Does the HLA-DRB1-genotype influence the course of disease in Danish sarcoidosis patients?

Background: The MHC class II region plays an important role in sarcoidosis, due to modulation of the immune response. HLA-DRB1*15 is associated with non-resolving disease in Swedish sarcoidosis patients (Grunewald et al. Respiratory Research 2010, 11:25). We evaluated the influence of the DRB1-genotype in Danish sarcoidosis patients. Subjects and methods: DRB1-genotyping was performed by PCR in 85 ethnic Danish sarcoidosis patients (52 men). Age at diagnosis was median 34 years (range 1-72). The follow-up period was median 37 months (range 0-516). Results: The prevalence of DRB1*01 was lower (p=0.0040) and the prevalence of DRB1*15 higher (p=0.00006) in sarcoidosis patients compared to controls. At follow-up, DRB1*07 was associated with a significantly lower frequency of non-resolving disease >2 years, whereas DRB1*15 was associated with a significantly higher frequency of non-resolving disease. Table 1. Course of sarcoid disease according to DRB1-genotypes DRB1-genotype Patients (n) Resolving disease (n) Non-resolving disease (n) P-value 1-4+8-13 81 26 55   vs 7 11 10 1 0.0003 1-4+8-13 81 26 55   vs 15 32 4 28 0.036 7 11 10 1   vs 15 32 4 28 0.000005 Fisher's exact test However, there were no significant differences between the DRB1-genotype groups concerning lung function tests (FEV1%, FVC%, DLCO% predicted) and chest X-ray stages according to Scadding. Conclusions: We have no biochemical markers of sarcoidosis. When the diagnosis has been confirmed, the DRB1-genotype may be used to predict the course of disease. In contrast to Swedish studies we found that DRB1*07 was associated with resolving disease, while our results confirmed the established association between DRB1*15 and non-resolving disease.