Mycobacterium avium complex infection in an immunocompetent young adult related to hot tub exposure.

An unusual case of Mycobacterium avium complex infection occurred in a young adult with no preexisting disease and no evidence of immunodeficiency. There was diffuse interstitial involvement of the lungs which suggested an active alveolitis. Diagnosis required open-lung biopsy. Restriction fragment length polymorphism analysis and multilocus enzyme electrophoresis indicated that the source of the infection was a hot tub. The infection proved to be exceptionally responsive to treatment, and there was complete resolution with a four-drug regimen.

Diffuse smooth muscle proliferation of the lungs with severe pulmonary hypertension.

We describe the second example of a distinctive clinicopathologic syndrome of severe pulmonary hypertension and interstitial lung disease caused by diffuse smooth muscle proliferation of the lungs (DSMPL) occurring in a 44-year-old man of normal intelligence with no cutaneous or neurological lesions. The smooth muscle proliferation involved the walls of bronchioles, alveoli, small pulmonary arteries, and pulmonary veins. DSMPL is distinct from pulmonary lymphangioleiomyomatosis and tuberous sclerosis, and does not appear to be neoplastic or reactive. The lesions are probably best regarded as multiple hamartomas or "native benign nodular smooth muscle proliferations."

Ciprofloxacin in patients with mycobacterial infections: experience in 15 patients.

In vitro and animal investigations have demonstrated the antimycobacterial activity of some fluoroquinolones, including ciprofloxacin, but information regarding their clinical usefulness in mycobacterial infections is sparse. This article presents treatment results of 11 patients with tuberculosis and 4 with atypical mycobacterial infections. They were treated with combinations of ciprofloxacin and one or two other antituberculosis agents. Susceptibility of the infecting organisms to ciprofloxacin was determined in 14 of the 15 patients: in 12 of them, minimum inhibitory concentrations ranged between 0.31 and 1.25 micrograms/mL, suggesting a good level of activity. Serum concentrations of ciprofloxacin, sampled one hour after dosing and measured by a specific HPLC assay, revealed considerable variability (range 0.22-8.41 micrograms/mL). Serial plasma samples taken under controlled conditions suggested that a decreased rate of absorption was responsible for low one-hour concentrations in one of the subjects. Adverse reactions to ciprofloxacin were few and included nausea in four patients, crystalluria in one, and febrile reaction in another. A satisfactory response in terms of clinical and radiologic improvement, bacteriologic conversion, and absence of relapse was seen in 13 of the 14 patients who completed an adequate course of therapy. A controlled clinical trial of this promising antimycobacterial agent is needed.

Ethambutol in tuberculosis.

Ethambutol gained rapid acceptance as a substitute for PAS in tuberculosis therapy because of improved patient tolerance and convenience of administration. Ocular toxicity was recognized early on but was thought to be a problem only at higher dosages. There have, however, been a number of reports of serious visual impairment on conventional dosage, with permanent blindness in some cases, and painfully slow recovery in others. The precise mechanism for the optic neuritis is not clear, and toxicity is difficult to predict in the individual patient. Ethambutol appears to contribute only marginally to modern short course regimens and should be replaced with a less toxic agent.

Toxic ocular effects of ethambutol.

Ethambutol hydrochloride has been used in the treatment of tuberculosis for 25 years. Its only important adverse effect, retrobulbar neuritis, is thought to be a minor concern with conventional dosages. The author presents four cases of serious visual impairment due to ethambutol therapy. Three of the patients were receiving a maintenance dosage of 15 mg/kg per day. The fourth patient was inadvertently given 25 mg/kg per day for 4 months. After therapy with the drug was stopped, improvement was slow, with complete recovery in two cases and only minor residual changes in a third. The patient who received the higher dosage of ethambutol suffered permanent, marked impairment. Ethambutol appears to contribute little to modern short-course antituberculous regimens that include more potent agents such as isoniazid and rifampin. In view of this and the potential for serious visual impairment, alternative antituberculous agents should be considered.

Tuberculosis in dialysis patients.

In a retrospective study over a 13-year period, data from one of the largest dialysis units in Canada were reviewed. Seven cases of active tuberculosis were identified among a dialysis population of 433 patients. Although this was not a controlled study the data suggests a greater than 10 fold increase in incidence of tuberculosis among patients with end stage renal disease compared to the total population. The majority of patients were over 40 years of age; race and immigrant status appeared to be risk factors, and tuberculin skin tests in the main were unhelpful diagnostically. Symptoms and signs mimicked that of underlying chronic renal disease in most instances, and extrapulmonary disease occurred in 3 of 7 patients. Therapy proved safe and effective in all cases. In terms of the epidemiological and clinical indices the present study tends to support the observations of investigators in other countries.

Clinical aspects of atypical mycobacterial infection.

SUMMARY: Atypical mycobacterial infections may give rise to various clinical difficulties. Case reports of six patients--three adult patients with pulmonary lesions, two children with cervical lymphadentis and one patient in whom the atypical mycobacterium appeared to be present as a commensal--illustrate these difficulties. Determination of the significance of the organism and differentiation of condition from tuberculosis and others requires consideration of the clinical picture, the results of skin testing, histologic features and cultural characteristics. Three patients, including the two children, were treated with a combination of surgery and chemotherapy, with satisfactory results. An elderly patient with chronic bronchitis and a pulmonary infection due to M. kansasii was treated successfully with antiuberculosis agents alone. Chemotherapy is being tried on a fifth patient with cavitary disease due to M. intracellulare, but is seems likely that an operation will also be required.

Serum enzymes in patients with carcinoma of lung: lactic-acid dehydrogenase, phosphohexose isomerase, alkaline phosphatase and glutamic oxaloacetic transaminase.

Serial determinations of serum lactic-acid dehydrogenase (LDH), phosphohexose isomerase (PHI), alkaline phosphatase (AP), and glutamic oxaloacetic transaminase (GOT) were carried out in 30 patients with primary and four with secondary neoplasms of the lung. Enzyme values were correlated with the stage of illness, with tumour histology, with chemotherapy and with the extent and site of metastases as determined at autopsy. The activity of the enzymes LDH and PHI was most frequently elevated; their values correlated closely. AP and GOT tended to become elevated only shortly before death. Although, in general, enzyme activity increased with tumour extension and often in relation to chemotherapy, assays provided little assistance in early diagnosis or prognosis except that, in most instances, elevated values of any of the four enzymes indicated the presence of metastases.