clinical applications of auto antibodies brig tahir aziz ahmed consultant immunologist armed forces...

Clinical applications of auto antibodies

Brig Tahir Aziz AhmedConsultant Immunologist

Armed Forces Institute of Pathology (AFIP)Rawalpindi-Pakistan

Dr Paul Ehrlich• 1854-1915• German• Nobel laureate• Diphtheria antiserum (with von Boehring)

only Boehring won Nobel prize-1901Ehrlich won it for Salvarsan a treatment for Syphilis-five years later

• Side-chain theory• Dr Paul Ehrlich’s magic bullet 1945

Auto antibodies

• Horror autotoxicus

• Auto antibodies relatively easy to detect• Some well defined disease and subset

associations• Some auto antibodies with defined role in

immunopathogenesis• Antibody levels may relate with disease activity

Thyroid

• Thyroid– Anti thyroid peroxidase antibodies

(anti thyroid microsomal antibodies)– Anti thyroglobulin antibodies– Anti TSH receptor antibodies

• Activating antibodies (Grave’s ophthalmopathy)• Inhibitory antibodies (thyrotropin binding inhibitory

immunoglobulins TBII-Thyroiditis)

Anti thyroid microsomal & thyroglobulin antibodies

Euthyroid Hyperthyroid Hypothyroid Total100-500

IU/ml2 7 7 16

501-1000 IU/ml

6 4 7 17

>1000 IU/ml

5 1 1 7

Anti Thyroglobulin antibodies< 100 IU/ml Normal> 100 IU/ml Elevated100-500 IU/ml High501-1000 IU/ml Very high>1000 IU/ml Extremely high(103 positive out of 248. One year local unpublished data)

Euthyroid Hyperthyroid Hypothyroid Total30-300 IU/ml 5 - 5 10>300 IU/ml 4 1 6 11

Anti thyroid peroxidase antibodies< 30 IU/ml Normal30-300 IU/ml High>300 IU/ml Very high(109 positive out of 496. One year local data unpublished)

When to test for thyroid antibodies

• Autoimmune thyroid disease– Grave’s disease– Hashimotos thyroiditis– Postpartum thyroiditis (OR: 11.5)– Idiopathic painless thyroiditis

• Thyroglobulin monitoring in thyroid cancer• Recurrent miscarraige (OR: 3.73)• Unexplained subfertility (OR: 1.5)• Preterm birth (OR: 1.9)• Autoimmune polyendocrine syndromes

• Anti thyroid antibodies in subclinical hypothyroidismTPO Abs positive: 11.2% of 1500 euthyroid pregnant Pakistani womenMiscarriage rate: 36.3% (1.8% in Ab neg women)Prematurity: 26.8% (8% in Ab neg women)(Ghaffor F et al. JCPSP 2006: 16(7); 468-471)

• Anti thyroid antibodies in population surveys– Overt hypothyroidism, Thyrotoxicosis = 0.4%– Subclinical hypothyroidism = 4.0%– TPO antibodies 8.6% males; 18.5% females

(Hoodgendoorn et al. Clin Chemistry 2006: 52(1); 104-111)

Pregnancy loss

• Anti cardiolipin antibodiesIgG, IgA, IgM

• Anti beta-2 glycoprotien 1 antibodiesIgG, IgA, IgM

• Lupus anti coagulant testTest to be positive with an interval of 8 weeks

Infertility

• Anti sperm agglutinating antibodies (12 /83)

• Anti sperm cytotoxic antibodies(Microagglutinating and complement mediated cytotoxicity tests)

• Anti ovarian cell antibodies(Indirect immunofluoroscence-ovarian tissue)

• Anti parathyroid antibodies(Indirect immunofluorescence-parathyroid tissue)

– 38% Idiopathic hypoparathyroidism– 26% Idiopathic addison’s diseases– 12% Hashimoto’s thyroiditis– 6% Control groupBlizzard RM. Clin. exp. Immunol. (1966) 1, 119-128.

• Anti calcium sensor receptor antibodies(Anti CaSR antibodies. Activating; inhibitory)(Brown EM. Endocrinol Metab Clin North Am. 2009 June ; 38(2): 437-)

• Anti pituitary antibodies

Interferon and antibodies• Seven out of 50 patients after interferon treatment developed thyroid

dysfunction(Hypothyroid: 5; Hyperthyroid: 2)

(Chaudhry N et al. PAFMJ 2011.)

(Chutto MA et al. JCPSP 2009.)

• Antibodies after interferon treatmentTPO (p=0.036); ANA (p=0.014)

Chronic HCV infected patients (32/106; 30%)

Interferon treatment (22/36; 61%)No treatment (12/32; 37.5%)

increase in autoimmunity significant in males: p=<.04(accepted for publication: Ahmad D et al. PAFMJ 2012;..)

Autoantibodies in liver disease

Antibody Disease Association CommentsMitochondrial antibody

Primary biliary cirrhosis >95%

Smooth muscle antibody

Autoimmune hepatitis

Primary biliary cirrhosis

70%

30%

LKM Autoimmune hepatitis

Drug induced hepatitis

Uncommon but specific antibody

ANA Autoimmune hepatitis 30%

Autoimmune hepatitis

• AFIP data (March 2010-March 2011)• Smooth muscle antibodies 397 38• SLA 11 1• LKM 307 3• AMA 275 5• Anti parietal cell antibodies

(Ahmed D et al. Pakistan J of Pathology 2009; 20(3): 70-73)

Anti pancreatic duct antibodies

Autoimmune pancreatitis

• IgG4 antibody levels• Anti pancreatic duct antibodies

Anti parietal cell antibodies

• Anti parietal cell antibodiesAtrophic gastritis & pernicious anemia(3 positive out of 46)

• Anti intrinsic factor antibodies(0 positive out of 27)– 12 patients positive for anti intrinsic factor

antibodies out of 78 vitamin B12 deficient patients(local study unpublished data)

Anti islet cell antibodies

Total Positive• Anti islet cell antibodies 10 0

1st degree relatives of IDDM

• Anti insulin antibodies1st degree relatives of IDDMInsulin resistance

Anti adrenal antibodies

• Addisons disease– 50% of idiopathic addison’s disease(Brown RM. Clin. exp. Immunol. (1967) 2, 19-30.)

– 83% of primary addison’s disease positive for anti adrenal antibodies (IF)

– 100% positive for anti 21-alpha hyroxylase antibodies in autoimmune addison’s disease(Betterle C et al.Endocrine Reviews 2002. 23(3):327–364)

• Premature ovarian failure– 3.2%positive for anti adrenal antibodies

Anti adrenal antibodies

• APS type 1 13%• APS type 2 41%• APS type 4 5%• Isolated autoimmune adrenal disease 41%

(Betterle C et al.Endocrine Reviews 2002. 23(3):327–364)

Autoimmune polyendocrine syndrome, type 1. candidiasis-hypoparathyroidism-Addison's disease-syndrome, Autoimmune Polyglandular Syndrome I,[2] APECED, or APS-IOther disease associations are:

– hypothyroidism– hypogonadism and infertility– vitiligo (depigmentation of the skin)– alopecia (baldness)– malabsorption– pernicious anemia– chronic active (autoimmune) hepatitis

Autoimmune polyendocrine syndrome, type II. autoimmune adrenal insufficiency

autoimmune thyroid disease and/or type 1 autoimmune diabetes mellitus defines

Conclusion

• Auto antibodies remain the only test to identify autoimmune nature of endocrine diseases.

• Auto antibodies may be tested using relatively simple laboratory techniques to help establish the diagnosis of relatively rare diseases.