Abstract

Background: Due to its low incidence, the management of Mycobacterium xenopi pulmonary infections is not clearly defined.

Methods: The objectives of this multicentre retrospective study were to describe the features of the disease and to evaluate its prognosis. All patients with M.xenopi satisfying the 1997 ATS/IDSA criteria were included from 13 hospitals of North East France (1983-2003). Clinical, radiological and bacteriological characteristics, management and outcome were collected.

Results: One hundred and thirty six patients were included. Only 12 patients presented no comorbidity. Three features could be distinguished: the classical cavitary form (n=39, 31%) occurred in patients with pre-existent pulmonary disease; the solitary nodular form (n=41, 33%) in immunocompetent patients and the acute infiltrate form (n=45, 36%) in immunosupressed patients. Fifty six patients did not receive any treatment. The other 80 patients received first-line treatment containing rifamycin (87.5%), ethambutol (75%), isoniazid (66.2%), clarithromycin (30%) or fluoroquinolones (21%). After a follow-up of 36 months, 80 patients (69.1%) were dead and the median survival was 16 months [10-22]. Two independent prognostic factors were found: the acute infiltrate form associated with a bad prognosis (HR 2.6 p=0.001) and a protective factor the rifamycin-containing regimen (HR 0.325 p=0.006). Clarithromycin-containing regimen did not improve the prognosis.

Conclusions: In contrast of recent guidelines, our study showed three different features of the disease (cavitary, nodular or diffuse infiltrate form) with different prognosis. In order to improve the survival, all patients with M.xenopi infection must be treated with a rifamycin-containing regimen. The usefulness of clarithromycin remains to be evaluated.