Pneumocystis spp. in Pigs: A Longitudinal Quantitative Study and Co-Infection Assessment in Austrian Farms

While Pneumocystis has been recognized as both a ubiquitous commensal fungus in immunocompetent mammalian hosts and a major opportunistic pathogen in humans responsible for severe pneumonias in immunocompromised patients, in pigs its epidemiology and association with pulmonary diseases have been rarely reported. Nevertheless, the fungus can be quite abundant in porcine populations with up to 51% of prevalence reported so far. The current study was undertaken to longitudinally quantify Pneumocystis carinii f. sp. suis and other pulmonary pathogens in a cohort of 50 pigs from five Austrian farms (i.e., 10 pigs per farm) with a history of respiratory disease at five time points between the first week and the fourth month of life. The fungus was present as early as the suckling period (16% and 26% of the animals in the first and the third week, respectively), yet not in a high amount. Over time, both the organism load (highest 4.4 × 105 copies/mL) and prevalence (up to 88% of positive animals in the third month) increased in each farm. The relative prevalence of various coinfection patterns was significantly different over time. The current study unravelled a complex co-infection history involving Pneumocystis and other pulmonary pathogens in pigs, suggesting a relevant role of the fungus in the respiratory disease scenario of this host.

Additional C-type lectin receptors mediate interactions with Pneumocystis organisms and major surface glycoprotein

Introduction. Pathogen-associated molecular patterns’ (PAMPs) are microbial signatures that are recognized by host myeloid C-type lectin receptors (CLRs). These CLRs interact with micro-organisms via their carbohydrate recognition domains (CRDs) and engage signalling pathways within the cell resulting in pro-inflammatory and microbicidal responses. Gap statement. In this article, we extend our laboratory study of additional CLRs that recognize fungal ligands against Pneumocystis murina and Pneumocystis carinii and their purified major surface glycoproteins (Msgs). Aim. To study the potential of newly synthesized hFc-CLR fusions on binding to Pneumocystis and its Msg. Methods. A library of new synthesized hFc-CLR fusions was screened against Pneumocystis murina and Pneumocystis carinii organisms and their purified major surface glycoproteins (Msgs) found on the respective fungi via modified ELISA. Immunofluorescence assay (IFA) was implemented and quantified to verify results. mRNA expression analysis by quantitative PCR (q-PCR) was employed to detect respective CLRs found to bind fungal organisms in the ELISA and determine their expression levels in the mouse immunosuppressed Pneumocystis pneumonia (PCP) model. Results. We detected a number of the CLR hFc-fusions displayed significant binding with P. murina and P. carinii organisms, and similarly to their respective Msgs. Significant organism and Msg binding was observed for CLR members C-type lectin domain family 12 member A (CLEC12A), Langerin, macrophage galactose-type lectin-1 (MGL-1), and specific intracellular adhesion molecule-3 grabbing non-integrin homologue-related 3 (SIGNR3). Immunofluorescence assay (IFA) with the respective CLR hFc-fusions against whole P. murina life forms corroborated these findings. Lastly, we surveyed the mRNA expression profiles of the respective CLRs tested above in the mouse immunosuppressed Pneumocystis pneumonia (PCP) model and determined that macrophage galactose type C-type lectin (Mgl-1), implicated in recognizing terminal N-acetylgalactosamine (GalNAc) found in the glycoproteins of microbial pathogens was significantly up-regulated during infection. Conclusion. The data herein add to the growing list of CLRs recognizing Pneumocystis and provide insights for further study of organism/host immune cell interactions.

Gene Expression in Lung Epithelial Cells Following Interaction with Pneumocystis carinii and its Specific Life Forms Yields Insights into Host Gene Responses to Infection

Pneumocystis spp. interacts with epithelial cells in the alveolar spaces of the lung. It is thought that the binding of Pneumocystis to host cell epithelium is needed for life cycle completion and proliferation. The effect of this interaction on lung epithelial cells have previously shown that the trophic form of this organism greatly inhibits p34cdc2 activity, a serine/threonine kinase required for transition from G2 to M phase in the cell cycle. To gain further insight into the host response during Pneumocystis pneumonia (PCP), we used microarray technology to profile epithelial cell (A549) gene expression patterns following Pneumocystis carinii interaction. Furthermore, we isolated separate populations of cyst and trophic forms of P. carinii, which were then applied to the lung epithelial cells. Differential expression of genes involved in various cellular functions dependent on the specific P. carinii life form in contact with the A549 cell were identified. The reliability of our data was further confirmed by Northern blot analysis on a number of selected up or down regulated transcripts. The transcriptional response to P. carinii was dominated by cytokines, apoptotic, and anti-apoptotic related genes. These results reveal several previously unknown effects of P. carinii on the lung epithelial cell and provide insight into the complex interactions of host and pathogen.

Headache, Uveitis, and Leptomeningeal Enhancement

A 35-year-old man sought care for a severe, acute-onset, pounding, bifrontal headache, photopsias, and nausea for 1 day. Initially, bilateral red eyes developed, and within 24 hours he had central blurred vision problems in the left eye. He reported that objects had a yellow tint with the left eye and looked “wavy” supranasally. An emergent evaluation documented bilateral red eyes, and an initial diagnosis of bilateral panuveitis was given. By 48 hours after symptom onset, he started vomiting. He also was feeling feverish and off-balance. He reported no tinnitus or hearing loss, any change in color of his eyelashes or eyebrows, alopecia, poliosis, or cognitive difficulties. An initial work-up for infectious processes was negative. Given the patient’s ethnic background, including Chinese, Japanese, and Filipino origin, and typical findings of uveomeningitis, he was diagnosed with probable Vogt-Koyanagi-Harada syndrome. There is no specific diagnostic test for this entity, and the diagnosis remains reliant on a combined interpretation of clinical and ancillary testing. The patient was kept on oral prednisone daily, and azathioprine was initiated, as well as prophylaxis against Pneumocystis carinii pneumonia and gastrointestinal tract hemorrhage. During the tapering phase of prednisone, liver function test abnormalities were found, so azathioprine was discontinued. At 1-year follow-up, he had some mild skin flaking and weight gain from the corticosteroid therapy but no other symptoms, despite having discontinued azathioprine for 3 months. He continued to taper off prednisone. He had development of bilateral hip pain; imaging showed bilateral aseptic hip necrosis. A decision was made to initiate tumor necrosis factor (TNF)-α‎ inhibitors. He lost all the weight gained and recovered from the aseptic necrosis of the hip to be able to continue running. The final diagnosis was recurrent Vogt-Koyanagi-Harada syndrome. Vogt-Koyanagi-Harada syndrome is an idiopathic inflammatory disease with panuveitis and neurologic involvement in the form of aseptic meningitis and/or hearing loss. Although the full spectrum of the disorder may involve many skin changes and additional findings, most patients have incomplete disease because they are urgently treated with corticosteroids and the disorder is steroid responsive.

The Role of Lactate Dehydrogenase (LDH) Compared to Arterial Blood Gases (ABG) in Diagnosing Pneumocystis Carinii Pneumonia (PCP) in HIV/AIDS Patients on Routine Antiretroviral Therapy

Background: The lungs are one of the primary target organs for HIV disease and a major source of morbidity and mortality, among others, caused by Pneumocystis carinii pneumonia (PCP) or recurrent bacterial pneumonia. In developing countries, the incidence of PCP infection has soared, with high mortality rates ranging from 20% to 80%. The increase in serum LDH plays an important role in determining the severity of the disease. This study aims to determine the role of LDH examination as a diagnostic tool for PCP and Arterial Blood Gases (ABG) in HIV and AIDS patients. Method: This research is an analytical study using an observational diagnostic test design, conducted from November 2020-January 2021 at the HIV Treatment Room at H. Adam Malik Hospital, Medan with 158 subjects. We calculate the value of sensitivity, specificity, positive predictive value, and negative predictive value. Results: 75.3% of the total sample was male, with the highest age group being 30-39 years old (46.2%) 126 samples (79.7%) had CD4 levels 200 cells/mm3, 98 samples (62%) had LDH levels > 500 U/L. In this study, 113 samples (71.5%) fell into the ABG criteria [PaO2] <70 mmHg). LDH has superior sensitivity and specificity value compared to ABG examination. In this case PaO2 or A-A DO2 in diagnosing PCP in HIV-AIDS patients. Conclusion: LDH examination combined with clinical and radiological examinations has good sensitivity and specificity in the diagnosis of PCP. Keywords: HIV, AIDS, Lactate dehydrogenase, PCP.

First case of low-dose umbilical cord blood therapy for pediatric acute respiratory distress syndrome induced by Pneumocystis carinii pneumonia

Objective This study aimed to present the case of a boy with acute distress syndrome (ARDS) treated with low-dose umbilical cord blood (UCB) therapy and explore the underlying possible mechanism. Methods A 7-year-old boy with severe Pneumocystis carinii pneumonia and severe ARDS was treated with allogeneic UCB as salvage therapy. Results The patient did not improve after being treated with lung protective ventilation, pulmonary surfactant replacement, and extracorporeal membrane oxygenation (ECMO) for 30 days. However, his disease reversed 5 days after allogeneic UCB infusion, and he weaned from ECMO after 7 days of infusion. Bioinformatics confirmed that his Toll-like receptor (TLR) was abnormal before UCB infusion. However, after the infusion, his immune system was activated and repaired, and the TLR4/MyD88/NF-κB signaling pathway was recovered. Conclusion Allogenic UCB could treat ARDS by repairing the TLR4/MyD88/NF-κB signaling pathway, thereby achieving stability of the immune system.

Clinical Analysis of 15 Cases of Non-Hodgkin Lymphoma Complicated with Pneumocystis carinii Pneumonia Treated with R-CHOP Regimen

Objective: To investigate the clinical features of R-CHOP regimen in the treatment of non-Hodgkin’s lymphoma with Pneumocystis carinii pneumonia (PCP) in order to improve the understanding of PCP and the side effects of Rituxan. Methods: A retrospective analysis of 90 patients with non-Hodgkin’s lymphoma treated with R-CHOP chemotherapy in our hospital from November 2015 to November 2020, of which 15 (16.7%) patients, combined with PCP clinical data, including clinical symptoms, physical signs, chest imaging examination and treatment data were used for to analysis and summarization. Results: The clinical features of R-CHOP chemotherapy combined with PCP were fever, cough, and sputum. Some patients had fewer clinical symptoms. Common imaging manifestations were double lung membrane glass shadow, patchy shadow, and flocculent shadow. It can occur in all clinical stages, and the incidence of late stage is high, and there is no clear correlation with bone marrow suppression. Pneumocystis was found in 2 cases of sputum, and the rest of the patients were clinically diagnosed. The main therapeutic drugs are sulfamethoxazole (8/15), compound sulfamethoxazole (6/15), clindamycin (1/15, sulfa drug allergy), and adrenal cortex hormones (4/15). Fourteen cases were cured and 1 case died. Conclusion: The incidence of R-CHOP in advanced non-Hodgkin’s lymphoma of PCP is high. Patients with clinical use of R-CHOP chemotherapy will encounter fever, cough, chest computed tomography (CT) film glass shadow, and diffuse patch shadow. Patients should be alert to the possibility of PCP and take sulfonamides as soon as possible for medical treatment.