Risk factors for cryptococcal meningitis in HIV-infected patients

Clinical features vary by the aetiology of meningitis in HIV seropositive patients: A four-year study from a tertiary hospital in India

Meningitis is a serious infection of the nervous system associated with high mortality in Human Immunodeficiency Virus (HIV) seropositive individuals. Asian clinical studies describing meningitis in people living with HIV are scarce. We describe the clinical features of meningitis in 116 HIV seropositive patients from a tertiary hospital in India as a cross-sectional observational study. The mean age of the patients in our study was 35±9 years with 70.6% of them being men. Eighty-five percent of the patients had an altered sensorium during the illness. Tuberculous meningitis [82.6%] was the most common cause. Clinical features varied by aetiology. Cranial nerve deficits [40%] were common in Cryptococcal meningitis. Hydrocephalus [3%], infarcts [15.9%] and IntraCranial Space Occupying Lesions (ICSOLs) [39.1%] were common in tuberculous meningitis.

Prevalence, correlates, and outcomes of cryptococcal antigen positivity among patients with AIDS, United States, 1986-2012

BACKGROUND

Cryptococcal meningitis (CM) is one of the most common causes of AIDS-related mortality worldwide, accounting for 33%-63% of all cases of adult meningitis in sub-Saharan Africa and >500 000 deaths annually. In sub-Saharan Africa, the World Health Organization recommends routinely screening AIDS patients with a CD4 count ≤100 cells/µL for cryptococcal infection. In the United States, there are no recommendations for routine screening. We aimed to determine the prevalence of cryptococcal infection and outcomes of those infected among people living with advanced AIDS in the United States, to inform updates in the prevention and management of CM.

METHODS

Using stored sera from participants in the Multicenter AIDS Cohort Study and the Women's Interagency HIV Study from 1986 to 2012, we screened 1872 specimens with CD4 T-cell counts ≤100 cells/µL for cryptococcal antigen (CrAg) using the CrAg lateral flow assay.

RESULTS

The overall prevalence of CrAg positivity within the study population was 2.9% (95% confidence interval, .2%-3.8%). Results from multivariable analysis revealed that a previous diagnosis with CM and a CD4 count ≤50 cells/µL were significantly associated with CrAg positivity. Participants who were CrAg positive had significantly shorter survival (2.8 years) than those who were CrAg negative (3.8 years; P = .03).

CONCLUSIONS

The prevalence of cryptococcal infection among advanced AIDS patients in the United States was high and above the published cost-effectiveness threshold for routine screening. We recommend routine CrAg screening among human immunodeficiency virus-infected patients with a CD4 count ≤100 cells/µL to detect and treat early infection.

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.

Central Nervous System Cryptococcosis among a Cohort of HIV Infected Patients from a University Hospital of North India

BACKGROUND

Cryptococcus neoformans is a ubiquitous encapsulated yeast that causes significant infections which range from asymptomatic pulmonary colonization to the life threatening meningoencephalitis, especially in immunocompromised individuals. Cryptococcal meningitis is one of the AIDS-defining illnesses. Recent data have indicated that, the incidence of the cryptococcal infection is high in developing countries like India. We conducted this study to find out the incidence of cryptococcosis in this area.

MATERIAL AND METHODS

The Cerebrospinal Fluid (CSF) specimens were collected from known HIV positive cases that had a clinical diagnosis of meningitis and they were processed by standard microbiological procedures. The cryptococcal isolates were identified by microscopy, their cultural characteristics, sugar assimilation and by the hydrolysis of urea.

RESULTS

The incidence of cryptococcal meningitis was 12.9%. All the strains were susceptible to amphotericin B, fluconazole, itraconazole and voriconazole.

CONCLUSION

The cryptococcal infection should be suspected in all cases of meningitis, especially among HIV infected persons. An early diagnosis and treatment may alter the prognosis of these patients and hence, an examination of the CSF for cryptococcosis should be considered in all the HIV infected persons who have the symptoms of meningitis.

A retrospective study of AIDS-associated cryptomeningitis

Cryptococcal meningitis has emerged as a leading cause of infectious morbidity and mortality in patients with AIDS. A retrospective analysis of records of HIV-infected individuals registered in the Immunodeficiency Clinic of a tertiary care hospital and research institute was carried out. Records of 6900 HIV-infected individuals who were enrolled in the clinic between January 2002 and March 2011 were analyzed. Records of 6900 HIV-infected individuals were screened. Ninety-one were diagnosed with cryptococcal meningitis (1.32%). In 68 individuals cryptococcal meningitis was the presenting illness. Nine patients developed meningitis within 6 months of starting antiretroviral treatment (ART). Six patients were receiving ART for more than 6 months at the time of diagnosis. The remaining eight patients were not on ART at the time of development of meningitis. The mean baseline CD4 count of patients was 77.7 ± 61 (range, 4-259, n=91) cells/mm(3). Seventy-four patients had a CD4 value of less than 100 at the time of diagnosis of cryptococcal meningitis. Eleven of these ninety-one patients had a relapse of cryptococcal meningitis while receiving a maintenance dose of fluconazole. During follow-up 37 died, two were lost to follow-up, while 52 patients were on regular ART. Mortality due to cryptococcal meningitis amounted to 0.54% (37/6900). There was no correlation between survival and duration of ART at the time of cryptomeningitis (Pearsons χ(2)=0.241, p=0.884). There was a significant difference in the CD4 counts of the HIV-infected individuals who died with cryptomeningitis and those who survived (Pearson's χ(2)=9.1, df=4, p=0.05). The frequency of cryptococcal meningitis was 1.32%. Cryptococcal meningitis leads to high mortality in HIV patients. Management of cryptococcal infection remains a key facet of AIDS care in India.

HIV-1 gp41 ectodomain enhances Cryptococcus neoformans binding to human brain microvascular endothelial cells via gp41 core-induced membrane activities

Cryptococcus neoformans causes life-threatening meningoencephalitis, particularly prevalent in AIDS patients. The interrelationship between C. neoformans and HIV-1 is intriguing, as both pathogens elicit severe neuropathological complications. We have previously demonstrated that the HIV-1 gp41 ectodomain fragments gp41-I33 (amino acids 579-611) and gp41-I90 (amino acids 550-639) can enhance C. neoformans binding to HBMECs (human brain microvascular endothelial cells). Both peptides contain the loop region of gp41. In the present study, we used immunofluorescence microscopy and transmission and scanning electron microscopy to explore the underlying mechanisms. Our findings indicated that both C. neoformans and gp41-I90 up-regulated ICAM-1 (intercellular adhesion molecule 1) on the HBMECs and elicited membrane ruffling on the surface of HBMECs. The HIV-1 gp41 ectodomain could also induce CD44 and β-actin redistribution to the membrane lipid rafts, but it could not enhance PKCα (protein kinase Cα) phosphorylation like C. neoformans. Instead, gp41-I90 was able to induce syncytium formation on HBMECs. The results of the present study suggest HIV-1 gp41-enhanced C. neoformans binding to HBMECs via gp41 core domain-induced membrane activities, revealing a potential mechanism of invasion for this pathogenic fungus into the brain tissues of HIV-1-infected patients.

Disseminated cryptococcosis in an AIDS patient with unusual clinical presentation

Disseminated cryptocococcosis is a rare and often fatal disease. Here in we report an unusual fatal case of disseminated cryptococcosis. The patient presented with a past history of postmenopausal bleeding with loss of consciousness, altered mental status, few seizures and a low grade fever. Lumbar puncture revealed elevated pressure, lymphocytic pleocytosis, elevated protein and markedly reduced glucose level. Cryptococcus neoformans was isolated from cerebrospinal fluid and blood. Serological assay revealed the presence of human immunodeficiency virus. The patient was treated with antifungal agents intravenously without any signs of improvement and the patient passed away after two weeks of therapy. This is the first case report of disseminated cryptococcosis in an AIDS patient suffering from cryptoccoccal vaginitis.

Asymptomatic serum cryptococcal antigenemia and early mortality during antiretroviral therapy in rural Uganda

OBJECTIVE

To evaluate the association between a positive serum cryptococcal antigen (CRAG) test at baseline and mortality during the first 12 weeks on antiretroviral therapy (ART). Cryptococcal meningitis is a leading cause of HIV-related mortality in Africa, but current guidelines do not advocate CRAG testing as a screening tool.

METHODS

Between May 2003 and December 2004, we enrolled HIV-1 infected individuals into a study of ART monitoring in rural Uganda. CRAG testing was conducted retrospectively on stored pre-ART serum samples of participants whose baseline CD4 cell count was <100 cells/mul and who were without symptoms suggestive of disseminated cryptococcal disease at enrolment.

RESULTS

Of 377 participants, 5.8% had serum CRAG titre >/=1:2. Of these, 23% died during follow-up. Controlling for CD4 cell count, HIV-1 viral load, anaemia, active tuberculosis and body mass index, relative risk of death during follow-up among those with asymptomatic cryptococcal antigenemia at baseline was 6.6 [95% confidence interval (CI) 1.86-23.61, P = 0.0036]. The population attributable risk for mortality associated with a positive CRAG at baseline was 18% (CI 2-33%), similar to that associated with active tuberculosis (19%, CI 1-36%).

CONCLUSION

Asymptomatic cryptococcal antigenemia independently predicts death during the first 12 weeks of ART among individuals with advanced HIV disease in rural Uganda. Routine screening and provision of azole antifungal therapy prior to or simultaneous with the start of ART should be evaluated for the potential to prevent mortality in this population.

HIV-1 gp41 ectodomain enhances Cryptococcus neoformans binding to HBMEC

Cryptococcus neoformans infection has significantly increased recently, particularly in AIDS patients and immunocompromised individuals. C. neoformans has a predilection to the brain, resulting in devastating meningoencephalitis. We have previously shown the invasion of C. neoformans into the human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. Here, we demonstrated that C. neoformans invasion of HBMEC was enhanced by HIV-1 gp41 protein. Peptide mapping defined its functional domain around the disulfide-bond linkage of gp41 molecule (a.a. 579-611). Recombinant protein gp41-I90 (a.a. 550-639) can also enhance the binding activity. The enhancement of C. neoformans binding to HBMEC is a strain-independent manner, suggesting that gp41 ectodomain peptide exerts its function directly on HBMEC. Importantly, the enhancement could be observed in mouse animal model. Our results suggest that HIV-1 gp41 ectodomain and C. neoformans may follow a similar invasion mechanism, possibly actin reorganization and/or membrane activation, during pathogen infections on HBMEC.

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.

Atteintes du système nerveux central et infection par le VIH-1

Central nervous system complications are common in HIV-1 infected patients and occur either as a result of concomitant immunosuppression (opportunistic infections, lymphoma and tumors), as a primary manifestation of HIV infection, or as an adverse effect of therapy (immune restoration and toxicity). These complications contribute largely to patient morbidity and mortality. In the era of highly active antiretroviral therapy (HAART) these disease states have changed in presentation, outcome and incidence. We review in detail the epidemiology, pathogenesis, clinical features, diagnosis, and management of these disorders.

AIDS-associated Cryptococcus infection before and after the highly active antiretroviral therapy era: emerging management problems

The frequency, the microbiology and clinical features of AIDS-related primary episodes and relapses of cryptococcosis, before and after the introduction of highly active antiretroviral therapy (HAART), were compared. The study covered 58 cases diagnosed before the introduction of HAART, and eight episodes since 1997. Because of negative cultures, we sought a sensitive laboratory assay such as detection of polysaccharide antigen. Despite later diagnosis, there was reduced disease mortality. Clinical suspicion for HIV-associated cryptococcosis should be maintained in immunocompromised subjects. The introduction of HAART has led to significant clinical and laboratory changes of HIV-related cryptococcosis.

Cryptococcal infection in a cohort of HIV-1-infected Ugandan adults

OBJECTIVE

Despite the recognition of Cryptococcus neoformans as a major cause of meningitis in HIV-infected adults in sub-Saharan Africa, little is known about the relative importance of this potentially preventable infection as a cause of mortality and suffering in HIV-infected adults in this region.

DESIGN

A cohort study of 1372 HIV-1-infected adults, enrolled and followed up between October 1995 and January 1999 at two community clinics in Entebbe, Uganda.

METHODS

Systematic and standardized assessment of illness episodes to describe cryptococcal disease and death rates.

RESULTS

Cryptococcal disease was diagnosed in 77 individuals (rate 40.4/1000 person-years) and was associated with 17% of all deaths (77 out of 444) in the cohort. Risk of infection was strongly associated with CD4 T cell counts < 200 x 10(6) cells/l(75 patients) and World Health Organization (WHO) clinical stage 3 and 4 (68 patients). Meningism was present infrequently on presentation (18%). Clinical findings had limited discriminatory diagnostic value. Serum cryptococcal antigen testing was the most sensitive and robust diagnostic test. Cryptococcal antigenaemia preceded symptoms by a median of 22 days (> 100 days in 11% of patients). Survival following diagnosis was poor (median survival 26 days; range 0-138).

CONCLUSIONS

Cryptococcal infection is an important contributor to mortality and suffering in HIV-infected Ugandans. Improvements in access to effective therapy of established disease are necessary. In addition, prevention strategies, in particular chemoprophylaxis, should be evaluated while awaiting the outcome of initiatives to make antiretroviral therapy more widely available.

The changing face of AIDS-related opportunism: cryptococcosis in the highly active antiretroviral therapy (HAART) era. Case reports and literature review

Only nine cases of AIDS-related cryptococcosis have been reported until now in patients receiving highly active antiretroviral therapy (HAART), all of them with abnormal clinical features. Two HIV-infected patients who experienced an atypical relapse of cryptococcosis shortly after the start of HAART and despite maintenance antifungal treatment, are described. Six different relapses of cryptococcal meningitis were observed in a 28-month period in a patient who obtained a poor immune recovery after HAART (as shown by a CD4+ lymphocyte count ranging from 78 to 149 cells/microL, opposed to a baseline level of 98 cells/microL). On the other hand, a patient with favorable immunological response to HAART (as expressed by a CD4+ count growing from 7 to 186 cells/microL), experienced isolated multiple indolent cryptococcal abscesses involving head, neck, the anterior thoracic wall, and regional lymph nodes, with repeatedly negative cultures, and diagnosis obtained by both histopathologic study and positive serum antigen assay. Both our case reports are representative of novel correlations between opportunistic pathogens and immune reactivity, descending from the introduction of HAART. The first episode describes an exceedingly elevated number of disease relapses despite HAART and antifungal maintenance treatment, which may descend from an incomplete immune response to antiretroviral therapy, possibly responsible for failure in obtaining eradication of yeasts, but also for lack of disease dissemination (usually leading to a lethal multivisceral involvement in the pre-HAART era). The abnormal disease course and localization of second reported patient well depicts an "immune reconstitution syndrome" probably representing a flare-up of a latent fungal infection, caused by a rapidly effective HAART. In patients treated with HAART, AIDS-related cryptococcosis cannot therefore be ruled out by the absence of neurological involvement, and by persistingly negative cultures.