4. Results
This series included 141 patients, with 120 (85.1%) women and 21 (14.9%) men. Regarding the clinical form, 47 (33.3%) had dcSSc, 88 (62.4%) had lcSSc, and 6 (4.3%) had sine scleroderma SSc. 
We also classified patients based on the main antinuclear antibody (ANA) patterns. The centromeric pattern was present in 25 patients (17.7%), nucleolar in 23 (16.3%), and other patterns in 61 (43.3%). In addition, 32 patients (22.7%) had a negative ANA result.
A confirmatory cardiac catheterism was performed in 14 of 19 patients diagnosed with PAH. The clinical features identified in this case series are listed in Table 1.
There was no evidence of an association between gender and any of the features considered (clinical forms, visceral involvement, or ANA and HLA alleles). 
We found no association of the HLA alleles with the clinical forms of the disease (diffuse, limited, and sine scleroderma) or with the main patterns of ANA that were considered (centromeric and nucleolar).
Concerning the clinical manifestations, evidence of an association was found between PF and PAH (P = 0.017). GI involvement was not associated with any HLA alleles. With respect to pulmonary fibrosis, there was an association with class I HLA-A*30 (P = 0.020) and class II DRB1*01 (P = 0.004), DQB1*05 (P < 0.001), and DQB1*04 (P = 0.019). The A*30 and DQB1*04 alleles were more frequent in patients with PF than in patients without PF. The presence of these two alleles was related to a higher risk for interstitial lung disease (PR = 1.86 and PR = 1.70, resp.). However, the HLA-DRB1*01 and DQB1*05 alleles appeared to be protective (PR = 0.38 and PR = 0.41, resp.) (Tables 2, 3, and 4). Pulmonary arterial hypertension was related only to class I B*35 (P = 0.035), C*03 (P = 0.044), and C*04 (P = 0.015) alleles. The HLA-B*35 and C*04 alleles were more frequent, resulting in a greater predisposition to this feature (PR = 2.58 and PR = 2.71, resp.). The C*03 allele was less frequent in these patients and was negatively correlated with this feature (PR = 0.13) (Tables 2, 3, 4 and 5).