Infections in Systemic Lupus Erythematosus.

OBJECTIVES: Infections are a major cause of morbidity and mortality in patients of Systemic Lupus erythematosus (SLE). We therefore aimed to determine the spectrum of infections in patients of SLE, find a correlation between various disease parameters and the severity and outcome of infections and to compare the outcome between different modalities of immunosuppressive therapy.
METHODS: A cross-sectional study was carried out by including all the diagnosed patients of Systemic lupus erythematosus (based on SLICC criteria[1]) aged 12 years and above who developed infections during the study period of 18 months. Immunocompromised patients because of coexisting diseases like diabetes, retroviral disease and cancer patients on immunosuppression were excluded. 139 cases of infections were identified in 104 patients of SLE during the study period.
RESULTS: 92 patients had one episode of infection, 19 patients had two episodes and 3 patients contracted infections thrice during the study period. The mean age of the sample population was 29.45 ± 7.9 years. 21-30 years age group constituted 51.75% (59/114) of the patients. 61/139 infections (44%) were bacterial, 22/139 (16%) fungal, 20/139 (14%) viral and 4/139 (3%) parasitic. Tuberculosis was the most common infection (40/139, 28.78%). Lower respiratory tract was the most common site of infections found in the study (37/139, 26.62%). 75/139 (54%) were major infections. 50% tuberculous infections were extrapulmonary. The mean duration of SLE until the time of infection was 35.84 ± 53.80 months. SLE Disease Activity Index (SLEDAI) was ≥ 5 in 92.09% of cases. End organ damage was found in 82.7% (115 cases) and amongst them, renal lupus was found in 110/115 cases. No association was found between end organ damage and severity or outcome of infections. In 89 cases patients were on prednisolone alone, in 29 cases patients were additionally on Cyclophosphamide or had received it in the past, and in 15 cases Mycophenolate mofetil (MMF) with prednisolone while in 6 cases all the three drugs had been given at some point of time. Tuberculosis was the most common infection amongst all the groups. The mean daily dose of prednisolone was 19.62 ± 16.04 mg/day. The mean cumulative steroid dose in patients of our study was 9165.76 ± 7833.72 mg. Central nervous system infections occurred more in patients who had received Cyclophosphamide (p = 0.01). Five deaths occurred due to life threatening infections and all of them were either on high dose prednisolone or on cytotoxic drugs (Cyclophosphamide/Mycophenolate mofetil [MMF]). There was no association between treatment modality and severity and outcome of infection.
CONCLUSION: SLE patients are predisposed to various minor as well as lifethreatening infections. It is essential to prevent infections by screening, reducing exposure to sources or contacts of infection and minimizing the exposure to immunosuppressive agents while controlling disease activity. © Journal of the Association of Physicians of India 2011.