Background Survival in patients of SLE has improved considerably over the last five decades. However in India, survival rate in SLE patients was reported to be poor. Infections remain a major cause of mortality in patients of SLE. Prospective studies analyzing the risk of infection in SLE patients are scarce.
Objectives To study the incidence, type and severity of infection in SLE and their relation to clinical severity of disease and treatment profile.
Methods This is a prospective controlled study carried out in a single centre at a tertiary care hospital during September 2008 to September 2014. We included 108 patients of SLE fulfilling at least 4 criteria of 1997 revised ACR Criteria and 100 RA patients as non SLE controls.
Clinical variables included age, sex, SLE mean disease duration, complement level, anti dsDNA level, presence of nephritis and other features of disease activity.
The patients reported any symptoms of infection in outpatient clinic, wherein diagnostic protocols were followed to confirm or rule out infection events. Patients were also followed up at three weekly intervals, during which laboratory and clinical evaluation to detect infections were done. The clinical and lab tests as well as treatment received were recorded.
Infections were confirmed by positive cultures and/or supportive clinical and radiological features. Where cultures were not available, infections were confirmed by response to antibiotic therapy.
Infections in SLE patients were compared with the control group of population that is RA. Risk factors such as disease activity (using mean SLEDAI score), presence of lupus nephritis, presence or absence of leucopenia, complement levels, average daily dose of prednisolone, mean duration of disease, use of cyclophosphomide, mycophenolate moefetil and azathioprine were noted for all the patients.
Results SLE Group comprised of 108 patients (102 females, 6 males). RA cohort patients consisted of 100 patients (92 females, 8 males). Mean follow up duration of SLE pateints was 22±10 months and 20±12 months in control. 55 patients of SLE suffered at least one infection (50.92%) (p<0.001) (RR- 4.38) versus 12 (12.0%) in controls. 91 infections were recorded in these 55 patients. Urinary tract infection (37%), skin and mucous membrane (31.8%). E.coli was the most common organism isolated (30.7%), followed by Candida Albicans (18.7%), Herpes Zoster (14.28%). Tuberculosis was diagnosed in 10.98%. Mean SLEDAI score during infections was 7.3. Renal activity (p<0.001), low complement level, leucopenia (<4000), prednisolone dose >10 mg and immunosuppressive therapy was associated in 55 episodes of infections. Total numbers of deaths were 8, out of which four were due to infection and 4 were due to SLE.
Conclusions The patients of SLE had an overall increased risk of infections. The numbers of infection episodes in SLE were significantly higher than in controls. The infection rate was higher in patients with high dose of steroids and immunosuppressant therapy. The infections were associated with higher disease activity and low complement level.
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Disclosure of Interest None declared