Disseminated Cryptococcosis with Marked Eosinophilia in a Postpartum Woman

The Th2 Response and Alternative Activation of Macrophages Triggered by Strongyloides venezuelensis Is Linked to Increased Morbidity and Mortality Due to Cryptococcosis in Mice

Cryptococcosis is a systemic mycosis that causes pneumonia and meningoencephalitis. Strongyloidiasis is a chronic gastrointestinal infection caused by parasites of the genus Strongyloides. Cryptococcosis and strongyloidiasis affect the lungs and are more prevalent in the same world regions, i.e., Africa and tropical countries such as Brazil. It is undeniable that those coincidences may lead to the occurrence of coinfections. However, there are no studies focused on the interaction between Cryptococcus spp. and Strongyloides spp. In this work, we aimed to investigate the interaction between Strongyloides venezuelensis (Sv) and Cryptococcus gattii (Cg) in a murine coinfection model. Murine macrophage exposure to Sv antigens reduced their ability to engulf Cg and produce reactive oxygen species, increasing the ability of fungal growth intracellularly. We then infected mice with both pathogens. Sv infection skewed the host's response to fungal infection, increasing lethality in a murine coinfection model. In addition to increased NO levels and arginase activity, coinfected mice presented a classic Th2 anti-Sv response: eosinophilia, higher levels of alternate activated macrophages (M2), increased concentrations of CCL24 and IL-4, and lower levels of IL-1β. This milieu favored fungal growth in the lungs with prominent translocation to the brain, increasing the host's tissue damage. In conclusion, our data shows that primary Sv infection promotes Th2 bias of the pulmonary response to Cg-infection and worsens its pathological outcomes.

Cryptococcal Neoformans and Varicella Zoster Meningitis in a Patient With Selective Innate Immunodeficiency: A Case Report

Cryptococcal neoformans (C. neoformans) and varicella-zoster (VZV) meningitis are opportunistic infections that are primarily seen in immunocompromised patients, including those with HIV, cancer, or receiving transplants. Despite treatment, infection in immunocompromised patients can be lethal, including those with T-cell dysfunction or deficiency. Whether innate immunodeficiencies also predispose to these infections remains less clear. Here, we report a case of disseminated C. neoformans and VZV meningitis in a young male with idiopathic hypereosinophilic syndrome and hypocomplementemia and no history of HIV infection, malignancy, or transplant. The patient presented with a pulsating headache, myalgia, joint pain, insomnia, night sweats, and subjective fever, along with clusters of vesicular lesions on his neck and back. A lumbar puncture and an MRI of the brain confirmed C. neoformans and VZV meningitis. Vesicular skin lesions proved to be VZV, and blood culture confirmed fungemia, suggesting disseminated disease. We investigated his medical history further to determine the underlying cause of his prior hypereosinophilia and current meningitis. The patient had idiopathic hypereosinophilia with high IgE levels, low complement levels, high rheumatoid factor levels, and an intermittent rash dating back two years, which had been treated intermittently with prednisone and hydroxyurea, with the most recent admission three weeks prior to this admission. Prior to admission, the patient had a peak absolute eosinophil count of 18.6 x10³/uL. The patient was discharged on a daily dose of 60 mg of prednisone without hydroxyurea. In further evaluating his immune status, we found he was HIV-negative, with a normal CD4 count and high IgE. We also tested lymphocyte subsets and proliferation, which showed a low CD16/56 level, suggesting possibly reduced natural killer (NK) cell quantity. The patient responded well to acyclovir, amphotericin, and flucytosine therapy. After follow-up cerebrospinal fluid (CSF) and blood cultures were negative, the patient was discharged with fluconazole as maintenance therapy.

Pregnancy-Related Tuberculous Meningitis and Immune Reconstitution Inflammatory Syndrome: A Case Series and Systematic Review

Background

Tuberculosis is a leading cause of death among women of reproductive age. However, tuberculous meningitis, the most severe form of extrapulmonary tuberculosis, is rarely discussed in pregnancy despite this being a unique period of immune modulation that may predispose women to active disease.

Methods

We identified and described cases of tuberculous meningitis among pregnant or postpartum women screened during meningitis clinical trials in Uganda from 2018 to 2022. We conducted a systematic literature review via PubMed/Medline and Embase for all English-language publications from 1970 to 10 July 2022, to identify additional cases.

Results

We identified 8 cases of pregnancy-related tuberculous meningitis in Ugandan women living with human immunodeficiency virus (HIV) and 40 additional cases via systematic literature review (none HIV-positive). Of all combined cases, 50% (24/48) were diagnosed postpartum; 50% (24/48) had initial onset during pregnancy, of which 38% (9/24) had worsening of symptoms or disease relapse following pregnancy cessation. Diagnosis was missed or delayed in 33% (16/48) of cases. For those with known outcomes, maternal mortality was 23% (11/48) and fetal/neonatal mortality was 30% (13/44). Of maternal survivors, 30% (11/37) had residual neurologic deficits.

Conclusions

The true incidence of tuberculous meningitis in pregnancy or the postpartum period is unclear but likely underappreciated. To date, nearly all published cases have occurred in HIV-negative or otherwise immunocompetent women. Given the well-described physiological immunosuppression during pregnancy and subsequent reconstitution postpartum, physicians must be aware of tuberculous meningitis and pregnancy-related immune reconstitution inflammatory syndrome, especially in countries with a high burden of tuberculosis and in women living with HIV.

Eosinophilic lung disease as a sequela of MSSA pneumonia

Eosinophilic lung diseases are a rare group of lung disorders with multiple known and unknown aetiologies and the diagnosis is often challenging. We present a case of a young man who was admitted with pneumonia due to methicillin-sensitive Staphylococcus aureus and was discharged on antibiotics. He presented to the emergency department approximately 2 weeks after discharge with high-grade fever, cough and shortness of breath associated with serum and bronchoalveolar lavage eosinophilia. He was then treated with steroids with complete resolution of disease process.

Animal Models of Cryptococcus neoformans in Identifying Immune Parameters Associated With Primary Infection and Reactivation of Latent Infection

Cryptococcus species are environmental fungal pathogens and the causative agents of cryptococcosis. Infection occurs upon inhalation of infectious particles, which proliferate in the lung causing a primary infection. From this primary lung infection, fungal cells can eventually disseminate to other organs, particularly the brain, causing lethal meningoencephalitis. However, in most cases, the primary infection resolves with the formation of a lung granuloma. Upon severe immunodeficiency, dormant cryptococcal cells will start proliferating in the lung granuloma and eventually will disseminate to the brain. Many investigators have sought to study the protective host immune response to this pathogen in search of host parameters that keep the proliferation of cryptococcal cells under control. The majority of the work assimilates research carried out using the primary infection animal model, mainly because a reactivation model has been available only very recently. This review will focus on anti-cryptococcal immunity in both the primary and reactivation models. An understanding of the differences in host immunity between the primary and reactivation models will help to define the key host parameters that control the infections and are important for the research and development of new therapeutic and vaccine strategies against cryptococcosis.

Eosinophilie bei pulmonalen Infektionen

Neben Allergien, Autoimmunerkrankungen, Vaskulitiden, Dermatosen, Malignomen und Medikamentennebenwirkungen können sowohl parasitäre als auch nichtparasitäre Infektionen Ursachen für eine Eosinophilie sein. Bei Tropenrückkehrern stellen parasitäre Infektionen die häufigste Ursache für eine Eosinophilie dar. Dabei kann das jeweilige Ausmaß der Eosinophilie Rückschlüsse auf die Art des Erregers liefern. Zur Abklärung der Eosinophilie nach Tropenaufenthalt sollten primär dreimalige Stuhluntersuchungen auf Wurmeier und zusätzlich ggf. Serologien bezüglich Helminthen veranlasst werden. Komplettiert wird die Diagnostik durch eine Thorax-Röntgenaufnahme, eine Sonographie des Oberbauchs und ein Elektrokardiogramm (EKG). In den letzten Jahren werden in spezialisierten Laboren molekulare Techniken (Multiplex-Polymerasekettenreaktion, PCR) für die Diagnostik von Wurmeiern und intestinalen Parasiten im Stuhl eingesetzt, die eine deutlich höhere Sensitivität als die klassischen Stuhlnachweismethoden haben. Nichtparasitäre Infektionen, die zu einer relevanten Blut- oder lediglich pulmonalen Eosinophilie (bronchoalveoläre Lavage, BAL) führen, umfassen die Kryptokokkose sowie endemische Systemmykosen (Kokzidioidomykose, sehr selten bei Histoplasmose) und Schimmelpilzinfektionen (Aspergillus fumigatus, Mucor spp.).

Eosinophils from Physiology to Disease: A Comprehensive Review

Despite being the second least represented granulocyte subpopulation in the circulating blood, eosinophils are receiving a growing interest from the scientific community, due to their complex pathophysiological role in a broad range of local and systemic inflammatory diseases as well as in cancer and thrombosis. Eosinophils are crucial for the control of parasitic infections, but increasing evidence suggests that they are also involved in vital defensive tasks against bacterial and viral pathogens including HIV. On the other side of the coin, eosinophil potential to provide a strong defensive response against invading microbes through the release of a large array of compounds can prove toxic to the host tissues and dysregulate haemostasis. Increasing knowledge of eosinophil biological behaviour is leading to major changes in established paradigms for the classification and diagnosis of several allergic and autoimmune diseases and has paved the way to a "golden age" of eosinophil-targeted agents. In this review, we provide a comprehensive update on the pathophysiological role of eosinophils in host defence, inflammation, and cancer and discuss potential clinical implications in light of recent therapeutic advances.