Clinical features, damage accrual, and survival in patients with familial systemic lupus erythematosus: data from a multi-ethnic, multinational Latin American lupus cohort

Objectives This study aimed to compare the clinical features, damage accrual, and survival of patients with familial and sporadic systemic lupus erythematosus (SLE). Methods A multi-ethnic, multinational Latin American SLE cohort was studied. Familial lupus was defined as patients with a first-degree SLE relative; these relatives were interviewed in person or by telephone. Clinical variables, disease activity, damage, and mortality were compared. Odds ratios (OR) and 95% confidence intervals (CI) were estimated. Hazard ratios (HR) were calculated using Cox proportional hazard adjusted for potential confounders for time to damage and mortality. Results A total of 66 (5.6%) patients had familial lupus, and 1110 (94.4%) had sporadic lupus. Both groups were predominantly female, of comparable age, and of similar ethnic distribution. Discoid lupus (OR = 1.97; 95% CI 1.08–3.60) and neurologic disorder (OR = 1.65; 95% CI 1.00–2.73) were significantly associated with familial SLE; pericarditis was negatively associated (OR = 0.35; 95% CI 0.14–0.87). The SLE Disease Activity Index and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) were similar in both groups, although the neuropsychiatric (45.4% vs. 33.5%; p = 0.04) and musculoskeletal (6.1% vs. 1.9%; p = 0.02) domains of the SDI were more frequent in familial lupus. They were not retained in the Cox models (by domains). Familial lupus was not significantly associated with damage accrual (HR = 0.69; 95% CI 0.30–1.55) or mortality (HR = 1.23; 95% CI 0.26–4.81). Conclusion Familial SLE is not characterized by a more severe form of disease than sporadic lupus. We also observed that familial SLE has a higher frequency of discoid lupus and neurologic manifestations and a lower frequency of pericarditis.

Familial lupus in Tunisia: a series of 14 families

The relatively high prevalence of systemic lupus erythematosus (SLE) in familial cases supports genetic susceptibility to this disease. Although many advances have been made in the identification of new genes implicated in lupus pathogenesis, to date, there has been no large study of familial SLE. We report what we believe to be the first study of familial SLE in the North African population. The objectives of this study were to determine the main clinical and laboratory features of familial lupus and to compare them to sporadic lupus in a population of Tunisian patients. Fourteen families in which the diagnosis of lupus could be verified in at least two relatives were included in the study. All patients fulfilled four or more criteria defined by the American College of Rheumatology. Twenty-seven patients (23 females and 4 males) with familial SLE among a cohort of 253 SLE patients were found, resulting in a frequency of 10.67%. No significant differences were found between familial SLE cases and their controls in terms of sex ratio, mean age at onset and clinical and serological manifestations, which is consistent with the results of other series reported in the literature. Our results support the importance of carrying out more genetic studies within families of SLE in order to have a better understanding of the genetic and molecular mechanisms of the disease.