Cryptococcosis in HIV-infected hospitalized patients in Germany: Evidence for routine antigen testing

Survival after cryptococcosis in Germany: A retrospective multicenter cohort study of patients diagnosed between 2004 and 2021

Cryptococcosis is the most prevalent fungal infection of the central nervous system worldwide. We performed a retrospective multicenter cohort study to gain insights into the epidemiology of cryptococcosis in Germany. We describe the use of diagnostic tests, clinical management and patient outcome. We included 64 patients with underlying HIV infection (55%) or other predispositions. Molecular typing by MLST documented 20 individual sequence types among 42 typed isolates. A fatal outcome was documented in 14% of patients in the first two months after diagnosis.

Asymptomatic cryptococcal antigenemia in HIV-infected patients: a review of recent studies

The prevalence of asymptomatic cryptococcal antigenemia (ACA) in human immunodeficiency virus (HIV) infected individuals has been observed to be elevated. The prevalence of ACA ranges from 1.3% to 13%, with different rates of prevalence in various regions of the world. We reviewed studies conducted internationally, and also referred to two established expert consensus guideline documents published in China, and we have concluded that Chinese HIV-infected patients should undergo cryptococcal antigen screening when CD4 T-cell counts fall below 200 cells/μL and that the recommended treatment regimen for these patients follow current World Health Organization guidelines, although it is likely that this recommendation may change in the future. Early screening and optimized preemptive treatment for ACA is likely to help decrease the incidence of cryptococcosis, and is lifesaving. Further studies are warranted to explore issues related to the optimal management of ACA.

Laboratory-Reflex Cryptococcal Antigen Screening Is Associated With a Survival Benefit in Tanzania

BACKGROUND

Cryptococcal antigen (CrAg) screening in persons with advanced HIV/AIDS is recommended to prevent death. Implementing CrAg screening only in outpatients may underestimate the true CrAg prevalence and decrease its potential impact. Our previous 12-month survival/retention in CrAg-positive persons not treated with fluconazole was 0%.

METHODS

HIV testing was offered to all antiretroviral therapy-naive outpatients and hospitalized patients in Ifakara, Tanzania, followed by laboratory-reflex CrAg screening for CD4 <150 cells/μL. CrAg-positive individuals were offered lumbar punctures, and antifungals were tailored to the presence/absence of meningitis. We assessed the impact on survival and retention-in-care using multivariate Cox-regression models.

RESULTS

We screened 560 individuals for CrAg. The median CD4 count was 61 cells/μL (interquartile range 26-103). CrAg prevalence was 6.1% (34/560) among individuals with CD4 ≤150 and 7.5% among ≤100 cells/μL. CrAg prevalence was 2.3-fold higher among hospitalized participants than in outpatients (12% vs 5.3%, P = 0.02). We performed lumbar punctures in 94% (32/34), and 31% (10/34) had cryptococcal meningitis. Mortality did not differ significantly between treated CrAg-positive without meningitis and CrAg-negative individuals (7.3 vs 5.4 deaths per 100 person-years, respectively, P = 0.25). Independent predictors of 6-month death/lost to follow-up were low CD4, cryptococcal meningitis (adjusted hazard ratio 2.76, 95% confidence interval: 1.31 to 5.82), and no antiretroviral therapy initiation (adjusted hazard ratio 3.12, 95% confidence interval: 2.16 to 4.50).

CONCLUSIONS

Implementing laboratory-reflex CrAg screening among outpatients and hospitalized individuals resulted in a rapid detection of cryptococcosis and a survival benefit. These results provide a model of a feasible, effective, and scalable CrAg screening and treatment strategy integrated into routine care in sub-Saharan Africa.

CD4 Cell Count Threshold for Cryptococcal Antigen Screening of HIV-Infected Individuals: A Systematic Review and Meta-analysis

Background

Current guidelines recommend screening all people living with human immunodeficiency virus (PLHIV) who have a CD4 count ≤100 cells/µL for cryptococcal antigen (CrAg) to identify those patients who could benefit from preemptive fluconazole treatment prior to the onset of meningitis. We conducted a systematic review to assess the prevalence of CrAg positivity at different CD4 cell counts.

Methods

We searched 4 databases and abstracts from 3 conferences up to 1 September 2017 for studies reporting prevalence of CrAg positivity according to CD4 cell count strata. Prevalence estimates were pooled using random effects models.

Results

Sixty studies met our inclusion criteria. The pooled prevalence of cryptococcal antigenemia was 6.5% (95% confidence interval [CI], 5.7%-7.3%; 54 studies) among patients with CD4 count ≤100 cells/µL and 2.0% (95% CI, 1.2%-2.7%; 21 studies) among patients with CD4 count 101-200 cells/µL. Twenty-one studies provided sufficient information to compare CrAg prevalence per strata; overall, 18.6% (95% CI, 15.4%-22.2%) of the CrAg-positive cases identified at ≤200 cells/µL (n = 11823) were identified among individuals with a CD4 count 101-200 cells/µL. CrAg prevalence was higher among inpatients (9.8% [95% CI, 4.0%-15.5%]) compared with outpatients (6.3% [95% CI, 5.3%-7.4%]).

Conclusions

The findings of this review support current recommendations to screen all PLHIV who have a CD4 count ≤100 cells/µL for CrAg and suggest that screening may be considered at CD4 cell count ≤200 cells/µL.

The CD4+ T-lymphocyte count is an important predictor for the prognosis of cryptococcosis

There is great heterogeneity of immunity among patients with cryptococcosis, and severe immunodeficiency can lead to negative clinical outcomes. Underlying disease is a poor surrogate for immune status and inferior in predicting an individual’s prognosis. This study was intended to determine whether T-lymphocyte subgroups would be more suitable indicators regarding the severity of infection and clinical outcomes of such patients. We retrieved clinical data on 101 patients with cryptococcosis and compared the validity of multiple parameters (underlying disease and T-lymphocyte subgroups) in predicting the severity of infection and clinical outcome in these patients. For patients with CD4⁺ T-lymphocyte counts lower than 400/μL, the odds ratio of disseminated cryptococcosis was 23.3 (P = 0.005). There was a moderate negative correlation between CD4⁺ T-cell count and Apache II score (−0.609, P < 0.001). Mortality among patients with low levels of CD4⁺ T lymphocytes was significantly higher than among those with normal levels (23.8% vs 5.3%, P = 0.016). However, the difference was not significant if the patients were grouped by underlying disease (P = 0.067). The CD4⁺ T-lymphocyte count in peripheral blood is a simple and more accurate biomarker for predicting severity of infection and clinical outcome in patients with cryptococcosis.

[Prevalence and factors associated with cryptococcal antigenemia in HIV-infected patients in Cotonou/Benin]

OBJECTIVE

Determine the prevalence of cryptococcal antigenemia and associated factors in HIV-infected patients in Cotonou in order to introduce systematic screening in national guidelines.

PATIENTS AND METHODS

This is a cross-sectional, descriptive and analytical study conducted from June to September 2015 in four outpatient treatment centers with adult patients infected with HIV, receiving or not antiretroviral treatment with a number of CD4≤200cell/μL and who have given their informed consent to participate in the study. For each enrolled patient, after signing the informed consent form, it was made a clinical examination and administration of a questionnaire to collect general information, treatment and biological data. Then a blood sample for counting CD4 lymphocytes and the search of cryptococcal antigenemia were done.

RESULTS

In total, 355 patients were included in the study with a mean age of 40±10.2years. The overall prevalence of cryptococcal antigenemia is 1.7%. All patient with cryptococcal antigenemia have a CD4 count below 100cells/μL with a majority having CD4 count below 50cells/μL. Body mass index<18.5kg/m², an alteration of the general condition with a CD4 lymphocyte counts<50cells/μL are the main factors associated with the occurrence of cryptococcal antigenemia.

CONCLUSION

This pilot study showed a low prevalence of cryptococcal antigenemia in the study population, but higher in highly immuno-deficient patients with CD4 counts<50cells/μl. Given the results obtained, the introduction of routine screening among patients infected with HIV could be reserved to those with CD4 counts<50cells/μl.