Nocardia infections among immunomodulated inflammatory bowel disease patients: A review

Abstract

Human nocardiosis, caused by Nocardia spp., an ubiquitous soil-borne bacteria, is a rare granulomatous disease close related to immune dysfunctions. Clinically can occur as an acute life-threatening disease, with lung, brain and skin being commonly affected. The infection was classically diagnosed in HIV infected persons, organ transplanted recipients and long term corticosteroid treated patients. Currently the widespread use of immunomodulators and immunossupressors in the treatment of inflammatory diseases changed this scenario. Our purpose is to review all published cases of nocardiosis in immunomodulated patients due to inflammatory diseases and describe clinical and laboratory findings. We reviewed the literature concerning human cases of nocardiosis published between 1980 and 2014 in peer reviewed journals. Eleven cases of nocardiosis associated with anti-tumor necrosis factor (TNF) prescription (9 related with infliximab and 2 with adalimumab) were identified; 7 patients had inflammatory bowel disease (IBD), 4 had rheumatological conditions; nocardia infection presented as cutaneous involvement in 3 patients, lung disease in 4 patients, hepatic in one and disseminated disease in 3 patients. From the 10 cases described in IBD patients 7 were associated with anti-TNF and 3 with steroids and azathioprine. In conclusion, nocardiosis requires high levels of clinical suspicion and experience of laboratory staff, in order to establish a timely diagnosis and by doing so avoid worst outcomes. Treatment for long periods tailored by the susceptibility of the isolated species whenever possible is essential. The safety of restarting immunomodulators or anti-TNF after the disease or the value of prophylaxis with cotrimoxazole is still debated.

Keywords: Immunomodulation; Inflammatory diseases; Nocardia spp.; Nocardiosis.

Figure 1

Torax computed tomography scan 73-year-old man with disseminated nocardiosis (cutaneous, pulmonary and cerebral involvements). A: Consolidations in upper right pulmonary lobe; B: Cavitation with heterogenous filling in right upper pulmonary lobe; C: Coronal image showing a cavitation in right lower pulmonary lobe.

Figure 2

Cerebral magnetic resonance of 73-year-old man with disseminated nocardiosis (cutaneous, pulmonary and cerebral involvements). A: Axial T2 FLAIR (Fluid attenuated inversion recovery). Multiple focal lesions in bilateral fronto-parietal subcortical white matter, with proeminent edema and mass effect resulting in sulcal effacement; B: Post-gadolinium T1 3D-MPRAGE, axial reformat. Ring enhancing lesions were depicted in post-contrast images; C: Post gadolinium T1 3D-MPRAGE, sagittal reformat. Ring enhancing lesions were depicted in post-contrast images, forming clusters in right occipital lobe.