Prevalence of premature ovarian failure in systemic lupus erythematosus patients treated with immunosuppressive agents in Thailand

Background Systemic lupus erythematosus (SLE) is an autoimmune disease that affects most women of reproductive age. The prevalence of premature ovarian failure (POF) in SLE patients is higher than that in the general population. However, the data on this condition are limited in Asian countries. Objectives To determine the prevalence and associated factors of POF in SLE patients who received immunosuppressive therapy. Methods Women aged 18–40 years who were diagnosed with SLE according to the 1997 revised criteria for the classification of SLE or patients with biopsy-proven lupus nephritis were evaluated. All patients had received at least one of the following immunosuppressive agents: cyclophosphamide (CYC), azathioprine, mycophenolate mofetil, chlorambucil or cyclosporine for more than six months. POF was diagnosed in those who had sustained amenorrhea for more than six consecutive months, with a level of estradiol ≤ 110 pmol/L (30 pg/mL) and follicle stimulating hormone ≥40 IU/L. Results Ninety two SLE patients were included in this study. Mean age at enrollment was 30 ± 6.9 years and disease duration was 103 ± 67.5 months. The mean Systemic Lupus International Collaborating Clinics/ American College of Rheumatology (SLICC/ACR) damage index was 1.7 ± 1.7. Seventy five patients (82%) had lupus nephritis. Sixty four patients (70%) received CYC. Eleven patients (12%) with POF were observed. For the binary logistic regression model, CYC cumulative dosage of more than 10 g was the only independent risk factor of POF (hazard ratio 17.0, 95%CI 1.96–147.72, p = 0.01). Conclusions From our data, 12% of SLE patients developed POF. A cumulative dose of CYC of more than 10 g was the only risk factor for POF. To prevent these events, systematic evaluation and early recognition of POF should be promoted in the care of SLE patients.