Lymphopenia with Altered T Cell Subsets in Hospitalized COVID-19 Patients in Pune, India.

The cellular immune cell subsets affecting COVID-19 disease severity are being studied by researchers from many countries. The current study was carried out to investigate the alteration of peripheral blood mononuclear cells (PBMCs) and their subsets in hospitalized COVID-19 patients in a tertiary care center in Pune, India. The PBMCs were isolated from enrolled study participants, and flow cytometry analysis was done to assess peripheral white blood cell alterations. The lymphocyte subsets of naive, effector, central memory, and effector memory CD4+ or CD8+ T cells were then evaluated in COVID-19 patients with different disease categories and compared to healthy controls. The immunophenotypic characterization of the immune cell subset was done for 139 COVID-19 patients and 21 healthy controls. These data were evaluated based on the disease severity. A total of 139 COVID-19 patients were classified as mild (n = 30), moderate (n = 57), or severe (n = 52) cases. The decreased percentages of total lymphocytes, CD3+ T cells, CD4+ T cells, naive T cells, central memory T cells, and Natural Killer (NK) cytotoxic cells were found, and there was increase in effector T (TEf) cells and effector memory T cells in patients with severe COVID-19 compared to healthy controls. The severity of SARS-CoV-2 infection has an effect on lymphocyte subsets, resulting in reduced T memory cells and NK cells but increased TEf cells in severe cases. Clinical Trial Registration: CTRI ID-CTRI/2021/03/032028.

Platelet derived exosomes disrupt endothelial cell monolayer integrity and enhance vascular inflammation in dengue patients.

Background: Thrombocytopenia is the most notable phenomenon in dengue. Activation status of platelets and interaction of platelets with endothelium contribute towards dengue disease pathogenesis. Platelets are the major cell types known to release extracellular vesicles, especially exosomes in circulation. However, the role of platelet derived exosomes (PLT-EXOs) in endothelial dysfunction during dengue infection remains unknown. Methods: In this study, we recruited 28 healthy subjects and 69 dengue patients categorized as WS- (n=31), WS+ (n=29) and SD (n=9). Platelets were isolated from platelet rich plasma of dengue patients and their activation was assessed by flow cytometry. PLT-EXOs were isolated by ultracentrifugation method. Western blot analyses were performed to characterize the exosomes. Exosome uptake experiment was carried out to see the internalization of exosomes inside endothelial cells (HUVECs). To observe the effect of exosomes on endothelial cells, exosomes were added on HUVECs and expression of adherens and tight junctional proteins were examined by immunofluorescence assay and western blot. Expression levels of vascular injury markers were measured in the culture supernatants of Exosome-HUVEC coculture and sera of dengue patients by MSD-multiplex assay. Results: As compared to healthy subjects, CD41/CD61 expression was significantly reduced (p<0.0001) and CD62p expression was significantly increased (p<0.0001) on platelets in dengue patients. PLT-EXOs isolated from the dengue patients showed higher expression of CD63 and CD9 proteins than the healthy subjects. With in-vitro immunofluorescence assays, we illustrated the internalization of PLT-EXOs by the HUVECs and observed disruption of endothelial cell monolayer integrity in the presence of PLT-EXOs from WS+ and SD patients. Furthermore, the significant reduction in the expressions of ZO-2, VE-Cadherin and CD31 in endothelial cells following exposure to PLT-EXOs from the dengue patients provide direct evidence of PLT-EXOs mediated vascular permeability. PLT-EXOs stimulated the release of inflammatory markers CRP, SAA, sVCAM-1 and sICAM-1 in the supernatants of HUVEC cells. Importantly, significantly higher levels of CRP, sVCAM-1 and sICAM-1 in the sera of severe than mild dengue patients (p<0.0001) suggest their role in disease severity. Conclusions: In summary, our data suggest that PLT-EXOs promote vascular leakage via release of proinflammatory mediators and compromise vascular barrier integrity in dengue patients.

Peripheral lymphocyte subset alteration in patients with COVID-19 having differential clinical manifestations.

Background & objectives: The COVID-19 disease profile in Indian patients has been found to be different from the Western world. Changes in lymphocyte compartment have been correlated with disease course, illness severity and clinical outcome. This study was aimed to assess the peripheral lymphocyte phenotype and subset distribution in patients with COVID-19 disease from India with differential clinical manifestations. Methods: Percentages of peripheral lymphocyte subsets were measured by flow cytometry in hospitalized asymptomatic (n=53), mild symptomatic (n=36), moderate and severe (n=30) patients with SARS-CoV-2 infection, recovered individuals (n=40) and uninfected controls (n=56) from Pune, Maharashtra, India. Results: Percentages of CD4+Th cells were significantly high in asymptomatic, mild symptomatic, moderate and severe patients and recovered individuals compared to controls. Percentages of Th memory (CD3+CD4+CD45RO+), Tc memory (CD3+CD8+CD45RO+) and B memory (CD19+CD27+) cells were significantly higher in the recovered group compared to both asymptomatic, mild symptomatic patient and uninfected control groups. NK cell (CD56+CD3-) percentages were comparable among moderate +severe patient and uninfected control groups. Interpretation & conclusions: The observed lower CD4+Th cells in moderate+severe group requiring oxygen support compared to asymptomatic+mild symptomatic group not requiring oxygen support could be indicative of poor prognosis. Higher Th memory, Tc memory and B memory cells in the recovered group compared to mild symptomatic patient groups might be markers of recovery from mild infection; however, it remains to be established if the persistence of any of these cells could be considered as a correlate of protection.

Multilocus sequence typing of Ochrobactrum spp. isolated from gastric niche.

The human stomach is colonized by diverse bacterial species. The presence of non-Helicobacter pylori bacteria in urease-positive biopsies of individuals has been reported. Bacteria belonging to the Ochrobactrum genus have been documented in the human gastric niche. The co-occurrence of Ochrobactrum spp. with H. pylori was previously reported in an antral biopsy of a non-ulcer dyspeptic (NUD) subject from Northern India. There is no information on the genetic diversity of Ochrobactrum spp. isolated from the gastric niche in the stomach. We aimed to study the species distribution and diversity of Ochrobactrum spp. with and without H. pylori in urease-positive biopsies across three different geographical regions in India. Sixty-two Ochrobactrum isolates recovered from patients with an upper gastric disorder (n=218) were subjected to molecular identification and multilocus sequence typing. H. pylori DNA was found in the majority of biopsies, which had a variable degree of Ochrobactrum spp present. Interestingly, some of the urease-positive biopsies only had Ochrobactrum without any H. pylori DNA. Based on phylogenetic analysis, the Ochrobactrum isolates were distributed into the O. intermedium, O. anthropi and O. oryzae groups. This indicates there are multiple species in the gastric niche irrespective of the presence or absence of H. pylori. Antibiotyping based on colistin and polymyxin B could differentiate between O. intermedium and O. anthropi without revealing the resistance-driven diversity. Considering the prevalence of multiple Ochrobactrum spp. in the human gastric niche, it is important to evaluate the commensal and/or pathogenic nature of non-H. pylori bacteria with respect to their geographical distribution, lifestyle and nutrition needs.

High risk for occupational exposure to HIV and utilization of post-exposure prophylaxis in a teaching hospital in Pune, India.

BACKGROUND: The risk for occupational exposure to HIV has been well characterized in the developed world, but limited information is available about this transmission risk in resource-constrained settings facing the largest burden of HIV infection. In addition, the feasibility and utilization of post-exposure prophylaxis (PEP) programs in these settings are unclear. Therefore, we examined the rate and characteristics of occupational exposure to HIV and the utilization of PEP among health care workers (HCW) in a large, urban government teaching hospital in Pune, India. METHODS: Demographic and clinical data on occupational exposures and their management were prospectively collected from January 2003-December 2005. US Centers for Diseases Control guidelines were utilized to define risk exposures, for which PEP was recommended. Incidence rates of reported exposures and trends in PEP utilization were examined using logistic regression. RESULTS: Of 1955 HCW, 557 exposures were reported by 484 HCW with an incidence of 9.5 exposures per 100 person-years (PY). Housestaff, particularly interns, reported the greatest number of exposures with an annual incidence of 47.0 per 100 PY. Personal protective equipment (PPE) was used in only 55.1% of these exposures. The incidence of high-risk exposures was 6.8/100 PY (n = 339); 49.1% occurred during a procedure or disposing of equipment and 265 (80.0%) received a stat dose of PEP. After excluding cases in which the source tested HIV negative, 48.4% of high-risk cases began an extended PEP regimen, of whom only 49.5% completed it. There were no HIV or Hepatitis B seroconversions identified. Extended PEP was continued unnecessarily in 7 (35%) of 20 cases who were confirmed to be HIV-negative. Over time, there was a significant reduction in proportion of percutaneous exposures and high-risk exposures (p < 0.01) and an increase in PEP utilization for high risk exposures (44% in 2003 to 100% in 2005, p = 0.002). CONCLUSION: Housestaff are a vulnerable population at high risk for bloodborne exposures in teaching hospital settings in India. With implementation of a hospital-wide PEP program, there was an encouraging decrease of high-risk exposures over time and appropriate use of PEP. However, overall use of PPE was low, suggesting further measures are needed to prevent occupational exposures in India.

Mortality & clinical characteristics of hospitalized adult patients with HIV in Pune, India.

BACKGROUND & OBJECTIVE: In India, data regarding mortality and clinical characteristics of hospitalized HIV-infected patients are sparse, which may limit the effectiveness of new hospital-based HIV programmes providing antiretroviral therapy (ART). The objective of our study was to determine mortality and clinical characteristics of hospitalized HIV-infected individuals in a high HIV prevalence region of India. METHODS: A retrospective chart review was done of known HIV-infected adults admitted to the Medical Service of a large, public hospital in Pune, India, from January 2002 to November 2003. RESULTS: A total of 655 HIV-infected patients were identified; 489 (74.7%) were male and 4 (0.6%) were on ART. The most common illnesses reported were tuberculosis (55.8%), diarrhoea (4.2%), and alcoholic liver disease (3.7%) . The inpatient mortality was 172 (26.3%). The most common causes of death of the 172 people were tuberculosis (52.9%) and cryptococcal meningitis (7.6%). In multivariate analysis, factors associated with increased mortality were male sex (adjusted odds ratio (AOR) 1.92, 95% CI: 1.08-3.41), haemoglobin level < 7 g/dl (AOR 2.75, 95% CI:1.23-6.14), length of stay < 2 days (OR 5.78, 95%, CI: 1.82-18.4), and cryptococcal meningitis (OR 4.44, 95% CI:1.19-16.6). INTERPRETATION & CONCLUSION: In the era prior to widespread ART, a high inpatient mortality of 26 per cent was found among hospitalized HIV-infected individuals. Thus, while hospitalization is an important access and referral point for HIV care and treatment, earlier identification of HIV-infected persons must occur to ensure they will optimally benefit from the government's ART programme.