Understanding the dynamics of IgM & IgG antibodies in COVID-19-positive patients.

Background & objectives: The pandemic caused by the SARS-CoV-2 has been a threat to humankind due to the rapid spread of infection and appearance of multiple new variants. In the present study, we report the dynamics and persistence of immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies in asymptomatic and symptomatic COVID-19 patients by chemiluminescent assay. Methods: A total of 463 serum samples from 218 SARS-CoV-2 PCR-positive patients were collected over a period of 124 days post-onset of disease (POD). Antibody levels were measured by chemiluminescence bioanalyzer. Neutralizing antibody titres were assessed by plaque reduction neutralization test (PRNT) for SARS-CoV-2. Results: Both IgM and IgG started appearing from day five post-infection in symptomatic and asymptomatic patients. IgM antibody response peaked around day 35 POD and rapidly diminished thereafter, with the last IgM-positive sample observed at 90 days POD. IgG antibody response peaked around 45 days POD and persisted till 124 days. The chemiluminescence immunoassay (CLIA) results showed a moderate correlation (R=0.5846, P<0.001) compared with PRNT. Additional analysis indicated a neutralizing titre of 250 corresponded to 12.948 AU/ml of YHLO iFlash SARS-CoV-2 IgG units. Interpretation & conclusions: Both symptomatic and asymptomatic COVID-19 patients seem to initiate production of antibody responses from day five of onset of disease. Although the CLIA gives high sensitivity and specificity and also its binding IgG antibody titres may correlate moderately with protective immunity, our results indicate that the values of binding antibody alone may not be a perfect guide to represent virus neutralization titre during donor selection for plasma therapy. However, IgM and IgG antibody detection may help in monitoring the status of disease progression and burden in the community.

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.

The Designing, Testing, and Utility of a 3D-Printed Respirator: A Hospital's Journey Into Self-Sustainability During COVID-19.

Objective The current global COVID-19 pandemic has disrupted supply chains and the production of essential goods and services. This includes personal protective equipment (PPE) kits, respirators, and other protective devices. Hence efforts were made to prototype and produce 3D-printed N95 respirators to fill the gap in supply. In addition, methods of sterilization were put into place for the respirators. As well as forming standard operating procedures. Methods With the use of vast open-source libraries and collaboration with engineers and doctors fighting the COVID-19 pandemic, respirator prototypes were produced with special consideration to the sizing to fit median facial sizes. Polymer plastics were mixed in various proportions to condition the respirator to be used by frontline workers in austere environments. Due to the shortage of medical-grade filter media, alternative sources were researched. Merv 13 and Merv 15 filters were selected due to their cheap costs, vast abundance, and proven filtration efficacy against particles of 0.03 microns. Studies conducted around the world have also shown its efficacy as an alternative to medical-grade air filter media. After developing standard operating procedures (SOPs) for sterilisation and respirator usage. Emergency approval was obtained and a limited number of healthcare workers were issued with this respirator (n=400). PPE kit satisfaction and self-efficacy scores were calculated from daily questionnaires during donning and doffing Results Qualitative fit-tests in all 400 healthcare workers matched those of a conventional N95 respirator. Almost all of the respondents in the PPE kit satisfaction responded positively. The self-efficacy score calculated from the general self-efficiency scale had an overall positive value, with the average score being 4.29. This demonstrated that the self-efficacy score was above average and indicated a high motivation to overcome obstacles and spend more time solving problems. The average self-efficacy score is defined between 2.5 - 3.5, and a low self-efficacy score is defined as a score below 2.5. Lastly, a regression analysis was done to test the correlation between PPE kit satisfaction and self-efficiency this demonstrated a positive correlation between PPE kit satisfaction using the 3D-printed respirator and self-efficacy (Slope: 0.416, Intercept: -1.066, R-value: 0.872, P-value: <0.01) Conclusions With supply chain disruptions and reduced or nonexistent supplies of essential medical goods. The need of a reusable, sterilisable, and efficient respirator has never been more evident. The materials used have made it sustain heavy use in austere environments. Studies have reported higher than average burnout rates in COVID-19-based healthcare workers. Studies have also shown that the rates of burnout are high in healthcare professionals without access to proper PPE kits in developing nations. This respirator was rated highly in PPE kit satisfaction and the self-efficacy score. Studies have demonstrated a correlation between high self-efficacy scores and low burnout rates in health care workers. There is also documented evidence of a positive correlation between high self-efficacy scores and general health. As the pandemic continues to evolve, so will the efforts to combat it, such as 3D printing. Interdisciplinary collaboration continues to drive our efforts to combat the pandemic and hopefully resolve it in the future.

Pro-inflammatory CXCL-10, TNF-α, IL-1ß, and IL-6: biomarkers of SARS-CoV-2 infection.

Currently, the world is witnessing the pandemic of COVID-19, a disease caused by the novel coronavirus SARS-CoV-2. Reported differences in clinical manifestations and outcomes in SARS-CoV-2 infection could be attributed to factors such as virus replication, infiltration of inflammatory cells, and altered cytokine production. Virus-induced aberrant and excessive cytokine production has been linked to the morbidity and mortality of several viral infections. Using a Luminex platform, we investigated plasma cytokine and chemokine levels of 27 analytes from hospitalized asymptomatic (n = 39) and mildly symptomatic (n = 35) SARS-CoV-2-infected patients (in the early phase of infection), recovered individuals (45-60 days postinfection) (n = 40), and uninfected controls (n = 36) from the city of Pune located in the state of Maharashtra in India. Levels of the pro-inflammatory cytokines IL-1ß, IL-6, and TNF-α and the chemokine CXCL-10 were significantly higher, while those of the antiviral cytokines IFN-γ and IL-12 p70 were significantly lower in both asymptomatic and mildly symptomatic patients than in controls. Comparison among the patient categories revealed no difference in the levels of the cytokines/chemokines except for CXCL-10 being significantly higher and IL-17, IL-4, and VEGF being significantly lower in the mildly symptomatic patients. Interestingly, levels of all key analytes were significantly lower in recovered individuals than in those in both patient categories. Nevertheless, the level of CXCL10 was significantly higher in the recovered patients than in the controls, indicating that the immune system of SARS-CoV-2 patients may take a longer time to normalize. Our data suggest that IL-6, IL-1ß, TNF-α, CXCL-10, and reduced antiviral cytokines could be used as biomarkers of SARS-CoV-2 infection.

Enteric pathogens in HIV infected and HIV uninfected individuals with diarrhea in Pune.

BACKGROUND: Diarrhea in HIV infected individuals is a common complication seen in about 90% of patients in developing countries. The objective of this study was to identify enteric pathogens in HIV infected and HIV uninfected individuals in Pune. METHOD: This study was conducted from January 2009 to May 2010 on 331 consecutive patients presenting with diarrhea admitted at Naidu Municipal Corporation Hospital, Pune and processed using conventional methods. RESULTS: Intestinal parasitic pathogens were detected in 60% (39/65) of HIV infected and 14.3 (38/266) of HIV uninfected individuals. Bacterial pathogens were detected in 34% (22/65) of HIV infected individuals and 28.2% (75/266) of the HIV uninfected individuals. The common enteric pathogens detected in HIV infected individuals were Cystoisospora belli (28%, 18/65) followed by Cryprotosporidium parvum (12%, 8/65). In HIV uninfected individuals Entamoeba histolytica (7.1%, 19/266) followed by Shigella flexnari (4.9%, 13/266) were the most common pathogens. The difference in detection of enteric parasites in HIV infected individuals and HIV uninfected individuals was found to be significant (p < 0.01). CONCLUSIONS: Intestinal parasitic pathogens are more common in HIV infected antiretroviral therapy naïve patients. Early detection of enteric pathogens by routine examination of stool samples will help in the management and to improve the quality of life for HIV infected individuals.