Background By 27 June 2020, almost half a million people had died due to COVID-19 infections. The susceptibility and severity of infection vary significantly across nations. The contribution of chronic viral and parasitic infections to immune homeostasis remains a concern. By investigating the role of interferon (IFN)-γ, we conducted this study to understand the connection between the decrease in numbers and severity of COVID-19 cases within parasitic endemic regions. Our research included 375 patients referred to hospitals for diagnosis of COVID-19 infection. Patients were subjected to full investigations, in particular severe acute respiratory syndrome coronavirus-2 nucleic acid and Toxoplasma IgM and IgG antibody detection, stool examination, and quantitative IFN-γ measurement. Results The majority of the studied cases had chest manifestation either alone (54.7%) or in association with gastrointestinal (GIT) manifestations (19.7%), whereas 25.6% had GIT symptoms. We reported parasitic infections in 72.8% of mild COVID-19 cases and 20.7% of severe cases. Toxoplasma gondii, Cryptosporidium, Blastocyst, and Giardia were the most common parasitic infections among the COVID-19 cases studied. Conclusion The remarkable adaptation of human immune response to COVID-19 infection by parasitic infections with high levels of IFN-γ was observed in moderate cases compared with low levels in extreme cases. The potential therapeutic efforts aimed at the role of parasitic infection in immune system modulation are needed if this hypothesis is confirmed.

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Background:The prevalence of pulmonary arterial hypertension (PAH) in Saudi adults with sickle cell disease (SCD), the mechanism of its development, and its prospective prognostic significance are unknown.Objective:To assess the prevalence of PAH among sickle cell disease patients attended hematology outpatient clinic at King Fahad Hospital, Al Hassa, Saudi Arabia.Methods:Doppler echocardiography was performed for assessments of pulmonary- arterial systolic pressure (PASP) on 203 consecutive patients (102 men and 101 women) aged > 11 years, attending hematology clinic at King Fahad Hospital, Al Hassa, Saudi Arabia. Pulmonary hypertension was prospectively defined as a tricuspid regurgitant jet velocity (TRJV) of at least 2.5 m per second which can be estimate PASP equal or more than 25 mmHg.Results:Doppler-defined pulmonary arterial hypertension was diagnosed in 37.1% among 202 patients included in study (after one female patient was excluded) using a cutoff of PASP ≥25 mmHg.Conclusion:The prevalence of PAH among adults Saudis with SCD is higher than that reported from the developed countries. Further assessment using invasive techniques is required coupled employing analytical study design to predict the factors that favor the development of PAH among Saudi patients are required.