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.

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.

Disseminated Cryptococcosis with Marked Eosinophilia in a Postpartum Woman

Disseminated cryptococcosis usually develops in immunosuppressed patients. A 33-year-old postpartum woman developed disseminated cryptococcosis with marked eosinophilia. She presented with a cough and a week-long fever. A computed tomography scan showed multiple pulmonary nodules randomly distributed. Eosinophils were observed to have increased in number in both her peripheral blood and bronchoalveolar lavage fluid. A transbronchial lung biopsy and cerebrospinal fluid specimens revealed findings consistent with cryptococcal infection. Disseminated cryptococcosis can present with marked eosinophilia of the peripheral blood and lung tissues. Additionally, the postpartum immune status may sometimes be involved in the development of opportunistic infections in previously healthy women.

Clinical characteristics of disseminated cryptococcosis in previously healthy children in China

Background

Disseminated cryptococcosis is a rare and fatal disease, and limited data exist regarding it in children. This study aimed to investigate the clinical characteristics of disseminated cryptococcosis in previously healthy children in China.

Methods

Hospitalized patients with disseminated cryptococcosis were enrolled during January 1996 to December 2015 in Beijing Children’s Hospital, Capital Medical University, China. Data on clinical manifestations, laboratory tests, treatment, and prognosis were evaluated.

Results

A total of 52 pediatric patients with no underlying disease were enrolled, including 38 boys and 14 girls. Only 10 cases had a history of exposure to pigeon droppings. Fever, cough, and hepatomegaly were 3 main manifestations of disseminated cryptococcosis. However, headache was more common in patients with central nervous system (CNS) invasion than in patients with non-CNS invasion (P < 0.05). Lung (96.2%, 50/52) was the most commonly invaded organ, but only 9.6% (5/52) of patients had respiratory signs. The most common findings on chest imaging were hilar or mediastinal lymphadenopathy (46.8%, 22/47), and nodules (44.7%, 21/47), including small nodules in a scattered distribution (57.1%, 12/21) or miliary distribution (42.9%, 9/25), especially localized in subpleural area. Subsequent invasion occurred in the CNS, abdomen lymph nodes, liver, spleen, peripheral lymph nodes, and skin. In all patients, 42.3% (22/52) and 51.9% (27/52) had elevated eosinophils or IgE, respectively. The positive rate of serum cryptococcal antigen was higher, especially in patients with CNS invasion (approximately 83.3%), than with other primary methods used for pathogen detection, including cerebrospinal fluid (CSF) cryptococcal antigen, cultures of blood, bone marrow, or CSF, and CSF ink staining. The overall mortality rate of pediatric patients in our study was 11.5% (6/52). Some cases had long-term sequela, including hydrocephalus, cirrhosis, or blindness.

Conclusions

Disseminated cryptococcosis can occur in previously healthy or immunocompetent children in China. Lung and CNS were most commonly invaded by this disease. Furthermore, most cases usually showed no obvious or specific symptoms or signs, and therefore pediatricians should pay more careful attention to identify this disease.

Collagenase digestion down-regulates the density of CD27 on lymphocytes

Collagenases are widely used for tissue digestion in experiments due to their potent hydrolysis of connective tissue. CD27, also known as tumor necrosis factor receptor superfamily 7 (TNFRSF7), is limited to be expressed on the cells of the lymphoid lineage. In our preliminary research, we found that CD27 on NK cells was almost disappeared with the digestion of type I collagenase for 90min. This phenomenon suggests that the process of tissue digestion may affect the density of CD27 on cells. In order to verify this, the lungs of mice were digested with types I and IV collagenase or grinded, respectively. The percentage of CD27(+) cells and the density of CD27 on cells were assayed by flow cytometry. The data presented that the percentage of CD27(+) cells and the density of CD27 on lymphocytes gradually decreased with the time of digestion with type I or IV collagenase. We also detected that the density of CD11b on NK cells was not affected by collagenase digestion. Collectively, the findings of the present study suggest that the collagenase digestion has a selective effect on the density of molecules on cells.