Prevalence of IgA deficiency in adult systemic lupus erythematosus and the study of the association with its clinical and autoantibody profiles.
BACKGROUND
IgA deficiency (IgAD) is the most common primary immunodeficiency, which can cause frequent infections. The association of IgA deficiency with systemic lupus erythematosus (SLE) is very important because of the high morbidity and mortality rates of infections in patients with this disease.


OBJECTIVE
To study the prevalence of IgA deficiency in SLE patients from southern Brazil and to compare the clinical and autoantibody profiles of SLE patients with and without IgA deficiency.


METHODS
One hundred and eighty-nine SLE patients were submitted to serum IgA measurement by nephelometry. Levels of IgA below 50mg/dL were considered to be IgAD. Demographic data, clinical profile (presence of arthritis, psychosis, seizures, stroke, serositis, hemolytic anemia, leucopenia, thrombocytopenia, and nephritis) and autoantibody profiles (ANA, anti-Ro, anti-La, anti-Sm, anti-DNA, anti-RNP, lupus anticoagulant, and anticardiolipin IgG and IgM) were obtained from reviewing medical records. As control, we used literature data from another study performed in the same geographical area. Data were analyzed through contingency and frequency tables, applying the Chi-square, Fisher, and Mann Whitney tests.


RESULTS
IgA deficiency was found in 11 (6.17%) patients (P < 0.001 in relation to controls). The association between IgA deficiency and clinical or autoantibody profile was not significant.


CONCLUSIONS
We concluded that a higher prevalence of IgA deficiency was observed in lupus patients than in controls. Deficiency of IgA did not have any particular laboratory or clinical effects on this population.
Rheumatology Department, Hospital Universitário Evangélico de Curitiba, Faculdade Evangélica de Medicina do PR (FEPAR), Curitiba, Brazil.
Ana Paula França
AP
Mantovani
Mariel Perini
MP
Monclaro
Thelma L
TL
Skare
D000293:Adolescent; D000328:Adult; D001323:Autoantibodies; D005260:Female; D006801:Humans; D017098:IgA Deficiency / Q000150:complications* / Q000453:epidemiology* / Q000276:immunology; D008180:Lupus Erythematosus, Systemic / Q000150:complications* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D055815:Young Adult
D001323:Autoantibodies