Micobacterium avium complex en paciente inmunodeprimido: reporte de un caso / Mycobacterium avium complex in immunosuppressed patient: a case report

INTRODUCCIÓN: Dentro de las micobacterias atípicas destaca el Complejo Micobacterium Avium, cuyo nicho principal en humanos son los pacientes con inmunodeficencia. PRESENTACIÓN DEL CASO: Paciente masculino, 30 años, con antecedentes de infección por Virus de Inmonudeficiencia Humana en terapia antirretroviral y por virus Hepatitis B. Hospitalizado por cuadro de dolor abdominal asociado a síndrome consuntivo. Durante hospitalización se realizó Tomografía Computarizada que mostró múltiples adenopatías. Luego se realizó biopsia ganglionar que concluyó Tuberculosis ganglionar, comenzando con tratamiento antituberculoso. En el transcurso del tratamiento el paciente inició con sintomatología respiratoria y sus baciloscopías de esputo persistieron positivas, manteniéndose con dicho cuadro hasta confirmar la presencia de Micobacterium Avium en el cultivo, comenzando su tratamiento específico, con positivos resultados. DISCUSIÓN: El Complejo Micobacterium Avium corresponde a la causa más común de enfermedad por micobacteria no tuberculosa en inmunosuprimidos. Por lo tanto, es un patógeno que merece ser considerado al menos como diagnóstico diferencial en dicho tipo de pacientes. En el presente caso se evidencia tanto una sospecha como un diagnóstico tardío, lo que llevó a una demora en el inicio del tratamiento y a complicaciones sintomáticas del paciente. Es necesario para la pesquisa precoz, realizar cultivos tanto para M. tuberculosis como para micobacterias atípicas para mejorar pronóstico y a su vez disminuir el riesgo de complicaciones.

INTRODUCTION: Among the atypical mycobacteria, the Micobacterium Avium Complex stands out. Its main niche in humans is immunodeficient patients. CASE REPORT: 30 years old male patient, with a history of infection by Human Immunodeficiency Virus on antiretroviral therapy, and Hepatitis B virus. Hospitalized for abdominal pain associated with consumptive syndrome. During his hospitalization, a computerized tomography was performed, showing multiple adenopathies. Then, a lymph node biopsy was performed that concluded nodal tuberculosis, beginning with antituberculous treatment. During the course of this treatment, patient presented respiratory symptoms and sputum bacilloscopy persisted positive, maintaining this condition until the presence of Mycobacterium Avium was confirmed in the culture, beginning with specific treatment, with positive results. DISCUSSION: The Mycobacterium Avium Complex is the most common cause of nontuberculous mycobacterial disease in immunosuppressed patients. Therefore, its a pathogen that has to be considered at least as a differential diagnosis in such patients. In the present case, suspicion and a late diagnosis are evidenced, which lead to a delay in the initiation of treatment and complications for the patient. It is necessary for early screening, culture for both M. tuberculosis and atypical mycobacteria to improve prognosis and to reduce the risk of complications.

Infección pulmonar por mycobacterium avium complex en el huésped inmunocompetente / Mycobacterium avium complex pulmonary disease in immunocompetent adult patients

Las micobacterias no tuberculosas (MNT) se reconocen cada vez más como importantes patógenos pulmonares. El complejo Mycobacterium avium-intracellulare (MAC) causa la mayoría de las infecciones pulmonares por MNT. Aunque el organismo fue identificado en la década de 1890, su potencial patogenicidad en seres humanos fue reconocida sólo cincuenta años después. Los pacientes con enfermedad pulmonar preexistente o inmunodeficiencia están en mayor riesgo de desarrollar infección por MAC. Sin embargo, la mayoría de los casos se producen en mujeres de edad avanzada inmunocompetentes en asociación con infiltrados nodulares y bronquiectasias. Recientemente, la enfermedad pulmonar también se ha descrito en pacientes inmunocompetentes expuestos a equipos de hidroterapia o jacuzzis contaminados con MAC. En relación a dos pacientes adultos inmunocompetentes con enfermedad pulmonar por MAC examinamos el cuadro clínico, los criterios diagnósticos y el tratamiento de esta entidad.

Nontuberculous mycobacteria (NTM) are increasingly recognized as important pulmonary pathogens. Mycobacterium avium intracellulare complex (MAC) causes most lung infections due to NTM. Although the organism was identified in the 1890s, its potential to cause human disease was only recognized 50 years later. Patients with preexisting lung disease or immunodeficiency are at greatest risk for developing MAC infection. The majority of MAC pulmonary cases, however, occur in immunocompetent elderly women in association with nodular infiltrates and bronchiectasis. More recently, pulmonary disease has also been described in immunocompetent patients after exposure to MAC-contaminated hot tubs. We describe two cases of MAC lung disease in immunocompetent adult patients without preexisting lung disease and we review clinical manifestations, diagnostic criteria and treatment of this entity.

Disease caused by non-tuberculous mycobacteria: diagnostic procedures and treatment evaluation in the North of Buenos Aires Province

Non-tuberculous mycobacteria (NTM) have emerged as pathogens frequently associated to HIV co-infection. The aims of this study were to describe the clinical importance of NTM in patients from the North of Buenos Aires Province and the drug-susceptibility patterns in relation with the therapy used. A total of 23,624 clinical specimens were investigated during the period 2004-2010. Ziehl-Neelsen stain and cultures were used for diagnosis. Molecular and biochemical tests were performed to identify the mycobacteria. TB and mycobacterioses cases were 2 118 and 108 respectively. Sixteen NTM species were found: Mycobacterium avium and Mycobacterium intracellulare as the main causative agents. Infections produced by more than one species at the same time were confirmed (4 cases). Macrolides and fluoroquinolones were the most active in vitro drugs. Treatment evaluation showed that 68.0 % of the cases completed the therapy, 20 % died; and 12 % were relapses. The cases in which the treatment outcome was evaluated received an individual tailor-made therapeutic scheme including those drugs showing in vitro activity and presumed in vivo usefulness. More than a quarter of the patients had HIV co-infection and the majority of the deaths were associated with this co-infection.

Enfermedad causada por micobacterias no tuberculosas: diagnóstico y evaluación del tratamiento en el norte del Gran Buenos Aires. Las micobacterias no tuberculosas (MNT) emergieron como patógenos frecuentemente asociados a la co-infección con el HIV. EL objetivo del estudio fue describir la importancia clínica de las MNT en pacientes de la región norte de la provincia de Buenos Aires y los patrones de drogo-sensibilidad en relación con la terapia empleada. Se investigó un total de 23.624 especímenes clínicos durante, el período 2004-2010. La tinción de Ziehl-Neelsen y los cultivos se utilizaron para diagnóstico. Las micobacterias fueron identificadas mediante pruebas bioquímicas y moleculares. Los casos de tuberculosis y micobacteriosis fueron 2 118 y 108, respectivamente. Se encontraron 16 especies de MNT, siendo las principales, Mycobacterium avium y Mycobacterium intracellulare. En 4 casos se confirmaron infecciones producidas por más de una especie al mismo tiempo. Los macrólidos y las fluoroquinolonas tuvieron mayor actividad in vitro. La evaluación del tratamiento confirmó que el 68 % de los casos completó la terapia; 20 % murió y el 12 % recayó. Los casos en los que se evaluó el tratamiento recibieron un esquema terapéutico individual incluyendo aquellas drogas que mostraron actividad in vitro. Más de un cuarto de los pacientes tuvieron co-infeccion con el HIV y la mayoría de las muertes estuvieron asociadas con esta co-infección.

Treatment Outcome of Combination Therapy Including Clarithromycin for Mycobacterium avium Complex Pulmonary Disease

BACKGROUND/AIMS: The frequency of nontuberculous mycobacteria pulmonary disease in HIV-negative patients is increasing; the most common pathogen in Korea is the Mycobacterium avium complex (MAC). However, few studies have evaluated the treatment outcome of MAC pulmonary disease in Korea. METHODS: The efficacy of a clarithromycin-containing regimen for MAC pulmonary disease was studied in 42 patients treated for more than 6 months between January 2005 and December 2008. All patients were treated with a regimen consisting of clarithromycin, rifampin, and ethambutol. Streptomycin was added in 10 patients. RESULTS: Among the 42 patients, a negative culture conversion was achieved in 33 (78.6%), and the median duration of treatment in these patients was 19 months (interquartile range [IQR], 16 to 22). Of the 33 patients with a negative culture conversion, 14 completed treatment. During the follow-up period (median, 10 months; IQR, 4 to 20) for the 14 patients, one relapsed at 24 months after treatment completion. The culture conversion rate was significantly higher in patients who were treated with more than 500 mg/day clarithromycin (87.1% vs. 54.5%, p = 0.038). CONCLUSIONS: The combined regimen including clarithromycin was effective against MAC pulmonary disease. High-dose clarithromycin of more than 500 mg/day may improve the outcome of patients with MAC pulmonary disease.

Surgical Treatment of Pulmonary Diseases Due to Nontuberculous Mycobacteria

Although the treatment of pulmonary diseases due to nontuberculous mycobacteria (NTM) requires the long-term use of antibiotics in combination, the treatment success rates are unsatisfactory. We evaluated the clinical characteristics and surgical outcomes of 23 patients with NTM lung diseases who had underwent pulmonary resection. The median age of the patients was 45 yr. Of the 23 patients, 10 had Mycobacterium avium-intracellulare complex infection, 12 had M. abscessus infection, and one had M. xenopi infection. The indications for surgery were antibiotic therapy failure (n=11), remnant cavitary lesion with high probability of relapse (n=8), and massive hemoptysis (n=4). The most common procedure was lobectomy (48%). Postoperative complications occurred in eight patients (35%), including postoperative pneumonia (n=3) and late bronchopleural fistula (n=2). Negative sputum culture conversion was achieved and maintained in all except two mortalities. Although it is associated with a relatively high complication rate, patients with NTM lung disease whose disease is localized to one lung and who can tolerate resectional surgery might be considered for surgery, if there has been poor response to drug therapy or if the patients develop significant disease-related complications such as hemoptysis.

Soft tissue abscess and lymphadenitis due to Mycobacterium avium Complex as an expression of immune reconstitution inflammatory syndrome after a second scheme of highly active antiretroviral therapy

Immune reconstitution inflammatory syndrome (IRIS) is an atypical and unexpected reaction related to highly active antiretroviral therapy (HAART) in human immunodeficiency virus (HIV) infected patients. IRIS includes an atypical response to an opportunistic pathogen (generally Mycobacterium tuberculosis, Mycobacterium avium complex, cytomegalovirus and herpes varicella-zoster), in patients responding to HAART with a reduction of plasma viral load and evidence of immune restoration based on increase of CD4+ T-cell count. We reported a case of a patient with AIDS which, after a first failure of HAART, developed a subcutaneous abscess and supraclavicular lymphadenitis as an expression of IRIS due to Mycobacterium avium complex after starting a second scheme of HAART.

El síndrome inflamatorio de reconstitución inmune (SIRI) es una reacción atípica e inesperada relacionada con el tratamiento antirretroviral de gran actividad (TARGA) en pacientes infectados por el virus de la inmunodeficiencia humana (VIH). El SIRI representa una respuesta inflamatoria frente a un patógeno oportunista (generalmente Mycobacterium tuberculosis, Complejo Mycobacterium avium, citomegalovirus y herpes varicela-zóster) en pacientes que responden a la TARGA con una marcada reducción de la carga viral en plasma y evidencia de una recuperación inmunológica expresada por el incremento de los niveles de linfocitos T CD4+. Presentamos el caso de un paciente con síndrome de inmunodeficiencia adquirida que desarrolló un absceso subcutáneo en muslo derecho y una adenitis supraclavicular izquierda como manifestación de SIRI por Complejo Mycobacterium avium luego del inicio de un segundo esquema de TARGA.

Infection with the Mycobacterium avium complex in patients without predisposing conditons: a case report and literature review

Nontuberculous Mycobacteria (NTM), especially Mycobacterium avium-intracellulare complex (MAC), has been considered responsible for human disease, especially in HIV patients. Nevertheless, it has been diagnosed in immunocompetent elderly men, frequently with previous pulmonary disease: chronic obstructive lung disease (COPD), complications of tuberculosis, pulmonary fibrosis and bronchiectasis. We relate the case of a female patient, 51 years old, with continuously acid fast bacilli (AFB) smears and with three previous treatments, which were conducted at the multiresistant tuberculosis (MRTB) service. MAC was identified in the sputum culture, and she received treatment for one year. The posterior sputum exams were negative. The cavity lesions observed in the high-resolution computed tomography (HRCT) were reduced, and some of the nodule lesions became bronchiectasis, even after the end of treatment. We agree with the literature reports that indicate that MAC is the cause of bronchiectasis. It is necessary to identify the type of mycobacteria in immunocompetent individuals with positive AFB smears that do not become negative with tuberculosis treatment.