Cryptococcosis and idiopathic CD4 lymphocytopenia

Disseminated Cryptococcus infection presenting as lytic skeletal lesions suggesting bony metastatic disease

A 76-year-old male diagnosed with sarcoidosis presented with atraumatic left anterior knee pain. Initial imaging of the left lower extremity revealed an eccentrically-based lytic lesion in the mid-distal femur with cortical erosion and an additional lytic lesion in the proximal tibia. Magnetic resonance imaging (MRI) demonstrated an aggressive lesion in the proximal tibia with surrounding marrow edema, cortical breach, and erosion into the distal patellar tendon. Given concern for metastatic bone lesions, a18-fluorodeoxyglucose positron emission tomography/computed tomography scan (FDG PET/CT) was performed which demonstrated concordant hypermetabolic lytic lesions at the left mid-distal femur and the left proximal tibia, as well as hypermetabolic diffuse lymphadenopathy. The patient was presumed to have metastatic lung cancer based on the presence of lung nodules. Due to concern for impending pathologic fracture, the patient underwent open biopsy with a plan for prophylactic fixation of both lesions. Intra-operatively, however, both lesions were found to contain pus, from which cultures ultimately grew Cryptococcus neoformans. This is a case of disseminated skeletal cryptococcosis masquerading as metastatic cancer in a patient without classic risk factors for disseminated cryptococcosis (defined as extrapulmonary evidence of infection). Classically, disseminated cryptococcosis is thought to occur in severely immunocompromised patients, such as those with human immunodeficiency virus (HIV) or organ transplant recipients. This case highlights the need to maintain a high index of suspicion in patients with underlying immunocompromising conditions, including less common conditions such as sarcoid, who present with bony lesions. This case report then discusses the diagnostic evaluation and treatment of disseminated skeletal cryptococcosis.

Importance of Clinical Isolates in Cryptococcus neoformans Research

The human pathogenic fungus Cryptococcus neoformans is a global health concern. Previous research in the field has focused on studies using reference strains to identify virulence factors, generate mutant libraries, define genomic structures, and perform functional studies. In this review, we discuss the benefits and drawbacks of using reference strains to study C. neoformans, describe how the study of clinical isolates has expanded our understanding of pathogenesis, and highlight how studies using clinical isolates can further develop our understanding of the host-pathogen interaction during C. neoformans infection.

Inborn Errors of Immunity Causing Pediatric Susceptibility to Fungal Diseases

Inborn errors of immunity are a heterogeneous group of genetically determined disorders that compromise the immune system, predisposing patients to infections, autoinflammatory/autoimmunity syndromes, atopy/allergies, lymphoproliferative disorders, and/or malignancies. An emerging manifestation is susceptibility to fungal disease, caused by yeasts or moulds, in a superficial or invasive fashion. In this review, we describe recent advances in the field of inborn errors of immunity associated with increased susceptibility to fungal disease.

Amphotericin B plus fluorocytosine combined with voriconazole for the treatment of non-HIV and non-transplant-associated cryptococcal meningitis: a retrospective study

Background

Our previous study explored Amphotericin B (AMB) plus 5-flucytosine (5-FC) combined with fluconazole (FLU) therapy in the induction period, which seemed to be better than the previous AMB + 5-FC antifungal therapy in non-HIV and non-transplant-associated CM. However, based on our clinical finding, the outcomes of some CM patients who received AMB plus 5-FC combined with FLU antifungal therapy were still poor. Therefore, we need to explore new antifungal methods in non-HIV and non-transplant-associated CM during the induction period.

Methods

Clinical data from 148 patients admitted to the Third Affiliated Hospital of Sun Yat Sen University from January 2011 to December 2020 were collected. These patients were stratified based on antifungal treatment methods in the induction period (group I with AMB + 5-FC + VOR, group II with AMB + 5-FC + FLU, group III with AMB + 5-FC).

Results

The first hospitalization time of Group I (median: 25 days, IQR: 20–34.5) was significantly shorter than that of Group II (median: 43 days, IQR: 29–62) (p < 0.001) and Group III (median: 50.5 days, IQR: 43–77.5) (p < 0.001). After 2 weeks of follow-up, Group I (26/49) had more patients reaching CSF clearance (p = 0.004) than Group II (18/71) and Group III (7/28). In multivariable analysis, Group II (OR: 3.35, 95%CI 1.43–7.82, p = 0.005) and Group III (OR: 3.8, 95%CI 1.23–11.81, p = 0.021) were associated with higher risk about CSF clearance failure at 2 weeks follow-up than Group I. After 10 weeks of follow-up, the incidence of hypokalemia in Group I was significantly lower than that in Group II (p = 0.003) and Group III (p = 0.004), and the incidence of gastrointestinal discomfort in Group I was significantly lower than that in Group II (p = 0.004).

Conclusion

AMB plus 5-FC combined with VOR may rapidly improve clinical manifestation, decrease CSF OP and clear the cryptococci in CSF during the early phase, substantially shorten the hospitalization time, and reduce the incidences of hypokalemia and gastrointestinal discomfort.

Case Report: Invasive Cryptococcosis in French Guiana: Immune and Genetic Investigation in Six Non-HIV Patients

Objectives

We describe the clinical, mycological, immunological, and genetic characteristics of six HIV-negative patients presenting with invasive cryptococcosis.

Methods

Patients with cryptococcosis without any of the classical risk factors, such as HIV infection, followed at Cayenne Hospital, were prospectively included. An immunologic and genetic assessment was performed.

Results

Five male patients and one female patient, 5 adults and one child, were investigated. All presented a neuromeningeal localization. Cryptococcus neoformans var. gattii and C. neoformans var. grubii were isolated in two and three patients, respectively, whereas one patient could not be investigated. Overall, we did not observe any global leukocyte defect. Two patients were found with high levels of circulating autoantibodies against Granulocyte macrophage-colony stimulating factor (GM-CSF), and none had detectable levels of autoantibodies against Interferon gamma (IFN-γ) Sequencing of STAT1 exons and flanking regions performed for four patients was wild type.

Conclusion

To better understand cryptococcosis in patients with cryptococcosis but otherwise healthy, further explorations are needed with repeated immune checkups and strain virulence studies.

Disseminated cryptococcosis with varicella-zoster virus coinfection of idiopathic CD4 + T lymphocytopenia: a case report and literature review

Background

Idiopathic CD4 + T lymphocytopenia (ICL) is a rare immunodeficiency syndrome, unaccompanied by various opportunistic infections. Cryptococcus and varicella-zoster viruse are the most common opportunistic infections.

Method

We described a case of disseminated cryptococcosis with varicella-zoster virus coinfection in a patient with ICL and reviewed all published reports. A total of 26 cases with cryptococcal meningitis in ICL were enrolled.

Discussion

ICL remains poorly understood to clinicians. Patients with cryptococcal meningitis in ICL mostly suffered with headache and fever in a subacute or chronic period, while some patients might have atypical manifestations which makes a difficulty for early diagnosis. Some characteristics of cerebrospinal fluid can help to predict the prognosis of the disease. Cryptococcosis with varicella-zoster virus coinfection is rare but serious.

Conclusion

We recommed CD4 + T cells should be assessed in patients with unusual or recurrent infections. As the underlying pathophysiology is poorly understood, there is no standard therapy for ICL. Increased awareness of the disease and early prevention for CD4 reduction are needed.

Use of Clinical Isolates to Establish Criteria for a Mouse Model of Latent Cryptococcus neoformans Infection

The mechanisms of latency in the context of C. neoformans infection remain poorly understood. Two reasons for this gap in knowledge are: 1) the lack of standardized criteria for defining latent cryptococcosis in animal models and 2) limited genetic and immunological tools available for studying host parameters against C. neoformans in non-murine models of persistent infection. In this study, we defined criteria required for latency in C. neoformans infection models and used these criteria to develop a murine model of persistent C. neoformans infection using clinical isolates. We analyzed infections with two clinical C. neoformans strains, UgCl223 and UgCl552, isolated from advanced HIV patients with cryptococcal meningitis. Our data show that the majority of C57BL/6 mice infected with the clinical C. neoformans isolates had persistent, stable infections with low fungal burden, survived beyond 90 days-post infection, exhibited weight gain, had no clinical signs of disease, and had yeast cells contained within pulmonary granulomas with no generalized alveolar inflammation. Infected mice exhibited stable relative frequencies of pulmonary immune cells during the course of the infection. Upon CD4+ T-cell depletion, the CD4DTR mice had significantly increased lung and brain fungal burden that resulted in lethal infection, indicating that CD4+ T-cells are important for control of the pulmonary infection and to prevent dissemination. Cells expressing the Tbet transcription factor were the predominant activated CD4 T-cell subset in the lungs during the latent infection. These Tbet-expressing T-cells had decreased IFNγ production, which may have implications in the capacity of the cells to orchestrate the pulmonary immune response. Altogether, these results indicate that clinical C. neoformans isolates can establish a persistent controlled infection that meets most criteria for latency; highlighting the utility of this new mouse model system for studies of host immune responses that control C. neoformans infections.

Characterization of an immunogenic cellulase secreted by Cryptococcus pathogens

Members of the C. neoformans/C. gattiii species complex are an important cause of serious humans infections, including meningoencephalitis. We describe here a 45 kDa extracellular cellulase purified from culture supernatants of C. neoformans var. neoformans. The N-terminal sequence obtained from the purified protein was used to isolate a clone containing the full-length coding sequence from a C. neoformans var. neoformans (strain B-3501A) cDNA library. Bioinformatics analysis indicated that this gene is present, with variable homology, in all sequenced genomes of the C. neoformans/C. gattii species complex. The cDNA clone was used to produce a recombinant 45 kDa protein in E. coli that displayed the ability to convert carboxymethyl cellulose and was therefore designated as NG-Case (standing for Neoformans Gattii Cellulase). To explore its potential use as a vaccine candidate, the recombinant protein was used to immunize mice and was found capable of inducing T helper type 1 responses and delayed-type hypersensitivity reactions, but not immune protection against a highly virulent C. neoformans var grubii strain. These data may be useful to better understand the mechanisms underlying the ability C. neoformans/C. gattii to colonize plant habitats and to interact with the human host during infection.

Associations between Cryptococcus Genotypes, Phenotypes, and Clinical Parameters of Human Disease: A Review

The genus Cryptococcus contains two primary species complexes that are significant opportunistic human fungal pathogens: C. neoformans and C. gattii. In humans, cryptococcosis can manifest in many ways, but most often results in either pulmonary or central nervous system disease. Patients with cryptococcosis can display a variety of symptoms on a spectrum of severity because of the interaction between yeast and host. The bulk of our knowledge regarding Cryptococcus and the mechanisms of disease stem from in vitro experiments and in vivo animal models that make a fair attempt, but do not recapitulate the conditions inside the human host. To better understand the dynamics of initiation and progression in cryptococcal disease, it is important to study the genetic and phenotypic differences in the context of human infection to identify the human and fungal risk factors that contribute to pathogenesis and poor clinical outcomes. In this review, we summarize the current understanding of the different clinical presentations and health outcomes that are associated with pathogenicity and virulence of cryptococcal strains with respect to specific genotypes and phenotypes.

Cryptococcus neoformans infection in Human Immunodeficiency Virus (HIV)-infected and HIV-uninfected patients at an inner-city tertiary care hospital in the Bronx

Cryptococcus neoformans causes life-threatening meningoencephalitis. Human immunodeficiency virus (HIV) infection is the most significant predisposing condition, but persons with other immunodeficiency states as well as phenotypically normal persons develop cryptococcosis. We retrospectively reviewed medical records of all patients with a diagnosis of cryptococcosis between 2005 and 2017 at our inner-city medical center in the Bronx, an epicenter of AIDS in New York City, and analyzed demographic data, clinical manifestations, laboratory findings, treatment, and mortality for these patients. In sum, 63% of the cases over this 12-year period occurred in HIV-infected patients. And 61% of the HIV-infected patients were non-adherent with antiretroviral therapy, 10% were newly diagnosed with AIDS, and 4% had unmasking cryptococcus-associated immune reconstitution inflammatory syndrome. The majority were Hispanic or black in ethnicity/race. HIV-uninfected patients (47/126) were older (P < .0001), and the majority had an immunocompromising condition. They were less likely to have a headache (P = .0004) or fever (P = .03), had prolonged time to diagnosis (P = .04), higher cerebrospinal fluid (CSF) glucose levels (P = .001), less CSF culture positivity (P = .03), and a higher 30-day mortality (P = .03). Cases in HIV-uninfected patients were often unsuspected during their initial evaluation, leading to a delay in infectious diseases consultation, which was associated with mortality (P = .03). Our study indicates that HIV infection remains the most important predisposing factor for cryptococcosis despite availability of antiretroviral therapy and highlights potential missed opportunities for earlier diagnosis and differences in clinical and prognostic factors between HIV-infected and HIV-uninfected patients.

Criptococosis y linfocitopenia T CD4 idiopática: Reporte de un caso

La linfocitopenia T CD4 idiopática (LCI) es un síndrome clínico inusual que se caracteriza por un déficit de células T CD4+ circulantes en ausencia de infección por VIH u otra condición de inmunosupresión. Los pacientes con dicha enfermedad pueden presentarse asintomáticos o con infecciones oportunistas, las más frecuentes son por criptococo, micobacterias o virales como herpes zoster. Presentamos el caso de un hombre de 32 años, sin antecedentes, en quien se descartó infección por retrovirus, con recuento de linfocitos T CD4+ menor a 300 células/m3; se diagnosticó LCI posterior al diagnóstico de criptococomas cerebrales mediante hallazgos imagenológicos los cuales fueron congruentes con estudios microbiológicos.

Cryptococcal infection in haematologic malignancies and haematopoietic stem cell transplantation

This review summarises both the recent and relevant studies about cryptococcal infections in haematologic malignancies and haematopoietic stem cell transplantation. Although uncommon in this patient population, this infection carries a high mortality, especially if left untreated. Given the limited data, we draw some conclusions with respect to management from the solid organ transplantation and HIV-infected literature. Herein, we discuss cryptococcosis with a particular attention to its background, epidemiology, risk factors, clinical presentation, diagnosis, treatment and prevention in this group.

Idiopathic CD4 Lymphocytopenia: Current Insights

Idiopathic CD4 lymphocytopenia is a condition characterized by low CD4 counts. It is rare and most of the information about this illness comes from case reports. Presentation is usually in the 4th decade of life with opportunistic infections, autoimmune disease or neoplasia. The pathophysiology of this condition is not well understood. Management revolves around treatment of the presenting condition and close follow-up of these patients. This review presents a narrative summary of the current literature on idiopathic CD4 lymphocytopenia.

Treatment of invasive fungal diseases in cancer patients-Revised 2019 Recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

BACKGROUND

Invasive fungal diseases remain a major cause of morbidity and mortality in cancer patients undergoing intensive cytotoxic therapy. The choice of the most appropriate antifungal treatment (AFT) depends on the fungal species suspected or identified, the patient's risk factors (eg length and depth of granulocytopenia) and the expected side effects.

OBJECTIVES

Since the last edition of recommendations for 'Treatment of invasive fungal infections in cancer patients' of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) in 2013, treatment strategies were gradually moving away from solely empirical therapy of presumed or possible invasive fungal diseases (IFDs) towards pre-emptive therapy of probable IFD.

METHODS

The guideline was prepared by German clinical experts for infections in cancer patients in a stepwise consensus process. MEDLINE was systematically searched for English-language publications from January 1975 up to September 2019 using the key terms such as 'invasive fungal infection' and/or 'invasive fungal disease' and at least one of the following: antifungal agents, cancer, haematological malignancy, antifungal therapy, neutropenia, granulocytopenia, mycoses, aspergillosis, candidosis and mucormycosis.

RESULTS

AFT of IFDs in cancer patients may include not only antifungal agents but also non-pharmacologic treatment. In addition, the armamentarium of antifungals for treatment of IFDs has been broadened (eg licensing of isavuconazole). Additional antifungals are currently under investigation or in clinical trials.

CONCLUSIONS

Here, updated recommendations for the treatment of proven or probable IFDs are given. All recommendations including the levels of evidence are summarised in tables to give the reader rapid access to key information.

Cryptococcal pneumonia in an adolescent with a gain-of-function variant in signal transduction and activator of transcription 1 (STAT1)

An adolescent male with a history of autoimmune enteropathy, autoimmune hypothyroidism, aphthous stomatitis and recurrent oral Candida infections only in the setting of curative antibiotic courses presented with cryptococcal pneumonia and perihilar adenitis, which was successfully treated with antifungal therapy. The patient had a complex history with several immunological anomalies. Whole exome sequencing revealed a known STAT1 pathogenic variant, associated with gain of function (GOF). This case expands our understanding of the broad clinical phenotype manifested by STAT1 GOF and emphasises the importance of consideration of this diagnosis in patients presenting with opportunistic infections and autoimmunity.

Modulation of host immune status by cryptococcus co-infection during HIV-1 pathogenesis and its impact on CD+4 cell and cytokines environment

BACKGROUND

Cryptococcus infection is the second most common opportunistic infection in HIV patients with an increased rate of morbidity and mortality. Altered immune system during HIV- Cryptococcus co-infection is yet to be explored by laboratory. This study evaluates pro- and the anti-inflammatory cytokines in HIV patients with Cryptococcus co-infection and correlate them with CD4+T cell counts as well as viral loads before the initiation of drug therapy. This information would enable to understand host immune modulation and cellular environment during co-infection and understand its impact on HIV pathogenesis.

METHODOLOGY

The study comprised four categories of patients with cryptococcosis, HIV, HIV-cryptococcosis co-infected and asymptomatic Healthy volunteers. All the patients and healthy individuals were subjected to CD4+T cells count by FACS using monoclonal antibody cocktail CD4+T cell count (counts per mm3) which was counted using multiSET software on FACS caliber. The viral loads were counted in terms of viral RNA copy numbers which was estimated by real-time PCR using by Artus HIV-1 RG. The sensitivity of kit was >70 IU/ml. ELISA was performed for IL-12 p70, IL-12, IL-4, IL-10, IL-6, TNF-α and IFN-Y using commercially kits (BD Biosciences, USA). Significant variations were assayed by Student's t-test and P values ≤ 0.05 were considered statistically significant.

RESULTS

Reduction in CD+4 cell counts was highly significant in HIV patients with or without cryptococcosis. CD4+T cell counts were inversely proportional to viral load. TNF-α levels were raised in cryptococcosis patients significantly higher than healthy individuals. TNF-α was more or less not dependent on viral load but it was more related to the cryptococcosis IL-12 levels were increased in patients with infection and was highest in the HIV infected group. Level of IL-4 was similar in healthy and patients with cryptococcosis but it was elevated in HIV-Crypto co-infected patients. HIV infected patients showed a significant increase in IL-4 level and it was elevated higher in co-infected patients. IL-10 and IL-6 were significantly higher in HIV patients. The fungal infection did not influence the levels of IL-10 in HIV group but IL-6 was low in fungal infected patients.

CONCLUSION

There are very limited studies related to the immune modulation status of HIV co-infected with Cryptococcus before the initiation of any drug therapy. Such information might through in-depth light to understand the initial state of the immune environment which certainly would play a pivotal role in the outcome of the immune modulation.

Pulmonary Cryptococcus infections as a manifestation of idiopathic CD4 lymphocytopenia: case report and literature review

Background

Idiopathic CD4 lymphocytopenia (ICL) is a rare clinical disease with relative CD4 deficiency in the absence of HIV infection. The pathogenicity of ICL is poorly understood with an unclear incidence rate in the general population. Sequelae of ICL includes AIDS-defining infections, which most commonly includes Cryptococcus neoformans. Typically, C. neoformans infections present with CNS involvement but rarely with extra-CNS manifestations. Here, we present a rare case of ICL with exclusively primary pulmonary cryptococcus and a review of the literature.

Case presentation

A 56-year-old female presented to our tertiary care hospital requiring a right hip open reduction intervention. The patient became febrile during admission, prompting a work-up that included a chest X-ray showing a peripheral pulmonary solitary nodule. Transthoracic biopsy revealed encapsulated yeast forms in keeping with C. neoformans. CD4 counts, repeated at least one month apart, were < 200 cells/mm³, with negative HIV testing. Flow cytometry and genetic testing were completed to elucidate the etiology of the immune deficiency, both of which were unremarkable. She was subsequently treated with 12 months of posaconazole with clinical resolution.

Conclusions

Our patient highlights a rare clinical disease, which a review of literature revealed only five cases in the literature with exclusive pulmonary Cryptococcus in ICL/ This case demonstrates the strong clinical acumen required to properly diagnose and ultimately manage the patient.

Central Nervous System Cryptococcal Infections in Non-HIV Infected Patients

Central nervous system (CNS) cryptococcosis in non-HIV infected patients affects solid organ transplant (SOT) recipients, patients with malignancy, rheumatic disorders, other immunosuppressive conditions and immunocompetent hosts. More recently described risks include the use of newer biologicals and recreational intravenous drug use. Disease is caused by Cryptococcus neoformans and Cryptococcus gattii species complex; C. gattii is endemic in several geographic regions and has caused outbreaks in North America. Major virulence determinants are the polysaccharide capsule, melanin and several ‘invasins’. Cryptococcal plb1, laccase and urease are essential for dissemination from lung to CNS and crossing the blood–brain barrier. Meningo-encephalitis is common but intracerebral infection or hydrocephalus also occur, and are relatively frequent in C. gattii infection. Complications include neurologic deficits, raised intracranial pressure (ICP) and disseminated disease. Diagnosis relies on culture, phenotypic identification methods, and cryptococcal antigen detection. Molecular methods can assist. Preferred induction antifungal therapy is a lipid amphotericin B formulation (amphotericin B deoxycholate may be used in non-transplant patients) plus 5-flucytosine for 2–6 weeks depending on host type followed by consolidation/maintenance therapy with fluconazole for 12 months or longer. Control of raised ICP is essential. Clinicians should be vigilant for immune reconstitution inflammatory syndrome.

Clinical Aspects of Immune Damage in Cryptococcosis

Purpose of review

To perform an extensive review of recent literature and provide an update on the current epidemiology, clinical features and management of cryptococcal disease with a focus on the differences between patients depending on their immune status.

Recent findings

Emerging literature has highlighted the inflammatory pathophysiology and varied manifestations of cryptococcal infections in patients who are apparently healthy but paradoxically have a more critical clinical course compared to their immunosuppressed counterparts.

Summary

Non-HIV cryptococcal meningitis has greater mortality compared to that seen in HIV patients. Basic science experiments closely analyzing the underlying pathophysiological response to this infection have demonstrated the predominant role of T cell-mediated inflammatory injury in causing worse clinical outcomes. Further studies are needed to define the need for immunosuppressive agents in the treatment of this illness.

Disseminated cryptococcal infection in a patient with treatment-naïve chronic lymphocytic leukemia (CLL)

We report a case of disseminated cryptococcosis in a treatment-naïve chronic lymphocytic leukemia (CLL) patient. A 60-year-old man presented with a two-week history of intermittent fevers, frontal headaches, night sweats, weight loss and multiple pink papules on hands and face. Cryptococcemia was found by blood culture unexpectedly. Further investigation confirmed cryptococcal meningitis and skin disease. He responded to two week amphotericin B and flucytosine followed by four-week amphotericin B and fluconazole, three-month high dose fluconazole (800 mg/day), and maintenance fluconazole (400 mg/day) thereafter. CSF pleocytosis persisted until day 203 while cryptococcal antigen in the CSF persisted at day 334 of treatment.

Disseminated Cryptococcosis in a Patient with Multiple Myeloma Treated with Daratumumab, Lenalidomide, and Dexamethasone

We report a case of disseminated cryptococcosis in a patient with multiple myeloma (MM) during treatment with daratumumab, lenalidomide, and dexamethasone (DRd). A 62-year-old woman, who was diagnosed with IgGλ type MM, was treated with three cycles of bortezomib and dexamethasone and subsequently treated with three cycles of DRd before admission. She reached a stringent complete response and presented with lethargy and seizure. Laboratory findings revealed severe CD4 lymphopenia, and Cryptococcus neoformans was detected in her cerebrospinal fluid and blood culture. The risk of developing an opportunistic infection should be considered in patients treated with daratumumab.

Fatal Cryptococcus gattii meningitis with negative cryptococcal antigen test in a HIV-non-infected patient

Cryptococcus gattii predominantly causes central nervous system and pulmonary infection in both immunocompromised and immunocompetent patients with substantial morbidity. We report a case of rapidly fatal meningitis by C. gattii in an HIV-non-infected man with CD4 lymphopenia who tested negative for cryptococcal antigen. This case may serve as an alert to its wider occurrence and less explored risk factors.

EQUAL Cryptococcus Score 2018: A European Confederation of Medical Mycology Score Derived From Current Guidelines to Measure QUALity of Clinical Cryptococcosis Management

Cryptococcocis is an opportunistic fungal infection with high morbidity and mortality. Guidelines to aid clinicians regarding diagnosis, management, and treatment can be extensive and challenging to comply with. There is no tool to measure guideline adherence. To create such a tool, we reviewed current guidelines from the Infectious Diseases Society of America, the World Health Organization, the American Society of Transplantation, and recent significant publications to select the strongest recommendations as vital components of our scoring tool. Items included diagnostic tests (blood, tissue, and cerebrospinal fluid cultures, Cryptococcus antigen, India ink, histopathology with special fungal stains, central nervous system imaging), pharmacological (amphotericin B, flucytosine, azoles) and nonpharmacological treatments (intracranial pressure management, immunomodulation, infectious disease consultation), and follow-up of central nervous system complications. The EQUAL Cryptococcus Score 2018 weighs and aggregates the recommendations for the optimal management of cryptococcosis. Providing a tool that could measure guideline adherence or facilitate clinical decision-making.

Clinical features of pulmonary cryptococcosis among patients with different levels of peripheral blood CD4+ T lymphocyte counts

Background

The clinical manifestation of pulmonary cryptococcosis varies notably between immunocompromised and immunocompetent patients. To better understand pulmonary cryptococcosis, we compared the clinical features of pulmonary cryptococcosis patients with or without decreased peripheral blood CD4⁺ T cell counts.

Methods

We retrospectively reviewed the medical records of 80 patients with cryptococcosis who had been treated in Jingling Hospital from January 2011 to January 2016. According to the normal range of peripheral blood CD4 + T-lymphocyte counts in our population, we chose CD4 = 378/μL as a cut-off value.

Results

The proportion of fever in the patients with decreased CD4+ T cells was higher than that of the patients with a normal amount of CD4+ T cells (86.7% vs 28.6%, P < 0.001). The incidence of clinical symptoms, such as cough (60.6% vs 64.7%, P = 0.729), chest pain (9.1% vs 26.5%, P = 0.064), and dyspnea (27.3% vs 23.5%, P = 0.725) showed no difference between patients with low CD4⁺ T cell counts and those with normal CD4+ T cell counts. The number of asymptomatic patients in the CD4⁺ T cell normal group was higher than that in the decreased CD4⁺ T cell group (17.1% vs 0%, P = 0.005). Nodules, masses, and halo signs were more common in the CD4⁺ T cell normal patients than in the low-CD4+ T cell patients (79.4% vs 54.5%, P = 0.03). The opposite trend was observed for cavitations (14.7% vs 51.5%, P = 0.001). The other CT findings, including pulmonary consolidation (P = 0.205), and pleural effusion (P = 0.641), did not differ significantly between the two groups.

Conclusions

CD4⁺ T lymphocytes have a significant impact on the clinical and radiological characteristics of pulmonary cryptococcosis. The patients with normal CD4⁺ T cell counts were found to have less fever and more nodule-like radiographic findings.

Trial registration

2011NJKY-023-01. Registered on January 10, 2011.

Cryptococcal meningitis in apparently immunocompetent patients: association with idiopathic CD4+ lymphopenia

We present two cases of cryptococcal meningitis in people subsequently diagnosed with idiopathic CD4+ lymphopenia. Both presented with new onset headaches without sinister features and were sent home on multiple occasions from emergency departments. Cryptococcal meningitis in HIV-negative patients poses major diagnostic and management problems; the associated mortality is 9%-27%. We suggest performing blood and cerebrospinal fluid cryptococcal antigen tests in all people with lymphocytic meningitis.

Idiopathic CD4 lymphocytopenia: Pathogenesis, etiologies, clinical presentations and treatment strategies

BACKGROUND

Idiopathic CD4 lymphocytopenia (ICL) is a rare condition characterized by an unexplained deficit of circulating CD4 T cells leading to increased risk of serious opportunistic infections. The pathogenesis, etiology, clinical presentation, and best treatment options remain unclear.

OBJECTIVE

To describe the clinical presentation, treatment strategies, and outcome of patients with ICL seen in a single referral center.

METHODS

In a retrospective study, from January 1993 to January 2014, the demographic characteristics, clinical presentation, and treatments of patients diagnosed with ICL were reviewed.

RESULTS

Twenty-four patients (14 female [58%] and 10 male [42%]) were evaluated. The mean age was 45 ± 17.6 years (range 7-76 years). Mean CD4 and CD8 T-cell counts at the time of diagnosis were 119 ± 84/mm³ (range 4-294/mm³) and 219 ± 258/mm³ (range 7-630/mm³), respectively. Seventeen patients (71%) had opportunistic infections, 4 (17%) had malignancies, and 3 (13%) had unexplained demyelinating disease and neurologic problems. Most patients had normal levels of immunoglobulins. Thirteen patients had abnormally low to absent response to phytohemagglutinin, concanavalin A, and antigens (candida and tetanus). Three patients had resolution of warts and 1 had mycobacterial lung infection on interleukin-2 with increases in CD4 count. The 11 patients on trimethoprim and sulfamethoxazole had no further hospital admissions for infections.

CONCLUSION

The pathogenesis of ICL remains unclear. Although only some patients are healthy, most patients present with opportunistic infections. There is no known standard treatment aside from prophylactic antibiotics.

Susceptibility to Cryptococcal Meningoencephalitis Associated With Idiopathic CD4+ Lymphopenia and Secondary Germline or Acquired Defects

Idiopathic CD4⁺ lymphopenia (ICL) predisposes to opportunistic infections (OIs) but can often remain asymptomatic and does not have a strong association with monogenic mutations. Likewise, cryptococcal meningoencephalitis, the most common OI in ICL, is not strongly associated with monogenic mutations. In this study, we describe 2 patients with ICL plus an additional immune defect: one from an E57K genetic mutation in the nuclear factor-κβ essential modulator, and the other with acquired autoantibodies to granulocyte-macrophage colony-stimulating factor. Thus, these cases may exemplify a "multi-hit model" in patients with ICL who acquire OIs.

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.

Characteristics and outcomes of cryptococcal meningitis in HIV seronegative children in Beijing, China, 2002-2013

Background

Data regarding HIV-seronegative pediatric patients with cryptococcal meningitis (CM) have been very limited.

Methods

We retrospectively reviewed non-HIV-infected in patients with CM from January 2002 through December 2013 in Beijing Children’s Hospital. Records of the all patients were obtained and compared.

Results

The 34 children had a median age of 5.6 years. Most of the patients were male (67.6 %). Only 23.5 % of the cases had identifiable underlying diseases. The sensitivity of the CSF cryptococcal antigen, India ink smear and CSF culture in our study were 81.5, 85.3 and 82.4 %, respectively. And the sensitivity of combinations of these tests was 91.2 %. Out of the 34 patients, 16 (47.1 %) had other organs involvement in addition to the brain. The main abnormal features via magnetic resonance imaging (MRI) were Virchow-Robin space dilatation (44.4 %), hydrocephalus (38.9 %), gelatinous pseudocysts (33.3 %), brain atrophy (33.3 %), meningeal enhancement (27.8 %) and local lesions (27.8 %). In total, 64.7 % of the patients were successfully treated at discharge, whereas treatment failed in 35.3 % of the patients.

Conclusions

Cryptococcal meningitis is an infrequent disease with a high fatality rate in children in China. The majority of patients were apparently healthy. Clinicians should consider cryptococcal infection as a potential pathogen of pediatric meningitis. Cryptococcal antigen, India ink smear and culture tests are recommended for diagnosis.

Disseminated cryptococcal infection in allogeneic stem cell transplant patients: a rare cause of acute kidney injury

Hematopoietic stem cell transplantation (HSCT) can be lifesaving for some of the deadliest hematologic diseases. However, immunosuppression, polypharmacy and risk of infectious complications associated with HSCT can increase morbidity and mortality for recipients. Incidence of acute kidney injury (AKI) after HSCT can be as high as 70%, and concomitant infection can be a therapeutic challenge for oncologists, nephrologists and infectious disease specialists. We illustrate this challenge in the case of a 31-year-old man with acute lymphoblastic leukemia who underwent a double cord HSCT complicated by GvHD, systemic cryptococcal and BK virus infections and AKI. Kidney biopsy showed round to cup-shaped organisms with occasional budding, consistent with Cryptococcus and thrombotic microangiopathy. We discuss our findings and a literature review of disseminated cryptococcal infection with renal involvement after HSCT.

Administration of interleukin-7 increases CD4 T cells in idiopathic CD4 lymphocytopenia

Idiopathic CD4 lymphopenia (ICL) is a rare syndrome defined by low CD4 T-cell counts (<300/µL) without evidence of HIV infection or other known cause of immunodeficiency. ICL confers an increased risk of opportunistic infections and has no established treatment. Interleukin-7 (IL-7) is fundamental for thymopoiesis, T-cell homeostasis, and survival of mature T cells, which provides a rationale for its potential use as an immunotherapeutic agent for ICL. We performed an open-label phase 1/2A dose-escalation trial of 3 subcutaneous doses of recombinant human IL-7 (rhIL-7) per week in patients with ICL who were at risk of disease progression. The primary objectives of the study were to assess safety and the immunomodulatory effects of rhIL-7 in ICL patients. Injection site reactions were the most frequently reported adverse events. One patient experienced a hypersensitivity reaction and developed non-neutralizing anti-IL-7 antibodies. Patients with autoimmune diseases that required systemic therapy at screening were excluded from the study; however, 1 participant developed systemic lupus erythematosus while on study and was excluded from further rhIL-7 dosing. Quantitatively, rhIL-7 led to an increase in the number of circulating CD4 and CD8 T cells and tissue-resident CD3 T cells in the gut mucosa and bone marrow. Functionally, these T cells were capable of producing cytokines after mitogenic stimulation. rhIL-7 was well tolerated at biologically active doses and may represent a promising therapeutic intervention in ICL. This trial was registered at www.clinicaltrials.gov as #NCT00839436.

Clinical Immunophenotype at Disease Onset in Previously Healthy Patients With Cryptococcal Meningitis

Cryptococcal meningitis (CM) is a global disease with significant morbidity and mortality. Although low peripheral blood cluster of differentiation 4 (CD4) cell counts are found to be related to a high burden of cryptococcus in HIV-infected patients, little is known about possible immune defects in previously healthy patients (PHPs). We performed a retrospective study of 41 CM patients treated from January 2005 to December 2014 who did not have HIV-infection. There were 33 PHPs and 8 not previously healthy patients (non-PHPs). We analyzed clinical test data pertaining to peripheral blood T cells, antibodies, inflammation markers, and cerebral spinal fluid (CSF) completed during the disease onset phase and 5 years following diagnosis. PHPs had significantly higher counts of cluster of differentiation 3 (CD3), cluster of differentiation 4 (CD4), and cluster of differentiation 45 (CD45) cells, and lower percentages of CD8 cells than non-PHPs (P < 0.05). Measurements of inflammatory markers and immunoglobulin in blood were comparable except for lower immunoglobulin A (IgA) levels in non-PHPs (P = 0.0410). Examination of CSF revealed lower white blood cell (WBC) counts in non-PHPs. Five-year mortality in PHPs was higher than in non-PHPs (22.0% vs 12.5%) but this was not statistically significant (P > 0.05). Multivariate analysis revealed that higher immunoglobulin G (IgG) levels in serum during disease onset may be an independent predictor of mortality (P = 0.015). In conclusion, PHPs demonstrate an immunophenotype that is distinct from that of non-PHPs, leading to an improved understanding of the immunology of cryptococcal meningitis.

Host immunity to Cryptococcus neoformans

Cryptococcosis is caused by the fungal genus Cryptococcus. Cryptococcosis, predominantly meningoencephalitis, emerged with the HIV pandemic, primarily afflicting HIV-infected patients with profound T-cell deficiency. Where in use, combination antiretroviral therapy has markedly reduced the incidence of and risk for disease, but cryptococcosis continues to afflict those without access to therapy, particularly in sub-Saharan Africa and Asia. However, cryptococcosis also occurs in solid organ transplant recipients and patients with other immunodeficiencies as well as those with no known immunodeficiency. This article reviews innate and adaptive immune responses to C. neoformans, with an emphasis on recent studies on the role of B cells, natural IgM and Fc gamma receptor polymorphisms in resistance to cryptococcosis.

Disseminated Cryptococcosis in a 63-year-old Patient with Multiple Sclerosis Treated with Fingolimod

We herein report the case of a 63-year-old man who presented with a 3-month history of a cutaneous nodular lesion of his jaw, low grade fever, lethargy and progressive cognitive impairment. He had a 30-year history of multiple sclerosis and had been treated with fingolimod for the previous 2 years. Laboratory data revealed CD4 lymphocytopenia and a tissue culture of the skin nodule was positive for Cryptococcus neoformans. Cerebrospinal fluid and serum cryptococcal antigen tests were also positive and we diagnosed him to have disseminated cryptococcosis. This dissemination might be associated with fingolimod-induced CD4 lymphocytopenia. The risk of an opportunistic infection should therefore be considered when encountering fingolimod-treated patients.

Abdominal Lymphonodular Cryptococcosis in an Immunocompetent Child

We describe our experience with an apparently immunocompetent child presenting with pyrexia of unknown origin without focal signs. Investigations revealed lymphadenopathy at lung hila, mesentery, and porta hepatis. The child had received at least two months of empiric antituberculous therapy (ATT) before she came to us. A CT-guided biopsy revealed granulomatous inflammation. PAS stain showed yeasts which stained blue with Alcian blue, suggesting C. neoformans.

Cryptococcus gattii infections

Understanding of the taxonomy and phylogeny of Cryptococcus gattii has been advanced by modern molecular techniques. C. gattii probably diverged from Cryptococcus neoformans between 16 million and 160 million years ago, depending on the dating methods applied, and maintains diversity by recombining in nature. South America is the likely source of the virulent C. gattii VGII molecular types that have emerged in North America. C. gattii shares major virulence determinants with C. neoformans, although genomic and transcriptomic studies revealed that despite similar genomes, the VGIIa and VGIIb subtypes employ very different transcriptional circuits and manifest differences in virulence phenotypes. Preliminary evidence suggests that C. gattii VGII causes severe lung disease and death without dissemination, whereas C. neoformans disseminates readily to the central nervous system (CNS) and causes death from meningoencephalitis. Overall, currently available data indicate that the C. gattii VGI, VGII, and VGIII molecular types more commonly affect nonimmunocompromised hosts, in contrast to VGIV. New, rapid, cheap diagnostic tests and imaging modalities are assisting early diagnosis and enabling better outcomes of cerebral cryptococcosis. Complications of CNS infection include increased intracranial pressure, severe neurological sequelae, and development of immune reconstitution syndrome, although the mortality rate is low. C. gattii VGII isolates may exhibit higher fluconazole MICs than other genotypes. Optimal therapeutic regimens are yet to be determined; in most cases, initial therapy with amphotericin B and 5-flucytosine is recommended.

Paradoxical Immune Responses in Non-HIV Cryptococcal Meningitis

The fungus Cryptococcus is a major cause of meningoencephalitis in HIV-infected as well as HIV-uninfected individuals with mortalities in developed countries of 20% and 30%, respectively. In HIV-related disease, defects in T-cell immunity are paramount, whereas there is little understanding of mechanisms of susceptibility in non-HIV related disease, especially that occurring in previously healthy adults. The present description is the first detailed immunological study of non-HIV-infected patients including those with severe central nervous system (s-CNS) disease to 1) identify mechanisms of susceptibility as well as 2) understand mechanisms underlying severe disease. Despite the expectation that, as in HIV, T-cell immunity would be deficient in such patients, cerebrospinal fluid (CSF) immunophenotyping, T-cell activation studies, soluble cytokine mapping and tissue cellular phenotyping demonstrated that patients with s-CNS disease had effective microbiological control, but displayed strong intrathecal expansion and activation of cells of both the innate and adaptive immunity including HLA-DR+ CD4+ and CD8+ cells and NK cells. These expanded CSF T cells were enriched for cryptococcal-antigen specific CD4+ cells and expressed high levels of IFN-γ as well as a lack of elevated CSF levels of typical T-cell specific Th2 cytokines -- IL-4 and IL-13. This inflammatory response was accompanied by elevated levels of CSF NFL, a marker of axonal damage, consistent with ongoing neurological damage. However, while tissue macrophage recruitment to the site of infection was intact, polarization studies of brain biopsy and autopsy specimens demonstrated an M2 macrophage polarization and poor phagocytosis of fungal cells. These studies thus expand the paradigm for cryptococcal disease susceptibility to include a prominent role for macrophage activation defects and suggest a spectrum of disease whereby severe neurological disease is characterized by immune-mediated host cell damage.

Cryptococcus is an important cause of fungal meningitis with significant mortality globally. Susceptibility to the fungus in humans has been related to T-lymphocyte defects in HIV-infected individuals, but little is known about possible immune defects in non HIV-infected patients including previously healthy individuals. This latter group also has some of the worst response rates to therapy with almost a third dying in the United States, despite available therapy. Here we conducted the first detailed immunological analysis of non-HIV apparently immunocompetent individuals with active cryptococcal disease. In contrast to HIV-infected individuals, these studies identified a highly activated antigen-presenting dendritic cell population within CSF, accompanied by a highly active T-lymphocyte population with potentially damaging inflammatory cytokine responses. Furthermore, elevated levels of CSF neurofilament light chains (NFL), a marker of axonal damage in severe central nervous system infections suggest a dysfunctional role to this acute inflammatory state. Paradoxically, CSF macrophage proportions were reduced in patients with severe disease and biopsy and autopsy samples identified alternatively activated tissue macrophage populations that failed to appropriately phagocytose fungal cells. Our study thus provides new insights into the susceptibility to human cryptococcal disease and identifies a paradoxically active T-lymphocyte response that may be amenable to adjunctive immunomodulation to improve treatment outcomes in this high-mortality disease.

DUSP4-mediated accelerated T-cell senescence in idiopathic CD4 lymphopenia

Idiopathic CD4 lymphopenia (ICL) is a rare heterogeneous immunological syndrome of unclear etiology. ICL predisposes patients to severe opportunistic infections and frequently leads to poor vaccination effectiveness. Chronic immune activation, expansion of memory T cells, and impaired T-cell receptor (TCR) signaling have been reported in ICL, but the mechanistic and causative links remain unclear. We show that late-differentiated T cells in 20 patients with ICL displayed defective TCR responses and aging markers similar to those found in T cells from elderly subjects. Intrinsic T-cell defects were caused by increased expression of dual-specific phosphatase 4 (DUSP4). Normalization of DUSP4 expression using a specific siRNA improved CD4(+) T-cell activity in ICL, as this restored TCR-induced extracellular signal-regulated kinase activation and increased the expression of the costimulatory molecules CD27 and CD40L. Conversely, repeated TCR stimulation led to defective signaling and DUSP4 overexpression in control CD4(+) T cells. This was associated with gradual acquisition of a memory phenotype and was curtailed by DUSP4 silencing. These findings identify a premature T-cell senescence in ICL that might be caused by chronic T-cell activation and a consequential DUSP4-dependent dampening of TCR signaling.

Mononuclear phagocyte-mediated antifungal immunity: the role of chemotactic receptors and ligands

Over the past two decades, fungal infections have emerged as significant causes of morbidity and mortality in patients with hematological malignancies, hematopoietic stem cell or solid organ transplantation and acquired immunodeficiency syndrome. Besides neutrophils and CD4(+) T lymphocytes, which have long been known to play an indispensable role in promoting protective antifungal immunity, mononuclear phagocytes are now being increasingly recognized as critical mediators of host defense against fungi. Thus, a recent surge of research studies has focused on understanding the mechanisms by which resident and recruited monocytes, macrophages and dendritic cells accumulate and become activated at the sites of fungal infection. Herein, we critically review how a variety of G-protein coupled chemoattractant receptors and their ligands mediate mononuclear phagocyte recruitment and effector function during infection by the most common human fungal pathogens.

The spectrum of opportunistic diseases complicating sarcoidosis

Sarcoidosis is an inflammatory disease marked by a paradoxical immune status. The anergic state, which results from various immune defects, contrasts with the inflammatory formation of granulomas. Sarcoidosis patients may be at risk for opportunistic infections (OIs) and a substantial number of cases have been reported, even in untreated sarcoidosis. It is not clear how OIs in patients with sarcoidosis are different from other groups at risk. In this review, we discuss the most common OIs: mycobacterial infection (including tuberculosis), cryptococcosis, progressive multifocal leukoencephalopathy, and aspergillosis. Unlike peripheral lymphocytopenia, corticosteroids are a major risk factor for OIs but the occurrence of Ols in untreated patients suggests more complex predisposing mechanisms. Opportunistic infections presenting with extrapulmonary features are often misdiagnosed as new localizations of sarcoidosis. Aspergillomas mostly develop on fibrocystic lungs. Overall, physicians should be aware of the possible occurrence of OIs during sarcoidosis, even in untreated patients.

Severe Pneumocystis jirovecii pneumonia in an idiopathic CD4+ lymphocytopenia patient: case report and review of the literature

INTRODUCTION

When diagnosing Pneumocystis jirovecii pneumonia (PJP), the clinical suspicion must be confirmed by laboratory tests. PJP is rarely described in patients with idiopathic CD4⁺ lymphocytopenia (ICL), a rare T-cell deficiency of unknown origin with persistently low levels of CD4⁺ T-cells (<300 µl^-1 or <20 % of total lymphocytes) but repeated negative human immunodeficiency virus (HIV) tests. We retrospectively analysed a case of an ICL patient with severe PJP associated with multiple opportunistic infections (OIs). We also reviewed the literature since 1986.

CASE PRESENTATION

A laboratory-confirmed case of PJP associated with invasive candidiasis and cytomegalovirus infection was reported in an ICL patient. Despite early treatment, the patient died of respiratory failure under polymicrobial pneumonia. According to the literature, the mortality rate of ICL patients is 10.4 % (33/316). In ICL patients, the risk of OI is 83.2 % (263/316), with viral infections being the most prevalent (58.2 %, 184/316), followed by fungal infections (52.2 %, 165/316) and mycobacterial infections (15.5 %, 49/316). Dysimmunity is reported in 15.5 % (49/316) of ICL patients. Among the fungal infections, cryptococcal infections are the most prevalent (24.1 %, 76/316), followed by candidiasis (15.5 %, 49/316) and PJP (7.9 %, 25/316).

CONCLUSIONS

The high risk of OIs underlines the importance of more vigorous preventative actions in hospitals. The response to therapy and the detection of early relapse of PJP may be monitored by several laboratory tests including quantitative PCR. It is essential to treat the ICL and to follow the guidelines concerning therapy and prophylaxis of OIs as given to HIV patients.

Cryptococcus neoformans meningoencephalitis in a patient with polyarteritis nodosa

Case of 59-year-old male with chronic obstructive pulmonary disease and a number of comorbidities, who has developed meningoencephalitis caused by Cryptococcus neoformans var. grubii with polyarteritis nodosa diagnosed during hospitalization, was presented. Before evidence of meningoencephalitis, the patient was being treated with ketoconazole and low doses of fluconazole (200 mg/day) for alleged candidiasis. The dosage was increased (800 mg/day) following laboratory diagnosis of C. neoformans based on positive latex agglutination test and biochemical identification of encapsulated yeast isolated from the blood and CSF. Later, the yeast identification was confirmed by sequencing analysis. Owing to inadequate clinical response, fluconazole therapy was switched to voriconazole (400 mg/day) and later to intravenous amphotericin B (1.0 mg/kg per day). Despite of a temporary stabilization and improvement, which correlated with decline of cryptococcal antigen titers (from 1:1024 to 1:8), after 6 weeks, the patient's underlying condition deteriorated due to severe pancolitis and serious nosocomial bacterial infections. The patient died of multiorgan failure several days later. Our case demonstrates a possible connection between the development of life-threatening cryptococcosis and an autoimmune vasculitis disease and emphasizes that the outcome of the management of cryptococcal meningoencephalitis is highly dependent on early diagnosis, adequate treatment, including dosage, and last but not least control of underlying disease and risk factors.

Cytokine immunomodulation for the treatment of infectious diseases: lessons from primary immunodeficiencies

Traditionally, management of infectious diseases focuses on identification of the causative microbe and the use of pathogen-targeted therapy. With increasing antimicrobial resistance, novel approaches are required. One strategy is to modulate those natural host immune responses that critically mediate resistance to specific microbes. Clinically, this host-directed tactic could be used either alone or in combination with antimicrobial therapy. While conceptually attractive, there is potential concern that the pathways governing host resistance to pathogens in animal models may not extrapolate linearly to humans. Targeting these immune processes clinically may precipitate damaging, epiphenomenal responses. The field of Primary Immunodeficiencies focuses on the characterization of humans with inborn errors of immunity. These rare conditions permit the identification of those molecular and cellular processes that are central to human susceptibility to microbes. In efforts to compensate for defective host responses, this field has also provided a wealth of clinical experience in the effective use of cytokines to treat various active infections, while demonstrating their safety. In this review, we provide a historical perspective of the treatment of infectious diseases, evolving from a focus on the microbe, to an understanding of human immunity; we then outline the growing contribution of Primary Immunodeficiencies to the rational use of adjunctive cytokine immunotherapy in the management of infections.

Idiopathic CD4 lymphocytopenia: clinical and immunologic characteristics and follow-up of 40 patients

Idiopathic CD4 T lymphocytopenia (ICL) is a rare and severe condition with limited available data. We conducted a French multicenter study to analyze the clinical and immunologic characteristics of a cohort of patients with ICL according to the Centers for Disease Control criteria.We recruited 40 patients (24 female) of mean age 44.2 ± 12.2 (19-70) years. Patients underwent T-lymphocyte phenotyping and lymphoproliferation assay at diagnosis, and experiments related to thymic function and interferon (IFN)-γ release by natural killer (NK) cell were performed. Mean follow-up was 6.9 ± 6.7 (0.14-24.3) years. Infectious, autoimmune, and neoplastic events were recorded, as were outcomes of interleukin 2 therapy.In all, 25 patients had opportunistic infections (12 with human papillomavirus infection), 14 had autoimmune symptoms, 5 had malignancies, and 8 had mild or no symptoms. At the time of diagnosis, the mean cell counts were as follows: mean CD4 cell count: 127/mm (range, 4-294); mean CD8: 236/mm (range, 1-1293); mean CD19: 113/mm (range, 3-547); and mean NK cell count: 122/mm (range, 5-416). Most patients had deficiency in CD8, CD19, and/or NK cells. Cytotoxic function of NK cells was normal, and patients with infections had a significantly lower NK cell count than those without (p = 0.01). Patients with autoimmune manifestations had increased CD8 T-cell count. Proliferation of thymic precursors, as assessed by T-cell rearrangement excision circles, was increased. Six patients died (15%). CD4 T-cell count <150/mm and NK cell count <100/mm were predictors of death.In conclusion, ICL is a heterogeneous disorder often associated with deficiencies in CD8, CD19, and/or NK cells. Long-term prognosis may be related to initial CD4 and NK cell deficiency.

Primary immunodeficiencies underlying fungal infections

PURPOSE OF REVIEW

We review the primary immunodeficiencies (PIDs) underlying an increasing variety of superficial and invasive fungal infections. We also stress that the occurrence of such fungal infections should lead physicians to search for the corresponding single-gene inborn errors of immunity. Finally, we suggest that other fungal infections may also result from hitherto unknown inborn errors of immunity, at least in some patients with no known risk factors.

RECENT FINDINGS

An increasing number of PIDs are being shown to underlie fungal infectious diseases in children and young adults. Inborn errors of the phagocyte NADPH oxidase complex (chronic granulomatous disease), severe congenital neutropenia (SCN) and leukocyte adhesion deficiency type I confer a predisposition to invasive aspergillosis and candidiasis. More rarely, inborn errors of interferon-γ immunity underlie endemic mycoses. Inborn errors of interleukin-17 immunity have recently been shown to underlie chronic mucocutaneous candidiasis (CMC), while inborn errors of caspase recruitment domain-containing protein 9 (CARD9) immunity underlie deep dermatophytosis and invasive candidiasis.

SUMMARY

CMC, invasive candidiasis, invasive aspergillosis, deep dermatophytosis, pneumocystosis, and endemic mycoses can all be caused by PIDs. Each type of infection is highly suggestive of a specific type of PID. In the absence of overt risk factors, single-gene inborn errors of immunity should be sought in children and young adults with these and other fungal diseases.

Idiopathic CD4 Lymphocytopenia: Spectrum of opportunistic infections, malignancies, and autoimmune diseases

Idiopathic CD4 lymphocytopenia (ICL) was first defined in 1992 by the US Centers for Disease Control and Prevention (CDC) as the repeated presence of a CD4+ T lymphocyte count of fewer than 300 cells per cubic millimeter or of less than 20% of total T cells with no evidence of human immunodeficiency virus (HIV) infection and no condition that might cause depressed CD4 counts. Most of our knowledge about ICL comes from scattered case reports. The aim of this study was to collect comprehensive data from the previously published cases to understand the characteristics of this rare condition. We searched the PubMed database and Science Direct for case reports since 1989 for Idiopathic CD4 lymphocytopenia cases. We found 258 cases diagnosed with ICL in 143 published papers. We collected data about age, sex, pathogens, site of infections, CD4 count, CD8 count, CD4:CD8 ratio, presence of HIV risk factors, malignancies, autoimmune diseases and whether the patients survived or died. The mean age at diagnosis of first opportunistic infection (or ICL if no opportunistic infection reported) was 40.7 ± 19.2 years (standard deviation), with a range of 1 to 85. One-sixty (62%) patients were males, 91 (35.2%) were females, and 7 (2.7%) patients were not identified whether males or females. Risk factors for HIV were documented in 36 (13.9%) patients. The mean initial CD4 count was 142.6 ± 103.9/mm³ (standard deviation). The mean initial CD8 count was 295 ± 273.6/mm³ (standard deviation). The mean initial CD4:CD8 ratio was 0.6 ± 0.7 (standard deviation). The mean lowest CD4 count was 115.4 ± 87.1/mm³ (standard deviation). The majority of patients 226 (87.6%) had at least one infection. Cryptococcal infections were the most prevalent infections in ICL patients (26.6%), followed by mycobacterial infections (17%), candidal infections (16.2%), and VZV infections (13.1%). Malignancies were reported in 47 (18.1%) patients. Autoimmune diseases were reported in 37 (14.2%) patients.