Abstract
BACKGROUND: Infection is common cause of morbidity and mortality in systemic lupus erythematosus (SLE). Our objective was to determine incidence and types of infections, particularly opportunistic infections, in SLE patients receiving cyclophosphamide, and to identify contribution of variables like demographics, steroid, other immunosuppressives, white blood cell and absolute neutrophil count to infection risk. PATIENTS AND METHODS: We did retrospective chart review of SLE patients in our institute over last 10 years, who received minimum six cyclophosphamide infusions. Types of infection, cumulative steroid dose, and maintenance medications were recorded. Statistical analyses were done using SAS software. RESULTS: 87.1% of the 31 patients were female. Mean age was 37.9 years, 48.4% Hispanic, 25.8% African American, 6.4% Asian and 19.4% were Caucasian. No one was on pneumocystis jirovecii pneumonia (PJP) prophylaxis. There were 42 episodes of infection in 31 patients. Different infections were urinary tract infections (UTI), upper respiratory infections (URI), line sepsis, bacterial pneumonia, PJP, mucocutaneous infections and viral gastroenteritis. Infection frequency was significantly higher among Asians compared to Caucasians (p =0.0152). Infection rate was significantly higher during cyclophosphosphamide induction phase (65.9%) compared to maintenance phase (34.1%) (p value=0.0041). Infection rate was higher with higher cumulative steroid dose and in patients on quarterly cyclophosphamide infusion compared to those on oral azathioprine or mycophenolate mofetil. No association found among baseline white blood cell (WBC) or absolute neutrophil count (ANC) and infection rate. CONCLUSION: We found higher infection rates among Asians and in patients with higher cumulative steroid dose. Single incidence of PJP noted despite absence of prophylaxis. Quarterly cyclophosphamide was associated with higher infection rates. Larger prospective studies are needed to confirm our results.