Chinese Lupus Treatment and Research group (CSTAR) registry: X. family history in relation to lupus clinical and immunological manifestations

Objective This study aimed to examine the associations between family history and clinical manifestations and immunologic characteristics of lupus in China. Methods Based on their family history, lupus patients from the Chinese Lupus Treatment and Research group (CSTAR) registry were categorised: familial lupus (FL), family history of other rheumatic disorders (RD), and sporadic lupus (SL). Demographic data, clinical manifestations, and laboratory data were compared among these three groups. Results A total of 2,104 patients from CSTAR were included, with 34 (1.6%) in the FL group, 50 (2.4%) in the RD group, and 2,020 (96.0%) in the SL group. There were no significant differences in age or gender among these groups (p= 0.36 and p= 0.75, respectively). The prevalence of discoid rash and positivity of anti-RNP antibodies differed significantly among the three groups. Photosensitivity and neurological disorder were marginally significantly different among the three groups (p= 0.05). No statistical differences were observed in other clinical manifestations or laboratory results. In the FL group, first-degree relatives (25/34, 73.5%) had higher susceptibility to lupus. Rheumatoid arthritis (RA) (35/50, 70.0%) was the most frequent non-lupus rheumatic disorder in the RD group. Conclusion Among lupus patients, the rate of familial lupus was lower in Chinese patients than among other ethnicities. Familial lupus cases are found mainly among their first-degree relatives. A family history of lupus did not significantly affect clinical phenotypes, except for higher frequency of discoid rash and anti-RNP in the FL group, and more anti-RNP positivity in the RD group.