Characterizing Systemic Lupus Erythematosus in Males: A Retrospective Chart Review Study from the Ottawa Hospital Lupus Clinic

Objectives Male systemic lupus erythematosus (SLE) remains uncommon but is often linked with more severe organ involvement, particularly lupus nephritis. Limited Canadian data describe the clinical characteristics and treatment patterns of this population. This study aimed to characterize male SLE patients at a tertiary lupus clinic, focusing on disease features, retinal toxicity outcomes, and lupus nephritis prevalence.

Methods A retrospective chart review was conducted on 37 male SLE patients followed at the Ottawa Hospital Lupus Clinic. Demographic, serologic, and clinical data were collected using a standardized form. Disease activity was assessed by SLEDAI-2K, and classification was based on EULAR/ACR 2019 criteria. Medication exposure, comorbidities, and organ system-specific complications were analyzed descriptively.

Results We identified 37 males in the current lupus cohort of 410 patients. The mean age at diagnosis was 38.9 ± 17.4 years, and the current mean age was 54.4 ± 14.8 years. Ethnicity was primarily Caucasian (76%). The mean BMI was 26.1 ± 5.0 kg/m². Most patients (62%) were nonsmokers and 46% reported alcohol use. Common comorbidities included hypertension (41%), chronic kidney disease (24%), and diabetes (19%). The median EULAR/ACR score at diagnosis was 20 [IQR 16-26], with renal (46%) and mucocutaneous (43%) domains most frequently affected. Mean SLEDAI-2K at last visit was 1.3 ± 1.7, indicating current low disease activity. Hydroxychloroquine (HCQ) was prescribed in 23 of 37 patients (62%), with a mean daily dose of 396 mg. An additional 8 patients (22%) discontinued HCQ due to retinal toxicity or drug intolerance. HCQ- associated retinal toxicity (as confirmed by optical coherence tomography or electroretinography) occurred in 6 patients (16.2%), after a mean exposure dose exposure of 350mg/day for 14 years. Two of these patients (33%) had prior chloroquine treatment on average for 16.5 years. Lupus nephritis (LN) was documented in 18 (49%) patients, most commonly Class IV (46%) and Class V (46%), with 2 cases of IV/V LN (16%). Neuropsychiatric and cardiopulmonary involvement each occurred in 13.5%, while hematologic manifestations were rare (2.7%). One death was reported in the cohort related to heart failure.

Conclusion Male SLE patients in this cohort demonstrated a high prevalence of renal disease and a notable incidence of Plaquenil-related retinal toxicity. These findings emphasize the importance of long-term ocular and renal monitoring in male SLE management. Further work comparing the female cohort to the male cohort will help highlight key sex-differences in manifestations, outcomes and prognosis.