Disseminated Mac Infection in a Patient with Anti Ifn Gamma Autoantibody

1Shonan Kamakura General Hospital, KAMAKURA, Japan

Meeting: Hospital Medicine 2014, March 24-27, Las Vegas, Nev.

Abstract number: 674

Case Presentation:

A 43‐year‐old female was admitted to our hosipital experiencing fever, cough, dyspnea, generalized lymphadenopathy and weight loss. She had been examined previously in another hospital and subsequently treated for community acquired pneumonia for 5 weeks. Her past medical history included repeated episodes of pneumonia treated with antibiotics, with the last episode being one and a half years prior to admission and bacterial arthritis of right knee secondary to Mycobacterium abscessus treated by surgically one year prior to admission.On admission, laboratory data revealed severe anemia, thrombocytopenia and elevated level of soluble interleukin‐2 receptor. Computed tomography showed right lober pneumonia, generalized lymphadenopathy involving the mediastinum and the intraperitoneal space, along with hepatosplenomegaly. Infection resulting from an underlying hematologic disease was strongly suspected. The patient underwent bone marrow biopsy, but the result was unrevealing. Mycobacterium avium complex (MAC) was identified in the sputum and bone marrow aspirates by acid‐fast bacillus culture and polymerase chain reaction (PCR). Furthermore MAC was also detected in the urine, pleural effusion and ascites. Disseminated MAC infection was diagnosed, and she was treated by standard antimycobacterial agents. Sadly, the patient succumbed to disseminated intravascular coagulation (DIC) and multi‐organ failure on the 42nd day of admission.

Discussion:

Usually disseminated MAC infection occurs in immunedeficient hosts such as in acquired immunodeficiency syndrome (AIDS) patients and individuals with hematological malignancy especially treated with chemotherapy. Examinations for anti‐HIV antibody and anti‐HTLV‐1 antibody were negative and the CD4 count was within the normal range. Post‐mortem examination was also undertaken, but it did not reveal any hematological malignancy.Recent studies have shown that the Th1 cytokine cascade, the interleukin 12 dependent high output interferon‐gamma pathway, is critically important for protection against intracellular organisms, including mycobacteria, because certain mutations in the genes for Th1 cytokines and their receptors have been reported to cause such infection. A recent report from Asia showed that anti‐interferon‐gamma autoantibodies were detected in 88% of HIV‐negative Asian adults with multiple opportunistic infections, including MAC.Serum anti‐interferon‐gamma autoantibody was investigated in this patient, and a high titer was detected. The cause of disseminated MAC infection in this case appeared to be anti‐IFN‐gamma autoantibody.

Conclusions:

In patients presenting with opportunistic infection without risk factors of HIV or HTLV‐1 infections, hematologic malignancy or drug‐induced immunosuppression, anti‐interferon‐gamma autoantibody should be considered and investigated appropriately, especially in patient with Asian ancestry.

Case Presentation:

A 43‐year‐old female was admitted to our hosipital experiencing fever, cough, dyspnea, generalized lymphadenopathy and weight loss. She had been examined previously in another hospital and subsequently treated for community acquired pneumonia for 5 weeks. Her past medical history included repeated episodes of pneumonia treated with antibiotics, with the last episode being one and a half years prior to admission and bacterial arthritis of right knee secondary to Mycobacterium abscessus treated by surgically one year prior to admission.

On admission, laboratory data revealed severe anemia, thrombocytopenia and elevated level of soluble interleukin‐2 receptor. Computed tomography showed right lober pneumonia, generalized lymphadenopathy involving the mediastinum and the intraperitoneal space, along with hepatosplenomegaly. Infection resulting from an underlying hematologic disease was strongly suspected. The patient underwent bone marrow biopsy, but the result was unrevealing. Mycobacterium avium complex (MAC) was identified in the sputum and bone marrow aspirates by acid‐fast bacillus culture and polymerase chain reaction (PCR). Furthermore MAC was also detected in the urine, pleural effusion and ascites. Disseminated MAC infection was diagnosed, and she was treated by standard antimycobacterial agents. Sadly, the patient succumbed to disseminated intravascular coagulation (DIC) and multi‐organ failure on the 42nd day of admission.

Discussion:

Usually disseminated MAC infection occurs in immunedeficient hosts such as in acquired immunodeficiency syndrome (AIDS) patients and individuals with hematological malignancy especially treated with chemotherapy. Examinations for anti‐HIV antibody and anti‐HTLV‐1 antibody were negative and the CD4 count was within the normal range. Post‐mortem examination was also undertaken, but it did not reveal any hematological malignancy.

Recent studies have shown that the Th1 cytokine cascade, the interleukin 12 dependent high output interferon‐gamma pathway, is critically important for protection against intracellular organisms, including mycobacteria, because certain mutations in the genes for Th1 cytokines and their receptors have been reported to cause such infection. A recent report from Asia showed that anti‐interferon‐gamma autoantibodies were detected in 88% of HIV‐negative Asian adults with multiple opportunistic infections, including MAC.

Serum anti‐interferon‐gamma autoantibody was investigated in this patient, and a high titer was detected. The cause of disseminated MAC infection in this case appeared to be anti‐IFN‐gamma autoantibody.

Conclusions:

In patients presenting with opportunistic infection without risk factors of HIV or HTLV‐1 infections, hematologic malignancy or drug‐induced immunosuppression, anti‐interferon‐gamma autoantibody should be considered and investigated appropriately, especially in patient with Asian ancestry.

To cite this abstract:

Watanabe T, Branch J, Tanaka E. Disseminated Mac Infection in a Patient with Anti Ifn Gamma Autoantibody. Abstract published at Hospital Medicine 2014, March 24-27, Las Vegas, Nev. Abstract 674. https://www.shmabstracts.com/abstract/disseminated-mac-infection-in-a-patient-with-anti-ifn-gamma-autoantibody/. Accessed December 10, 2018.

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