Cerebral Mycobacterium avium abscesses: Late immune reconstitution syndrome in an HIV-1-infected patient receiving highly active antiretroviral therapy

Difficulty in diagnosing intracranial infection caused by Mycobacterium avium in an AIDS patient: case report and review of the literature

BACKGROUND

Mycobacterium avium complex (MAC) is an uncommon clinical pathogen, especially in the central nervous system (CNS), and carries a poor prognosis. MAC infections commonly present as immune reconstitution disease (IRD) in HIV patients. Herein, we report a case of intracranial infection caused by MAC in an AIDS patient without disseminated MAC (DMAC) and immune reconstitution inflammatory syndrome (IRIS).

CASE PRESENTATION

A 31-year-old HIV-positive male presented us with progressively worsening CNS symptoms, and neuroimaging revealed ring-enhancing lesions. The intracranial lesions worsened after the empirical therapy for toxoplasma encephalitis and fungal infection. Due to the rapid progression of the disease, the patient died. Mycobacterium avium was the only pathogen in brain tissue after cultures and molecular biology tests.

CONCLUSION

MAC infection in CNS is challenging to diagnose in HIV patients. Our findings emphasize that obtaining tissue samples and applying molecular biology methods is essential to help diagnose the patient as soon as possible to receive adequate treatment.

Neurological manifestations of nontuberculous mycobacteria in adults: case series and review of the literature

Introduction

Nontuberculous mycobacteria (NTM) mediated infections are important to consider in cases with neuroinflammatory presentations. We aimed to characterize cases of NTM with neurological manifestations at the National Institutes of Health (NIH) Clinical Center and review the relevant literature.

Materials and methods

Between January 1995 and December 2020, six cases were identified. Records were reviewed for demographic, clinical, and radiological characteristics. A MEDLINE search found previously reported cases. Data were extracted, followed by statistical analysis to compare two groups [cases with slow-growing mycobacteria (SGM) vs. those with rapidly growing mycobacteria (RGM)] and evaluate for predictors of survival. NIH cases were evaluated for clinical and radiological characteristics. Cases from the literature were reviewed to determine the differences between SGM and RGM cases and to identify predictors of survival.

Results

Six cases from NIH were identified (age 41 ± 13, 83% male). Five cases were caused by SGM [Mycobacterium avium complex (MAC) n = 4; Mycobacterium haemophilum n = 1] and one due to RGM (Mycobacterium abscessus). Underlying immune disorders were identified only in the SGM cases [genetic (n = 2), HIV (n = 1), sarcoidosis (n = 1), and anti-interferon-gamma antibodies (n = 1)]. All cases were diagnosed using tissue analysis. A literature review found 81 reports on 125 cases (SGM n = 85, RGM n = 38, non-identified n = 2). No immune disorder was reported in 26 cases (21%). Within SGM cases, the most common underlying disease was HIV infection (n = 55, 65%), and seizures and focal lesions were more common. In RGM cases, the most common underlying condition was neurosurgical intervention or implants (55%), and headaches and meningeal signs were common. Tissue-based diagnosis was used more for SGM than RGM (39% vs. 13%, p = 0.04). Survival rates were similar in both groups (48% SGM and 55% in RGM). Factors associated with better survival were a solitary CNS lesion (OR 5.9, p = 0.01) and a diagnosis made by CSF sampling only (OR 9.9, p = 0.04).

Discussion

NTM infections cause diverse neurological manifestations, with some distinctions between SGM and RGM infections. Tissue sampling may be necessary to establish the diagnosis, and an effort should be made to identify an underlying immune disorder.

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.

A Rare Case of Disseminated Mycobacterium avium-intracellulare Presenting as Proctitis

Mycobacterium avium intracellulare (MAI) infections are common in Human Immuno-deficiency Virus (HIV) positive patients. MAI infection can have localized or disseminated presentation, patients with low CD4 count presenting with disseminated infection. Fever, abdominal pain, diarrhea, and weight loss are generally the presenting symptoms of disseminated MAI. We present a rare case of a patient with HIV and low CD4 count presenting with proctitis as manifestation of disseminated MAI infection. A 25 year-old-man with HIV came to the emergency room (ER) with complaints of intermittent rectal bleeding for two months. His CD4 count was less than 20 cells/µL. He was MSM (men having sex with men) and has receptive anal intercourse with men. His stool work-up was unrevealing for infectious etiology. Swabs for gonorrhea and chlamydia were negative. Colonoscopy revealed erythematous, congested, friable rectal mucosa with two superficial ulcers. Biopsies of the ulcer were positive for acid fast staining bacteria and the culture grew MAI. His blood culture was negative for growth of acid-fast bacteria (AFB). However, liver biopsy performed for elevated alkaline phosphatase of 958 units/L revealed noncaseating granuloma. Gastro-duodenoscopy with duodenal biopsy did not reveal any mucosal abnormality. He was managed as with disseminated MAI infection using clarithromycin, ethambutol, and rifabutin in addition to HAART therapy. Interval Colonoscopy in 20 months showed resolution of rectal ulcer. The gut is often involved in patients with disseminated MAI infection, with the duodenum being the most common site. MAI infection should be suspected as possible etiology for proctitis in HIV positive patient with low CD4 count, as proctitis, though infrequent can be the sole presentation for disseminated MAI infection in patients with HIV and low CD4 count.

Intracranial abscess due to Mycobacterium avium complex in an immunocompetent host: a case report

Background

Mycobacterium avium complex (MAC) is a ubiquitous pathogen, widely distributed in the environment including water, soil and animals. It is an uncommonly encountered clinical pathogen; primarily causing pulmonary infections in patients with underlying lung disease or disseminated disease in immunocompromised hosts. Sporadically, extra-pulmonary infections have been documented including involvement of the liver, spleen, skin, soft tissue and lymph nodes. Central nervous system (CNS) infections due to MAC are exceedingly rare and carry a poor prognosis. Additionally, such infections are largely reported in patients infected with HIV. Herein we report the first case of intracranial abscess due to MAC in an immunocompetent man with a normal CD4 count and negative HIV status.

Case presentation

A previously healthy 40-year-old male presented to us with progressively worsening CNS symptoms. The patient’s presentation was uncharacteristic of MAC infection in immunocompetent hosts, as he developed subacute, progressive symptoms that included severe frontal headaches, left eyelid swelling, blurry vision, and diplopia, without any pulmonary or systemic manifestations. Neuroimaging revealed multiple ring-enhancing lesions, which required neurosurgical intervention. MAC was the only pathogen that grew from intraoperative tissue cultures. The patient was subsequently treated with a 12-month regimen consisting of Clarithromycin, Ethambutol, and Rifampin, with successful clinical resolution.

Conclusion

Our findings indicate that it is important to consider rare infections such as MAC in immunocompetent patients, regardless of atypical symptoms. Despite the severity of this infection, with timely diagnosis effective treatment is available.

Central nervous system immune reconstitution inflammatory syndrome in AIDS: experience of a Mexican neurological centre

BACKGROUND

Highly active antiretroviral therapy (HAART) restores the inflammatory immune response in AIDS patients and it may unmask previous subclinical infections or paradoxically exacerbate symptoms of opportunistic infections. Up to 25% of patients receiving HAART develop immune reconstitution inflammatory syndrome (IRIS). We describe six patients with IRIS central nervous system (CNSIRIS) manifestations emphasizing the relevance of CSF cultures and neuroimaging in early diagnosis and management.

METHODS

Patients with CNSIRIS were identified among hospitalized HIV-infected patients that started HAART from January 2002 through December 2007 at a referral neurological center in Mexico.

RESULTS

One-hundred and forty-two HIV-infected patients with neurological signs were hospitalized, 64 of which had received HAART, and six (9.3%) developed CNSIRIS. Five patients were male. Two cases of tuberculosis, two of cryptococcosis, one of brain toxoplasmosis, and one possible PML case were found. IRIS onset occurred within 12 weeks of HAART in five patients. Anti-infective therapy was continued. In one case, HAART was temporarily suspended. In long-term follow-up the clinical condition improved in all patients.

CONCLUSIONS

CNSIRIS associated to opportunistic infections appeared in 9% of patients receiving HAART. Interestingly, no cases of malignancy or neoplasm IRIS-related were found. Frequent clinical assessment and neuroimaging studies supported diagnosis and treatment. Risk factors were similar to those found in other series.