Clinical characteristics and aetiological analysis of combined central and pulmonary cryptococcal infection: Clinical cases

This paper presents a summary of seven cases of combined pulmonary and central cryptococcal infection and analyses of their clinical features, treatment and prognosis. No clear correlation was identified between the intracranial cryptococcal capsular antigen titre and either the intracranial pressure or the amount of protein in the cerebrospinal fluid. Pulmonary lesions may develop in any of the lung lobes and manifest in multiple forms. Infection at the central level is predominantly meningitis. As the central cerebrospinal fluid (CSF) capsular antigen titre can be considerably elevated even when serum capsular antigen titres are markedly low, lumbar puncture and subsequent analysis are essential for every case of pulmonary cryptococcal infection. Patients with renal insufficiency or who refused intravenous treatment opted for oral fluconazole therapy, and their prognoses were favourable.

Cryptococcal meningitis in apparently immunocompetent patients

Cryptococcal meningitis (CM) is an invasive fungal disease that currently poses a threat to human health worldwide, with high morbidity and mortality, particularly in immunocompromised patients. Although CM mainly occurs in HIV-positive patients and other immunocompromised patients, it is also increasingly seen in seemingly immunocompetent hosts. The clinical characteristics of CM between immunocompromised and immunocompetent populations are different. However, few studies have focussed on CM in immunocompetent individuals. This review summarizes the clinical characteristics of apparently immunocompetent CM patients in terms of aetiology, immune pathogenesis, clinical presentation, laboratory data, imaging findings, treatment strategies and prognosis. It is of great significance to further understand the disease characteristics of CM, explore new treatment strategies and improve the prognosis of CM in immunocompetent individuals.

Pulmonary Cryptococcosis

Pulmonary cryptococcosis describes an invasive lung mycosis caused by Cryptococcus neoformans or Cryptococcus gattii complex. It is often a high-consequence disease in both immunocompromised and immunocompetent populations, and may be misdiagnosed as pulmonary malignancy, leading to a delay in therapy. Epidemiology follows that of cryptococcal meningoencephalitis, with C. gattii infection more common in certain geographic regions. Diagnostic tools include histopathology, microscopy and culture, and the detection of cryptococcal polysaccharide antigen or Cryptococcus-derived nucleic acids. All patients with lung cryptococcosis should have a lumbar puncture and cerebral imaging to exclude central nervous system disease. Radiology is key, both as an adjunct to laboratory testing and as the initial means of detection in asymptomatic patients or those with non-specific symptoms. Pulmonary cryptococcomas (single or multiple) may also be associated with disseminated disease and/or cryptococcal meningitis, requiring prolonged treatment regimens. Optimal management for severe disease requires extended induction (amphotericin B and flucytosine) and consolidation therapy (fluconazole) with close clinical monitoring. Susceptibility testing is of value for epidemiology and in regions where relatively high minimum inhibitory concentrations to azoles (particularly fluconazole) have been noted. Novel diagnostic tools and therapeutic agents promise to improve the detection and treatment of cryptococcosis, particularly in low-income settings where the disease burden is high.

Meningitis Caused by Cryptococcus neoformans in an Apparently Immunocompetent Patient

Cryptococcal meningitis (CM), as a life-threatening opportunistic infection, often is among cases with cell-mediated immunodeficiencies, such as AIDS, hematologic malignancies, and solid organ transplant recipients. Cryptococcal meningitis in healthy individuals is uncommon, and its detection in immunocompetent cases may be tricky because the presentation is generally more indolent than the traditional meningitis presentation, leading to late diagnosis and potential sequels. We present a CM case in an immunocompetent Iranian male patient who was treated successfully.

Cryptococcal meningitis in an immunocompetent individual: A case report

Cryptococcal meningitis (CM) is mostly seen in immune-compromised patients and rarely occurs in immune-competent individuals. Immunocompetent individuals with CM present with indolent neurological disease and have better clinical outcomes after treatment. However, misdiagnosis is common and these patients may suffer from serious complications with high mortality.

A Multicenter, Longitudinal Cohort Study of Cryptococcosis in Human Immunodeficiency Virus-negative People in the United States

BACKGROUND

Cryptococcosis is increasingly recognized in people without human immunodeficiency virus (HIV).

METHODS

A multicenter, prospective cohort study was performed in 25 US centers. Consenting patients were prospectively followed for ≤2 years. Neurological morbidities were assessed with longitudinal event depiction and functional scores (Montreal Cognitive Assessment [MoCA]). Risks of death were analyzed using Cox regression.

RESULTS

One hundred forty-five subjects were enrolled. Most were male (95; 65.5%) and had immunosuppression (120; 82.8%), including solid organ transplant (SOT; 33.8%), autoimmunity (15.9%), and hematologic malignancies (11.7%). Disease involved the central nervous system (CNS) in 71 subjects (49%). Fever was uncommon, documented in 40 (27.8%) subjects, and absence was associated with diagnostic delay (mean: 48.2 vs 16.5 days; P = .007). Abnormal MoCA scores (<26) were predictive of CNS disease; low scores (<22) were associated with poor long-term cognition. Longitudinal event depiction demonstrated frequent complications in people with CNS disease; 25 subjects (35.2%) required >1 lumbar puncture and 8 (11.3%) required ventriculostomies. In multivariable models, older age (>60 years) was associated with higher risks of death (hazard ratio [HR], 2.14; 95% confidence interval [CI], 1.05-4.38; P = .036), and lower risks were noted with underlying hematologic malignancy (HR, 0.29; 95% CI, 0.09-0.98; P = .05) and prior SOT (HR, 0.153; 95% CI, 0.05-0.44; P = .001).

CONCLUSIONS

Despite aggressive antifungal therapies, outcomes of CNS cryptococcosis in people without HIV are characterized by substantial long-term neurological sequelae. Studies are needed to understand mechanism(s) of cognitive decline and to enable better treatment algorithms.

Cryptococcal infection in HIV-infected patients with CD4+ T-cell counts under 100/μL diagnosed in a high-income country: a multicentre cohort study

OBJECTIVES

The World Health Organization recommends routinely screening HIV-infected patients with CD4⁺ T-cell counts <100/μL for cryptococcal infection to prevent cryptococcal meningitis (CM), based on studies in Sub-Saharan Africa where the prevalence of positive cryptococcal antigen (CrAg+) is ≥ 3% in this subgroup. Data about such prevalence in Spain are unavailable and rare in other European countries. Thus, the Spanish AIDS Study Group guidelines do not recommend routinely screening. We aim to determine the prevalence and outcomes of cryptococcal infection in this subgroup of patients in Spain.

METHODS

We determined CrAg using a lateral flow assay in banked plasma from participants in the cohort of the Spanish AIDS Research Network. Eligible patients had CD4⁺ T-cell counts ≤100/μL at the time of plasma collection and a follow-up >4 weeks, unless they died.

RESULTS

We included 576 patients from June 2004 to December 2017. Of these, 43 were CrAg+ for an overall prevalence of 7.5%. There were no differences depending on birthplace. The CrAg+ was independently associated with a higher mortality at eight weeks (hazard ratio (HR) 5.36, 95% confidence interval (CI) 1.46-19.56) and 6 months (HR 3.12, 95% CI 1.19-8.21). CM was reported in 10 of the 43 CrAg+ patients. There were no cases among negatives. Five patients had CM when the plasma was collected and five developed it during the follow-up. The number of subjects needed to screen to anticipate the diagnosis of one CM case was 114.

CONCLUSIONS

The CrAg+ prevalence among HIV-infected patients with CD4⁺ T-cell counts ≤100/μL diagnosed in Spain, both immigrants and native-born Spanish, is >7%. Consequently, the Spanish AIDS Study Group guidelines have to be updated and recommend routine screening for cryptococcal infection in these patients. Future studies should explore whether this recommendation could be firmly applied to other European populations.

Surgical treatment and operation time in human immunodeficiency virus-negative cryptococcal meningitis

There are still no unified guidelines of surgical treatment and timing for human immunodeficiency virus (HIV)-negative patients with cryptococcal meningitis (CM).The clinical data and follow-up data were collected from HIV-negative CM patients in Xiangya Hospital of Central South University from January 2009 to November 2018, and 42 patients who were treated with surgical intervention were enrolled in the present study. These 42 patients were divided into ventriculoatrial (VA) group, ventriculoperitoneal group, external ventricle drainage (EVD) group, hydrocephalus (HYC) group, non-HYC group, EVD group, and non-EVD group (VA/ ventriculoperitoneal) according to different surgical procedures. Statistical analyses were conducted using SPSS (version 19.0, Chicago, IL).Signs of headache, fever, and loss of consciousness in the VA group were significantly improved compared with the EVD group at 1 week after operation (P < .05). The mortality rate of the VA group was significantly lower than that of the EVD group (P < .05). Moreover, male patients were more prone to have HYC (P < .05). Younger patients tended to develop HYC (P < .05). Cerebrospinal fluid sugar in the non-HYC group was significantly lower compared with the HYC group (P < .05). Time of CM-to-operation in the non-HYC group was markedly shorter compared with the HYC group (P < .01).VA procedure could be one of the first choices for the treatment of uncontrollable intracranial hypertension caused by CM. Severe uncontrollable headache, loss of consciousness, and cerebral hernia were indications of emergency surgery. Repeated headache, hearing impairment, and especially progressive loss of vision were indications of early surgery to avoid permanent damage to nerve functions of HIV-negative CM patients.

Cryptococcal meningitis: a review of cryptococcal antigen screening programs in Africa

INTRODUCTION

Cryptococcal meningitis remains a significant contributor to AIDS-related mortality despite widened access to antiretroviral therapy. Cryptococcal antigen (CrAg) can be detected in the blood prior to development of meningitis. Development of highly sensitive and specific rapid diagnostic CrAg tests has helped facilitate the adoption of CrAg screening programs in 19 African countries.

AREAS COVERED

The biological rationale for CrAg screening and the programmatic strategies for its implementation are reviewed. We describe the approach to the investigation of patients with cryptococcal antigenemia and the importance of lumbar puncture to identify individuals who may have cryptococcal meningitis in the absence of symptoms. The limitations of current treatment recommendations and the potential role of newly defined combination antifungal therapies are discussed. A literature review was conducted using a broad database search for cryptococcal antigen screening and related terms in published journal articles dating up to December 2019. Conference abstracts, publicly available guidelines, and project descriptions were also incorporated.

EXPERT OPINION

As we learn more about the risks of cryptococcal antigenemia, it has become clear that the current management paradigm is inadequate. More intensive investigation and management are required to prevent the development of cryptococcal meningitis and reduce mortality associated with cryptococcal antigenemia.

Cell wall polysaccharides from pathogenic fungi for diagnosis of fungal infectious disease

Invasive fungal diseases are associated with significant morbidity and mortality, particularly in immunocompromised individuals. Early and accurate diagnosis is crucial for effective treatment. Despite traditional methods such as microbiological culture, histopathology, radiology and direct microscopy are available, antigen/antibody-based diagnostics are emerging for diagnosis of invasive fungal infections (IFI). Fungal cell wall is a unique structure composed of polysaccharides that are well correlated with fungal burden during fungal infections. Based on this feature, cell wall polysaccharides have been explored as antigens in IFIs diagnostics such as the galactomannan assay, mannan test, β-glucan assay and cryptococcal CrAg test. Herein, we provide an overview on the cell wall polysaccharides from three opportunistic pathogens: Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans, and their applications for IFIs diagnosis. The clinical outcome of newly developed cell wall polysaccharides-based diagnostics is also discussed.

Methods for rapid diagnosis of meningitis etiology in adults

Infectious meningitis can be caused by viral, bacterial or fungal pathogens. Despite widely available treatments, many types of infectious meningitis are still associated with significant morbidity and mortality. Delay in diagnosis contributes to poor outcomes. Cerebrospinal fluid cultures have been used traditionally but are time intensive and sensitivity is decreased by empiric treatment prior to culture. More rapid techniques such as the cryptococcal lateral flow assay (IMMY), GeneXpert MTB/Rif Ultra (Cepheid) and FilmArray multiplex-PCR (Biofire) are three examples that have drastically changed meningitis diagnostics. This review will discuss a holistic approach to diagnosing bacterial, mycobacterial, viral and fungal meningitis.

Immune reconstitution inflammatory syndrome following Cryptococcal neoformans infection in an immunocompetent host: A case report and review of the literature

We present a case of Cryptococcus neoformans in an immunocompetent middle-aged woman with a disseminated manifestation of pulmonary cryptoccoma and cryptococcal meningitis resulting in bilateral blindness. The presentation was complicated by delayed diagnosis resulting in optic neuritis and an infected percutaneous lumbar drainage with methicillin resistant staphylococcus aureus (MRSA) and a paradoxical reaction of suspected immune reconstitution inflammatory syndrome (IRIS). We discuss the pathogen, the clinical manifestations and diagnostic approach (through laboratory and radiology findings), differential diagnosis, treatment, and proposed pathogenesis of IRIS and C. neoformans in an immunocompetent patient.

Unique clinical features of cryptococcal meningitis among Chinese patients without predisposing diseases against patients with predisposing diseases

The clinical features of cryptococcal meningitis (CM) in patients without predisposing diseases (PD) remain unclear. In sum, 162 of the 167 patients without PD and 162 of the 309 patients with PD were enrolled after propensity score matching. Demographic characteristics, symptoms, blood, and cerebrospinal fluid (CSF) characteristics were compared between the two groups. Kaplan-Meier curves and a Cox proportional hazards model were used to assess the factors associated with 10-week mortality. In total, approximately 35.1% of CM patients were without PD. CM patients without PD had blood profiles of higher white blood cells (WBC) [8.9(6.7-11.0) × 109/l], hemoglobin (128.4 ± 20.9 g/l), platelets [(226.2 ± 64.1) × 109/l], and serum albumin (41.2 ± 5.8 g/l) (all P ≤ .001) and CSF profiles of lower glucose (2.0 ± 1.2 mmol/l), pleocytosis [65.0 (18.0-160.0) × 106/l] and higher total protein [0.9 (0.7-1.4)g/l] (all P < .05). CM patients without PD had lower Cryptococcus culture positivity in CSF (62.5% vs. 74.1%, P = .039) but higher 2-week of CSF culture sterilization rates (69.4% vs. 51.3%, P = .031). The overall 10-week survival rate was 84.7% in patients without PD and 81.1% in patients with PD (Log-rank P = .439). CSF glucose <1.5 mmol/l, CSF fungal burden >20 cells/high power field and treatment lacking amphotericin B had a 3-4 times higher risk of death in patients without PD, whereas serum albumin <35 g/l, CSF glucose < 1.5 mmol/l, and CSF WBC <55 × 106 cell/l were risk factors for patients with PD. CM patients without PD had unique blood and CSF profiles, especially, had lower Cryptococcus culture positivity in CSF, and higher 2-week CSF culture sterilization. Low CSF glucose levels, higher fungal burden, and treatment without amphotericin B were risk factors for 10-week mortality.

Cryptococcosis in solid organ transplantation-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of cryptococcosis in the pre- and post-transplant period. The current update now includes a discussion of cryptococcosis, which is the third most common invasive fungal infection in SOT recipients. Infection often occurs a year after transplantation; however, early infections occur and donor-derived infections have been described within 3 months after transplant. There are two main species that cause infection, Cryptococcus neoformans and C gattii. Clinical onset may be insidious, but headaches, fevers, and mental status changes should warrant diagnostic testing. The lateral flow cryptococcal antigen assay is now the preferred test from serum and cerebrospinal fluid due to its rapidity, accuracy, and cost. A lumbar puncture with measurement of opening pressure is recommended for patients with suspected or proven cryptococcosis. Lipid amphotericin B plus 5-flucytosine is used as initial treatment of meningitis, disseminated infection, and moderate-to-severe pulmonary infection, followed by fluconazole as consolidation therapy. Fluconazole is effective for mild-to-moderate pulmonary infection. Immunosuppression reduction as part of management may lead to immune reconstitution syndrome that may resemble active disease.