Pulmonary Mycobacterium fortuitum infection with cervical lymphadenitis in a patient carrying autoantibodies to interferon-γ

Anti-interferon-γ Antibody-seropositive Disseminated Nontuberculous Mycobacterial Infection Mimicking POEMS and TAFRO Syndromes

Disseminated nontuberculous mycobacterial infection (DNTM) is typically observed in immunocompromised hosts. Recently, it has been reported that healthy individuals with serum neutralizing autoantibodies for interferon (IFN)-γ can also develop DNTM. We herein report a case of anti-IFN-γ antibody-seropositive DNTM caused by Mycobacterium kansasii with symptoms mimicking TAFRO or POEMS syndrome, including anasarca, organomegaly, skin pigmentation, polyneuropathy, osteosclerotic change, thrombocytopenia, serum M protein, high C-reactive protein level, and reticulin fibrosis. The combination of antimicrobial chemotherapy with glucocorticoid and intravenous immunoglobulin improved his symptoms. Glucocorticoids may be an effective method of suppressing the production of anti-IFN-γ antibodies in DNTM.

Intravenous Cyclophosphamide Therapy for Anti-IFN-Gamma Autoantibody-Associated Mycobacterium abscessus Infection

Introduction

Anti-interferon-gamma (IFN-γ) autoantibodies are increasingly recognized as a cause of adult-onset immunodeficiency (AOID) worldwide. These patients are susceptible to various intracellular pathogens especially nontuberculous mycobacteria. Most of the patients have a refractory clinical course. Herein, we report the use of immunotherapy with pulse intravenous cyclophosphamide (IVCY) in patients who had progressive, refractory Mycobacterium abscessus infection.

Method

We included patients, seen at Srinagarind Hospital, Thailand, infected with M. abscessus, who had received ≥3 courses of parenteral antibiotics within the last 12 months and who received pulse IVCY with a tapering dose of prednisolone.

Results

There were 8 AOID patients who met the criteria and received pulse IVCY between January 2011 and December 2015. One patient was lost to follow-up after 5 courses of IVCY: he had died at home 3 months later. Five patients had favorable outcomes: 2 were able to discontinue NTM therapy, and 3 had stable disease and were on NTM treatment without hospitalization for parenteral antibiotics. Two patients relapsed and needed hospitalization. The IFN-γ Ab titers among the 7 patients were significantly decreased during treatment, and the median initial antibody titer started at 200,000 and then decreased to 5,000 after 2 years of treatment (P < 0.0001). The antibody titer reduction among responsive vs. nonresponsive patient was significantly different after 6 months of treatment: the median antibody titer was 5,000 and 100,000, respectively (P = 0.0467).

Conclusion

IVCY therapy might be an alternative treatment for AOID patients infected with M. abscessus and refractory to antimycobacterial therapy.

Disseminated cutaneous Mycobacterium kansasii infection presenting with Rosai-Dorfman disease-like histological features in a patient carrying anti-interferon-γ autoantibodies

Typical cutaneous non-tuberculous mycobacteria (NTM) infections show a histopathology pattern of granulomas with admixed Langhans giant cells, and abscesses may be observed in acute lesions. Herein, we describe a patient carrying a high titer of autoantibodies to interferon (IFN)-γ with disseminated Mycobacterium kansasii infection presenting with emperipolesis and Rosai-Dorfman disease (RDD)-like histopathological features characterized by remarkable, large, pale-staining "RD cells", which were CD68 and S100 positive and CD1a negative. The patient was misdiagnosed with RDD initially, but exhibited a poor response to all interventions. A re-biopsy revealed Langhans-type multinucleated giant cells; multiple definite acid-fast bacilli were also found. M. kansasii was isolated from cultured tissues. Anti-NTM treatment was initiated. After treatment, all lesions resolved almost completely within the following month. High-titer anti-IFN-γ autoantibodies were detected during follow up, leading to the diagnosis of adult-onset immunodeficiency syndrome. In conclusion, patients carrying high-titer autoantibodies to IFN-γ who also have a disseminated cutaneous M. kansasii infection may present with RDD-like histopathological features, which may be a pitfall in the diagnosis of disseminated cutaneous NTM infections.

Patient ethnicity and causative species determine the manifestations of anti-interferon-gamma autoantibody-associated nontuberculous mycobacterial disease: a review

Nontuberculous mycobacteria (NTM) infections involving anti-interferon-gamma (IFN-γ)-neutralizing autoantibodies have been described in previously immunocompetent adults. To investigate the factors underlying various disease manifestations, we reviewed 35 articles published between January 2004 and November 2016 and identified 111 NTM patients with anti-IFN-γ autoantibodies. Rapidly growing mycobacteria (RGM) accounted for 53% of the isolated species. RGM were predominant among the NTM species isolated from Thai (73%), Chinese (58%) and Filipino (56%) patients, whereas M. avium complex (MAC) was predominant among Japanese (58%) and non-Asian (80%) patients. The commonly involved organs included the lymph nodes (79%), bones/joints (34%) and lungs (32%). Compared with the patients with MAC, the patients with RGM had a higher incidence of lymph node lesions (P<0.05) and a lower incidence of bone/joint (P<0.01), lung (P<0.01), soft tissue (P<0.01), bronchus (P<0.01) and muscle (P<0.05) lesions. Clinical manifestations of NTM disease with anti-IFN-γ-neutralizing autoantibodies differ across ethnicities and NTM species.