Table 3.

Risk of developing pulmonary hypertension in presence of anti-topoisomerase II α (anti-topo II α) autoantibodies and the class I HLA-B35 antigen in 85 systemic sclerosis patients

Factor	Patients	No. of patients	Odds ratio	P*
Anti-topo II α	All	85	6·36	< 0·001
Anti-topo II α	HLA-B35-negative patients	57	7·50	< 0·05
HLA-B35	All	85	6·25	< 0·001
HLA-B35	Anti-topo II α-negative patients	67	6·80	< 0·02
Combined HLA-B35 and anti-topo II α	All	85	21·00	< 0·0001

^*P values were calculated using χ² tests with Yate's correction.