Failure of tuberculosis chemotherapy in a human immunodeficiency virus-infected patient

Correlates for disease progression and prognosis during concurrent HIV/TB infection

Mycobacterium tuberculosis (Mtb) and the human immunodeficiency virus (HIV) are both life-threatening pathogens in their own right, but their synergic effects on the immune system during co-infection markedly enhance their effect on the host. This review focuses on the bidirectional interaction between HIV and Mtb and discusses the relevance of sputum smear examination, CD4+ counts, viral load at baseline and after initiation of anti-retroviral therapy, as well as additional existing and new potential immune correlates of disease progression and prognosis. These markers include beta2-microglobulin, neopterin, tumor necrosis factor receptor II (TNFRII), CD8+/CD38+, soluble urokinase plasminogen activator receptor (suPAR) and CXCL10 (or IP-10).

Fluoroquinolones, tuberculosis, and resistance

Although the fluoroquinolones are presently used to treat tuberculosis primarily in cases involving resistance or intolerance to first-line antituberculosis therapy, these drugs are potential first-line agents and are under study for this indication. However, there is concern about the development of fluoroquinolone resistance in Mycobacterium tuberculosis, particularly when administered as monotherapy or as the only active agent in a failing multidrug regimen. Treatment failures as well as relapses have been documented under such conditions. With increasing numbers of fluoroquinolone prescriptions and the expanded use of these broad-spectrum agents for many infections, the selective pressure of fluoroquinolone use results in the ready emergence of fluoroquinolone resistance in a diversity of organisms, including M tuberculosis. Among M tuberculosis, resistance is emerging and may herald a significant future threat to the long-term clinical utility of fluoroquinolones. Discussion and education regarding appropriate use are necessary to preserve the effectiveness of this antibiotic class against the hazard of growing resistance.

Acquired drug resistance in Mycobacterium tuberculosis isolates recovered from compliant patients with human immunodeficiency virus-associated tuberculosis

We describe five compliant patients with human immunodeficiency virus (HIV)-associated tuberculosis (TB) that relapsed, with acquisition of resistance by the original Mycobacterium tuberculosis strains. Both the first and second isolates from each patient had the same IS (insertion sequence) 6110-based DNA fingerprint patterns. Three of the five patients developed TB that was resistant to rifampin alone; no mutation in the region of the rpoB gene was detected by a line probe assay in two of the isolates from these patients. We discuss several factors presumably associated with acquired drug resistance in HIV-infected patients, including exogenous reinfection, drug interactions, malabsorption of drugs, and the presence of a large organism burden.

Tuberculosis and human immunodeficiency virus infection

Mycobacterium tuberculosis infects one third of the world's population, and tuberculosis remains one of the most common infectious diseases of humans. From a global perspective, tuberculosis may be one of the most common HIV-related opportunistic infections. HIV immunosuppression has had a dramatic influence on the epidemiology, natural history and clinical presentation of tuberculosis. Treatment is highly effective for drug susceptible tuberculosis and has been shown to have a significant impact on resistant, especially multidrug-resistant, tuberculosis if started promptly. Directly observed therapy and rigorous adherence to infection control principles have helped control the tuberculosis epidemic in the United States.

The changing epidemiology of acquired drug-resistant tuberculosis in San Francisco, USA

BACKGROUND

The increasing incidence of tuberculosis caused by drug-resistant Mycobacterium tuberculosis is thought in part to reflect inadequate implementation of standard tuberculosis control measures. However, in San Francisco, USA, which has an effective tuberculosis control programme, we have recently observed an increase in cases of acquired drug-resistance.

METHODS

To explore further this observation, we analysed the secular trend of acquired drug-resistance and conducted a population-based case-control study of all reported tuberculosis cases in the city of San Francisco between 1985 and 1994.

FINDINGS

We identified 14 patients with tuberculosis caused by fully susceptible M tuberculosis who subsequently developed drug-resistance. Of these acquired drug-resistance cases, two occurred between 1985 and 1989, whereas 12 occurred between 1990 and 1994 (p = 0.028). In the case-control study, AIDS (odds ratio 20.2, 95% CI 1.12-363.6), non-compliance with therapy (19.7, 1.66-234.4), and gastrointestinal symptoms (11.5, 1.23-107.0) were independently associated with acquired drug-resistance. Between 1990 and 1994, one in 16 tuberculosis patients with AIDS and either gastrointestinal symptoms or non-compliance developed acquired drug- resistance.

INTERPRETATION

The substantial increase in acquired drug- resistance in San Francisco seems to be a product of the increasing prevalence of HIV/M tuberculosis coinfection. Our data suggest that the interface of the HIV and tuberculosis epidemics fosters acquired drug-resistance, and that traditional tuberculosis control measures may not be sufficient in communities with high rates of HIV infection.

Tuberculosis in the AIDS era

A resurgence of tuberculosis has occurred in recent years in the United States and abroad. Deteriorating public health services, increasing numbers of immigrants from countries of endemicity, and coinfection with the human immunodeficiency virus (HIV) have contributed to the rise in the number of cases diagnosed in the United States. Outbreaks of resistant tuberculosis, which responds poorly to therapy, have occurred in hospitals and other settings, affecting patients and health care workers. This review covers the pathogenesis, epidemiology, clinical presentation, laboratory diagnosis, and treatment of Mycobacterium tuberculosis infection and disease. In addition, public health and hospital infection control strategies are detailed. Newer approaches to epidemiologic investigation, including use of restriction fragment length polymorphism analysis, are discussed. Detailed consideration of the interaction between HIV infection and tuberculosis is given. We also review the latest techniques in laboratory evaluation, including the radiometric culture system, DNA probes, and PCR. Current recommendations for therapy of tuberculosis, including multidrug-resistant tuberculosis, are given. Finally, the special problem of prophylaxis of persons exposed to multidrug-resistant tuberculosis is considered.

Tuberculosis and acquired immunodeficiency syndrome: a historical perspective on recent developments

The incidence of tuberculosis has increased in recent years, at least in part as a result of the ongoing worldwide epidemic of acquired immunodeficiency syndrome (AIDS). In addition, the occurrence of outbreaks caused by multidrug-resistant Mycobacterium tuberculosis organisms has greatly heightened concern. In retrospect, a number of seminal studies that have appeared during the past decade have helped to define changing concepts concerning the epidemiology, pathogenesis, approaches to preventive care, diagnosis, and treatment of tuberculosis in HIV-infected persons. Such reports have shown that the variable clinical manifestations of tuberculosis in patients with AIDS are greatly influenced by the degree of HIV-induced immunosuppression. Explosive outbreaks of tuberculosis occurring in closed environments have emphasized that patients with AIDS and pulmonary tuberculosis may be highly contagious, especially when diagnosis and implementation of appropriate infection control measures are delayed. The extent to which homelessness and illicit drug use complicate management of tuberculosis have been examined, and the high risk of persons who are both tuberculin-positive and HIV-positive ultimately developing active tuberculosis, unless chemoprophylaxis is completed, has been clearly shown. The utility of sputum smears, bronchoscopy, and newer technologies such as polymerase chain reaction for diagnosis has been examined. The risk of relapse appears to be low when patients with AIDS with drug-sensitive tuberculosis complete appropriate multiple-drug therapy. Recent reports have addressed important hospital infection control, tuberculin testing, and chemoprophylaxis issues. This paper describes this evolution of understanding, focusing on reports that we believe have been conceptually important.

Acute and long-term efficacy of antituberculous treatment in HIV-seropositive patients with tuberculosis: a study of 36 cases

Thirty-six consecutively observed HIV-seropositive patients with tuberculosis, including 31 patients with AIDS, who received antituberculous treatment, were followed up to evaluate its efficacy. Treatment with standard antituberculous regimens was intended except when an individual's condition required a modified therapeutic approach. Therapeutic failure occurred in five patients (14%) while on treatment, one also had a post-treatment relapse. Treatment failure was associated with drug resistance and non-compliance in three patients and in another two, both of whom died early in the course of their disease, with HIV-related conditions other than tuberculosis. The median relapse-free post-treatment follow-up time in 24 patients in whom treatment did not fail was 13 months (range 4-67). Standard antituberculous treatment is highly effective in the immediate and long-term treatment of HIV-related tuberculosis provided that drug susceptibility and treatment compliance are confirmed.

Failure of therapy for tuberculosis in human immunodeficiency virus infection

Optimum treatment of tuberculosis in persons with human immunodeficiency virus (HIV) infection is still being defined. Tuberculosis treatment failure in an HIV-infected patient is described and 10 similar cases from the medical literature are reviewed to search for common patterns associated with an adverse outcome of therapy in this setting. Six patients were poorly compliant. In nine patients, the subsequent episode of tuberculosis was disseminated or extrapulmonary; in four the central nervous system was involved. In five patients, a problem with rifampin usage was encountered: Three had rifampin-resistant Mycobacterium tuberculosis, one experienced an adverse reaction to rifampin, leading to withdrawal from the regimen after 1 week, and one was receiving a drug that may interfere with rifampin's antimycobacterial effect. This case report and literature review suggest that particular attention should be directed toward ensuring that patients with HIV infection comply with treatment of tuberculosis. For the majority of patients, the already stretched resources available for the treatment of tuberculosis and HIV infection should be devoted to compliance enhancement rather than to more prolonged or intensive drug regimens. However, it should be emphasized that patients with disseminated tuberculosis or central nervous system disease and those who are not able to receive rifampin because of drug resistance or an adverse reaction should be managed individually.

Susceptibility of strains of the Mycobacterium tuberculosis complex to fusidic acid

The activity of fusidic acid was studied in 40 strains of M. tuberculosis (of which 20 strains were mono- or multiresistant to standard antituberculosis drugs) and 10 strains of M. bovis. Minimum inhibitory concentration (MIC) was determined by the radiometric (BACTEC) broth method. The MIC for the 50 strains varied between 8 and 32 mg/l, with a MIC90 of 16 mg/l for M. tuberculosis and a MIC90 of 32 mg/l for M. bovis. Minimal bactericidal concentration (MBC, defined as the lowest concentration of fusidic acid which killed 99% or more of the population) varied between 32 mg/l and 500 mg/l, with a MBC90 of 250 mg/l for M. tuberculosis and 500 mg/l for M. bovis. No cross-resistance to other antituberculosis drugs (ethambutol, isoniazid, rifampicin, streptomycin, pyrazinamide, ofloxacin, ciprofloxacin) was observed as strains resistant to one or more standard antituberculosis drugs were as susceptible to fusidin as sensitive strains of M. tuberculosis. No synergism or antagonism could be demonstrated when fusidic acid was combined with either ethambutol, isoniazid, rifampicin or streptomycin against strains of M. tuberculosis resistant to one or more standard antituberculosis drugs. Addition of pooled human serum to the medium increased both MIC and MBC by factors of 4 and 8 at serum concentrations of 10% and 50%, respectively. Single-step mutation to high-level resistance to fusidic acid at a frequency of less than 1.7 x 10(-8) could be readily selected at four times the MIC. These fusidic acid-resistant organisms had a generation time 2.0-2.7 x longer than their parent organisms.

Tuberculous meningitis in patients infected with the human immunodeficiency virus

BACKGROUND AND METHODS

Tuberculosis is a frequent complication of human immunodeficiency virus (HIV) infection. We describe the clinical manifestations and outcomes of tuberculous meningitis in patients with HIV infection, and compare them with those in non-HIV-infected patients. We reviewed the records from 1985 through 1990 at two large referral hospitals in Madrid for patients who had Mycobacterium tuberculosis isolated from cerebrospinal fluid.

RESULTS

Of 2205 patients with tuberculosis, 455 (21 percent) also had HIV infection, of whom 45 had M. tuberculosis isolated from the cerebrospinal fluid. Of the 37 HIV-infected patients with tuberculous meningitis for whom records were available, 24 (65 percent) had clinical or radiologic evidence of extrameningeal tuberculosis at the time of admission. In 18 of 26 patients (69 percent), a CT scan of the head was abnormal. In most patients, analysis of cerebrospinal fluid showed pleocytosis (median white-cell count, 0.234 x 10(9) per liter) and hypoglycorrhachia (median glucose level, 1.3 mmol per liter), but in 43 percent (15 of 35), the level of protein in cerebrospinal fluid was normal. In four patients with HIV infection, tuberculosis was only discovered after their deaths. Of the 33 patients who received antituberculous treatment, 7 died (in-hospital mortality, 21 percent). Illness lasting more than 14 days before admission and a CD4+ cell count of less than 0.2 x 10(9) per liter (200 per cubic millimeter) were associated with a poor prognosis. Comparison with tuberculous meningitis in patients without HIV infection showed that the presentation, clinical manifestations, cerebrospinal fluid findings, and mortality were generally similar in the two groups. However, of the 1750 patients without HIV infection, only 2 percent (38 patients) had tuberculous meningitis, as compared with 10 percent of the HIV-infected patients (P less than 0.001).

CONCLUSIONS

HIV-infected patients with tuberculosis are at increased risk for meningitis, but infection with HIV does not appear to change the clinical manifestations or the outcome of tuberculous meningitis.