Cryptococcal meningitis (CM) is a severe opportunistic infection in people living with HIV (PLWH). We report a 54-year-old man with advanced HIV infection who presented with CM due to Cryptococcus neoformans . Induction therapy with liposomal amphotericin B (4 mg/kg/day) plus fluconazole (800 mg/day) was prolonged to 10 weeks because flucytosine was initially unavailable; intravenous flucytosine (25 mg/kg q6h) was introduced when accessible. Maintenance fluconazole (800 mg/day) was continued, and antiretroviral therapy (ART) with dolutegravir plus emtricitabine/tenofovir disoproxil was initiated after 8 weeks. One year later, despite virological suppression, he developed neurological deterioration compatible with recurrent CM in the absence of culture confirmation. He underwent re-induction with liposomal amphotericin B plus flucytosine, followed by off-label secondary prophylaxis with oral isavuconazole (200 mg/day). Over 6 months, he maintained HIV-RNA suppression, showed CD4+ T-cell recovery (from 94 to 165 cells/mm 3 ), and experienced neurological stabilization without further CM episodes or drug-related toxicity. Isavuconazole’s pharmacokinetic profile, oral availability, and limited antiretroviral drug–drug interactions supported its use as extended secondary prophylaxis in this setting, although limited access in low- and middle-income countries remains a concern. This case highlights isavuconazole as a potential alternative prophylactic strategy when fluconazole is ineffective or not tolerated.

IntroductionThe crosstalk between immune cells through plasma extracellular vesicles (EVs) during SARS-CoV-2 infection may represent a significant determinant of clinical course in COVID-19 patients. EVs from SARS-CoV-2 virus-infected cells deliver their informational content to immune cells implicated in COVID-19 pathogenesis, thereby modulating pro-inflammatory immune responses during infection. γδ T cells are innate cells known for their pleiotropic properties spanning both innate and adaptive immunity and for their possible contribution to inflammation. This study aimed to characterize the biophysical profile and protein content of EVs derived from patients with severe and mild COVID-19, and to analyze their impact on the functional activity of Vδ2 T cells.MethodsPlasma samples from 42 COVID-19 hospitalized patients (17 severe and 25 mild) were enrolled at the National Institute for Infectious Diseases Lazzaro Spallanzani in Rome. Twenty-three healthy donors (HD) served as the control group. Plasma cytokines were quantified by an automated multiplex immunoassay. EVs were purified using nickel-based isolation (NBI) and analyzed by quantitative LC-MS proteomics. Data are available via ProteomeXchange with identifier PXD072061. Characterization of EVs was performed using multiparametric flow cytometry, as well as the Vδ2 T cell functional assays. Peripheral blood mononuclear cells from 10 HD were utilized for immunological assays.ResultsCytometric characterization revealed that EVs from severe COVID-19 patients were enriched in platelet components compared to HD and mild patients. Protein expression of EVs from severe patients clustered differently in PCA and heatmap analyses with respect to HD and mild patients. A volcano plot revealed several proteins that were differentially expressed between EVs from mild and severe patients. A significant induction of several processes, including platelet degranulation, complement, coagulation, and innate immunity, was observed in the pathway analysis. EVs from severe COVID-19 patients enhanced the responsiveness of Vδ2 T cells to phosphoantigen, increasing their activation and proinflammatory cytokine production (TNF-α).ConclusionsProteomic differential analysis reveals the expression/regulation of innate immune-related proteins in EVs from severe patients compared to mild patients/HD and supports their potential role in modulating innate immunity. Specifically, functional analysis of Vδ2 T cells suggests that EVs may contribute to the pathogenesis of severe COVID-19 by delivering molecular signals that exacerbate innate immune-driven inflammation.

OBJECTIVES:To assess early cabotegravir (CAB) long-acting (LA) plasma concentrations following initiation of HIV pre-exposure prophylaxis (PrEP). METHODS:This was a prospective pharmacokinetic study of individuals initiating CAB-LA PrEP, administered as 600 mg intramuscular injections into the gluteal muscle (two initial doses 28 days apart, followed by injections every 56 days). Plasma samples for therapeutic drug monitoring were collected on days 3, 7, 28, and 84 after the first injection; days 28 and 84 corresponded to pre-injection troughs. CAB plasma concentrations were quantified by liquid chromatography-tandem mass spectrometry (lower limit of quantification, 40 ng/mL) and categorized according to the protein-adjusted (PA) IC90 (166 ng/mL) and 4×PA-IC90 (664 ng/mL). A multilevel regression model was fitted to log-transformed CAB concentrations, with visit day as a categorical predictor and participant-level characteristics (age, BMI, ethnicity) as covariates. RESULTS:Sixty-four male participants initiated CAB-LA PrEP (median age, 37 years [IQR 32-42]; median BMI, 24.0 kg/m² [IQR 22.2-26.4]). All participants had concentrations above the PA IC90 at every time point. Median CAB concentrations were 637 ng/mL (IQR 448-1568; 50% >4×PA-IC90), 966 ng/mL (IQR 616-1895; 71.4%), 936 ng/mL (IQR 582-1739; 67.7%), and 1480 ng/mL (IQR 1067-2006; 93.8%) on days 3, 7, 28, and 84, respectively. Higher BMI was inversely associated with CAB concentrations (β = -0.044; 95% CI, -0.080 to -0.009; p = 0.016). CONCLUSIONS:CAB-LA PrEP achieved protective plasma concentrations within the first week of initiation and demonstrated consistent accumulation with subsequent injections.

OBJECTIVES:Integrated strategies for early HIV diagnosis and treatment among pregnant women with HIV (pWWH) have reduced mother-to-child transmission (MTCT) to below 2%. We aim to evaluate pregnancy outcomes and antiretroviral therapy (ART) changes in pWWH during pregnancy planning and delivery. METHODS:We included pWWH enrolled in the ICONA Cohort in 2011-2024. Wilcoxon rank-sum and Chi-squared or Fisher's exact tests described population characteristics. ART modifications, maternal immunovirological status, and MTCT rates were analyzed. Multivariable regression analysis assessed the likelihood of viral suppression at delivery. RESULTS:419 pregnancies in 311 pWWH were evaluated; outcomes were available for 333 pregnancies (100 ART-naive, 233 ART-experienced) in 255 pWWH: 267 live-born births (80%), 35 miscarriages, 28 voluntary interruptions, 2 stillbirths, and 1 intrauterine death. HIV was diagnosed during pregnancy in 83 women. ART changes occurred in 29.6% of ART-naïve during pregnancy. Among ART-experienced, 6% changed in the six months before pregnancy, 25.8% during the first trimester, and 4.7% afterward. Tenofovir disoproxil/emtricitabine was the most used backbone. A significant proportion of pregnancies were exposed to PIs, but use of INSTIs increased over time. Caesarean section occurred in 44.4%, vaginal deliveries in 24.9%. Two HIV-positive newborns were observed (1.1%). CONCLUSION:Despite improved viral suppression, late or missed HIV diagnoses during pregnancy continue to drive MTCT. Strengthening early HIV testing, antenatal care access, and retention in care is critical to eliminate perinatal transmission.

Introduction:Monkeypox virus (MPXV) infection induces robust humoral immune responses; however, the kinetics of IgG avidity maturation following natural infection remain poorly characterized. Since IgG avidity reflects antibody affinity maturation over time, its evaluation may provide additional information for the interpretation of MPXV serology and infection staging. This study longitudinally assessed MPXV-specific IgG avidity in patients with confirmed mpox infection up to one year after symptom onset. Methods:Serum samples from 16 PCR-confirmed mpox patients (clade IIb) were collected within 30 days from symptom onset (T1) and at 3 (T2), 6 (T3), and 12 (T4) months of follow-up, each comprising 13 samples. Anti-MPXV (clade IIb) IgG titers and avidity indices (AI) were evaluated using an in-house indirect immunofluorescence assay (iIFA) performed with and without 4.5 M urea treatment. Neutralizing antibodies (nAbs) were measured by plaque reduction neutralization test (PRNT50). ROC curve analysis was performed to assess the ability of AI to discriminate early from late infection time points. Results:All patients developed detectable anti-MPXV IgG within the first month after symptom onset, followed by a progressive decline in antibody titers over time, with average reductions of 1.5-, 2.9-, and 5.8-fold at T2, T3, and T4, respectively. In contrast, IgG avidity progressively increased during follow-up. Mean AI values increased from 0.132 at T1 to 0.619, 0.653, and 0.689 at T2, T3, and T4, respectively. ROC analysis identified an AI cutoff of 0.25 capable of discriminating samples collected within 30 days from those collected at later time points with high accuracy. An inverse correlation between AI and nAbs titers was observed (Spearman's r = -0.5131, p < 0.0001), suggesting distinct temporal dynamics between antibody maturation and neutralizing activity. Discussion:These findings provide one of the first longitudinal descriptions of IgG avidity maturation following natural MPXV infection and support the potential utility of avidity assessment as a complementary serological parameter for distinguishing recent from past infection. Further studies in larger and more diverse cohorts are needed to validate these observations and better define the clinical applicability of MPXV IgG avidity testing.

OBJECTIVES:The aim of this study was to describe virological outcomes in people with HIV (PWH) after discontinuation of long-acting (LA) cabotegravir (CAB) plus rilpivirine (RPV). METHODS:All PWH enrolled in the Icona Cohort who discontinued CAB/RPV LA and had at least one follow-up after discontinuation were included. RESULTS:A total of 84 out of 805 (10.4%) PWH discontinued CAB/RPV, mainly due to toxicity or adverse events (67.9%). Most individuals (72.6%) returned to the same oral antiretroviral regimen used prior LA therapy. The 12-month cumulative probability of discontinuing oral ART after CAB/RPV was 19.9% (95% confidence interval [CI] 11.9-32.2%). After switching back to oral ART all individuals except one maintained or achieved HIV RNA levels below 50 copies/mL. CONCLUSION:These findings suggest that PWH who discontinue LA CAB/RPV and resume oral ART maintain or achieve high rates of virologic suppression.

BACKGROUND:The COVID-19 pandemic profoundly disrupted healthcare services. This study assessed the impact of the pandemic on the incidence, characteristics, and outcomes of late HIV diagnosis (LD) in Italy. METHODS:All people with HIV (PWH) enrolled in Italian Cohort Naïve Antiretrovirals during 2016-2019 (prepandemic) and 2021-2024 (postpandemic), and diagnosed with HIV within 3 months before enrolment, were included. LD was defined as CD4 < 350 cells/mm³ or an AIDS-defining event (ADE) within 3 months of HIV diagnosis; AIDS presentation (AIDS-P) was considered an ADE at diagnosis. Annual incidence, socio-demographic determinants, and survival outcomes were compared between periods using Poisson regression, Cox proportional hazards models, and Fine-Gray competing risk models. RESULTS:Among 5724 newly diagnosed PWH, 56% were enrolled in prepandemic and 44% postpandemic. Overall, 58% presented late and 13% as AIDS-P, with proportions stable across periods. Risk factors for LD-female sex, older age, foreign nationality, heterosexual transmission, lower education, and unemployment-remained consistent, with no significant interaction by time (P = 0.39). During follow-up, 151 deaths occurred. LD and especially AIDS-P were associated with substantially increased all-cause mortality compared with non-LD, particularly within the first-year postdiagnosis. Adjusted hazard ratios were 2.96 for LD and 6.51 for AIDS-P prepandemic, and 8.64 and 17.99 postpandemic. No excess risk was observed for non-AIDS-related mortality. CONCLUSION:The prevalence and determinants of LD and AIDS-P in Italy remained stable before and after the COVID-19 pandemic. However, late presentation continues to carry a heavy mortality burden, underscoring the urgent need to strengthen early testing and prompt linkage to care.

Next-generation sequencing (NGS) has improved HIV-1 genotypic resistance testing (GRT) by enabling the detection of minority drug-resistance variants, although interpretation of low-frequency mutations remains challenging because of sequencing artifacts. This study compared the analytical performance and workflow efficiency of two Ion Torrent platforms, GeneStudio S5 (S5) and Genexus (GX), for routine HIV-1 GRT. A total of 134 plasma samples from people with HIV were prospectively collected, and 100 samples successfully sequenced on both platforms were included in the comparative analysis. Overall concordance for resistance-associated mutations was 88.0%, with agreement rates of 97.0% for protease, 90.0% for reverse transcriptase, and 100% for integrase. Both platforms generated clinically interpretable resistance profiles; however, 13 discordant mutations were identified. Application of a standardized confirmation algorithm, integrating Stanford HIVdb analysis with manual read-level inspection in Geneious software (version 2025.2.2), reclassified several discordant mutations as low-confidence or non-confirmed variants. Operationally, GX provided a fully automated workflow with approximately 24 h turnaround time and minimal hands-on processing, whereas S5 required approximately 72 h and substantially greater operator involvement. These findings support both platforms for routine HIV-1 GRT while emphasizing the importance of standardized bioinformatic review for reliable variant interpretation.

Background: Torquetenovirus (TTV) viremia is increasingly recognized as a biomarker of host immune competence. We assessed the association between baseline TTV DNA levels and immune responses to the Mpox virus (MPXV) and dengue virus (DGV) vaccines in two prospective cohorts. Methods: A total of 248 individuals were enrolled, and TTV DNA was quantified before vaccination. Humoral and cellular responses to MVA-BN (for MPXV) and QDENGA (for DGV) vaccines were measured by using serology, neutralization assays, and interferon-γ ELISpot, and correlations with TTV viremia were investigated. Results: TTV DNA was detected in 81.2% of individuals, with a significantly higher prevalence and viral loads in the Mpox-Vac group than in the DGV-Vac group. Between both groups, the only significant association observed was an inverse correlation between pre-vaccination TTV load and DGV neutralizing antibody titers in the DGV-Vac group and was limited to the subset of TTV-positive individuals; no additional correlations with antibody and T responses were identified. For the Mpox-Vac group, stratified analyses in people living with HIV (PLWH) confirmed this lack of association. Conclusions: TTV viremia does not predict vaccine immunogenicity in immunocompetent or mildly immunosuppressed individuals. These results, which derive from within-cohort analyses and do not rely on direct comparisons between heterogeneous vaccine populations, support the role of TTV as a marker of immune status along a continuum of immunosuppression, with predictive value likely confined to populations with more severe immune impairment.

BACKGROUND:Among people with HIV (PWH) on antiretroviral therapy (ART), serious non-AIDS-events (SNAEs) are linked to inflammation. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio (LMR) are inflammatory biomarkers. We investigated their performance in PWH. METHODS:PWH enrolled in the national cohort Italian Cohort Naive Antiretrovirals who started ART over 1997-2021 with measures of NLR, PLR, and/or LMR within 6 months pre-ART ("baseline") were included. Biomarkers were grouped using tertiles of their distribution (Q1, Q2, and Q3). Association between baseline biomarkers values and risk of SNAEs, AIDS, and all-cause mortality were tested using Kaplan-Meier and Cox proportional hazard models adjusting for baseline age, CD4 + count, human immunodeficiency virus-ribonucleic acid (HIV-RNA), HCV-status, and year of starting ART. RESULTS:We included 9248, 8727, and 1090 individuals in the PLR, NLR, and LMR analyses, respectively: 77% male, median age 38. Baseline PLR, NLR, and LMR mean values were 248.9, 2.7, and 8.2, respectively. After adjusting for confounders, the risk of SNAEs was higher for Q1-PLR vs Q2 and Q3 [adjusted-hazard ratio (HR) 0.76 (95% CI: 0.64 to 0.90) and 0.78 (95% CI: 0.66 to 0.94), respectively], and mortality [adjusted-HR 0.54 (95% CI: 0.41 to 0.70), and 0.68 (95% CI: 0.53 to 0.87), respectively], and the risk of AIDS was lower for Q2-PLR (adjusted-HR = 0.74, 95% CI: 0.60 to 0.90). Mortality was higher for Q3-NLR [adjusted-HR 1.32 (95% CI: 1.01 to 1.72)]. Q1-LMR showed higher risks of SNAEs, AIDS, and mortality, but this weakened after adjusting for confounders. CONCLUSIONS:A baseline PLR below 93.2 was associated with SNAEs, AIDS, and mortality, and NLR above 2.04 was associated with mortality. Derived from routinely collected blood parameters, PLR, and NLR may help clinicians identifying PWH at risk of poor outcomes.

Introduction: Cognitive dysfunction (“brain fog”) is a common manifestation of post-acute COVID-19 syndrome (PACS) and may persist long after the acute infection. While cross-sectional studies have described cognitive deficits, longitudinal evidence on recovery trajectories remains limited. Methods: We conducted a longitudinal observational study of neurocognitive performance and neuropsychiatric symptoms in patients with PACS. Participants underwent assessment with 20 standardized tests covering five cognitive domains (memory, attention, language, executive functions, psychomotor processing speed); anxiety, depression, and sleep quality were assessed at three time points. Changes were analysed using the Friedman test. Results: Forty-two patients were included (median age 57 years; 35.7% female) from a predominantly hospitalized cohort (81% hospitalised; 66.7% requiring respiratory support). Patients who completed all three assessments (completers, n = 42) were compared with those who attended the first evaluation but did not complete follow-up (non-completers, n = 544); completers were more severely ill during the acute phase rather than healthier or more motivated. At the group level, statistically significant improvements over time were observed across the whole sample in verbal short-term learning, visuospatial memory, working memory, constructional praxis, phonological verbal fluency, and psychomotor processing speed (all p ≤ 0.05); after Benjamini–Hochberg adjustment across the twenty cognitive outcomes, visuospatial span forward and backward and psychomotor processing speed remained significant (all FDR-adjusted p ≤ 0.013), with the change confined to the first six months. Sleep quality also improved (p < 0.0001). Conclusion: In this cohort, group-level performance improved in six of the twenty tests administered, of which three remained significant after correction for multiple comparisons, while 28 of 42 patients (66.7%) still scored in the impaired range on at least one test at 12 months, and 17 (40.5%) on two or more. These findings highlight the importance of long-term neuropsychological monitoring and integrated cognitive-psychiatric evaluation in post-COVID care. Given the small, predominantly hospitalized sample, improvements should be interpreted cautiously and confirmed in larger controlled studies, although the use of alternate forms for part of the battery makes task-specific learning an incomplete explanation.

Extensive real-world data in people with HIV (PWH) switching from non-nucleoside reverse transcriptase inhibitors (NNRTIs), in particular from rilpivirine (RPV)-based regimens to bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF), are lacking. This is a single-center retrospective study. Inclusion criteria were PWH aged ≥ 18 years, virologically suppressed on NNRTI triple antiretroviral regimens. The primary endpoint was the proportion of PWH with HIV-RNA < 50 cp/mL at 12 months from time of switch to B/F/TAF. Overall, 214 PWH were included, of whom 105 (49.1

A previously healthy 39-year-old man developed highly symptomatic post-COVID-19 condition (also known as long COVID) marked by cognitive dysfunction, disabling fatigue, and autonomic symptoms unresponsive to multiple multidisciplinary interventions. Given the presence of markedly elevated serum autoantibodies against G protein-coupled receptors, high-dose intravenous immunoglobulin therapy was initiated at 400 mg/kg per day for 5 consecutive days. After 4 weeks, a maintenance dose of 500 mg/kg was administered for 1 day, followed by two further maintenance cycles consisting of 500 mg/kg per day for 3 consecutive days, each given at 4-week intervals. In parallel, the patient underwent a cognitive stimulation intervention. Neurological symptoms were assessed with the Fatigue Assessment Scale and the WHO Disability Assessment Schedule 2.0, and the immunological profile was longitudinally analysed during intravenous immunoglobulin treatment. Fatigue scores normalised, neurocognitive performance returned to normal value, and quality of life improved after the first infusion and fully recovered within 1 year. Immunological profiling revealed the presence of an inverted CD4 to CD8 T-cell ratio that persisted during the whole follow-up. We also identified a CD8+ T cell-monocyte complex and spontaneous IFNγ release. Intravenous immunoglobulin therapy was associated with a significant reduction of these complexes, spontaneous IFNγ and TNF production, markers of endothelial inflammation, and circulating autoantibody titres. This patient provides exploratory evidence that high-dose intravenous immunoglobulin was associated with sustained clinical recovery from long COVID over 1 year of follow-up, accompanied by immunological changes consistent with modulation of post-viral immune dysregulation, including a reduction in pathogenic T cell-monocyte synapses. Although causal inference cannot be established from a single patient, these findings suggest that this cellular interaction can contribute to long COVID and that immunomodulation could represent a rational therapeutic approach to be evaluated in selected patients.

Importance:Progressive multifocal leukoencephalopathy (PML) is a life-threatening demyelinating disease caused by reactivation of the JC virus (JCV) in immunocompromised patients. While immune checkpoint inhibitors (ICIs) show therapeutic potential, responses vary and predictive biomarkers are lacking. Objective:To determine whether pretreatment JCV- and/or BK virus-specific T cells in the blood are associated with treatment efficacy. Design, Setting, and Participants:This retrospective cohort study included 111 patients with PML who were treated with ICIs stratified by peripheral virus-specific T cell presence (ELISpot/flow cytometry) between August 2021 and May 2024, with a median (IQR) follow-up of 7 (1-13) months. Of 112 patients with definite PML across 39 centers, 1 patient refused participation; 111 patients were included. Exposure:Patients received pembrolizumab (n = 81), nivolumab (n = 28), or atezolizumab (n = 2) per availability and prescribing practices at participating centers. Main Outcome and Measures:Clinical outcomes, diagnostic parameters, and immune-related adverse events were compared; association of virus-specific T-cell responses with survival was analyzed using the Kaplan-Meier method. Results:The study cohort consisted of 111 patients (median [IQR] age, 61 [50-70] years; 74 male [66.6%]). Twenty-one patients had detectable virus-specific T cells prior to therapy, 22 were T cell-negative and 68 had an unknown T-cell status. T cell-positive patients showed significantly higher response rates and improved survival compared to both T cell-negative patients (18/21 [86%] vs 5/22 [23%]; P < .001; median survival time, none [95% CI, undefined] vs 136.5 days [95% CI, 19 to ∞]; P = .002) and those with unknown T-cell status (18/21 [86%] vs 29/68 [43%]; P = .001; median survival time, none vs 162 days [95% CI, 66 to ∞]; P = .004). They achieved better functional outcomes (median [IQR] modified Rankin Scale score, 3 [2-4] vs 4 [3-6]; P = .009) and lower JC viral load in cerebrospinal fluid (median [IQR], 0 copies/mL [0-502.5] vs 2500 copies/mL [0-6900]; P = .01) during follow-up compared to T cell-negative patients. Immune-related adverse events were most frequent in T cell-negative patients (10/20 [50%]), including the most severe events, and least frequent in T cell-positive patients (2/20 [10%]) (P = .02). Conclusions and Relevance:Preexisting functional virus-specific T cells were associated with better clinical response, longer survival, and lower toxicity in PML. These findings suggest the likely importance of preexisting antiviral immunity for successful ICI therapy.

Recent mpox outbreaks have shown a predominant transmission through sexual contact. Replication-competent virus has been detected in seminal fluid, while in female patients, vaginal lesions, vertical transmission, and miscarriage risk have been reported. This study explored the susceptibility of the lower female genital tract (LFGT) to monkeypox virus (MPXV) infection, the role of sex-hormones in modulating viral replication, and host-virus molecular interactions. Human vaginal (VK2/E6E7) and ectocervical (Ect1/E6E7) epithelial cells were exposed to MPXV clade IIb, and viral replication was assessed. The influence of sex-hormones was evaluated after pretreatment with physiological concentrations of 17-β-estradiol or progesterone. Cellular genes' expression was determined by RT-qPCR and RNAseq, and ELISA was used for protein release analysis. Both cell lines supported productive MPXV infection. 17-β -estradiol and progesterone slightly reduced viral replication in Ect1/E6E7. At 48 hours post-infection, compared to uninfected control, 216 differentially expressed genes (DEGs) were identified in MPXV infected VK2/E6E7 and 11 in Ect1/E6E7, with nine shared DEGs involved in protein folding (HSPA6), chemotaxis (CXCL3, ARC), inflammation and lymphoproliferation (IL11, IL1RL1, MMP-1), and tissue remodeling (IGFN1, MMP-1). MPXV infection significantly increased MMP-1 release in both cell lines, and MMP-1 inhibitors reduced infectious virus production. IFN-β and IFN-λ1 were induced earlier and more pronouncedly in Ect1/E6E7 which also showed slower viral replication than VK2/E6E7. Our analysis demonstrated the MPXV-mediated modulation of common and tissue-specific cellular pathways in the LFGT. The perturbation of tissue remodeling and inflammation in this district has the potential to affect reproductive health and susceptibility to sexually-transmitted-infections.

Patient-reported outcomes (PROs) are often regarded in clinical practice as less reliable than biomarkers because they are patient-dependent and not objectively measurable in the same way as circulating molecules or imaging findings. This view may be reductive. Biomarkers are frequently considered reliable because they are easily quantifiable, yet biological meaning does not depend solely on measurement. In precision and personalized medicine, the absolute level of a circulating hormone, cytokine, or metabolite is often insufficient unless interpreted in relation to how a given patient, at a given time, responds to that molecular signal. If biomarkers are considered less absolute and more context-dependent, the relevance of PROs becomes clearer. Standardized PROs capture the subjective impact of disease on the patient system in a reproducible and clinically interpretable manner. This is particularly relevant in Long COVID, where no validated diagnostic biomarker is currently available, and severity stratification cannot rely exclusively on objective biological measures. Among available tools, the Fatigue Assessment Scale (FAS) may be particularly useful for quantifying the fatigue burden in Long COVID, including both physical and mental components. Moreover, FAS scores have been shown to correlate with the number of symptoms reported by patients, suggesting that this scale may help stratify patients not only according to fatigue severity but also according to overall symptom burden. Greater standardization of clinical characterization through instruments such as the FAS may improve comparability across cohorts and facilitate interpretation of data from different clinical trials.