ABSTRACT
The long-term symptoms of COVID-19 are the subject of public and scientific discussions. Understanding how those long COVID symptoms co-occur in clusters of syndromes may indicate the pathogenic mechanisms of long COVID. Our study objective was to cluster the different long COVID symptoms. We included persons who had a COVID-19 and assessed long-term symptoms (at least 4 weeks after first symptoms). Hierarchical clustering was applied to the symptoms as well as to the participants based on the Euclidean distance h of the log-values of the answers on symptom severity. The distribution of clusters within our cohort is shown in a heat map.From September 2021 to November 2023, 2371 persons with persisting long COVID symptoms participated in the study. Self-assessed long COVID symptoms were assigned to three symptom clusters. Cluster A unites rheumatological and neurological symptoms, cluster B includes neuro-psychological symptoms together with cardiorespiratory symptoms, and a third cluster C shows an association of general infection signs, dermatological and otology symptoms. A high proportion of the participants (n = 1424) showed symptoms of all three clusters. Clustering of long COVID symptoms reveals similarities to the symptomatology of already described syndromes such as the Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) or rheumatological autoinflammatory diseases. Further research may identify serological parameters or clinical risk factors associated with the shown clusters and might improve our understanding of long COVID as a systemic disease. Furthermore, multimodal treatments can be developed and scaled for symptom clusters and associated impairments.
ABSTRACT
Antiretroviral (ARV) therapy, comprising a backbone of two nucleos(t)ide reverse transcriptase inhibitors (NRTIs) plus another ARV, is the recognized standard of care (SOC), which has helped extend life expectancy in people living with HIV. In a quest to reduce lifelong drug exposure and minimize or avoid the toxicity of NRTIs, "NRTI-reducing" regimens have been investigated. This descriptive review assessing the results of NRTI-reducing strategies from the largest randomized trials focuses on virological efficacy, resistance, regimen safety (in terms of bone mineral density, renal function, lipids and central nervous system function) and simplicity. The review considers efficacy across various NRTI-sparing strategies, for example an integrase strand transfer inhibitor (INSTI) plus a ritonavir-boosted protease inhibitor (PI/r) or PI/r + lamivudine (3TC), in both naïve and switch regimes. Of 10 key studies in treatment-naïve adults assessing five NRTI-reducing strategies, only four studies demonstrated noninferiority vs. SOC [GARDEL, NEAT 001, AIDS Clinical Trials Group 5142 and PROGRESS]. In switch settings, 17 studies (10 randomized) were reviewed that used four strategies, including three studies assessing an INSTI plus a nonnucleoside reverse transcriptase inhibitor . Noninferiority of the NRTI-reducing arm was shown in six of 10 studies (ATLAS-M, SALT, DUAL, OLE, LATTE-2 and SWORD). In general, NRTI-reducing therapy did not always result in an improvement in short- or long-term adverse events; however, in many cases, these endpoints were not reported. Some of these studies reported higher virological failure rates with more frequent emergence of resistance mutations. None of these NRTI-reducing strategies has been compared against a single-pill regimen, including those containing tenofovir alafenamide. Only strategies demonstrating noninferior efficacy, a benefit in safety/tolerability, and a favourable cost-efficacy ratio, preferably in a single pill, will eventually match the current SOC of triple ARV therapy.
