Disseminated nontuberculous mycobacterial infection with cryptic immunodeficiency mimicking malignancy: a case report.

BACKGROUND: Nontuberculous mycobacteria (NTM) usually invades vulnerable hosts. Disseminated NTM (dNTM) infection can affect nearly all organs and be easily misdiagnosed as metastatic carcinoma or other systemic diseases, especially in seemingly immunocompetent hosts. Identification of underlying immunodeficiency is critical for the diagnosis and treatment of dNTM. Adult-onset immunodeficiency (AOID) with anti-IFN-γ autoantibodies has recently been recognized as a crucial but frequently neglected risk factor for dNTM infection. Frequent relapses of infection are common in AOID patients despite appropriate anti-infective treatment and B-cell-depleting therapy has shown some promising results. Herein, we report a case of dNTM infection mimicking malignancy in an AOID patient who was successfully treated with rituximab. CASE PRESENTATION: A middle-aged male presented with fever, productive cough, multifocal skin abscesses and multiple osteolytic lesions with pathological fractures. Chest CT revealed consolidation of the lingula while bronchoscopy showed a mass completely blocking the airway opening of the inferior lingual segment. Metagenomic next-generation sequencing and mycobacterial culture of skin pus and bronchoalveolar lavage fluid reported Mycobacterium Colombiense, confirming the diagnosis of dNTM infection. However, anti-NTM antibiotics alone failed to prevent disease relapse and progression. Further evaluation indicated undetectable serum IFN-γ concentration and high-titer autoantibodies against IFN-γ, suggesting that AOID was the underlying reason for dNTM. Rituximab was added to treatment and successfully controlled the infection without relapse at one-year follow-up. CONCLUSION: We reported a rare case of disseminated Mycobacterium Colombiense infection manifested with pulmonary mass, pathological fracture and dermapostasis in a host with AOID. Our case demonstrated that AOID should be screened when patients get the episode of disseminated NTM infection particularly when other risk factors are excluded. Besides prolonged anti-NTM therapy, AOID-associated NTM infection should be treated with B-cell-depleting therapy to prevent recurrence.

Clinical findings of Talaromyces marneffei infection among patients with anti-interferon-γ immunodeficiency: a prospective cohort study.

BACKGROUND: Talaromyces marneffei (T. marneffei) infection has been associated with adult-onset immunodeficiency due to anti-IFN-γ autoantibodies. We aimed to investigate the clinical features of non-HIV-infected patients with T. marneffei infection in southern China. METHODS: Between January 2018 and September 2020, we enrolled patients with T. marneffei infection who were HIV-negative (group TM, n = 42), including anti-IFN-γ autoantibody-positive (group TMP, n = 22) and anti-IFN-γ autoantibody-negative (group TMN, n = 20) patients and healthy controls (group HC, n = 40). Anti-IFN-γ autoantibodies were detected by ELISA. Clinical characteristics and clinical laboratory parameters were recorded. RESULTS: Compared with anti-IFN-γ autoantibody-negative patients with T. marneffei infection, anti-IFN-γ autoantibody-positive patients did not have underlying respiratory disease; more frequently exhibited dissemination of systemic infections with severe pleural effusion; had higher WBC counts, C-reactive protein levels, erythrocyte sedimentation rates, and neutrophil and CD8+ T cell counts; had lower hemoglobin levels; and were more likely to have other intracellular pathogen infections. Most of these patients had poor outcomes despite standardized antimicrobial therapy. CONCLUSION: T. marneffei-infected patients with higher anti-IFN-γ autoantibody titers have more severe disease and complex clinical conditions.

Disseminated Nontuberculous Mycobacterial Infection in a Patient with Anti-IFN-γ Autoantibodies.

We treated a 72-year-old Japanese female with sustained high fever and overall body exhaustion. An infectious liver cyst and right lung pneumonia were suspected causes. Hepatic cystectomy and various antibiotics did not resolve symptoms. Pneumonia exacerbation and ascitic fluid retention, left lumbar spinal osteomyelitis, and peri-gastric lymph node abscess penetrating the stomach were observed. Mycobacterium avium was identified in sputum, ascites, vertebral body abscess puncture specimen, and pus mucus secretion in the stomach. We diagnosed a disseminated nontuberculous mycobacterial infection. She seemed immunocompetent, without signs of AIDS or hematological malignancy. Serum anti-IFN-γ autoantibodies tested positive and were suspected to be involved in the illness onset.

Brain Nocardiosis and Pulmonary Talaromycosis Infection in a Patient with Anti-IFN-γ Autoantibodies: A Case Report.

Adult-onset acquired immunodeficiency caused by anti-IFN-γ autoantibodies is associated with severe opportunistic infection. Due to lack of specific symptoms and different manifestations, this form of infection can be easily misdiagnosed or overlooked. Herein, we present a case of Nocardia farcinica and Talaromyces marneffei co-infection in a patient with anti-IFN-γ autoantibodies (AIGAs). The patient, a 54-year-old man, presented with a 1-month history of fever, coughing and expectoration, dizziness, headache and gait imbalance. Laboratory workup revealed increased inflammatory markers, negative anti-HIV antibody and a high positive titer of AIGAs. Chest computed tomography (CT) showed multiple patches of high-density shadows in both lungs, and brain enhanced magnetic resonance imaging (MRI) showed an irregular lesion. The patient underwent a craniotomy for resection of the lesion. Pulmonary T. marneffei infection was diagnosed through sputum and bronchoalveolar lavage fluid culture, and brain nocardiosis was confirmed via purulent fluid culture of brain tissue. With regular antibiotic therapy, his symptoms improved and there was no recurrence during 18-month follow-up. This may be the first detailed case report detailing infection with these two distinct pathogens in disparate anatomical locations.

Intravenous Cyclophosphamide Therapy for Anti-IFN-γ Autoantibody-Associated Talaromyces marneffei Infection.

High titers of anti-interferon-γ autoantibodies (AIGAs) are an important factor leading to persistent, relapsed, and refractory infections in HIV-negative hosts infected with Talaromyces marneffei (TM). We report 5 patients treated with pulses of high-dose intravenous cyclophosphamide (IVCY) who were followed for 2 years. Before IVCY therapy, all patients had multiple relapses, with a median (interquartile range [IQR]) of 2 (1-3) instances of relapse. The median serum AIGA titers (IQR) were 58 753 (41 203-89 605) ng/mL at diagnosis, 48 189.4 (15 537-83 375) ng/mL before IVCY therapy, and 10 721.2 (5637-13 245) ng/mL at the end of IVCY therapy (P < .05). After 3 months of follow-up, the median AIGA titers (IQR) rose gradually to 21 232.6 (9896-45 626) ng/mL, and to 37 464.2 (19 872-58 321) ng/mL at 24 months (P < .05). Five patients discontinued antimicrobial therapy within 3-12 months after completion of IVCY therapy, but only 1 patient had a relapse. In conclusion, pulses of short-term and high-dose IVCY can effectively reduce AIGA titers.

Sweet's Syndrome Accompanied by Coinfection with Multiple Pathogens and Disseminated Mycobacterium phlei Infection Presenting with Osteolytic Destruction During 12 Years of Follow-Up: A Rare Case Report.

Background: Anti-IFN-γ autoantibodies (AIGAs) are closely related to the disseminated infection of multiple pathogens. Mycobacterium phlei (M. phlei) is a nonpathogenic nontuberculous mycobacteria (NTM), and M. phlei infection of the bone is extremely rare. We report a rare case of high-titer AIGAs presenting with Sweet's syndrome (SS) accompanied by opportunistic coinfection with multiple pathogens during 12 years of follow-up. The patient in this case also developed disseminated M. phlei infection with osteolytic destruction after treatment for SS. Case Presentation: A 68-year-old Chinese woman was admitted to our hospital in August 2009 due to fever and cough with expectoration for 3 months. The patient was successively infected with Klebsiella pneumoniae, herpes zoster virus and Candida. Chest computed tomography (CT) showed recurrent consolidations in different lung fields. After 15 months of antimicrobial treatment, the patient experienced partial recovery. In September 2010, the patient was pathologically diagnosed with SS due to the presence of multiple rashes. After prednisone and thalidomide treatment, the rashes subsided, and the pulmonary lesions had completely absorbed. In May 2011, the patient was diagnosed with disseminated tuberculosis and was administered anti-tuberculosis therapy for 3 months without improvement. NTM was subsequently cultured from her sputum and chest wall pus, and she improved after 20 months of anti-NTM therapy. In March 2016, the patient developed osteolytic destruction of the C7-T2 vertebral bodies with a back abscess. NTM was eventually cultured from the dorsal abscess pus and further identified as M. phlei. High-titer AIGAs were detected in the patient's serum. After another round of aggressive anti-NTM therapy, the patient was finally cured. Conclusion: Patients with AIGA-associated anti-cytokine autoantibody disease can present with multiple opportunistic infections and SS involving the lung. AIGA-associated immunodeficiency leads to infection with nonpathogenic M. phlei, which is refractory, can cause relapse, and even leads to osteolytic destruction.

Case report: Drug rash with eosinophilia and systemic symptoms syndrome in a patient with anti-interferon-γ autoantibody-associated immunodeficiency.

A 56-year-old Chinese woman with previous disseminated mycobacterium avium complex infection and recurrent cervical abscesses from Burkholderia cepacia complex visited our hospital. She was diagnosed with adult-onset immunodeficiency (AOID) and tested positive for interferon-γ-neutralizing autoantibody. Ceftazidime was administered as the initial antimicrobial treatment, which was later combined with sulfamethoxazole-trimethoprim (SMZ-TMP). She developed drug rash with eosinophilia and systemic symptoms (DRESS) syndrome after SMZ-TMP administration and improved after withdrawal of the culprit antibiotic and systemic glucocorticoids treatment. Her cervical infection was eventually cured after combined therapy of long-term antibiotics and anti-IFN-γ autoantibodies (AIGA) titer-lowering treatments including glucocorticoids, rituximab, and plasmapheresis. This is the first case of DRESS syndrome in the setting of AIGA-induced AOID and is worthy of notice.

Disseminated Mycobacterium avium complex infection in a woman with anti-interferon-γ autoantibodies.

Defects in the interleukin-12/interferon-gamma (IFN-γ) pathway and anti-IFN-γ antibodies have been associated with severe nontuberculous mycobacteria (NTM) infections. Consequently, disseminated NTM infections should prompt investigations for immunodeficiency. Herein, we report a case of a treatment refractory and ultimately disseminated and fatal Mycobacterium avium complex infection in a 71-year-old woman of Thai origin. Simultaneously, she had recurrent Salmonella kentucky cultured from stool samples and chronic perianal HSV-2 lesions. Late in the course of disease, anti-IFN-γ autoantibodies were demonstrated. Clinical studies investigating immunomodulating therapy and treatment among patients with anti-IFN-γ autoantibodies are lacking and, in this case, treatment seemed of a more palliative nature.

Retrospective Analysis of 10 Cases of Disseminated Nontuberculous Mycobacterial Disease with Osteolytic Lesions.

PURPOSE: Disseminated nontuberculous mycobacterial (DNTM) infection can involve multiple organs, including the lungs, skin and soft tissues and lymph nodes. However, NTM infection leading to osteolysis has been rarely reported. Here, we analyzed the clinical features, osteolytic mechanisms, treatment and prognosis of patients with DNTM disease with osteolytic lesions. PATIENTS AND METHODS: This retrospective study was conducted between January 1, 2011, and December 31, 2020, at the First Affiliated Hospital of Guangxi Medical University and the Fourth People's Hospital of Nanning City. Patients who had culture and/or histopathological proof of DNTM disease with osteolytic lesions were included. RESULTS: Ten HIV-negative patients with DNTM disease with osteolytic lesions were enrolled. Five of these patients had underlying diseases. Seven and three of the patients were positive and negative for anti-interferon-γ autoantibodies (AIGAs), respectively. The AIGA positivity rate was 70% (7/10). Ostealgia and anemia were the most common symptoms, followed by fever, emaciation, cough, expectoration, anorexia, subcutaneous abscesses and lymphadenopathy. Leukocyte and neutrophil counts were increased. The most common sites were the vertebrae, sternum, clavicle and ribs, although the femur, ilium, humerus, and scapula were also involved. Radiography and computed tomography (CT) showed moth-eaten or irregular destruction of bone, bone defects, pathological fracture, periosteal proliferation and surrounding abscesses. Emission CT (ECT) bone scans showed significantly increased uptake in many skeletal regions. Positron emission tomography(PET)/CT showed metabolic activity in multiple bones. All patients received anti-nontuberculous therapy, and five underwent surgery. Two died during treatment. CONCLUSION: DNTM infection of bone and leading to osteolysis usually occurs in patients with AIGA-positive antibodies. DNTM disease with osteolysis is characterized by increased leukocytes and neutrophil counts, focal suppurative granulomas, and multiple areas with moth-eaten or irregular destruction of bone with increased radioactive concentrations. Early diagnosis and timely, effective combination anti-NTM therapy can improve the prognosis.

Use of QuantiFERON-TB Gold In-tube assay in screening for neutralizing anti-interferon-γ autoantibodies in patients with disseminated nontuberculous mycobacterial infection.

OBJECTIVE: Anti-interferon- γ (IFN-γ) autoantibodies (anti-IFN-γ Abs) have been increasingly recognized as an important cause of disseminated nontuberculous mycobacterial (DNTM) infection, and identification of this immunodeficiency impacts clinical management. However, the protean disease manifestations and inaccessibility to diagnostic tests in clinical settings hamper its early diagnosis. Here, we sought to determine whether QuantiFERON-TB Gold In-tube (QFT-GIT), a commercialized IFN-γ release assay, could be used to screen for neutralizing anti-IFN-γ Abs among previously healthy adults with DNTM infection. METHODS: Non-HIV patients with DNTM infection were prospectively enrolled for the QFT-GIT assays. We measured their plasma concentration of anti-IFN-γ Abs and their neutralizing capacity through enzyme-linked immunosorbent assay and flow cytometry. We then analysed the correlation between QFT-GIT results and the presence of neutralizing anti-IFN-γ Abs among patients with and without previously recognized immunosuppression, respectively. RESULTS: Irrespective of the autoantibody concentration or disease activity, all patients with neutralizing anti-IFN-γ Abs (100%, 30/30) had indeterminate QFT-GIT results because of extremely low or undetectable IFN-γ levels in the mitogen tubes. None of the four DNTM patients who were previously healthy and tested negative of anti-IFN-γ Abs had an indeterminate QFT-GIT result, and their IFN-γ levels in the mitogen tube were significantly higher than those of the patients with anti-IFN-γ Abs (8.28 IU/mL vs. 0.05 IU/mL, p 0.001). CONCLUSION: An indeterminate QFT-GIT result because of undetectable or extremely low IFN-γ level in the mitogen tube suggests the presence of neutralizing anti-IFN-γ Abs in a previously healthy patient with DNTM infection.