Nontuberculous mycobacterial infections

The acquired immunodeficiency syndrome (AIDS) pandemic has led to greater understanding and respect for the pathogenic potential of non-tuberculous mycobacteria. Mycobacterium avium complex (MAC) has emerged as the most common systemic bacterial infection in AIDS, causing debilitating disseminated disease in late-stage HIV-infected patients. With the release of the macrolide antibiotics, clarithromycin and azithromycin, effective and well-tolerated therapeutic regimens for MAC have been developed which prolong survival and increase quality of life. The macrolides and rifabutin are also effective as preventive therapy for MAC in patients with AIDS. Mycobacterium kansasii, which causes pulmonary disease similar to tuberculosis as well as disseminated disease in AIDS, is treatable with isoniazid, rifampin and ethambutol. Clinical syndromes and therapeutic options for other non-tuberculous mycobacteria in AIDS are also reviewed.     

Nontuberculous mycobacterial cervical adenitis

Granulomatous inflammation is a common finding in pathologic evaluation of surgically excised chronic lymphadenopathy in children. Confusion exists regarding diagnosis and management of these lesions. Over a 10-year period at The Children's Hospital of Philadelphia, a total of 81 children were identified with biopsy-confirmed granulomatous lesions of the head and neck, with nontuberculous mycobacteria (NTM) accounting for 67 of the cases. The typical presentation was that of a nontender mass in the cervicofacial area present for weeks to months, unresponsive to antimicrobials. All underwent surgical excision, which was curative in 54 patients; 13 children required additional procedures. This paper reviews NTM, its typical clinical presentation, difficulty in diagnosis, and the methods of treatment.     

Nontuberculous mycobacterial infection of the central nervous system in patients with AIDS

Infections due to nontuberculous mycobacteria (NTM) are especially common in patients with AIDS. Meningitis due to NTM, however, is rare. A search for CSF cultures positive for NTM over the past 11 years at our hospital yielded 16 cases. Of these, 15 were caused by Mycobacterium avium-intracellular (MAI), and one was caused by M fortuitum. All patients with MAI infection had widespread dissemination and at least one risk factor for AIDS. Clinical features included weight loss, altered mentation, and seizures. Analysis of cerebrospinal fluid revealed a mildly elevated leukocyte count with lymphocyte predominance and normal protein and glucose values. All direct smears were negative for acid-fast bacilli. In-hospital mortality was 67%. The patient with infection due to M fortuitum had a preexisting diagnosis of AIDS and had a right upper lobe pneumonia and headaches. Cranial CT showed an enlarged infundibulum of the pituitary gland. Results of CSF analysis were essentially normal, and direct smears were negative. He left the hospital against medical advice. Our study indicates that the finding of MAI in the CSF in patients with AIDS is associated with an in-house mortality of 67% indicating a very poor prognosis.     

Cytomegalovirus encephalitis in an immunocompetent adult

Cytomegalovirus encephalitis in immunologically normal patients is rarely reported in the literature. Only seven cases have been previously reported. CMV infection was diagnosed in a 24-year-old, immunologically normal female presenting a severe clinical picture due to encephalitis. Diagnosis was based on detection of CMV DNA in the CSF with the polymerase chain reaction. Administration of ganciclovir was followed by an immediate improvement.     

Coeliac disease in the adult

Coeliac disease can by defined as a chronic disease characterized by a typical mucosal lesion of the small intestine and an impaired nutrient absorption which improves on withdrawal of gluten from the diet. The prevalence rate has increased over the last decades and just 1/3 of cases are diagnosed in childhood. There is a striking association with class II histocompatibility antigens, HLA-DR3 and HLA-DQ2. Cellular immune response mediated by intraepithelial and lamina propria lymphocytes is the primary event in the small intestine damage. Up to 50% of adult coeliac patients don't present intestinal symptoms being more frequent subclinic forms. The immunological markers of coeliac disease are antigliadin, antireticulin and antiendomysial antibodies, being the last one the most specific. Mortality of coeliac patient is increased mainly for malignancies, being the most frequent the intestinal T lymphoma.     

Bartonella henselae infection in immunocompetent patients: cat scratch disease

BACKGROUND: Cat scratch disease, whose etiologic agent is Bartonella henselae, is a benign disease in immunocompetent subjects, characterized by lymphadenopathy of prolonged course and occasional involvement of other organs such as liver, spleen, central nervous system, eye and lung. In immunocompromised patients, the infection is bacteremic and disseminated. AIM: To report Chilean cases of cat scratch disease. PATIENTS AND METHODS: Ten children (seven male, aged between 6 and 13 years old) with histologically or serologically confirmed cat scratch disease are reported. RESULTS: Lymphadenopathy location was pre auricular in four cases, axillary in two, inguinal in two and epitrochlear in two. Three children had fever over 39 degrees C and two had a parinaud syndrome. Nine children had a history of cat scratch and one of a cat byte. Six had an erythrocyte sedimentation rate over 40. Lymph node ultrasound examination was a useful diagnostic tool. Two patients had splenic granulomas. Lymph node biopsies were obtained in four cases, showing a suppurative granulomatous lymphadenitis in all and a positive Warthin-Starry stain in two. Serology, done in patients without histological confirmation was positive with titles ranging from 1:64 to 1:8192. All patients had a satisfactory outcome with regression of lymphadenopathy. CONCLUSIONS: Infections by Bartonella hemselae occur in the Chilean population and must be considered in the differential diagnosis of regional lymph node enlargement.     

Atypical mycobacterial pulmonary disease and bronchial obstruction in HIV-negative children

Atypical mycobacterial infection in HIV-negative children usually presents with cervical lymphadenopathy. We report on 10 children who are HIV-negative and who presented with pulmonary disease, in whom either culture-proven atypical mycobacterium infection (four), positive avian Mantoux test (five), or lack of response to human tuberculosis treatment (one) had been observed. One case was subsequently diagnosed as chronic granulomatous disease and illustrates that children with atypical mycobacterial pulmonary infection should have their immune status fully investigated. Bronchial obstruction was observed in eight cases, and of these, endobronchial disease was found in six children. The diagnosis of atypical mycobacterial disease is difficult, and a negative avian Mantoux test does not exclude the diagnosis. The availability of clarithromycin and rifabutin has offered new therapeutic options in treating atypical mycobacterial pulmonary infection, but management of these cases can be prolonged and difficult.     

Nontuberculous mycobacterial cutaneous infection confirmed by biochemical tests, polymerase chain reaction-restriction fragment length polymorphism analysis and sequencing of hsp65 gene

We report a woman in whom a slow-growing scotochromogenic strain of Mycobacterium was cultured from skin lesions. According to its phenotypic and biochemical characteristics we could predict only that it might be M. szulgai, M. scrofulaceum or M. gordonae. Polymerase chain reaction amplification of the hsp65 gene and subsequent restriction fragment length polymorphism analysis on the isolated strain showed that its restriction pattern differed from both M. scrofulaceum and other scotochromogenic species. Ninety-nine per cent similarity was detected between the isolated strain and M. gordonae by sequencing of the hsp65 gene. This result suggests that the isolated strain may be either a slow-growing scotochromogenic Mycobacterium most resembling M. gordonae or a novel mycobacterial species.     

Staphylococcal scalded skin syndrome in an immunocompetent adult: possible implication of low-dosage prednisone

Staphylococcal scalded skin syndrome (SSSS) mainly affects infants and young children. Very few cases of adult SSSS have been reported. Adult SSSS is usually associated with immunosuppression, overwhelming sepsis, and kidney failure. We report the case of an immunocompetent 51-year-old woman without renal failure who sustained SSSS after a 7-day course of oral prednisone administered postoperatively.     

Transfusion-associated graft-versus-host disease in immunocompetent patient: early diagnosis and therapy

Splenic marginal zone lymphoma (SMZL) most commonly presents with splenomegaly and stage IV disease. To our knowledge, there have been only two reported cases of SMZL without associated splenomegaly; one was detected incidentally after a bicycle accident. This previously reported case represented an early-stage SMZL with monoclonality confirmed by immunohistochemistry. We report a case of early-stage SMZL detected incidentally following a motor vehicle accident; monoclonality was confirmed by polymerase chain reaction analysis of paraffin-embedded tissue owing to the inability of confirmation by immunohistochemical techniques. We describe our findings and emphasize the importance of recognizing early stages of SMZL in incidental splenectomies by polymerase chain reaction analysis of paraffin-embedded tissue. Frozen tissue is not generally available in such cases.