Non-tuberculous mycobacterial infection in patients with systemic lupus erythematosus

Rheumatology (Oxford). 2007 Feb;46(2):280-4. doi: 10.1093/rheumatology/kel206. Epub 2006 Jul 22.

Abstract

Objectives: Patients with systemic lupus erythematosus (SLE) are susceptible to opportunistic infections. To examine the clinical manifestations of non-tuberculous mycobacterial (NTM) infections with those of Mycobacterium tuberculosis (MTB) infections in SLE patients.

Methods: Medical records of a cohort of 725 SLE patients were reviewed for previous NTM infections. Demographic characteristics, predisposing factors and clinical outcomes were compared with patients who had previous MTB infections (n = 39).

Results: Eleven (nine female and two male) cases were identified (prevalence 1.5%). The mean +/- S.D. age at the time of infection was 42.8 +/- 13.9 yrs, 9.3 +/- 5.8 yrs after the onset of SLE. The mean +/- S.D. time taken from onset of symptoms to the diagnosis of NTM infection was 5.7 +/- 7.2 months. Sites of involvement included skin and soft tissue (n = 8), chest (n = 2) and disseminated infection (n = 1). NTM infections were more likely to involve extrapulmonary sites (P = 0.006), presented in patients with longer lupus disease duration (P < 0.001), occurred in older patients (P < 0.001) and in those who had a higher cumulative dose of prednisolone (P = 0.01) than MTB infections. Using a stepwise logistic regression, disease duration was found to be the only independent predictive factor (P = 0.005) for NTM infections. Ten (25.6%) patients with MTB infections but none of the patients with NTM infections presented concomitantly at the onset of SLE (P = 0.09). There were no differences in the recurrence rate (P = 0.64) and frequency of disseminated infections (P = 0.40) between NTM and MTB infections.

Conclusions: NTM infections tended to develop in SLE patients later in their disease course than MTB infections. A high index of suspicion is required for its diagnosis.

MeSH terms

  • Adult
  • Aged
  • Cohort Studies
  • Female
  • Humans
  • Lupus Erythematosus, Systemic / complications*
  • Male
  • Middle Aged
  • Mycobacterium Infections, Nontuberculous / complications*
  • Mycobacterium Infections, Nontuberculous / diagnosis
  • Opportunistic Infections / complications*
  • Opportunistic Infections / diagnosis
  • Prognosis
  • Risk Factors
  • Time Factors
  • Tuberculosis / complications