Sarcopenia in people living with HIV in Hong Kong: which definition correlates with health outcomes?

INTRODUCTION: Sarcopenia is an important clinical syndrome in older people living with HIV (PLWH). With a change to the Asia sarcopenia definition in 2019, we aimed to determine whether health outcomes were associated with different definitions of sarcopenia among Asian PLWH. METHODS: We performed a prospective cross-sectional study enrolling PLWH aged ≥35 years from January 2018 to November 2021. We defined sarcopenia by the Asia Working Group of Sarcopenia (AWGS) criteria in 2014 and 2019. AWGS-2014 included low muscle mass plus weak handgrip strength and/or slow gait speed. AWGS-2019 included low muscle mass plus low muscle strength or physical performance, while the presence of all defines severe sarcopenia. We measured appendicular skeletal muscle mass using dual-energy X-ray absorptiometry, handgrip strength, usual gait speed, five-time chair stand test and Short Physical Performance Battery. Correlations between each sarcopenia definition and health-related quality of life (using EQ-5D-5L and SF-36) and functional disability were determined. RESULTS: One hundred and fifty Asian PLWH were enrolled, 132 (88%) were male, mean age was 60±10 years, duration of HIV diagnosis was 13 (IQR 8-18) years and current CD4 count was 574 (IQR 362-762) cells/mm3 , 67 (45%) had multimorbidity, 64 (43%) had polypharmacy. Prevalence of sarcopenia by AWGS-2014, AWGS-2019 and severe sarcopenia was 17.3%, 27.3% and 18.0%, respectively. Age, education and polypharmacy were associated with sarcopenia. Sarcopenia (AWGS-2014) and severe sarcopenia were associated with mobility, physical functioning and physical component score (SF-36). All three criteria were associated with impaired instrumental activities of daily living (IADL). After age and sex adjustment, sarcopenia (AWGS-2014) (adjusted odds ratio/aOR 5.4, 95% confidence interval/CI 2.0-15.1) and severe sarcopenia (aOR 5.1, 95% CI 1.9-14.0) were associated with mobility and physical component score (SF-36) (ß coefficients -5.3342, p = 0.022 and -5.412, p = 0.019). Sarcopenia (AWGS 2014) (aOR 5.2, 95% CI 1.7-16.2), sarcopenia (AWGS-2019) (aOR 4.5, 95% CI 1.5-13.1) and severe sarcopenia (aOR 3.5, 95% CI 1.1-10.9) were associated with impaired IADL in fully adjusted models. CONCLUSIONS: In a sample of Asian PLWH, 17.3%, 27.3% and 18.0% had sarcopenia as defined by AWGS-2014, AWGS-2019 and severe sarcopenia, respectively. Sarcopenia by AWGS-2014 and severe sarcopenia correlated with parameters of poor health outcomes, while sarcopenia by AWGS-2019 correlated with functional disability.

Trajectory patterns of SARS-CoV-2 neutralising antibody response in convalescent COVID-19 patients.

Background: The adaptive immune responses of COVID-19 patients contributes to virus clearance, restoration of health and protection from re-infection. The patterns of and the associated characteristics with longitudinal neutralising antibody (NAb) response following SARS-CoV-2 infection are important in their potential association with the population risks of re-infection. Methods: This is a longitudinal study with blood samples and clinical data collected in adults aged 18 or above following diagnosis of SARS-CoV-2 infection. NAb levels were measured by the SARS-CoV-2 surrogate virus neutralisation test (sVNT). Anonymous clinical and laboratory data were matched with surveillance data for each subject for enabling analyses and applying latent class mixed models for trajectory delineation. Logistic regression models were performed to compare the characteristics between the identified classes. Results: In 2020-2021, 368 convalescent patients in Hong Kong are tested for NAb. Their seroconversion occur within 3 months in 97% symptomatic patients, the level of which are maintained at 97% after 9 months. The NAb trajectories of 200 symptomatic patients are classified by the initial response and subsequent trend into high-persistent and waning classes in latent class mixed models. High-persistent (15.5%) class patients are older and most have chronic illnesses. Waning class patients (84.5%) are largely young adults who are mildly symptomatic including 2 who serorevert after 10 months. Conclusions: Characteristic sub-class variabilities in clinical pattern are noted especially among patients with waning NAb. The heterogeneity of the NAb trajectory patterns and their clinical association can be important for informing vaccination strategy to prevent re-infection.

Serologic Responses in Healthy Adult with SARS-CoV-2 Reinfection, Hong Kong, August 2020.

In March 2020, mild signs and symptoms of coronavirus disease developed in a healthy 33-year-old man in Hong Kong. His first infection did not produce virus neutralizing antibodies. In August, he had asymptomatic reinfection, suggesting that persons without a robust neutralizing antibody response might be at risk for reinfection.