Immune Reconstitution Inflammatory Syndrome Induced by Mycobacterium avium Complex Infection Presenting as Chronic Inflammatory Demyelinating Polyneuropathy in a Young AIDS Patient

Antiretroviral therapy (ART) can restore protective immune responses against opportunistic infections (OIs) and reduce mortality in patients with human immunodeficiency virus (HIV) infections. Some patients treated with ART may develop immune reconstitution inflammatory syndrome (IRIS). Mycobacterium avium complex (MAC)-related IRIS most commonly presents as lymphadenitis, soft-tissue abscesses, and deteriorating lung infiltrates. However, neurological presentations of IRIS induced by MAC have been rarely described. We report the case of a 31-year-old man with an HIV infection. He developed productive cough and chronic inflammatory demyelinating polyneuropathy (CIDP) three months after the initiation of ART. He experienced an excellent virological and immunological response. Sputum culture grew MAC. The patient was diagnosed with MAC-related IRIS presenting as CIDP, based on his history and laboratory, radiologic, and electrophysiological findings. Results: Neurological symptoms improved after plasmapheresis and intravenous immunoglobulin (IVIG) treatment. To our knowledge, this is the first reported case of CIDP due to MAC-related IRIS. Clinicians should consider MAC-related IRIS in the differential diagnosis of CIDP in patients with HIV infections following the initiation of ART.

Mycobacterium avium complex (MAC) genomics and transmission in a London hospital

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental microorganisms and opportunistic pathogens in individuals with pre-existing lung conditions such as cystic fibrosis (CF) and non-CF bronchiectasis (BX). Whilst recent studies of Mycobacterium abscessus have identified transmission within single CF centres as well as nationally and globally, transmission of other NTM species is less well studied. We sequenced 1000 Mycobacterium avium complex (MAC) isolates from CF and non-CF patients at the Royal Brompton Hospital (RBH), London. Epidemiological links were identified from patient records. Previously published genomes were used to characterise global population structures. Analysis of the three most predominant MAC species identified putative transmission clusters that contained patients with CF, BX and other lung conditions, although few epidemiological links could be identified. For M. avium, lineages were largely limited to single countries, whilst for M. chimaera, global transmission clusters previously associated with heater cooler units (HCUs) were found. However, the origin of the major HCU-associated outbreak was a lineage already circulating in patients with pre-existing lung conditions. CF and non-CF patients share transmission chains even in the presence of CF patient-focussed hospital control measures, although the lack of epidemiological links suggests that most transmission is indirect and may be due to environmental foci or else asymptomatic carriage in the wider population. The major HCU-associated M. chimaera lineage being derived from an already circulating lineage, suggests that HCUs are not the sole vector nor the ultimate source of this lineage. Future studies should include sampling of environmental reservoirs and potential asymptomatic carriers.

Probably the Mycobacterium avium Complex around the Staple Line Exacerbated after Radiation Therapy

The space around the staple line after lung surgery is at high risk of nontuberculosis Mycobacterium pulmonary disease (NTM-PD). Solitary nodules of NTM-PD around the staple line are difficult to distinguish from lung cancer. There is no clear identification from laboratory data and radiologic findings without histological examination. In the present case, we misdiagnosed the pulmonary granulomas with Mycobacterium avium complex pulmonary disease (MAC-PD) as a recurrence of lung cancer. We conducted radiation therapy. The pulmonary granulomas with MAC-PD were exacerbated by irradiation. The effects of radiation therapy for MAC-PD are unknown. When radiation therapy is performed for the patient coexistence with MAC-PD, we should pay attention to exacerbation of MAC-PD.