Central and effector memory T cells in peripheral blood of patients with interstitial pneumonia: preliminary clues from a COVID-19 study.

BACKGROUND: SARS-CoV-2 pre-existing T-cell immune reactivity can be present in some people. A general perturbation of the main peripheral lymphocyte subsets has been described in severe COVID-19 patients, but very few studies assessed the general memory T-cell homeostasis in the acute phase of COVID-19. Here, we performed a general analysis of the main memory T cell populations in the peripheral blood of patients admitted to the hospital for a confirmed or probable COVID-19 diagnosis. METHODS: In this cross-sectional study, adult patients (aged ≥ 18 years) needing hospital admission for respiratory disease due to confirmed or probable COVID-19, were recruited before starting the therapeutic protocol for this disease. In addition to the assessment of the general lymphocyte subpopulations in the early phase of COVID-19, central memory T cells (Tmcentr cells: CD45RO+CCR7+) and effector memory T cells (Tmeff cells: CD45RO+CCR7-) were assessed by multi-color flow cytometry, in comparison to a control group. RESULTS: During the study period, 148 study participants were recruited. Among them, 58 patients turned out positive for SARS-CoV-2 PCR (including both patients with interstitial pneumonia [PCR+Pn+] and without this complication [PCR+Pn-]), whereas the remaining 90 patients resulted to be SARS-CoV-2 PCR negative, even though all were affected with interstitial pneumonia [PCR-Pn+]. Additionally, 28 control patients without any ongoing respiratory disease were recruited. A clear unbalance in the T memory compartment emerged from this analysis on the whole pool of T cells (CD3+ cells), showing a significant increase in Tmcentr cells and, conversely, a significant decrease in Tmeff cells in both pneumonia groups (PCR+Pn+ and PCR-Pn+) compared to the controls; PCR+Pn- group showed trends comprised between patients with pneumonia (from one side) and the control group (from the other side). This perturbation inside the memory T cell compartment was also observed in the individual analysis of the four main T cell subpopulations, based upon the differential expression of CD4 and/or CD8 markers. CONCLUSION: Overall, we observed both absolute and relative increases of Tmcentr cells and decrease of Tmeff cells in patients affected with interstitial pneumonia (regardless of the positive or negative results of SARS-CoV-2 PCR), compared to controls. These results need confirmation from additional research, in order to consider this finding as a potential biological marker of interstitial lung involvement in patients affected with viral respiratory infections.

Clinicopathological profile of gastrointestinal tuberculosis: a multinational ID-IRI study.

Data are relatively scarce on gastro-intestinal tuberculosis (GITB). Most studies are old and from single centers, or did not include immunosuppressed patients. Thus, we aimed to determine the clinical, radiological, and laboratory profiles of GITB. We included adults with proven GITB treated between 2000 and 2018. Patients were enrolled from 21 referral centers in 8 countries (Belgium, Egypt, France, Italy, Kazakhstan, Saudi Arabia, UK, and Turkey). One hundred four patients were included. Terminal ileum (n = 46, 44.2%), small intestines except terminal ileum (n = 36, 34.6%), colon (n = 29, 27.8%), stomach (n = 6, 5.7%), and perianal (one patient) were the sites of GITB. One-third of all patients were immunosuppressed. Sixteen patients had diabetes, 8 had chronic renal failure, 5 were HIV positive, 4 had liver cirrhosis, and 3 had malignancies. Intestinal biopsy samples were cultured in 75 cases (78.1%) and TB was isolated in 65 patients (86.6%). PCR were performed to 37 (35.6%) biopsy samples and of these, 35 (94.6%) were positive. Ascites samples were cultured in 19 patients and M. tuberculosis was isolated in 11 (57.9%). Upper gastrointestinal endoscopy was performed to 40 patients (38.5%) and colonoscopy in 74 (71.1%). Surgical interventions were frequently the source of diagnostic samples (25 laparoscopy/20 laparotomy, n = 45, 43.3%). Patients were treated with standard and second-line anti-TB medications. Ultimately, 4 (3.8%) patients died and 2 (1.9%) cases relapsed. There was a high incidence of underlying immunosuppression in GITB patients. A high degree of clinical suspicion is necessary to initiate appropriate and timely diagnostic procedures; many patients are first diagnosed at surgery.