Meningitis In AIDS Patients Research Articles

Comparison of a Lateral Flow Assay and a Latex Agglutination Test for the Diagnosis of Cryptococcus Neoformans Infection

Infections by the basidiomycete yeast Cryptococcus neoformans are life-threatening diseases claiming more than 600,000 lives every year. The most common manifestation is cryptococcal meningitis in AIDS patients. Diagnosis primarily relies on antigen testing from serum and cerebrospinal fluid (CSF). Current guidelines recommend rapid antigen testing with a focus on point-of-care assays. Over the recent years, a range of new lateral flow assays (LFAs) was launched. There is still a lack of data evaluating the CE-certified Biosynex RDT CryptoPS LFA. We compared the performance of this LFA with a latex agglutination assay (LAA; Latex-Cryptococcus Antigen Detection System, IMMY) from blood and CSF samples. Blood and/or CSF samples of 27 patients with proven cryptococcal infections caused by different species and blood–CSF pairs of 20 controls were tested applying LFA and LAA. Upon combined analysis of blood and CSF, both assays were able to identify all C. neoformans infections. Based on CSF analysis only, the LFA and the LAA had sensitivities of 100% and 93%. Neither test gave false-positive results nor was reactive in two cases of C. non-neoformans/non-gattii species infections. Both assays have high sensitivities and specificities for the diagnosis of C. neoformans infection. Contrarily to the IMMY LAA, the RDT CryptoPS LFA is suitable as a point-of-care test but is limited in the quantification of antigen reactivity.

Mechanisms by Which Interleukin-12 Corrects Defective NK Cell Anticryptococcal Activity in HIV-Infected Patients.

ABSTRACTCryptococcus neoformans is a pathogenic yeast and a leading cause of life-threatening meningitis in AIDS patients. Natural killer (NK) cells are important immune effector cells that directly recognize and kill C. neoformans via a perforin-dependent cytotoxic mechanism. We previously showed that NK cells from HIV-infected patients have aberrant anticryptococcal killing and that interleukin-12 (IL-12) restores the activity at least partially through restoration of NKp30. However, the mechanisms causing this defect or how IL-12 restores the function was unknown. By examining the sequential steps in NK cell killing of Cryptococcus, we found that NK cells from HIV-infected patients had defective binding of NK cells to C. neoformans. Moreover, those NK cells that bound to C. neoformans failed to polarize perforin-containing granules to the microbial synapse compared to healthy controls, suggesting that binding was insufficient to restore a defect in perforin polarization. We also identified lower expression of intracellular perforin and defective perforin release from NK cells of HIV-infected patients in response to C. neoformans. Importantly, treatment of NK cells from HIV-infected patients with IL-12 reversed the multiple defects in binding, granule polarization, perforin content, and perforin release and restored anticryptococcal activity. Thus, there are multiple defects in the cytolytic machinery of NK cells from HIV-infected patients, which cumulatively result in defective NK cell anticryptococcal activity, and each of these defects can be reversed with IL-12.

Candida parapsilosis meningitis in a patient with AIDS. Report of a case and review of the literature

BackgroundCandida parapsilosis is an important species in the genus Candida that plays a significant role in hospitalized patients with nosocomial infections. In patients with HIV infection or AIDS, central nervous system involvement by Candida species is exceptional. Case reportHere we report a case of an acute meningoencephalitis due to C. parapsilosis in an adult patient with AIDS. We describe the clinical manifestations, the diagnosis methods, antifungal therapy and outcome. ConclusionsC. parapsilosis is uncommonly reported as a cause of meningitis in AIDS patients. A higher index of suspicion and culture is necessary to confirm the diagnosis of candidal meningoencephalitis.

Utility of molecular and serodiagnostic tools in cerebral toxoplasmosis with and without tuberculous meningitis in AIDS patients: A study from South India

Background:Antemortem diagnosis of cerebral toxoplasmosis, the second most common opportunistic infection (OI) in HIV-infected individuals in developing countries is a challenge.Materials and Methods:Toxoplasma gondii (T.gondii) -specific serology and nested polymerase chain reaction (nPCR) were evaluated in sera and ventricular/lumbar cerebrospinal fluid (CSF) of 22 autopsy confirmed cases of cerebral toxoplasmosis with HIV and 17 controls. Frequency of concomitant T.gondii infection was investigated in 17 cases of HIV-associated tuberculous meningitis (TBM).Results:The sensitivity, specificity, and positive and negative predictive values of T. gondii IgG on CSF (ventricular and lumbar) and sera was 100% in histology proven cerebral toxoplasmosis (concentrations: 258 ± 50, 231 ± 36, and 646 ± 243 IU/mL, respectively); majority (94%) being high avidity type, suggesting reactivation/reinfection. The sensitivity of B1 nPCR was 100% on ventricular CSF, whereas it was only 77% on lumbar CSF. Based on histology, nPCR, and IgG serology, T. gondii co-infection with TBM was observed in 65% (11/17) of cases.Discussion and Conclusion:CSF IgG serology and nPCR are tests with high sensitivity and specificity for the diagnosis of cerebral toxoplasmosis. TBM and cerebral toxoplasmosis can coexist and should be considered in the background of HIV infection in developing countries.

Acute bacterial meningitis in HIV, pacients in southern Brazil: Curitiba, Paraná, Brazil

Acute communitarian bacterial meningitis and AIDS are prevalent infectious disease in Brazil. The objective of this study was to evaluate the frequency of acute communitarian bacterial meningitis in AIDS patients, the clinical and cerebrospinal fluid (CSF) characteristics. It was reviewed the Health Department data from city of Curitiba, Southern Brazil, from 1996 to 2002. During this period, 32 patients with AIDS fulfilled criteria for acute bacterial meningitis, representing 0.84% of the AIDS cases and 1.85% of the cases of bacterial meningitis. S. pneumoniae was the most frequent bacteria isolated. The number of white blood cells and the percentage of neutrophils were higher and CSF glucose was lower in the group with no HIV co-infection (p 0.12; 0.008; 0.04 respectively). Bacteria not so common causing meningitis can occur among HIV infected patients. The high mortality rate among pneumococcus meningitis patients makes pneumococcus vaccination important.

Efficacy of amphotericin B in a fat emulsion for the treatment of cryptococcal meningitis in AIDS patients

Several formulae have been developed in an attempt to reduce the toxicity of amphotericin B (AmB), but their high costs preclude widespread use. The aim of this study was to evaluate the efficacy of amphotericin B in a fat emulsion, i.e. Intralipid (AmB-IL), in 37 AIDS patients with cryptococcal meningitis (CM). We retrospectively reviewed data collected in a non-comparative open study between January 1999 and December 2001. The therapeutic cure was defined as complete resolution or improvement of the clinical symptoms or complete absence or improvement of the mycological alterations of the CSF. The outcomes were evaluated at 2 weeks, induction phase (IP), and at the end of treatment or consolidation phase (CP) with the last available CSF. Prior to the diagnosis of CM, 72% of patients had had one or more OI and 67.57% had a concomitant OI. The median CD4-cell count was 32 cells/mm(3), the median leukocyte count in the CSF was 29 cells/mm(3) and the median cumulative dose of AmB-IL was 1,200 mg (300-2,500). The therapeutic cure was 57.14% in the IP and 64.86% in the CP. During IP, 9 patients died (24.32%) and 4 (10.81%) during the CP (p=0.2). Thus, the overall mortality rate was 35.14%. AmB-IL, an inexpensive preparation, might be an alternative to conventional AmB. Some questions remain such as its compatibility, stability and level of toxicity. The benefit is especially important in developing countries, where no drugs other than AmB are available to treat systemic fungal infections.

Cryptococcus neoformans causing meningitis in AIDS patients.

Cryptococcus neoformans causes meningitis in AIDS patients. In the São José Hospital, reference center for patients with AIDS in Fortaleza--Ceará State--Brazil, 54 samples of the cerebrospinal fluid were analyzed from January 1st through December 31st 2000. Direct examination with India ink and culture in Sabouraud's agar at 37 degrees C were done. Of the specimens studied 5(9.25%) were positive.

Cryptococcal meningitis in AIDS patients: an emerging opportunistic infection in Senegal

Cryptococcal meningitis in AIDS patients: an emerging opportunistic infection in Senegal

A retrospective study on the efficacy and safety of amphotericin B in a lipid emulsion for the treatment of cryptococcal meningitis in AIDS patients

To evaluate the efficacy and safety of Amphotericin B dissolved in dextrose (Amb) or in a lipid emulsion (Intralipid, Amb-IL) in AIDS patients with cryptococcal meningitis, we conducted a retrospective study in 30 AIDS patients with cryptococcal meningitis. A clinical complete resolution was obtained in 11 patients (55%) treated with Amb, and in six patients (60%) treated with Amb-IL. Intralipid did not decrease the infusion-related adverse effects, in particular nephrotoxicity and anaemia. Our results indicate that Amb-IL formulation is useful in the treatment of cryptococcal meningitis in AIDS patients, but it does not reduce the infusion-related adverse events.

Peptide epitopes recognized by a human anti-cryptococcal glucuronoxylomannan antibody.

Cryptococcus neoformans causes meningitis in 6 to 8% of individuals with AIDS. Recently, immunotherapeutic modalities including antibody therapy have been proposed for the treatment of cryptococcal meningitis in AIDS patients. This is a rational approach because existing antifungal agents fail to eradicate the infection in the setting of profound immunosuppression. Both murine and human antibodies elicited by the investigational cryptococcal capsular polysaccharide vaccine glucuronoxylomannan-tetanus toxoid (GXM-TT) have been shown to be biologically functional in different model systems. The human immunoglobulin M (lambda) GXM monoclonal antibody (MAb) 2E9 expresses idiotypes that are also found in naturally occurring anti-GXM antibodies and opsonic GXM-TT sera. However, the specificity of human anti-GXM antibodies and their possible role in protection against cryptococcosis are not known. In an effort to discover epitopes that are recognized by human anti-GXM antibodies, we screened a random decapeptide phage display library with the human anti-GXM MAb 2E9. An enzyme-linked immunosorbent assay (ELISA)-based screening method led to the selection of phages with peptide inserts that bound 2E9 and inhibited 2E9-GXM binding. Analysis of the amino acid sequences of these phages revealed an increased frequency of combinations of QTGLD residues. Inhibition ELISAs demonstrated that phages with QTG/TL/D motifs inhibited 2E9-GXM binding better than phages with different motifs. A peptide synthesized from one of the inhibitory phages, peptide 13 (GMDGT QLDRW), inhibited GXM binding to solid-phase 2E9 and 2E9 binding to solid-phase GXM. Peptide 13 also inhibited the GXM binding of GXM-TT immune sera and naturally occurring serum antibodies from human immunodeficiency virus (HIV)-negative, but not HIV-positive, individuals. Taken together, our data indicate that the peptide epitopes selected by 2E9 mimic GXM epitopes and that peptide 13 may be a mimotope of a GXM epitope that is recognized by human anti-GXM antibodies.

Persistence, replacement, and microevolution of Cryptococcus neoformans strains in recurrent meningitis in AIDS patients.

Six separate human immunodeficiency virus-positive patients with cryptococcal meningitis were each found to have been infected with a unique strain of Cryptococcus neoformans on the basis of genomic DNA finger-printing analysis with the microsatellite sequence-containing oligonucleotide probe (GGAT)4 and by random amplification of polymorphic DNA. Two patients (A and B) experienced a recurrent episode of infection. Between 12 and 16 single-colony isolates recovered from primary isolation media (> 50% of C. neoformans colonies recovered) from cerebrospinal fluid specimens were fingerprinted from both patients during each episode. The fingerprints of both isolate collections from patient B were very similar, although minor polymorphisms were evident in both sets of profiles. The fingerprints of the isolate collection from the initial episode of infection in patient A were also identical to each other, apart from minor polymorphisms, but they were clearly different from the corresponding profiles of the isolate collection from the recurrent episode, the latter of which were completely identical, apart from minor polymorphisms in a single isolate. Furthermore, prolonged storage and in vitro subculture of the isolates did not alter the fingerprint profiles. These results provided convincing evidence that patients A and B were each infected with a single C. neoformans strain during each episode of infection and that in patient B, the same strain persisted and caused both episodes, while in patient A, a different strain was responsible for each episode. The prevalence of polymorphisms in multiple single-colony isolates from both patients also suggested that C. neoformans populations may undergo microevolution.

P98 Design of a phase III trial of cryptococcal meningitis in AIDS patients

P98 Design of a phase III trial of cryptococcal meningitis in AIDS patients

P98 Design of a phase III trial of cryptococcal meningitis in AIDS patients

P98 Design of a phase III trial of cryptococcal meningitis in AIDS patients

Polymerase chain reaction for rapid diagnosis of tuberculous meningitis in AIDS patients.

We used a test based on the polymerase chain reaction (PCR) for the detection of Mycobacterium tuberculosis DNA in 11 CSF samples from 10 HIV-seropositive patients in whom tuberculous meningitis was suspected. PCR was positive in nine samples from eight patients in whom clinical data, CSF findings, evidence of tuberculosis at an extraneural site, and response to antituberculous drug therapy supported the diagnosis, whereas cultures were positive in five of these nine samples and staining in only one. The PCR was negative in 14 CSF samples from the control group.

Parenteral and Oral Fluconazole for Acute Cryptococcal Meningitis in Aids: Experience with Thirteen Patients

Cryptococcus neoformans infections of the central nervous system affect up to ten percent of AIDS patients. Standard therapy with amphotericin B with or without 5-flucytosine has a high rate of failure, relapse, and toxicity. Fluconazole is a new triazole antifungal agent available in both oral and intravenous forms that has shown efficacy in the primary and maintenance treatment of cryptococcal meningitis in AIDS patients. In this open, noncomparative trial, we evaluated the safety and efficacy of intravenous fluconazole followed by oral fluconazole in the treatment of acute cryptococcal meningitis in AIDS patients. Thirteen AIDS patients with acute cryptococcal meningitis, or relapse after successful primary therapy, received 400 mg of intravenous fluconazole daily for 12-16 days followed by oral fluconazole 400 mg/d for the duration of primary therapy. If cerebrospinal fluid (CSF) cultures converted to negative within 32 weeks of treatment, the fluconazole dose was decreased to 200 mg/d as maintenance therapy. Fluconazole therapy was successful in six patients (46 percent) and unsuccessful in seven (54 percent). Of the seven patients considered unsuccessful, one demonstrated clinical improvement but remained CSF-culture positive, five were clinical failure and were switched to amphotericin B therapy, and one died after two weeks secondary to cryptococcal meningitis. No patient experienced any adverse reactions necessitating discontinuation of therapy. In this small group of patients, moderate doses of parenteral and oral fluconazole for acute cryptococcal meningitis in AIDS patients demonstrated failure rates similar to those reported in other studies with fluconazole and with amphotericin B. As there was no difference in initial Karnofsky scores or the severity of disease in treatment successes versus failures, it is difficult to determine who might respond to fluconazole as initial therapy or who should be treated initially with another agent. Further studies and clinical experience are needed.

Systemically administered antifungal agents. A review of their clinical pharmacology and therapeutic applications.

Systemic antifungal agents express great diversity in their pharmacokinetic profiles, mechanisms of action, and toxicities. Understanding the diverse pharmacokinetic properties of systemic antifungals is critical to their appropriate application. Amphotericin B, drug of choice for most invasive mycoses, has unique pharmacokinetic properties, binding initially to serum lipoproteins and redistributing from blood to tissues. Dosing recommendations are based on the specific infection and the status of the host. Lipid formulations of amphotericin B may be able to attenuate some of its toxicities. Flucytosine is a water-soluble, fluorinated pyrimidine that possesses excellent bioavailability. It is administered only in combination with amphotericin B because of frequent development of secondary drug resistance, and is associated with dose-dependent bone marrow suppression. The antifungal azoles are relatively well tolerated, have broad spectrum antifungal activity, and are fungistatic in vitro. Ketoconazole and itraconazole are highly bound to plasma proteins, are extensively metabolised by the liver, and are relatively insoluble in aqueous solution. By comparison, fluconazole is only weakly bound to serum proteins, is relatively stable to metabolic conversion, and is water soluble. Fluconazole penetrates the cerebrospinal fluid well and is approved for primary and suppressive therapy of cryptococcal meningitis in AIDS patients. The echinocandins have a narrow spectrum of antifungal activity, being effective only against Candida spp.

Fluconazole: A New Triazole Antifungal Agent

Fluconazole is a recently approved agent for the treatment of certain fungal infections. Based on available studies, the drug is clearly effective in oropharyngeal candidiasis in immunosuppressed hosts. Current evidence suggests it may be more efficacious than other azole drugs for oropharyngeal disease. It is probably also effective in other infections due to Candida species, but controlled studies are lacking. Fluconazole is also efficacious in the treatment of cryptococcal meningitis, but recent reports question its use as initial therapy in HIV-infected patients with this illness. The drug, however, is clearly more effective than amphotericin B in the suppression of cryptococcal meningitis in AIDS patients and is the treatment of choice in this situation.

A Statistical Comparison of Drug Safety in Controlled Clinical Trials: The Genie Score as an Objective Measure of Lab Abnormalities

The concept of the GENIE SCORE (GS) has been shown to be an effective data reduction tool for the review of lab data in clinical trials, and a convenient tool for monitoring the most severely involved individuals over the course of a study. As defined in an earlier paper, this score requires: 1. the standardization of each lab value to make it dimensionless and permit it to be combined mathematically, and 2. the computation of the score from a weighted linear combination of the absolute deviations from the reference range for the values of a functionally related group of laboratory parametersThe emphasis in this paper is to explore the effectiveness of the GENIE SCORE as a measure for comparing drug safety in controlled clinical trials. Four studies were analyzed: the first study compared two drugs in the treatment of cryptococcal meningitis in AIDS patients; the second study compared two drugs in the prevention of cryptococcal meningitis in AIDS patients who recently recovered from the disease; the third...