M184V is a single-base mutation in the YMDD domain of reverse transcriptase (RT). The M184V resistance-associated mutation is related to virological unresponsiveness to lamivudine (3TC) and emtricitabine (FTC) and induces high-level resistance to these two antiretroviral agents. M184V is rapidly selected in the setting of non-suppressive antiretroviral therapy (ART) and accumulates in the HIV reservoir. There were continuous efforts to evaluate the impact of M184V mutation on the treatment outcomes in people with HIV (PWH). Since lamivudine remains an extensively used part of recommended antiretroviral combinations, M184V is commonly detected in patients with virological failure. ART guidelines do not recommend the use of drugs impacted by resistance-associated mutations as they have been confirmed to comprise a risk factor for virological failure. However, previous authors suggest that 3TC/FTC can remain active even in the presence of M184V. Obtaining the viral resistance profile for each individual both treated or ART-naïve is a key challenge for lifelong treatment management.Given the potential benefits of lamivudine in the ART combinations, the investigation of M184V remains of high interest for clinicians and researchers. This is a review of literature for the challenges in treating both naïve and experienced individuals carrying the M184V resistance mutation, including virological failure, virological suppression, and resistance to ART.

COVID-19 is characterized by a heterogeneous clinical presentation and prognosis. Risk factors contributing to the development of severe disease include old age and the presence of comorbidities. However, the genetic background of the host has also been recognized as an important determinant of disease prognosis. Considering the pivotal role of innate immunity in the control of SARS-CoV-2 infection, we analyzed the possible contribution of several innate immune gene polymorphisms (including TLR2-rs5743708, TLR4-rs4986790, TLR4-rs4986791, CD14-rs2569190, CARD8-rs1834481, IL18-rs2043211 and CD40-rs1883832) in disease severity and prognosis. A total of 249 individuals were enrolled and further divided into five (5) groups, according to the clinical progression scale provided by the World Health Organization (WHO) (asymptomatic, mild, moderate, severe and critical). We identified that elderly patients with obesity and/or diabetes mellitus were more susceptible to developing pneumonia and respiratory distress syndrome after SARS-CoV-2 infection, while the IL18-rs1834481 polymorphism was an independent risk factor for developing pneumonia. Moreover, individuals carrying either the TLR2-rs5743708 or the TLR4-rs4986791 polymorphisms exhibited a 3.6- and 2.5-fold increased probability for developing pneumonia and a more severe disease, respectively. Our data supports the notion that the host’s genetic background can significantly affect COVID-19 clinical phenotype, also suggesting that the IL18-rs1834481, TLR2-rs5743708 and TLR4-rs4986791 polymorphisms may be used as molecular predictors of COVID-19 clinical phenotype.