Localized Mycobacterium avium Complex Infection of Vertebral and Paravertebral Structures in an HIV Patient on Highly Active Antiretroviral Therapy

Vertebral osteomyelitis caused by non-tuberculous mycobacteria: Predisposing conditions and clinical characteristics of six cases and a review of 63 cases in the literature

Background Several case series have reported on clinical and radiographic characteristics of patients with vertebral osteomyelitis (VO) caused by non-tuberculous mycobacteria (NTM). However, only a few patients were included, and systematic reviews are still lacking. The aim of this study was to update and summarise the pre-disposing conditions, clinical and radiographic characteristics of such cases due to NTM. Methods In this study, a systematic review was conducted of the English-language literature from 1961-2014 to investigate the pre-disposing conditions and characteristics of cases of VO due to NTM. Also, six additional cases diagnosed in the study hospitals were described; these cases are included in an analysis of a total of 69 cases of NTM VO. Results The most common species, regardless of the presence of HIV co-infection, was M. avium Complex followed by M. xenopi. Ten cases with HIV infection had a median CD4 lymphocyte count of 320/mm(3) (range = 41-465/mm(3)) at the time of diagnosis of NTM VO. The VO in the cases with HIV infections occurred at an earlier age and more often involved the thoracic spine than in the cases without HIV infection. Pre-disposing trauma or surgery was reported in 14.5% (10/69) of the cases. A variety of immunosuppressive diseases were observed in 49.3% of the patients, including the 10 with HIV infections and corticosteroids were used in 27.5% of the cases. Surgery was performed in 67.6% and improvement was reported in 80.6%. Conclusion NTM should be considered in immunocompromised patients with indolent VO without confirmation of tuberculosis.

Mycobacterium avium Complex Osteomyelitis in Persons With Human Immunodeficiency Virus: Case Series and Literature Review

In persons with advanced immunosuppression, Mycobacterium avium complex (MAC) typically causes disseminated disease with systemic symptoms. We report 2 cases in which MAC caused localized osteomyelitis in human immunodeficiency virus (HIV)-infected individuals on antiretroviral therapy with rising CD4 counts. We summarize 17 additional cases of HIV-associated MAC osteomyelitis from the literature and compare CD4 count at presentation for vertebral cases versus nonvertebral cases, which reveals a significantly higher CD4 at presentation for vertebral cases (median 251 cells/µL vs 50 cells/µL; P = .043; Mann-Whitney U test). The literature review demonstrates that the majority of cases of MAC osteomyelitis, especially vertebral, occurs in individuals with CD4 counts that have increased to above 100 cells/µL on antiretroviral therapy. Among HIV-infected individuals with osteomyelitis, MAC should be considered a possible etiology, particularly in the setting of immune reconstitution.

Nontuberculous mycobacterial osteomyelitis

Osteomyelitis caused by nontuberculous mycobacteria (NTM) can have severe consequences and a poor prognosis. Physicians therefore need to be alert to this condition, especially in immunocompromised patients. Although the pathogenesis of NTM osteomyelitis is still unclear, studies in immunodeficient individuals have revealed close relationships between NTM osteomyelitis and defects associated with the interleukin-12-interferon-γ-tumor necrosis factor-α axis, as well as human immunodeficiency virus infection, various immunosuppressive conditions, and diabetes mellitus. Culture and species identification from tissue biopsies or surgical debridement tissue play crucial roles in diagnosing NTM osteomyelitis. Suitable imaging examinations are also important. Adequate surgical debridement and the choice of appropriate, combined antibiotics for long-term anti-mycobacterial chemotherapy, based on in vitro drug susceptibility tests, are the main therapies for these bone infections. Bacillus Calmette-Guerin vaccination might have limited prophylactic value. The use of multiple drugs and long duration of treatment mean that the therapeutic process needs to be monitored closely to detect potential side effects. Adequate duration of anti-mycobacterial chemotherapy together with regular monitoring with blood and imaging tests are key factors determining the recovery outcome in patients with NTM osteomyelitis.

Immune tolerance after total lymphoid irradiation for heart transplantation: immunosuppressant-free survival for 8 years

A 51-year-old African American man underwent orthotopic heart transplantation in 1995 for post-viral cardiomyopathy. Refractory rejection occurred, and he subsequently required total lymphoid irradiation to prevent further rejection. Disseminated Mycobacterium avium complex developed in 2000, and the patient decided to discontinue all drugs after the antibiotics caused intolerable medication side effects. The patient did not subsequently die of rejection, and he was discovered to have profound suppression of several lymphocytes subsets, presumably from the previous total lymphoid irradiation. This induced immunotolerance appears to have enabled his prolonged immunosuppressant-free survival.

Two-stage (posterior and anterior) surgical treatment of spinal osteomyelitis due to atypical mycobacteria and associated thoracolumbar kyphoscoliosis in a nonimmunocompromised patient

STUDY DESIGN

A case report of atypical mycobacterial spinal osteomyelitis.

OBJECTIVE

To describe a rare case of spinal osteomyelitis and associated thoracolumbar kyphoscoliosis caused by atypical mycobacteria, and successful treatment by a 2-stage surgical intervention.

SUMMARY OF BACKGROUND DATA

Vertebral osteomyelitis caused by atypical mycobacteria is very rare.

METHODS

The patient was an 18-year-old woman with vertebral osteomyelitis of Th12-L1 caused by Mycobacterium avium complex. Plain radiographs revealed vertebral collapse of Th12, scoliosis, and kyphosis.

RESULTS

Two-stage surgical treatment (first: posterior instrumentation; second: anterior debridement and bone graft) was performed. At 5 years after surgery, the patient is almost free of the preoperative symptoms with no evidence of disease recrudescence. Plain radiograph film demonstrated amelioration of scoliosis and kyphosis, and consolidation of the anterior bone graft.

CONCLUSION

A rare case of intractable spinal osteomyelitis due to atypical mycobacteria in a nonimmunocompromised patient was treated successfully with 2-stage surgical treatment.