Duarte‐García, Alí

Objective To estimate the annual incidence and prevalence of and frequency of mortality associated with antiphospholipid syndrome ( APS ). Methods An inception cohort of patients with incident APS in 2000–2015 from a geographically well‐defined population was identified based on comprehensive individual medical records review. All cases met the 2006 Sydney criteria for APS (primary definition) or had a diagnosis of APS confirmed by physician consensus (secondary definition). Levels of lupus anticoagulant, IgM and IgG anticardiolipin antibodies, and anti–β2‐glycoprotein I antibodies were tested in a centralized laboratory. Incidence rates were age‐ and sex‐adjusted to the 2010 US white population. Prevalence estimates were obtained from the incidence rates, assuming that there was no increased mortality associated with APS and that migration in or out of the area was independent of disease status. Results Among this cohort in 2000–2015, 33 cases of incident APS , as defined by the Sydney criteria, were identified (mean age of patients 54.2 years; 55% female, 97% white). The annual incidence of APS in adults ages ≥18 years was 2.1 (95% confidence interval [95% CI ] 1.4–2.8) per 100,000 population. Incidence rates were similar in both sexes. The estimated prevalence of APS was 50 (95% CI 42–58) per 100,000 population, and was similar in both sexes. Six patients (18%) had a concurrent diagnosis of systemic lupus erythematosus. The most frequent clinical manifestation was deep vein thrombosis. The overall frequency of mortality among patients with APS was not significantly different from that in the general population (standardized mortality ratio 1.61, 95% CI 0.74–3.05). Conclusion APS occurred in ~2 persons per 100,000 population per year. The estimated prevalence was 50 per 100,000 population. Overall mortality was not notably different from that observed in the general population.

Objective To identify fixed and time-varying predictors of incident proteinuria. Methods This analysis was based on patients who did not have a history of diabetes and who did not have a prior episode of renal involvement. We defined an incident case of proteinuria as two or more measures of urine protein to creatinine ratio (or 24-hour protein measure) greater than 0.5 in two visits separated by more than 30 days and less than 180 days. We estimated rates of incident proteinuria in subgroups of patients with lupus defined by time-invariant and time-varying predictors. Results Among 895 patients included in the analysis, 840 (94%) were female, and 518 (58%) were Caucasian, 304 (34%) African-American, with mean age of 42 years at the start of follow-up. We observed 57 incident cases of proteinuria over a span of 4669 person-years of cohort follow-up. The overall rate of incident proteinuria was 12.2 per 1000 person-years. The rate was significantly lower among those of older age, and higher among those who were not Caucasian. In those with a very low C3 measure in a previous cohort visit, the rate was increased by a factor of 16.1 and in those with a very low C4 by 16.3. The rate among those prescribed hydroxychloroquine or ACE inhibitors/ARB was similar to those not on them. Conclusions Older patients with SLE are at low risk for developing proteinuria. There was not strong evidence that hydroxychloroquine or angiotensin-converting-enzyme (ACE) inhibitor reduced the risk of proteinuria. The highest rates of incident proteinuria were among those with recent low complement.