HIV-1 DNA and Immune Activation Levels Differ for Long-Lived T-Cells in Lymph Nodes, Compared with Peripheral Blood, during Antiretroviral Therapy.

Elucidating the mechanisms underlying the persistence and location of the HIV reservoir is critical for developing cure interventions. While it has been shown that levels of T-cell activation and the size of the HIV reservoir are greater in rectal tissue and lymph nodes (LN) than in blood, the relative contributions of T-cell subsets to this anatomic difference are unknown. We measured and compared HIV-1 DNA content, expression of the T-cell activation markers CD38 and HLA-DR, and expression of the exhaustion markers programmed cell death protein 1 (PD-1) and T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) in naive, central memory (CM), transitional memory (TM), and effector memory (EM) CD4+ and CD8+ T-cells in paired blood and LN samples among 14 people with HIV who were receiving antiretroviral therapy. HIV-1 DNA levels, T-cell immune activation, and TIGIT expression were higher in LN than in blood, especially in CM and TM CD4+ T-cell subsets. Immune activation was significantly higher in all CD8+ T-cell subsets, and memory CD8+ T-cell subsets from LN had higher levels of PD-1 expression, compared with blood, while TIGIT expression levels were significantly lower in TM CD8+ T-cells. The differences seen in CM and TM CD4+ T-cell subsets were more pronounced among participants with CD4+ T-cell counts of <500 cells/µL within 2 years after antiretroviral therapy initiation, thus highlighting increased residual dysregulation in LN as a distinguishing feature of and a potential mechanism for individuals with suboptimal CD4+ T-cell recovery during antiretroviral therapy. IMPORTANCE This study provides new insights into the contributions of different CD4+ and CD8+ T-cell subsets to the anatomic differences between LN and blood in individuals with HIV who have optimal versus suboptimal CD4+ T-cell recovery. To our knowledge, this is the first study comparing paired LN and blood CD4+ and CD8+ T-cell differentiation subsets, as well as those subsets in immunological responders versus immunological suboptimal responders.

Risk factors and epidemiology of Clostridium difficile infection in hematopoietic stem cell transplant recipients during the peritransplant period.

BACKGROUND: Hematopoietic stem cell transplant (HSCT) recipients represent a high-risk group for developing Clostridium difficile (CD) infection (CDI). We aimed to identify specific risk factors for CDI in an HSCT patient population during the peritransplant period. METHODS: We performed a case-control study within a cohort of HSCT patients who received a transplant from November 2010 to March 2013. Cases had a clinical presentation compatible with CDI and a positive stool sample Xpert® C. difficile test. Controls were CDI negative and matched on age, gender, and transplant type. Peritransplant period was defined as -30 days or time of stem cell mobilization maneuver to 30 days post transplant in autologous SCT or 90 days post transplant in allogeneic SCT. RESULTS: Of 781 HSCTs performed during the study period, 650 (83.2%) had a stool sample submitted for CD testing. Eight-six (13.2%) cases with CDI were identified. Most of the cases were diagnosed within a week after transplantation (median of 5 days). In adjusted analysis, prior hospitalization (odds ratio [OR]: 2.01, 95% confidence interval [CI] 1.2-3.36), prior cephalosporin administration (OR 2.72, 95% CI: 1.54-4.83), and prior chemotherapy (OR: 3.26, 95% CI: 1.92-5.5) were significantly associated with CDI. CONCLUSIONS: Hospitalization, and prior antibiotic and chemotherapy use are risk factors that are not easily modifiable, which emphasizes the need to start investigating preventive or prophylactic strategies in this high-risk population.

COVID-19 Infection Outcomes and Testing Outreach Efforts Among People Living With HIV in Milwaukee, Wisconsin.

INTRODUCTION: Since the beginning of the COVID-19 pandemic, the incidence and severity of COVID-19 co-infection in people living with HIV (PLWH) has been an area of investigative research. Clinic databases of PLWH provide opportunities to investigate outcomes of COVID-19 co-infection and efficacy of outreach efforts, which are integral to patient care during health crises. METHODS: All PLWH over 18 years of age who receive care at the Froedtert & Medical College of Wisconsin Adult Infectious Disease Clinic and who had a COVID-19 test performed during May 2020 through March 2021 were included for analysis. All patients received an individualized phone call with COVID-19 testing education and information. Automated data collection and manual chart review were used to acquire information on demographics, outreach efforts, COVID-19 testing results, and COVID-19 clinical course. RESULTS: Four hundred sixty-two COVID-19 tests completed on 793 PLWH were included, with 40 (8.7%) positive tests and 422 (91.3%) negative tests on a predominantly young, male, and virally suppressed cohort. Most patients had mild to moderate COVID-19 infection (20/27, 74.07%), with 1 patient requiring hospitalization and zero deaths. Three hundred fourteen (39.59%) patients accepted outreach for COVID-19 testing; 171 were tested in our health system, with 72 of those tests occurring within 2 weeks. Outreach efforts demonstrated a statistically significant increase in COVID-19 testing (P < 0.001). CONCLUSIONS: In this largely young, male, virally suppressed cohort of PLWH, most COVID-19 co-infections were associated with mild to moderate disease severity, with 1 hospitalization and zero deaths. Individualized patient outreach efforts were associated with a significant increase in COVID-19 testing, most of which occurred after a single phone call. This outreach process could have utility in other public health arenas, though may be limited by larger patient populations.

Characteristics and Antibiotic Use Associated With Short-Term Risk of Clostridium difficile Infection Among Hospitalized Patients.

OBJECTIVES: Polymerase chain reaction (PCR) has been shown to have an excellent sensitivity and specificity for the detection of Clostridium difficile infection (CDI). Little is known about risk factors for CDI within 14 days of an initial negative test. We sought to determine the characteristics among hospitalized patients associated with risk of short-term acquisition of CDI. METHODS: A case-control study was conducted. Cases were patients who converted from PCR negative to positive within 14 days. Each case was matched with three controls. Conditional logistic regression was used to estimate the association between patient characteristics and CDI. RESULTS: Of the 30 patients in our study who had a positive PCR within 14 days of a first negative PCR (cases), 15 (50%) occurred within 7 days of the initial test. Cases had a higher proportion of intravenous vancomycin use in the previous 8 weeks (odds ratio [OR], 3.38; 95% confidence interval [CI], 1.34-8.49) and were less likely to have recent antiviral agent use (OR, 0.30; 95% CI, 0.11-0.83) compared with controls. CONCLUSIONS: In hospitalized patients, treatment with intravenous vancomycin within the prior 8 weeks of a first negative PCR test for C difficile is a risk factor for short-term risk for hospital-acquired CDI. Repeat testing guidelines for C difficile PCR should take into consideration patients who may be at high risk for short-term acquisition of CDI.