"The Sarcoidosis Map": A Joint Survey of Clinical and Immunogenetic Findings in Two European Countries

We pooled immunogenetic data obtained in independent studies in two European populations (Italian and Czech) of patients affected by sarcoidosis. Correspondence analysis was used to investigate the associations between clinical and immunogenetic data. Two hundred and thirty-three patients were enrolled in the study, of which 126 were from the Czech Republic and 107 from Italy. Using a common protocol, we examined each patient for sex, age of disease onset, roentgenologic stage, extrapulmonary spread, and clinical course. One thousand and ten healthy individuals, HLA typed for class I and II serologic polymorphisms, served as controls. Findings that were essentially in agreement in both populations were: (1) a positive association of sarcoidosis with HLA-A1, B8, and DR3 markers, and a negative association with HLA-B12 and DR4; (2) a prevalence of HLA-DR3 and DR4 among females and of DR5 among males; (3) a relationship of B13 and B35 with early onset and of A30, B8, DR3, and DR4 with late onset of disease; (4) an association of B27 with sarcoidosis restricted to the lungs; (5) a relationship of A1, B8, B27, and DR3 to roentgenologic stage I and of B12 and DR4 to stage III; and (6) an association of HLA-DR3 with a good outcome. Population-restricted findings essentially concerned the alleles HLA-B13 and B22, the former being associated with the disease, male sex, early onset, extrapulmonary localization and relapse only in Czechs, and the latter to disease spread only in Italians. Our results seem to support the concept that immunogenetic background may at least partly account for the clinical heterogeneity of sarcoidosis.