Abstract
The novel, highly transmissible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has triggered a pandemic of acute respiratory illness worldwide and remains a huge threat to the healthcare system’s capacity to respond to COVID-19. Elderly and immunocompromised patients are at increased risk for a severe course of COVID-19. These high-risk groups have been identified as developing diminished humoral and cellular immune responses. Notably, SARS-CoV-2 RNA remains detectable in nasopharyngeal swabs of these patients for a prolonged period of time. These factors complicate the clinical management of these vulnerable patient groups. To date, there are no well-defined guidelines for an appropriate duration of isolation for elderly and immunocompromised patients, especially in hospitals or nursing homes. The aim of the present study was to characterize at-risk patient cohorts capable of producing a replication-competent virus over an extended period after symptomatic COVID-19, and to investigate the humoral and cellular immune responses and infectivity to provide a better basis for future clinical management. In our cohort, the rate of positive viral cultures and the sensitivity of SARS-CoV-2 antigen tests correlated with higher viral loads. Elderly patients and patients with diabetes mellitus had adequate cellular and humoral immune responses to SARS-CoV-2 infection, while immunocompromised patients had reduced humoral and cellular immune responses. Our patient cohort was hospitalized for longer compared with previously published cohorts. Longer hospitalization was associated with a high number of nosocomial infections, representing a potential hazard for additional complications to patients. Most importantly, regardless of positive SARS-CoV-2 RNA detection, no virus was culturable beyond a cycle threshold (ct) value of 33 in the majority of samples. Our data clearly indicate that elderly and diabetic patients develop a robust immune response to SARS-CoV-2 and may be safely de-isolated at a ct value of more than 35.
Keywords: COVID-19; SARS-CoV-2; comorbidities; diabetes mellitus; elderly patients; immunocompromised.
【저자키워드】 COVID-19, SARS-CoV-2, Comorbidities, Diabetes Mellitus, elderly patients, immunocompromised., 【초록키워드】 coronavirus, immune response, pandemic, Hospitalized, Hospitalization, Cellular immune response, SARS-COV-2 infection, hospital, elderly, Comorbidities, Diabetes Mellitus, Immunocompromised patients, Respiratory illness, diabetes, severe acute respiratory syndrome Coronavirus, elderly patients, virus, Immunocompromised patient, Nasopharyngeal swab, sensitivity, Cohort, cycle threshold, nasopharyngeal swabs, symptomatic, immune responses, Patient, Isolation, Immunocompromised, Ct value, Complication, Clinical management, SARS-CoV-2 RNA, humoral immune response, SARS-CoV-2 antigen, novel, nursing homes, group, viral culture, humoral immune responses, patients, Humoral and cellular immune responses, cellular, SARS-CoV-2 RNA detection, symptomatic COVID-19, Healthcare system, humoral, Nosocomial infections, Diabetic, acute respiratory syndrome, Factor, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, acute respiratory illness, increased risk, patient groups, viral loads, cohorts, cellular immune responses, positive, patient cohort, MOST, replication-competent virus, robust, diabetic patient, Course, develop, detectable, reduced, majority, correlated, representing, triggered, producing, respond, diabete, complicate, patients with diabete, 【제목키워드】 elderly, clinical, monitoring,