Primary prevention of cryptococcal meningitis by fluconazole in HIV-infected patients

Primary prophylaxis for cryptococcal meningitis and impact on mortality in HIV: a systematic review and meta-analysis

AIM

To determine the role of primary antifungal prophylaxis in the prevention of cryptococcal meningitis and all-cause mortality in advanced HIV infection.

MATERIALS & METHODS

This was a systematic review and meta-analysis of randomized trials and observational studies. Google Scholar™, PubMed and Embase databases were searched for relevant studies. Quality was assessed using different criteria, depending on study type. Publication bias was assessed and subgroup and sensitivity analyses were performed. When the results of the meta-analysis were homogeneous, the fixed-effects model was used; when the results of the meta-analysis were heterogenous, the random effects model was used.

RESULTS

Primary prophylaxis prevented cryptococcal meningitis but did not confer protection against overall mortality, although there was evidence of a reduction in cryptococcal-specific mortality in resource-limited settings.

CONCLUSION

Primary antifungal prophylaxis should be recommended in patients with advanced HIV infection in resource-limited settings with a high incidence of cryptococcal meningitis.

New Insights into HIV/AIDS-Associated Cryptococcosis

Cryptococcal meningitis is a life-threatening opportunistic fungal infection in both HIV-infected and HIV-uninfected patients. According to the most recent taxonomy, the responsible fungus is classified into a complex that contains two species (Cryptococcus neoformans and C. gattii), with eight major molecular types. HIV infection is recognized worldwide as the main underlying disease responsible for the development of cryptococcal meningitis (accounting for 80-90% of cases). In several areas of sub-Saharan Africa with the highest HIV prevalence despite the recent expansion of antiretroviral (ARV) therapy programme, cryptococcal meningitis is the leading cause of community-acquired meningitis with a high mortality burden. Although cryptococcal meningitis should be considered a neglected disease, a large body of knowledge has been developed by several studies performed in recent years. This paper will focus especially on new clinical aspects such as immune reconstitution inflammatory syndrome, advances on management, and strategies for the prevention of clinical disease.

Primary prophylaxis of cryptococcal disease with fluconazole in HIV-positive Ugandan adults: a double-blind, randomised, placebo-controlled trial

BACKGROUND

Cryptococcal disease remains an important cause of morbidity and mortality in HIV-infected individuals in sub-Saharan Africa, despite the introduction of antiretroviral therapy. We studied fluconazole as primary prophylaxis against cryptococcal disease in patients awaiting or starting antiretroviral therapy in Uganda.

METHODS

In this prospective, double-blind randomised controlled trial, we enrolled HIV-positive adults with CD4 counts less than 200 cells per μL, cryptococcal antigen (CrAg)-negative, naive for antiretroviral therapy, and coming from five local AIDS organisations in Masaka district, Uganda. Enrolment took place between Sept 14, 2004, and Feb 1, 2008. Participants were randomly allocated to placebo or 200 mg fluconazole three times per week (1:1) in blocks of 40. Randomisation was done with ralloc procedure in Stata. Participants were reviewed after 4 weeks and referred for antiretroviral therapy, then seen every 8 weeks. Participants discontinued trial treatment when CD4 counts reached 200 cells per μL (median 197 days). Primary endpoints were invasive cryptococcal disease and all-cause mortality. Secondary endpoints were time to first episode and incidence of oesophageal candidosis, time to first episode and incidence of oropharyngeal or vaginal candidosis, and time to first hospital admission or death. The primary safety endpoint was cessation of trial drug because of transaminase concentrations higher than five times the upper limit of normal (ULN), or other major adverse events. Analyses were done by intention to treat and included all participants enrolled in the trial. Participants and researchers were masked to group assignment. This trial is registered with controlled-trials.com, number ISRCTN 76481529.

RESULTS

Of 1519 individuals enrolled, 760 participants received fluconazole and 759 received placebo. 19 developed cryptococcal disease, one in the fluconazole group and 18 in the placebo group (p=0·0001); adjusted HR (aHR) 18·7 (95% CI 2·5-140·7). One case of cryptococcal disease could be prevented by treating 44·6 patients with baseline CD4 counts lower than 200 cells per μL. Fluconazole was effective against cryptococcal disease both before (aHR=11·0 [1·4-85·3]) and after start of antiretroviral therapy (no cases in fluconazole vs seven cases on placebo). Seven participants died from cryptococcal disease, none in the fluconazole group. All-cause mortality (n=189) did not differ between the two groups (p=0·46). Fluconazole reduced the time to first episode of oesophageal, and oropharyngeal and vaginal candidosis, as well as the incidence of all candidosis (p<0·0001), but had no effect on hospital admission or death. The frequency of elevated transaminases (>5×ULN) was similar between groups (aHR=0·94 [0·65-1·35]).

CONCLUSIONS

Fluconazole was safe and effective as primary prophylaxis against cryptococcal disease, both before and during early antiretroviral treatment. Cryptococcal infection was less common than anticipated because of the rapid commencement of antiretroviral therapy and exclusion of those with positive CrAg. In patients with negative CrAg on screening, fluconazole prophylaxis can prevent cryptococcal disease while waiting for and in the early weeks of antiretroviral therapy, particularly in those with CD4 counts of less than 100 cells per μL.

FUNDING

Medical Research Council, UK, and Rockefeller Foundation.

Prevention of cryptococcosis in HIV-infected patients with limited access to highly active antiretroviral therapy: evidence for primary azole prophylaxis

Despite advances in the treatment of HIV disease, the incidence and mortality of invasive cryptococcal disease remain significant. A matched, case-control study was performed to examine the impact of highly active antiretroviral therapy (HAART) and azole use on the incidence of invasive cryptococcal disease in HIV-infected patients. The study was performed at a metropolitan hospital with a large indigent population and an incidence of seven cases of cryptococcal disease per 1000 persons with AIDS. Bivariate analysis, matched on CD4 count, revealed that both HAART use [odds ratio (OR) 0.43; 95% confidence interval (CI) 0.23-0.99] and azole use (OR 0.14; 95% CI 0.06-0.34) had a protective effect. Conditional logistic regression stratified on CD4 lymphocyte count revealed a protective role for azole use (OR 0.15; 95% CI 0.06-0.40) but not for HAART use (OR 0.47; 95% CI 0.18-1.26). Of note, the prevalence of HAART use was low in both cases and controls, with only 12% of cases and 23% of controls on HAART. The results of this study support previous evidence that azole use prevents invasive cryptococcal disease. Although current guidelines for the prophylaxis of opportunistic infections do not suggest routine prophylaxis for cryptococcal infection, this issue should be reconsidered, especially in populations that have a low prevalence of HAART use.

Antifungal interventions for the primary prevention of cryptococcal disease in adults with HIV

BACKGROUND

Cryptococcal disease is an opportunistic infection that causes significant morbidity and mortality in adults with HIV. Primary prophylaxis with antifungal interventions may decrease cryptococcal disease incidence and associated mortality.

OBJECTIVES

To assess the efficacy of antifungal interventions for the primary prevention of cryptococcal disease in adults with HIV.

SEARCH STRATEGY

We searched the following databases: MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), ClinicalTrials.gov, Database of Abstracts of Reviews of Effectiveness (DARE), Latin American and Caribbean Literature on the Health Sciences (LILACS), and the Cochrane Controlled Trials Register (CCTR). We reviewed abstracts from the following relevant conferences: International AIDS Conference, International AIDS Society Conference on HIV Pathogenesis and Treatment, and Conference on Retroviruses and Opportunistic Infections. We searched reference lists for all primary and other pertinent articles identified. We attempted to contact experts in the field, particularly primary authors of included studies, to better ensure completeness of included studies. We also approached pharmaceutical companies for any available and relevant unpublished data. The time period searched was from 1980 to August 2004. We placed no language restrictions on the search. Key words used include: meningitis, cryptococcal, cryptococcus, cryptococcosis, acquired immunodeficiency syndrome, human immunodeficiency virus, prophylaxis, chemoprevention, antifungal agents, and the Cochrane screen for randomized controlled trials.

SELECTION CRITERIA

Randomized controlled trials using antifungal interventions for the primary prevention of cryptococcal disease in adults with HIV were selected.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial eligibility and quality. Trial authors, experts, and pharmaceutical companies were contacted for additional and/or missing information. Data were abstracted by two reviewers. Data were pooled, where appropriate, to yield summary estimates.

MAIN RESULTS

Five studies (N=1316) were identified. All study patients had CD4 cell counts <300 cells/microl, and the majority of patients had CD4 cell counts <150 cells/microl. When all five studies are analyzed as a single group (N=1316), the incidence of cryptococcal disease was decreased in those taking primary prophylaxis (RR 0.21, 95% CI 0.09, 0.46) compared to those taking placebo. However, there was no significant difference in overall mortality observed (RR 1.01, 95% CI 0.71, 1.44). When the three studies using itraconazole as the intervention were analyzed together (N=798), the incidence of cryptococcal disease was decreased in those taking itraconazole for primary prophylaxis (RR 0.12, 95% CI 0.03, 0.51) compared to those taking placebo; however, there was no significant difference in overall mortality (RR 1.12, 95% CI 0.70, 1.80). When the two studies using fluconazole as the intervention were analyzed together (N=518), the incidence of cryptococcal disease was decreased in those taking fluconazole for primary prophylaxis (RR 0.25, 95% CI 0.07, 0.87) compared to those taking placebo; however, there was no significant difference in overall mortality (RR 0.59, 95% CI 0.14, 2.62).

AUTHORS' CONCLUSIONS

Antifungal primary prophylaxis with either itraconazole or fluconazole is effective in reducing the incidence of cryptococcal disease in adults with advanced HIV disease. However, neither of these interventions has a clear effect on overall mortality. Further research is needed to better understand these interventions and the populations in which they may be most effective.

Cryptococcal meningitis

Cryptococcal meningitis is a common opportunistic infection in AIDS patients, particularly in Southeast Asia and Africa. Cases also occur in patients with other forms of immunosupression and in apparently immunocompetent individuals. Mortality from HIV-associated cryptococcal meningitis remains high (10-30%), even in developed countries, because of the inadequacy of current antifungal drugs and the complication of raised intracranial pressure. In cohorts of HIV-infected patients from sub-Saharan Africa, cryptococcosis has accounted for 13-44% of all deaths. Optimal current therapy is with amphotericin B 0.7-1 mg/kg/day plus flucytosine 100 mg/kg/day for 2 weeks, followed by fluconazole 400 mg/day for 8 weeks and 200 mg/day thereafter. Saline loading reduces amphotericin B nephrotoxicity. If there is no contraindication on CT head scan, repeat lumbar puncture with drainage of cerebrospinal fluid (CSF) is recommended for patients with very raised CSF opening pressure. Expansion of antiretroviral programmes raises the prospect of transforming the long-term prognosis of these patients, provided that they survive the acute phase of the illness. Studies are needed to define more fungicidal drug regimens and to improve the treatment of raised intracranial pressure.

Risk factors for cryptococcal meningitis in HIV-infected patients

To identify the risk factors for cryptococcal meningitis in patients with HIV disease we conducted a nested case-control study of 37 incident cases of cryptococcal meningitis and 74 controls, identified from a cohort of more than 2000 HIV-infected patients. Conditional logistic regression was used to study demographic and AIDS-related variables in addition to fluconazole and steroid use. No difference in demographic variables, HIV risk factors, or stage of AIDS was detected between cases and controls. Exposure to fluconazole for more than 90 days reduced the risk of cryptococcal meningitis by 82% (OR=0.18; 95% CI=0.04-0.85; p=0.03). We did not find a difference in steroid use between cases and controls for either the length or amount of steroid exposure (p=0.41). No difference in survival during follow-up in the clinic was observed by the log-rank test (p=0.74). Among the cases, a cryptococcal antigen was positive in more than 97% of the CSF or blood samples. CSF and blood cultures were positive in 81 and 44% of the samples, respectively. We conclude that demographic factors did not affect the risk of cryptococcal meningitis in an inner city United States population. While fluconazole use has a protective effect, steroid use was not associated with an increased risk of cryptococcal meningitis in HIV-infected patients.

Human immunodeficiency virus infection, Part II

The acceptance of highly active antiretroviral therapy (HAART) among patients and health care providers has had a dramatic impact on the epidemiology and clinical characteristics of many opportunistic infections associated with human immunodeficiency virus (HIV). Previously intractable opportunistic infections and syndromes are now far less common. In addition, effective antibiotic prophylactic therapies have had a profound impact on the risk of patients developing particular infections and on the incidence of these infections overall. Most notable among these are Pneumocystis carinii, disseminated Mycobacterium avium complex, tuberculosis, and toxoplasmosis. Nevertheless, infections continue to cause significant morbidity and mortality among patients who are infected with HIV. The role of HAART in many clinical situations is unquestioned. Compelling data from clinical trials support the use of these therapies during pregnancy to prevent perinatal transmission of HIV. HAART is also recommended for health care workers who have had a "significant" exposure to the blood of an HIV-infected patient. Both of these situations are discussed in detail in this article. In addition, although more controversial, increasing evidence supports the use of HAART during the acute HIV seroconversion syndrome. An "immune reconstitution syndrome" has been newly described for patients in the early phases of treatment with HAART who develop tuberculosis, M avium complex, and cytomegalovirus disease. Accumulating data support the use of hydroxyurea, an agent with a long history in the field of myeloproliferative disorders, for the treatment of HIV. Newer agents, particularly abacavir and adefovir dipivoxil, are available through expanded access protocols, and their roles are being defined and clarified.

Accumulation of fluconazole in scalp hair

The accumulation in scalp hair of the antimycotic triazole, fluconazole, was studied during and after administration. Fluconazole 50 mg was administered to 12 healthy subjects as a single capsule each day for 28 days. The concentration of fluconazole 5 hours after administration was measured in different 1-cm sections of scalp hair at intervals during treatment and for 6 months after the end of treatment. In each section of scalp hair the concentration of fluconazole increased during treatment and was consistently higher than values found in plasma. For example, the mean concentration in the first hair section on day 28, 19.8 micrograms/g, corresponded to a mean penetration ratio relative to plasma of 9.42. During administration, the maximal concentration of fluconazole was found in the first hair section. After cessation of administration, the measured concentrations of fluconazole decreased and greater concentrations were found in the distal hair sections, presumably as a result of hair growth. Fluconazole was detectable, however, in the hair of 9 of the 12 subjects even 6 months after treatment. The mean concentration of fluconazole in hair bulbs on day 28 was 12.1 micrograms/g (n = 6), corresponding to a mean penetration ratio of 5.99. In a second study, fluconazole was administered as a single oral 150-mg capsule per week for 4 weeks to a group of 8 healthy subjects. The mean fluconazole concentration in whole scalp hair 5 hours after the last dose was 3.2 micrograms/g.

Fever of unknown origin in the HIV-infected patient: new scenario for an old problem

Many conditions may present as fever of unknown origin in the HIV-infected patient, and their relative frequency is influenced by multiple factors. The history and physical examination may provide some useful clues for the diagnosis. Haematological, biochemical, and conventional radiological tests are rarely diagnostic; even serological and/or microbiological tests have some limitations in these patients. The geographical setting and the local prevalence of diseases are of the utmost importance. Infections that have a world-wide distribution, such as tuberculosis, should be intensively searched for, particularly in areas of high prevalence. The measurement of the CD4+ cell count is essential, as there is a strong association between this count and certain opportunistic diseases that may manifest as fever of unknown origin. Imaging procedures, such as CT and radionuclide scans, are useful for the location of inflammatory and neoplastic lesions. Liver and bone marrow biopsies are helpful in certain subsets of patients and the efficacy of empirical treatments has been clearly documented in certain infections. Some HIV-infected patients with fever of unknown origin remain undiagnosed after a thorough investigation; these individuals should be managed conservatively. Finally, symptomatic treatment is the best option for terminally ill patients in whom benefit from a detailed investigation of the cause of fever is not expected.

Antifungal prophylaxis during neutropenia and immunodeficiency

Fungal infections represent a major source of morbidity and mortality in patients with almost all types of immunodeficiencies. These infections may be nosocomial (aspergillosis) or community acquired (cryptococcosis), or both (candidiasis). Endemic mycoses such as histoplasmosis, coccidioidomycosis, and penicilliosis may infect many immunocompromised hosts in some geographic areas and thereby create major public health problems. With the wide availability of oral azoles, antifungal prophylactic strategies have been extensively developed. However, only a few well-designed studies involving strict criteria have been performed, mostly in patients with hematological malignancies or AIDS. In these situations, the best dose and duration of administration of the antifungal drug often remain to be determined. In high-risk neutropenic or bone marrow transplant patients, fluconazole is effective for the prevention of superficial and/or systemic candidal infections but is not always able to prolong overall survival and potentially selects less susceptible or resistant Candida spp. Primary prophylaxis against aspergillosis remains investigative. At present, no standard general recommendation for primary antifungal prophylaxis can be proposed for AIDS patients or transplant recipients. However, for persistently immunocompromised patients who previously experienced a noncandidal systemic fungal infection, prolonged suppressive antifungal therapy is often indicated to prevent a relapse. Better strategies for controlling immune deficiencies should also help to avoid some potentially life-threatening deep mycoses. When prescribing antifungal prophylaxis, physicians should be aware of the potential emergence of resistant strains, drug-drug interactions, and the cost. Well-designed, randomized, multicenter clinical trials in high-risk immunocompromised hosts are urgently needed to better define how to prevent severe invasive mycoses.

Incidence and factors associated with extrapulmonary cryptococcosis among persons with HIV infection in Los Angeles County

OBJECTIVE

To determine the incidence and factors associated with extrapulmonary cryptococcosis among a cohort of persons with HIV in Los Angeles County.

DESIGN

Records-based cohort study.

METHODS

Data were analysed from a cohort of 3836 persons aged > or = 13 years with HIV infection enrolled from four outpatient facilities in Los Angeles from 1990 to 1995. The potential association between cryptococcosis and demographic risk behavior and clinical factors was assessed. Possible seasonal clustering was evaluated and an estimate of survival following cryptococcosis was calculated. Multivariate analysis was performed using a Cox proportional hazards approach.

RESULTS

Cryptococcosis was identified in 112 patients (2.9%) representing a crude incidence rate of 1.7 cases per 100 person-years experience. The rate of cryptococcosis was higher among men than women (1.9 and 0.6, respectively; P < 0.01) and in Hispanics than in whites (2.3 and 1.2, respectively, P < 0.01). A significant trend of decreasing cryptococcosis was observed with increasing age (P < 0.01). Cryptococcosis increased with declining CD4+ lymphocyte count, with risk being greatest at CD4+ cell counts below 100 x 10(6)/l (P < 0.001). In bivariate analysis persons with a history of antifungal medication had a marginally lower rate of cryptococcosis, but this difference was not statistically significant. The rate of cryptococcosis was significantly higher in fall and winter months [rate ratio (RR), 1.45; 95% confidence interval (CI), 1.0-2.3; P = 0.05]. After controlling for other variables, cryptococcosis was more common in men than women (adjusted RR, 3.2; 95% CI, 1.0-10.4) and in Hispanics than whites (adjusted RR, 1.6; 95% CI, 0.9-2.7). Both CD4+ count and age continued to be strongly associated with the occurrence of cryptococcosis. After controlling for other factors a substantial protective effect was observed for antifungal therapy (adjusted RR, 0.48; 95% CI, 0.29-0.79).

CONCLUSION

Our data suggest that HIV-infected men, Hispanics, persons aged under 45 years and those with CD4+ counts under 100 x 10(6)/l have an increased risk of extrapulmonary cryptococcosis. A fall-winter seasonality in the occurrence of cryptococcosis may exist. Significant primary protection against cryptococcal disease is afforded by antifungal therapy. These results may provide insight into possible routes of transmission and sources of cryptococcal infection and help guide both primary prophylaxis and early recognition and diagnosis in persons likely to be at increased risk.

Fungal disease in the immunocompromised host

A variety of superficial and deep mycoses may affect the immunocompromised patient. Among the superficial mycoses, candidal infections are common in all groups, but dermatophyte and pityrosporum infections may also be found. Although not primarily dangerous, they may lead to secondary bacterial infections and morbidity. Of the systemic mycoses, candidiasis, aspergillosis, and mucor-mycosis are frequently lethal and require early diagnosis and aggressive antifungal treatment. Endemic mycoses, such as histoplasmosis and coccidioidomycosis, may result in severe and often fatal infections in those patients with cellular immune alterations. The identification and prophylaxis of high-risk patients and the development of more effective antifungal therapies are beginning to have an impact on the control of fungal disease in this population.

Fungal infections in patients with acquired immunodeficiency syndrome

The incidence and severity of fungal infections appear to increase with progression of HIV disease. Because of the significant morbidity and mortality associated with the mycoses discussed, knowledge of the clinical syndromes, early diagnosis, and prompt institution of therapy are crucial for a favorable outcome. For disseminated or invasive fungal infections, suppressive therapy must be continued to prevent relapse.