL-7 receptor.

• Part of IL-2, 4 ,7, 9, 15, 21 receptor

• T-, B+, NK- (non functional B-cells)

• Over 50% of SCID cases.

• Small body weight, failure to thrive, diarrhea, sepsis, otitis media.

• Opportunistic infections (Candidiasis, Pneumocystis carnii pneumonia).

X-LINKED SEVERE COMBINED IMMUNODEFICIENCY

SEVER COMBINED IMMUNODEFICIENCIES

The SCID phenotype can be caused by various gene defects

David Vetter, 12 years in a bubble

• Mutation of Jak3 kinase – IL-7 receptor-mediated signaling – T-B+NK- (IL-15-NK, non-functional B-cells) (less than 10%)

• IL-7Rα deficiency – T-B+NK+ 11% of SCID cases.• Defect in the catabolism of purin bases

– Adenosine deaminase (ADA) mutation – T- B- NK- dATP accumulation - inhibition of ribonucleotide reductase 15% of SCID cases. Underdeveloped thymus Neurological problems: hearing and visual impairment,

mental retardation, low muscle tone and movement disorders

AUTOSOMAL SCID

• Mutation of RAG enzymes – T-B-NK+• Mutation of DNA-PK/Artemis – T- B-NK+ • Omenn syndrome – T+B-/low, hypomorphic mutation of RAG1/2 (or

Artemis)– T-cell counts are normal to elevated– Restricted TCR repertoire– Activated Th2 phenotype– Eosinophilia, elevated IgE level– Recurrent infections,

mainly opportunistic– Autoimmunity: T-cell infiltration:

GI tract, skin, hepatosplenomegaly, lymphadenopathy

– Exfoliative dermatitis (erythroderma)– Failure to thrive, RAPIDLY FATAL

AUTOSOMAL SCID

• Bare lymphocyte syndrome – BLS I

TAP1/2 deficiency – low abundance of MHC I

Selective loss of CD8+ T-cells– BLS II

Lack of MHC II – CD4+ T-cells fail to develop

Compromises all aspects of adaptive immunity

DOI: 10.1152/nips.01462.2003

AUTOSOMAL SCID

• Gene therapy.• Bone marrow transplantation (BMT), preferably from a

histocompatible sibling.• Often SCID babies need to be stabilized first before BM-transplant

as they have severe infections when brought to the clinic. • Survival of HEALTHY SCID babies after BMT is over 95%!• Testing before diseases develops??? EARLY DIAGNOSIS CAN SAVE

MANY LIVES !!!!

TREATMENT

EARLY DIAGNOSIS OF SCID PATIENTS TREC-ASSAY

At TCR recombination T-cell receptor excision circle (TREC) is produced as a result of excision of the δ segments from the TCRA locus.

TRECs can be detected with Q-PCR.

Early diagnosis practically no false positives.

WISKOTT-ALDRICH SYNDROME (WAS)A disease of defective reorganization of the actin

cytoskeletonGenetic defect:– Mutation in the WAS protein (WASP) expressed in white blood cells and megakaryocytes. X-

linked.

Symtomps:– Thrombocytopenia, small platelet size (decreased production of platelets in bone marrow,

increased destruction in spleen).

WAS VERSUS NORMAL PLATELETS



linked.


increased destruction in spleen).– Rearrangement of cytoskeleton upon T-cell activation in the polarized contact with B-cells,

macrophages and target cells is defective.

WT,ctrl.

WASP-/-, α-CD3WASP-/-ctrl.

WT,α-CD3

CAPPING OF TCR IS DEFECTIVE IN WASP NEGATIVE T-CELLS



linked.



macrophages and target cells is defective.– Normal lymphocyte surface is covered with abundant microvilli, which are sparse or absent

from the patient's lymphocytes. – The marginal zone which contains B lymphocytes and specialized macrophages is severely

reduced in size.

SEVERE REDUCTION OF THE MARGINAL ZONE IN THE SPLEEN FROM WISKOTT–ALDRICH

SYNDROME PATIENTSThe germinal centers (GC) are surrounded by the mantle (M) and by the marginal zone (MZ), which contains B lymphocytes and specialized macrophages.

In patients with WAS, the MZ is severely reduced in size.

WISKOTT-ALDRICH SYNDROME (WAS)A disease of defective reorganization of the actin cytoskeleton

Genetic defect:– Mutation in the WAS protein (WASP) expressed in white blood cells and megakaryocytes. X-

linked.



macrophages and target cells is defective.– Normal lymphocyte surface is covered with abundant microvilli, which are sparse or absent

from the patient's lymphocytes. – The marginal zone which contains B lymphocytes and specialized macrophages is severely

reduced in size.– No antibodies to carbohydrate antigens (role for T-cells?).– Low IgM high IgA, IgE serum levels. – Eczema.– B-cell lymphomas.– Pyogenic and opportunistic bacterial infections.– Severe infection with varichella (chicken pox) and herpes simplex (impaired CD8+ T-cell

response).

Treatment: Bone marrow transplantation

CONGENITAL GENE DEFECTS DISRUPT LYMPHOCYTE DEVELOPMENT AT VARIOUS STAGES

Cγ-chain, IL-7Rα, Jak3 deficiencies, SCID

CLP

Non-Bruton’s/ Bruton’s agammaglobulinemia (µ, λ5, lgα, lgß, btk)

Autosomal hyper IgM syndrome (AID)Selective IgA deficiency

proB

preBI

preBII

Imm. B

TeffMat.T

SPImm

.TDP

preT

proT

Mat.B

Beff

XLHIMCD40L

ADA deficiency

SCID

RAG, DNA-PK, Artemis deficiencies, SCID

WASCVID?

BLS(TAP, RFX,CIITA)

THE END

primaryimmunodeficiencies arpad lanyi phd. immunodeficiencies inherited (primary) loss of function...

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