Objective: Our aims were to define the incidence rate and predictors of opportunistic infection (OI) in systemic lupus erythematosus (SLE) patients.
Materials and Methods: A historical cohort study was conducted on patients over 15 years of age diagnosed with SLE, who attended the out-patient clinic or were admitted to Srinagarind Hospital, Khon Kaen, Thailand, between January 1, 2009 and December 31, 2014.
Results: The medical records of 132 SLE patients were reviewed. The female to male ratio was 13:1. Among the total 713.9 personyears, 6 cases had OI during follow-up with an incidence rate of 0.7 per 100 person-years (95% CI 0.9 to 1.7). Three of the cases received high-dose steroid with or without immunosuppressant for an incidence of 0.42 per 100 person-years (95% CI 0.13 to 1.30) and three had no high-dose steroid treatment during OI detection for an OI incidence of 0.28 per 100 person-years (95% CI 0.07 to 1.12). Pulmonary nocardiosis was the most common OI (4 cases; 66.7%), followed by disseminated candidiasis (1 case; 16.7%), and cryptococcal meningitis (1 case; 16.7%). Full recovery of OI occurred in 3 of 4 of with pulmonary nocardiosis and in 1 with cryptococcal meningitis, while one with pulmonary nocardiosis and one with disseminated candidiasis died at 33 and 6 days after OI, respectively.
Conclusion: The occurrence of OI in SLE is not common. Pulmonary nocardiosis was the most common OI, and all received moderate to high dose with and without immunosuppressant.

Keywords: Systemic lupus erythematosus; Infection; Opportunistic infection; Incidence rate