Autoimmune Hemolytic Anemia

Young Rok Do, M.D., Ph.DDivision of HematoOncology,

Department of Internal Medicine,

Keimyung University, Dongsan Medical Center

Contents

• Case • Approach to Hemolytic Anemia• Classification of Hemolytic Anemia• AutoImmune Hemolytic Anemia

-Warm Ab-Cold Ab,-Paroxysmal Cold Hemoglobinuria-Drug Induced

• Summary

69세, 여자, 노작성 호흡곤란

• HgB 9.2 g/dL Ref) 12-18

• WBC 6.25 x103/u Ref) 5.2-12.4

• MCV 97.5 fl Ref) 80-99

• Platelet 226 x103/u Ref) 130-400

• Bilirubin(T/D) 2.5/0.5mg/dL Ref) (0.2-1.2/0.0-0.4)

말초혈액도말검사;

우선적으로 다음에시행할 검사는?

1) Serum folate

2) Serum ferritin

3) Reticulocyte count

4) ABO, Rh typing

5) Electrophoresis

• Direct Coombs test (+)

• Indirect Coombs test(-)

• LDH; 565.4mg/dL Ref) 50-320

• Haptoglobin; <45.24mg/dL Ref) 50-320

• Reticulocyte 9.52% Ref) 0.5-1.5

진단은?

1) Hereditary Spherocytosis

2) Immune Hemolytic Anemia

3) ABO incompatibility

4) Severe Burn

5) Heinz Body Anemia

초치료로 선택할 약제는?

1) Steroid

2) Azathioprine

3) Rituximab

4) ImmuneGlobulin

5) Chlorambucil

66세, 남자, 피로감

• HgB 7.2 g/dL Ref) 12-18

• WBC 5.48 x103/u Ref) 5.2-12.4

• MCV 95.1 fl Ref) 80-99

• Platelet 226 x103/u Ref) 130-400

• Reticulocyte 7.5% Ref) 0.5-1.5

• Direct Coombs test (+)• Indirect Coombs test(-)• LDH; 701.2mg/dL Ref) 50-320• Haptoglobin; 7.5mg/dL Ref) 50-320• Bilirubin T/D; 3.5/0.5mg/dL Ref)-1.2/-0.4• C3; 64.4mg/dL Ref) 90-180• C4; <5.9mg/dL Ref) 10-40

진단은?I

상기 빈혈에 대한 설명으로 옳은 것은?

1) 정상인에서는 cold agglutinin이 없다.

2) 주로 IgM이다.

3) 감염증 이후 발생하는 저온응집소는단클론 항체이다.

4) 만성저온응집병은 주로젊은 연령층에 발생한다.

5) 대부분 Steroid에 잘 치료된다.

Approach to Hemolytic Anemia

History• Age; AIHA usually middle aged or older• Sex; not specific, AIHA sl more in ♀• Symptom

Pallor, fatigue, dizznessPiemented gall stoneSplenomegalyAcute pain in bone and chest

• Family historyPositive Medical history

• Drug history; analgesicsanti-malaria antibacterial

Exam

• Pallor• Jaundice• Tachycardia, murmur• Sign of CHF• Splenomegaly• Cholelithiasis

Investigation

• CBC; Red cell index, Reticulocyte• Coombs test(DAT)• Serum level; bilirubin, haptoglobin,

plasma hemoglobin, LDH, u hemosiderin• BM exam; erythroid hyperplasia• Other test; Osmotic Fragility, enzyme

assay, Hb electrophoresis

Treatment

• Transfusion; if neededSlowly transfuse to prevent destruction

• Discontinue offending agent• Supply folic acid during active hemolysis• Corticosteroid in AIHA• IVIG; a few pt respond

Surgical Care

Splenectomy;• Hereditary Spherocytosis

• in AIHA other measures failed

• not indicated in cold agglutinin HARBC lysed in liver

Immunization against H.influenzae, S.pneumoniae in advance of procedure

Hemolytic Anemia

Anemia of increased destruction

-Shortened RBC survival

-Reticulocytosis: response to increased RBC destruction

-Increased indirect bilirubin

-Increased LDH

Classification of Hemolytic Anemia

• Drug-Related Hemolysis

• Alloimmune Hemolysis

-Hemolytic Transfusion Reaction

-Hemolytic Disease of the Newborn

• Autoimmune Hemolysis

-Warm autoimmune hemolysis

-Cold autoimmune hemolysis

II

Hemolysis

Acquired

Inherited/

Congenital

Immune hemolysis

Autoimmune

Drug

Alloimmune

Traumatic

(micro and macro)

TTP/HUS/HELLP

DIC

Vasculitis

Eclampsia

Malignant HTN

Prosthetic heart valve

Arterial grafts

Hypersplenism

Membrane abnormalities

Acanthocytes(spur cells)

Echinocytes (burr cells)

PNH

Thermal injury (burns)

RBC

membranopthies

RBC

enzymopathies

Hemoglobinopathy

# 간질환:↓염증성질환:↑

Extravascular

Hematologic

PBS

reticulocyte count

BM exam

Plasma or serum

bilirubin

haptoglobin#

plasma hemoglobin

LDH

Urine

bilirubin

hemosiderin

hemoglobin

Intravascular

Polychromatophilia

↑

Erythroid hyperplasia

↑ Unconjugated

↓, Absent

N - ↑

↑ (variable)

0

0

0

Polychromatophilia

↑

Erythroid hyperplasia

↑ Unconjugated

Absent

↑ ↑

↑ ↑ (variable)

0

+

+ in severe disease

Classification of HA

-MAHA-Valve hemolysis-Chemical agents-Osmotic lysis-Infections-PNH-Cold agglutinin ds-Venoms

Intravascular hemolysis

Causes of Acquired Hemolytic Anemia

I. Entrapment

II. Immune

A. Warm-reactive (IgG) Ab.

B. Cold-reactive IgM Ab. (cold agglutinin ds.)

C. Cold-reactive IgG Ab. (Paroxysmal cold hemoglobinuria)

D. Drug-dependent ab

1. Autoimmune

2. Haptene

III. Paroxymal nocturnal hemoglobinuria

IV. Traumatic hemolytic anemia

A. Impact hemolysis

B. Macrovascular defects-prostheses

C. Microvascular causes

1. TTP/HUS

2. Other causes of microvascular abnormalities

3. DIC

V. Hemolytic anemia d/t toxic effects on the membrane

A. Spur cell anemia

B. Metals (ex. Copper)

C. Organic compounds

Reticulocyte countnot elevated

Hemolysis or Blood loss

no sx. or signs of

blood loss

Hemolysis

Acquired Inherited/Congenital

elevated

Approach to Hemolytic Anemia

Classification-Immune Hemolytic Anemia

• Autoantibodies

Induced by IgG or IgM antibodies with specific

for antigens associated with patient’s RBC

• Alloantibodies

Transfused RBC may be hemolyzed by

alloantibodies directed against foreign antigens

on those cells

Hemolysis due to Antibodies

Warm-Ab Immnehemolytic AnemiaIdiopathic

Lymphoma: CLL, NHL, HD (infrequent)

SLE & other collagen-vascular ds.

Drugs

a. α-Methyldopa type (autoab. to Rh ag.)

b. Penicillin type (stable hapten)

c. Quinidine type (unstable hapten)

Postviral infections

Other tumors (rare)

Cold-Ab Immunehemolytic AnemiaCold agglutinin ds.

a. Acute: Mycoplasma infection, infectious mononucleosis

b. Chronic: idiopathic, lymphoma

c. PCH (paroxysmal cold hemoglobinuria)

Cold-reacting antibodies

(agglutinins or Donath-Landsteiner antibody),

Most drug-related antibodies, IgM antibodies,

IgG antibodies of low affinity,

Activation of complement immune complexes

YesNo

Antibodies to glycoprotein antigens, SLEYesYes

Antibodies to Rh proteins,

Hemolysis caused by α-methyldopa or penicillin:

Not seen in SLE

NoYes

CausesAnti-C3Anti-IgG

Coombs’ test

AutoImmune Hemolytic Anemia

A. Warm-reactive (IgG) Ab.

B. Cold-reactive IgM Ab. (cold agglutinin ds.)

C. Cold-reactive IgG Ab. (Paroxysmal cold hemoglobinuria)

D. Drug-dependent ab

1. Autoimmune

2. Haptene

III

AIHA-Warm Ab

• Autoantibody: IgG,

react at body temperature (370C)

• Pathophysiology

1. Immune adherence

: Ab+C` on RBC ↔ Fc Rc on phagocyte of RES

2. Complement activation->RBC mb. destruction

Clinical ManifestationCommon in adults, women-25%: underlying disease affecting immune system-Presentation and course: variable anemia, spherocytosis, splenomegaly

※ Evans’ syndrome: immune thrombocytopenia + im. Hem. anemia: separate antibodies against platelets and RBC

→ AHA + ITP

Spherocytosis Loss of membrane Hereditary

spherocytosis,

immunehemolytic A.

Morphology Cause Syndromes

RBC Morphology in HA

Nature Reviews Rheumatology 8, 458-468 (August 2012)

Prednisone 40 mg/m2 (60-100 mg/d)

7 days

Response

Folic acid (1-5 mg/d)

Continue until normal ofHb & hematocrit

Increase dose to60 mg/m2

ResponseSlow dose reduction(6-8 wks)

Hemolysis PRD maintenance10-20 mg/d

Withdraw PRDin 3-6 ms (30%)

splenectomy

RemissionIVIG, 면역억제제등

yes no

3 wksyes

yes

no

no

no

no25-30%

60-70%

10-15%

50-70%

•Transfusion: Hb < 4 g/dL or Sx(+) --- 0.5 – 1U PRC

Treatment of AIHA

Prognosis

1. In most patients, controlled by glucocorticoid, splenectomy or combination

2. Fatal courses

overwhelming hemolysis

impared host defenses by steroid, splenectomy

immunosuppressive agents

rarely major thrombotic events may occur

AIHA-Cold Ab

• Cold reactive antibody

-IgM, react at lower than 370C (0-100C)

-monoclonal Ab: lymphocytic neoplasm, paraneoplasm

-polyclonal Ab: infection

transient cold agglutinin: Mycoplasma pn. infection,

infectious mononucleosis

Specificity of Ab

Anti-I : cold agglutinin reacting more strongly to adult RBC

than fetal (cord) RBC

: benign lymphoproliferation

Anti-i : reacting more strongly with cord RBC

: aggressive lymphoma and inf. mononucleosis

•Clinical Manifestations

-intravascular agglutination (acrocyanosis),

-hemolysis d/t complement

•Diagnosis

Direct Coombs’ test

-IgM cold agglutin: low affinity for RBC memb. at 370C

-C3: stable at 370C, 그러므로상온에서 C3 만양성

IV

Morphology Cause Syndromes

Agglutinated cells IgM ab (+) Cold agglutinin ds.

※한랭응집소검사한랭응집소검사한랭응집소검사한랭응집소검사 (Cold agglutinin test)

-방법: At 00C, normal RBC <-> pt plasma

plasma를점점희석시키면서응집반응유무확인

-목적: Mycoplasma pneumoniae 감염, 용혈성빈혈등에서나타나는 cold agglutinin 검출

-원리: Cold agglutinin은 autohemagglutinin으로서환자자신의적혈구를 0℃～20℃에서응집시킨다(때로실온, 드물게 30℃～37℃에서도응집시킴).

모든혈액형의타인적혈구도응집시킴.

-결과및해석: 정상치〈 1:16

Treatment of Cold AIHA

1. Avoid cold, underlying disease

2. Treatment; glucocorticoid, splenectomy

: no value

3. chlorambucil and cyclophosphamide

:effective in 50-60%,

hemolysis associated with monoclonal

gammopathy

4. AntiCD20

5. Plasmapheresis, plasma exchange

6. Transfusion: 370C로 warming 후수혈

AIHA-Paroxysmal Cold Hemoglobinuria

•Cause

: Tertiary syphilis or secondary to viral infection,

autoimmune ds.

•Pathogenesis

: Donath-Landsteiner Ab --- IgG Ab against P Ag

-> Complement mediated hemolysis

Donath-Landsteiner test • 목적: Paroxysmal cold hemoglobinuria(PCH) 진단

• 원리: PCH 환자의 cold hemolysin은 반응온도가biphasic하여 0℃~10℃에서 정상 적혈구 표면에부착하나, 온도가 15~30℃로 증가하여야 용혈되며 보체를 필요로 한다.

• 방법: 37℃ 채혈(EDTA) → 0℃ 냉각 → 37℃ 보온→ 용혈유무 관찰

•Clinical Manifestations

-attacks are precipitated by exposure to cold

-hemoglobinemia, hemoglobinuria

-chills and fever

-back, abdominal pain, headache, malaise

• Diagnosis

-demonstrating cold reacting IgG antibodies

by lytic test or special antiglobulin tests

AIHA-Drug Induced

• Ab agaianst to drug or its metabolite• 4 Mechanism

Penicillin type(drug adsorption)Immune complexMembrane modificationDrug independent

Penicillin type• Penicillin or its metabolite adsorbed onto

RBC surface • Ab will attached to drug, causing DAT(+)• Immune hemolysis is less frequent

• Penicillin• Methicillin• Nafcillin• Tetracycline• cephalothin

• Erythromycin • Carbomal• Cefazolin• Cefamandole

Immune complex• After patient receiving the drug, a drug-

antidrug complex may form • The complex adsorbed loosely to RBC • Comoplement is activated, and RBC are

considered as ‘innocent bystander’, resulting in hemolysis

• Quinine, quinidine

V

Membrane modification; drug modify RBC cell membrane, usually antineoplastic(ex. Carboplatin)Rarely associated with RBC destruction

Drug independent type; very similar to WAIHAMethyl-dopa; HBP drug, suppress T cell fxn, elaboration of autoAb

Summary

Blood. 2010;116(11):1831-1838

Character WAIHA Cold Aggl. Ds PCH

isotype Ig G(rare A,M) IgM IgG

DAT IgG and/or C3 C3 C3

Ag Specificity Vary, mainly Rh i/I, Pr P

Lysis site ExtraVs, mainly ExtraVs, mainly IntraVs

Combine Ds B-NHL,LymProDs, collagen-vs

Virus, tumor Syphilis, Virus