Search Results (970)

Background: People living with HIV (PLWH) constitute a vulnerable population during the COVID-19 pandemic; however, it remains uncertain whether long-term suppressive antiretroviral therapy (ART) restores sufficient immune competence to support robust hybrid immunity. While vaccination followed by breakthrough infection—termed hybrid immunity—typically elicits potent humoral responses in immunocompetent individuals, the functional quality and breadth of these responses against evolving Omicron subvariants remain poorly characterized in PLWH. This study aimed to assess functional antibody responses, including neutralizing activity and Fc effector functions, in vaccinated and unvaccinated PLWH who experienced breakthrough infection with Omicron subvariants BA.4/5 or BF.7. Methods: We enrolled three cohorts between December 5 and December 20, 2022: 25 HIV-negative individuals with breakthrough infection (BTI-HC), 20 ART-experienced PLWH with breakthrough infection following three-dose COVID-19 vaccination (BTI-HIV), and 10 ART-experienced PLWH with primary infection without prior vaccination (PI-HIV). All HIV-positive participants were receiving suppressive ART with regimens based on non-nucleoside reverse transcriptase inhibitors or integrase strand transfer inhibitors for a median of 3.4 years. We measured receptor-binding domain (RBD)-specific IgG, neutralizing antibody titers against ancestral D614G, Delta, BA.1, BA.4/5, BF.7, XDV, KP.2, and KP.3 variants, and antibody-dependent cellular cytotoxicity (ADCC) responses. Results: Despite lower absolute CD4⁺ T cell counts, BTI-HIV participants mounted RBD-binding IgG, neutralizing antibody, and ADCC responses that were comparable to BTI-HC and significantly exceeded PI-HIV across all tested variants. Both breakthrough infection cohorts exhibited immunological imprinting, with higher neutralizing titers against ancestral D614G than infecting BA.4/5 or BF.7 variants. Emerging variants XDV, KP.2, and KP.3 demonstrated substantial neutralization escape in all groups. PI-HIV showed markedly diminished neutralization breadth and failed to generate enough responses against all tested Omicron strains. Conclusions: Suppressive ART enables PLWH to mount hybrid immunity—conferred by vaccination followed by BF.7 or BA.4/5 breakthrough infection—with neutralizing and ADCC responses comparable to HIV-negative individuals, and significantly exceeding those of unvaccinated PLWH with primary infection. This underscores the critical role of vaccination in establishing effective hybrid immunity in this population. However, we observed immunological imprinting, with higher titers against ancestral strains than against infecting variants, and substantial escape by emerging sublineages XDV, KP.2, and KP.3 across all groups. These findings support prioritizing updated variant-containing vaccines for HIV-positive populations and reinforce the essential role of vaccination in this vulnerable group. Full article

Nontuberculous mycobacteria (NTM) are ubiquitous environmental organisms capable of causing diverse clinical manifestations. Their epidemiology among people with HIV remains insufficiently characterized. This study examined the epidemiology of NTM among people with HIV admitted to the Hospital for Infectious Diseases in Warsaw between 2017 and 2023. Data on CD4+ T-cell counts, type of NTM involvement, species identification, and antimicrobial resistance were obtained from medical records. In the analyzed group the median of the CD4+ T-cell count was 25 cells/mm³ (IQR 65 cells/mm³). Late HIV diagnosis was observed in n = 45/50 (90.0%) patients. NTM colonization was identified in n = 20 (33.9%) patients, while n = 39 (66.1%) had active NTM disease, including pulmonary (53.9%), disseminated (41.0%), and extrapulmonary (5.1%) forms. Mycobacterium kansasii was the most common species among colonized patients, n = 7/24 (29.2%), whereas Mycobacterium avium predominated among patients with NTM disease, n = 30/42 (71.4%). Among patients with NTM disease, in vitro resistance to at least one antimicrobial agent was observed in 80.0% of M. avium isolates. High levels of resistance of M. avium were noted for ethambutol (n = 8/8, 100%), moxifloxacin (n = 16/22, 72.8%) and linezolid (n = 9/21, 42.9%). Proper identification of Mycobacterium species and its antibiotic resistance might be helpful in selecting effective antimicrobial therapy. Early HIV diagnosis is needed to prevent NTM disease. Full article

Circulating tumor cells (CTCs) are valuable liquid-biopsy biomarkers, yet their extreme rarity makes high-purity, high-throughput enrichment challenging. In spiral inertial microfluidics, high cell loading induces long-range hydrodynamic interactions that broaden the focused blood-cell stream; consequently, a subpopulation completes the ~0.5 and ~1.0 Dean-cycle migrations with a phase delay, compressing the CTC–blood cell gap and degrading purity. Here we propose a Dean-cycle phase-regulated double-spiral design informed by this phenomenon. This design aims to mitigate the stream-broadening effect by boosting the Dean number during the first half-cycle to promote synchronized blood-cell migration and shifting the CTC equilibrium position near one full cycle to further widen the CTC–blood cell separation. We implement this strategy in a second-generation double-spiral microfluidic chip (SDMC) and scale it to a four-channel parallel array (ASDMC). Under optimized conditions, ASDMC processes diluted whole blood (hematocrit = 4%) without the need for red blood cell (RBC) lysis or antibody labeling, achieving a sample throughput of 1200 μL·min⁻¹. Specifically, it exhibits a mean recovery rate of 98.8% across three spiked tumor cell lines (MCF-7, PC-9, and Mahlavu) and a mean white blood cell (WBC) depletion efficiency of 93.3%. In a pilot clinical testing of 20 patients (NSCLC and HCC), enriched fractions enabled immunofluorescence identification of CK⁺CD45⁻DAPI⁺ CTCs, with an exploratory trend of increasing CTC counts with advanced disease stage (4–34 cells·mL⁻¹). These results describe a scalable, label-free platform, and the observed purification performance aligns with our proposed mechanism: Dean-cycle phase regulation to mitigate blood-cell migration lag. Our findings support further technical validation and clinical assessment in larger cohorts. Full article

Cytomegalovirus (CMV) pneumonia presents diagnostic challenges in AIDS patients, as plasma monitoring often fails to reflect pulmonary viral burden. This retrospective study evaluated the prognostic value of bronchoalveolar lavage fluid (BALF) CMV DNA loads in 189 AIDS patients with pulmonary infections and CD4⁺ T cell counts < 200 cells/μL. CMV DNA in BALF and plasma was quantified to analyze associations with immune status and 90-day all-cause mortality. CMV detection was significantly more frequent in BALF (49.7%) than plasma (26.6%), indicating viral compartmentalization. An optimal BALF cutoff of 10,000 copies/mL was established for mortality prediction. Patients exceeding this threshold exhibited significantly lower CD4⁺ counts, increased mechanical ventilation requirements (34.4% vs. 11.5%), and prolonged hospital stays. Crucially, a BALF CMV load > 10,000 copies/mL was identified as an independent predictor of 90-day mortality (adjusted odds ratio = 3.78; 95% CI: 1.12–12.71). In conclusion, pulmonary CMV replication is prevalent and often compartmentalized in AIDS patients. A BALF CMV DNA load exceeding 10,000 copies/mL serves as a biomarker of profound immunosuppression and independently predicts poor clinical outcomes, highlighting the necessity of quantitative BALF monitoring for risk stratification. Full article

Background/Objectives: Hidradenitis suppurativa (HS) is a chronic, immune-mediated inflammatory skin disease characterized by painful nodules, abscesses, sinus tracts, and progressive fibrosis. Vascular activation is becoming increasingly acknowledged as an important factor in HS pathogenesis; however, the effects of tumor necrosis factor alpha (TNF-α) blockade on vascular remodeling in HS remain poorly characterized. This study investigated the impact of TNF-α inhibition by adalimumab (ADA) on endothelial and fibroblast-associated markers in HS lesions. Methods: Formalin-fixed paraffin-embedded skin samples from 71 HS patients were analyzed, including treatment-naive (n = 38) and adalimumab-treated (n = 33) cases. Histopathology and immunofluorescence were performed using antibodies against CD31, von Willebrand factor (vWF), α-smooth muscle actin (αSMA), vimentin, Ki-67 (proliferation), and cleaved Caspase-3 (apoptosis). ImageJ software was used to determine the immunoexpression of selected markers and vascular density. Vascular density, assessed as vessel count per mm², was designated as the primary endpoint. Sex-related differences were analyzed as exploratory endpoints. Results: Adalimumab-treated tissue exhibited significantly reduced vascular density (p < 0.01) compared to the treatment-naive group. Conversely, vimentin immunoexpression was significantly higher (p < 0.01) in the adalimumab-treated group. No significant differences were found in endothelial Ki-67 or cleaved Caspase-3 expression between treatment groups, indicating that the observed reduction in vascular density is not associated with direct effects on endothelial cell proliferation or apoptosis, but rather may occur indirectly through attenuation of the pro-angiogenic inflammatory milieu. Exploratory sex-stratified analysis revealed that treatment-naive males had significantly higher endothelial proliferation (Ki-67; p = 0.031) and vimentin expression (p = 0.017) compared to treatment-naive females. In the ADA-treated group, males exhibited significantly lower vascular density (p = 0.036) and higher endothelial apoptosis (p = 0.039) compared to females, whereas females showed a significant increase in vimentin expression following treatment (p = 0.008), suggesting possible sex-dependent differences in vascular remodeling. Conclusions: TNF-α blockade is associated with reduced vascular density, consistent with indirect anti-angiogenic effects, suggesting that adalimumab exerts disease-modifying effects on the microenvironment beyond inflammatory cytokine suppression. Sex-dependent differences in vascular regression underscore the importance of considering sex as a biological variable in HS pathogenesis and treatment response. These results highlight the significance of vascular interactions in HS and support adalimumab as a disease-modifying treatment. These exploratory findings require confirmation in longitudinal studies with paired biopsies. Full article

Background/Objectives: Histologic remission has emerged as a key treatment target in inflammatory bowel disease (IBD), but routine assessment requires repeated endoscopy and biopsies. Blood-based indices reflecting inflammation, nutritional status and atherogenic risk are inexpensive and widely available, yet their integrated contribution to histologic activity remains unclear. This study addresses this gap by simultaneously analyzing a broad panel of 44 variables—including nutritional status indicators, CBC-derived inflammation indices, and atherogenic lipid indices—in IBD patients. Methods: In this retrospective study, 100 patients with IBD (50 Crohn’s disease [CD], 50 ulcerative colitis [UC]) without additional comorbidities and with concomitant histologic assessment were analyzed. Histologic activity was coded as active vs. remission. At the time of biopsy, the complete blood count, biochemistry and lipid profile were used to calculate immuno-nutritional indices (CONUT score, prognostic nutritional index), inflammatory indices (neutrophil-to-platelet ratio, platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio [LMR], systemic immune-inflammation index, systemic immune-inflammation index, systemic inflammation response index [SIRI], aggregate index of systemic inflammation, C-reactive protein to albumin ratio) and atherogenic indices (atherogenic index of plasma [AIP], triglyceride-to-HDL cholesterol ratio). Variable selection was performed separately for CD and UC using least absolute shrinkage and selection operator (LASSO) regression and sparse partial least squares discriminant analysis (sPLS-DA). Independently associated predictors were then entered into multivariable logistic regression models, and their discriminative performance was evaluated using ROC analysis with bootstrap-derived 95% confidence intervals. Results: LASSO analysis identified a broadly similar systemic profile associated with histologic activity in CD and UC, dominated by the CONUT score, SIRI, AIP, LMR and red blood cell parameters, whereas demographic features and most routine biochemical markers were shrunk towards zero. Cross-validated AUCs for the LASSO models were 0.93 in CD and 0.87 in UC. sPLS-DA confirmed this pattern: CONUT, SIRI and AIP consistently showed the highest variable importance in projection scores and loadings on the first latent component. In multivariable regression, the CONUT score, SIRI and AIP remained independent predictors of histologic activity in CD, while hematocrit, CONUT score, SIRI and AIP were independently associated with histologic activity in UC. In ROC analysis, AUCs for CONUT, SIRI and AIP were 0.81, 0.89 and 0.87 in UC, and 0.72, 0.82 and 0.83 in CD, respectively. Conclusions: Histologic activity in IBD is characterized by a coupled systemic profile in which immuno-nutritional compromise (captured by CONUT) forms the core signal, supplemented by systemic inflammation (SIRI) and atherogenic dyslipidemia (AIP). These readily available blood-based indices may help to approximate histologic disease activity in clinical practice. However, considering that comorbid diseases may affect these indices, the strict exclusion criteria applied in this study may limit the generalizability of the findings among patients with IBD. Consequently, further validation in larger prospective cohorts is warranted. Full article

Background: Islatravir (ISL) is a first-in-class nucleoside reverse transcriptase translocation inhibitor with high potency and long half-life in peripheral blood mononuclear cells (PBMCs). However, treatment and prevention of HIV with oral ISL in humans has been associated with decreases in total lymphocytes, CD4 T-cells, and B-cells in a dose-dependent manner. We investigated in macaques the effects of oral ISL on lymphocytes, monocytes, granulocytes, and gene expression in PBMCs. Methods: Female pig-tailed macaques (n = 5) received an HIV pre-exposure prophylaxis dose of oral ISL adjusted allometrically once a week for 12 weeks. Complete blood counts and B- and T-cells were monitored prior to, during, and after ISL treatment, and changes in counts were evaluated by using a repeated measures model. Changes in gene expression were investigated in PBMCs during treatment and following treatment discontinuation. Results: ISL treatment was associated with declines in lymphocytes (11.9%, p = 0.0015) and monocytes (22.4%, p = 0.0003), but not granulocytes (0.3%, p = 0.9781). Total lymphocytes and monocytes returned to pre-treatment levels 6 weeks after treatment cessation (p = 0.8244 and p = 0.4620, respectively). Lymphocyte subpopulation analyses showed a significant decline in CD8 (−18.4%, p = 0.0364) and CD20 (−35.3%; p = 0.0002) cells but not CD4 cells (−7.4%; p = 0.3470). Gene set enrichment analysis showed negative enrichment (p_adj < 0.05) of gene pathways associated with immune regulation, cell proliferation, and inflammation. Conclusions: ISL treatment resulted in significant reductions in lymphocytes reproducing clinical toxicity. This effect was reversed after treatment cessation as observed in humans. Our results highlight the value of the macaque model to study immune alterations at the preclinical stage. Full article

HIV infection can promote persistent immune activation and endothelial dysfunction, contributing to atherosclerosis. Carotid intima–media thickness (cIMT) is an established marker of subclinical atherosclerosis. We evaluated the association between cIMT severity and two routinely available markers of immune dysregulation (CD4/CD8 ratio and nadir CD4+ cell count) in people living with HIV (PLWH). We conducted an Italian multicenter cross-sectional study including 1148 PLWH who underwent carotid color Doppler ultrasound. We classified cIMT as ≤0.9, 1.0–1.4, or >1.4 mm and analyzed these categories using multinomial logistic regression, reporting adjusted odds ratios (aORs) with 95% confidence intervals (CIs). We adjusted models for age, sex, BMI, HIV acquisition risk factor, hypertension, diabetes, dyslipidemia/statin use, triglycerides, integrase inhibitor use, and ART duration. cIMT was ≤0.9 mm in 615 (53.6%) participants, 1.0–1.4 mm in 379 (33.0%), and >1.4 mm in 154 (13.4%). Using nadir CD4+ ≥ 200 cells/µL and CD4/CD8 ≥ 1.0 as reference, PLWH with nadir CD4+ < 200 and CD4/CD8 ≥ 1.0 had higher odds of cIMT 1.0–1.4 mm (aOR 1.66, 95% CI 1.02–2.69) and >1.4 mm (aOR 3.45, 95% CI 1.68–7.07). In conclusion, CD4+ nadir and this combined pattern were associated with greater cIMT severity, supporting a role for immune dysregulation in subclinical atherosclerosis. Full article

Objectives: To investigate the potential associations between the daily consumption of unprocessed/minimally processed foods and serum phosphorus levels, CD3+, and CD45+ cell counts in clinically stable people living with HIV (PLHIV). Methods: This is a descriptive cross-sectional study. A total of 92 PLHIV of both sexes participated. Sociodemographic information, physical activity level, anthropometric and body composition data, dietary habits, and blood samples were collected. Results: The mean age of participants was 43.0 ± 12.0 years, with a body mass index of 26.5 ± 6.3 kg/m². The majority were male (60.8%), single (64.1%), had low educational attainment (55.4%), were non-smokers (64.1%) and did not consume alcoholic beverages (51.1%), and were physically active (70.7%). A positive association was observed between the daily consumption of unprocessed/minimally processed foods and serum phosphorus levels (p = 0.01), as well as CD3+ (p = 0.04) and CD45+ (p = 0.04) cell counts. Furthermore, positive correlations were identified between this dietary pattern and serum phosphorus (p = 0.001; r = 0.33) and the percentages of CD3+ (p = 0.03; r = 0.21) and CD45+ (p = 0.03; r = 0.22). Conclusions: The present study suggests that habitual consumption of unprocessed/minimally processed foods is positively associated with serum phosphorus levels, CD3+, and CD45+ cell counts in PLHIV. While these associations do not imply causality or enhanced antiviral immunity, they highlight the potential role of diet quality in the metabolic and immunological maintenance of stable patients. Full article

A novel HIV-1 vaccine candidate under development targeting the highly conserved protease cleavage regions reduced viral acquisition and delayed disease progression in a macaque SIV-challenge model. Breakthrough virus isolated from vaccinees and control animals were sequenced in the regions surrounding the SIV protease cleavages. We identified unique viral mutations that were associated with alterations in viral load and maintenance of CD4+ T cell counts in vaccinees. To evaluate whether the vaccine-elicited mutations were detrimental to virus fitness, we produced 11 mutant constructs and transfection-derived viral stocks harboring mutations in both PCS2 (in CA/p2) and PCS12 (in Nef) that had emerged at high frequency during breakthrough viremia. Virus preparations harboring mutations displayed impaired proteolytic Gag processing, reduced viral RNA incorporation and p27-CA content. These mutants were also compromised in their ability to replicate in primary cells and cell lines. Interestingly, we observed only partial compensation of these PCS2 defects by downstream mutation at PCS12. In sum, we demonstrate that vaccine-elicited immunity directed to viral protease cleavage regions impair viral escape, and breakthrough virus cannot easily restore replicative fitness. Full article

Background: Advanced HIV disease (AHD) remains highly prevalent and is associated with increased morbidity and mortality. Missed opportunities for early diagnosis continue to represent a major public health challenge. Methods: We conducted a multicenter retrospective cohort study including antiretroviral-naive people with HIV (PWH) presenting with AHD (CD4 < 200 cells/µL and/or AIDS) diagnosed between 1 January 2019 and 31 December 2024 in four Italian infectious diseases units. Demographic, clinical and viro-immunological data were collected at baseline and during follow up. Information on healthcare contacts, HIV-related symptoms, and prior HIV testing in the two years preceding diagnosis was obtained through structured interviews. Results: Among 658 newly diagnosed participants with HIV, 224 (34%) presented with AHD, of whom 54% presented with AIDS. Most participants (86.2%) had never undergone HIV testing before diagnosis. In the year preceding diagnosis 29.3% accessed healthcare services for symptoms compatible with HIV infection without being tested for HIV. At one year, 84.2% achieved virological suppression, with a median CD4 count of 260 cells/µL. Overall loss to follow-up was 27.2%. Five-year survival was significantly higher in non-AIDS presenters compared with AIDS presenters (100% vs. 85%, p = 0.005). Conclusions: Missed diagnostic opportunities remain frequent among PWH presenting with AHD, despite prior healthcare contacts. Wider implementation of indicator condition-guided HIV testing is urgently needed to reduce late diagnosis and improve long-term outcomes. Full article

Background/Objectives: Ofatumumab is a fully human anti-CD20 monoclonal antibody approved for the treatment of relapsing forms of multiple sclerosis (MS). While its efficacy and safety have been demonstrated in clinical trials, real-world data focusing on laboratory changes and detailed immunophenotyping during treatment remain limited. The objective of this study was to assess routine laboratory parameters and immunophenotyping profiles in ofatumumab-treated patients in a real-world setting. Methods: We conducted a retrospective, single-center real-world study including 59 patients with relapsing–remitting MS treated with ofatumumab. Routine laboratory parameters were analyzed at the baseline and 6–12 months after treatment initiation. Immunophenotyping by flow cytometry was available for a subset of 29 patients. Infections were assessed during a follow-up period of at least six months. Paired comparisons were performed using the Wilcoxon signed-rank test. Results: Ofatumumab induced a profound and sustained depletion of CD19+ B cells (p < 0.001). Total T cells, CD4+ and CD8+ T-cell counts, the CD4/CD8 ratio, and natural killer (NK) cells remained largely stable over time. NK cells and helper T cells showed a numerical increase without statistical significance. IgM levels and relative lymphocyte percentages showed a statistically significant decrease compared with baseline (p = 0.047 and p = 0.016, respectively), while remaining within reference ranges. Other routine laboratory parameters remained stable. Reported infections were infrequent and predominantly mild. Conclusions: In this real-world cohort, ofatumumab demonstrated a favorable immunological and laboratory profile consistent with its known mechanism of action. These findings suggest that routine laboratory monitoring is sufficient for most patients, while immunophenotyping may be reserved for selected clinical scenarios. Further prospective studies integrating clinical and radiological outcomes are needed to better define the clinical relevance of these immunological findings. Full article

Cold exposure may influence reproductive health through vascular changes, yet its mechanisms remain underexplored. This study aimed to investigate the impact of cold exposure on uterine blood vessels and the expression of the AMPK/PGC-1α gene and protein in adult female SD rats. A primary dysmenorrhea model was established in female Sprague Dawley rats and subjected to continuous cold exposure. Changes in body weight, ear temperature, and estrous cycle were observed. Superoxide dismutase (SOD) activity and adenosine triphosphate (ATP) levels were measured to assess oxidative stress. Uterine tissue morphology was assessed via small animal ultrasound, microcirculation observed using RFLSI imaging, and vascular morphology along with caspase-3 and AMPK expression evaluated histologically and immunohistochemically. CD31 and TUNEL double immunofluorescence were used to assess vascular endothelial apoptosis levels. Western blot was used to analyze Bax, BCL-2, and pAMPK/AMPK expression levels. In vitro injury models were used to treat human umbilical vein endothelial cells (HUVECs) with cold stimulus using the AMPK inhibitor Compound C. RT-PCR quantified Bax, AMPK, p53, and PGC-1α expression. Hypothermia-exposed rats exhibited significantly reduced body weight and ear temperature (p < 0.05), prolonged estrous cycle (p < 0.01), and decreased uterine index (p < 0.01), accompanied by reduced SOD and ATP levels (p < 0.01, p < 0.05). Ultrasound and flow imaging revealed decreased uterine blood flow velocity in the hypothermia group (p < 0.01). Histomorphology revealed disorganized uterine cell arrangement, reduced uterine vessel count (p < 0.01), and increased mean vessel area (p < 0.01) in cold-exposed uteri. Immunofluorescence detection revealed increased vascular endothelial cell apoptosis (p < 0.05). Western blot results showed that proapoptotic protein Bax was upregulated (p < 0.01), Bcl-2 was downregulated (p < 0.05), p-AMPK and p-AMPK/AMPK ratio were elevated (p < 0.01) after cold exposure; Rt-qPCR results indicated that Bax and P53 mRNA were increased (p < 0.01), while PGC-1α expression was elevated (p < 0.01). Rt-qPCR results showed elevated Bax and p53 mRNA (p < 0.01), along with increased AMPK and PGC-1α expression (p < 0.01) in the cold-exposed group. In human umbilical vein endothelial cells (HUVECs), compound C attenuated cold-induced effects (p < 0.01) and downregulated Bax and AMPK expression (p < 0.01). Cold exposure exacerbates uterine oxidative stress and energy imbalance, disrupts microcirculatory homeostasis, and induces endothelial cell apoptosis. Excessive phosphorylation of AMPK may co-activate PGC-1α, jointly contributing to cold-induced uterine dysfunction and exacerbated dysmenorrhea. This study reveals potential signaling pathways underlying cold-induced uterine vascular abnormalities, providing novel theoretical foundations and targeted intervention strategies for the prevention and treatment of primary dysmenorrhea. Full article

Sildenafil, a selective phosphodiesterase-5 (PDE5) inhibitor, supports vascular remodeling, but its effects on angiogenesis and regeneration of ischemic muscle tissue are not fully understood. We investigated the function of sildenafil by employing a murine hindlimb model of ischemia, in which ischemia and angiogenesis is induced by femoral artery ligation (FAL) in the lower leg of mice. Then, 7 days after FAL or sham operation, gastrocnemius muscles of sildenafil-treated and control mice were isolated and processed for histological and immunofluorescence analyses. Sildenafil treatment led to reduced apoptotic areas within the ischemic tissue (ascertained via TUNEL assay) and increased angiogenesis, evidenced by a higher capillary-to-muscle fiber ratio and an augmented number of proliferating capillary cells (CD31⁺/CD45⁻/BrdU⁺), compared to controls. We observed a decrease in the total count of leukocytes (CD45⁺) in sildenafil-treated mice. Regarding macrophage infiltration, we found a reduced total number of macrophages (CD68⁺), along with a shift in macrophage polarization toward the pro-angiogenic and anti-inflammatory M2-like phenotype (CD68⁺/MRC1⁺). In summary, we show that sildenafil treatment contributes to angiogenesis and the regeneration of ischemic muscle tissue, most likely by attenuating inflammatory responses and influencing macrophage polarization in direction to regenerative M2-like polarized macrophages. Full article

Primary prophylaxis of Pneumocystis jirovecii pneumonia (PCP) in people with HIV (PWH) and CD4+ counts <200 cells/µL using trimethoprim/sulfamethoxazole (TMP-SMX) is highly effective but often poorly tolerated. Alternative agents may have limited efficacy or availability. Although rezafungin demonstrated PCP protection comparable to TMP-SMX in animal models, human data are limited to the ongoing ReSPECT trial, and evidence in PWH is lacking. We report the first use of rezafungin as PCP prophylaxis in a PWH. A 43-year-old man presenting with AIDS (HIV-RNA 8.48 × 10⁶ copies/mL; CD4+ 20 cells/µL) was admitted with disseminated tuberculosis and multiple bowel perforations requiring urgent surgery. The postoperative course was marked by infectious and surgical complications. Antitubercular therapy and TMP-SMX prophylaxis were initiated postoperatively, followed by antiretroviral therapy (ART). Later, TMP-SMX was discontinued due to hypersensitivity. Because drug–drug interactions precluded atovaquone or dapsone and pentamidine was unavailable, rezafungin was started. No adverse events or fungal breakthrough infections occurred despite abdominal complications. Further data are needed to determine whether rezafungin represents a viable prophylactic option when standard agents are contraindicated or unavailable. Full article