The effect of age on CD4+ T-cell recovery in HIV-suppressed adult participants: a sub-study from AIDS Clinical Trial Group (ACTG) A5321 and the Bone Loss and Immune Reconstitution (BLIR) study

Older age could be a risk factor for suboptimal CD4+ T-cell recovery in HIV-infected patients despite successful viral suppression. However, evaluation of this effect could be confounded by age-related immune processes such as decreased thymus output, increased immune activation and exhaustion. Here, we established a semi-mechanistic population model simultaneously describing naïve and memory CD4+ T-cell trajectories in 122 participants. Covariate analysis accounting for immune activation showed that older age was significantly associated with faster apparent elimination rate of the naïve T-cells. In addition, female sex predicted slower apparent elimination rate of memory T-cells. Simulations showed that the median maximal CD4+ T-cell count on ART treatment was 593 cells/μL (IQR 442-794) in patients aged 50 years or above and 738 cells/μL (IQR 548-1002) in patients aged 18-35 years. The differences in the percentage of subjects achieving sufficient immune reconstitution (CD4+ T-cell count> 500 cells/μL) between the two age groups were 15, 21 and 26% at year 1, 4 years and steady state, respectively, suggesting that advanced age may have a greater impact on long-term CD4+ T-cell recovery.

Investigating the risk factors for seroprevalence and the correlation between CD4+ T-cell count and humoral antibody responses to Toxoplasma gondii infection amongst HIV patients in the Bamenda Health District, Cameroon

Background Toxoplasmosis is caused by an obligate intracellular tissue protozoan parasite, Toxoplasma gondii that infect humans and other warm-blooded animals. Transmission to humans is by eating raw or inadequately cooked infected meat or through ingestion of oocysts that cats have passed in faeces. Studies have shown life-threatening and substantial neurologic damage in immunocompromised patients; however, 80% of humans remain asymptomatic. The aim of this study was to determine the seroprevalence of Toxoplasma gondii infection in HIV positive patients and the risk factors associated with the infection, and to investigate the correlation between CD4+ T-cell count and toxoplasma specific antibodies as possible predictors of each other amongst HIV patients in the Bamenda Health District of the North West Region of Cameroon. Methods A cross-sectional study was conducted, in which 325 HIV patients were recruited for administration of questionnaire, serological diagnosis of T. gondii and measurement of CD4+ T-cell count. Bivariate and multivariate logistic regression was used to identify risk factors associated with T. gondii infection while the linear regression was used to investigate the relationship between CD4+ T-cell count and antibody levels against T. gondii. Results The findings showed that, majority (45.8%) of HIV patients suffered from chronic (IgG antibody) infection, and 6.5% from acute (IgM and IgM/IgG antibody) toxoplasma infection. The overall sero-prevalence of T. gondii infection amongst HIV patients was 50.5%. On the whole, 43 men (45.7%) and 127 women (55%) presented with anti- T. gondii antibodies; however, there was no significant difference amongst males and females who were positive to T. gondii infection (p = 0.131). Marital status (p = 0.0003), contact with garden soil (p = 0.0062), and garden ownership (p = 0.009), were factors that showed significant association with T. gondii infection. There was no significant difference (p = 0.909) between the mean CD4+ T-cell count of HIV patients negative for toxoplasma infection (502.7 cells/mL), chronically infected with T. gondii (517.7 cells/mL) and acutely infected with T. gondii (513.1 cells/mL). CD4+ T-cell count was neither a predictor of IgM antibody titer (r = 0.193, p = 0.401), nor IgG antibody titer (r = 0.149, p = 0.519) amongst HIV patients acutely infected with T. gondii. Conclusion The findings from this study underscore the need to implement preventive and control measures to fight against T. gondii infection amongst HIV patients in the Bamenda Health District.

13 Isolated exercise-induced pulmonary hypertension is associated with clinical worsening and poor immunological control in HIV patients

Aims Exercise-induced pulmonary hypertension (Ex-PH) may represent the earliest sign of pulmonary arterial hypertension (PAH) in human immunodeficiency virus (HIV) patients. We investigated its association with clinical and immunological status, virologic control, and response to antiviral therapy. Methods and results In 32 consecutive HIV patients with either low (n = 29) or intermediate probability (n = 3) of PH at rest, we evaluated the association of isolated Ex-PH with: time to HIV diagnosis; CD4+ T-cell count; clinical progression to acquired immunodeficiency syndrome (AIDS); development of resistance to antiretroviral therapy (ART); HIV RNA levels; time to beginning of ART; current use of protease inhibitors; combination of ART with boosters (ritonavir or cobicistat); immuno-virologic response to ART; and ART discontinuation. Isolated Ex-PH at stress echocardiography (ESE) was defined as absence of PH at rest and systolic pulmonary arterial pressure (sPAP) >45 mmHg or a > 20 mmHg increase during low-intensity exercise cardiac output (<10 l/min). In our cohort, 22% (n = 7) of the enrolled population developed Ex-PH which was inversely related to CD4+ T-cell count (P = 0.047), time to HIV diagnosis (P = 0.014) and time to onset of ART (P = 0.041). Patients with Ex-PH had a worse functional class than patients without Ex-PH (P < 0.001). Ex-PH and AIDS showed a trend (P = 0.093) to a direct relationship. AIDS patients had a higher pulmonary vascular resistance compared to patients without Ex-PH (P = 0.020) at rest echocardiography. Conclusions The presence of isolated Ex-PH associates with a worse clinical status and poor immunological control in HIV patients. Assessment of Ex-PH by ESE may help identify subgroups of HIV patients with a propensity to develop subclinical impairment of pulmonary circulation following poor control of HIV infection.

Frequency, Histologic, and Prognostic Significance of CD30 Expression in AIDS-associated Diffuse Large B-Cell Lymphoma

Introduction: AIDS-related Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease, with a variable response to chemotherapy depending on, and not limited to, cell of origin, double/triple hit, or MYC/BCL-2 co-expression status. Similar to DLBCL, AIDS-related DLBCL (ARL) with non-germinal center histology or MYC expression reports poorer response to treatment. In the immunocompetent population CD30+ DLBCL defines a histology with improved survival, however, the characteristics and outcomes of ARL expressing CD30 are not well studied. Methods: We assessed 3 cohorts of ARL. The first cohort, consisted of of an immunohistochemistry tissue microarray (TMA) of 30 ARL patients, followed by two validation cohorts. The first validation was a TMA of 80 ARL, from the AIDS Cancer Specimen Resource. Both TMAs were stained for CD10, BCL6, MUM1, CD20, Ki67, EBER, MYC (by IHC) cut off at 40%, BCL2 (by IHC) cut off 50%, and CD30 (considered positive if any CD30 was expressed on the malignant cells). The third validation cohort was from the County Hospital AIDS Malignancy Project (CHAMP), a prospective database of patients with hematological malignancies and HIV. Of the 100 cases with ARL, only 25 cases were found to have CD30 staining performed, thus only those cases were included. In total, 135 patients diagnosed with ARL were assessed. Cell of origin and germinal (GCB) vs. non-germinal center (NGC) was determined by the Hans algorithm. Statistical differences between groups were analyzed by the fisher exact test. Survival data, when available, was estimated using the Kaplan-Meier method and compared using the log-rank test. Results: Of the 135 ARL, 30% (n=41) were CD30+. Ninety-one% of the cohort was male. EBER was 23% positive in the entire cohort (n=29/126). EBER was positive in the CD30+ vs. CD30- population, 59% (N=17) vs 26% (p<0.01). Despite 59% of the CD30+ population being EBER positive, 92% of the population had a NGC phenotype, 2% was germinal, and 5% had a null phenotype (p<0.01). Of the 86 patients that were CD30-, 88% were GC vs. 12% NGC (P<0.01). The CD4+ T-cell count at presentation was higher in the CD30- cohort with a mean CD4+ T-cell count of 234 vs.164 cells/ul (p<0.05), similar to historical studies demonstrating a similar effect in germinal vs. non-germinal center ARL. Ki67 > 80% was also higher in the CD30- vs the CD30+ cohort 75 vs.60%, (p=0.052). Myc, BCL2, and double expressor lymphomas were identified 59 vs. 57%, 59 vs. 57%, and 31 vs. 28%, respectively, in the CD30+ ARL vs. the CD30- population, none were statistically significant. Survival data was only obtained for 56 of the patients. In the patients treated in the combined anti-retroviral era (ART), there was no difference in survival in the CD30+ vs. CD30- population, 74% (n=18) vs. 84% (n=12) at 5 years (p=0.8). In the 15 patients treated in the early ART era, the OS at 5 years was 48% for the CD30+ vs. 52% (p=0.4), the rest were treated in the pre-ART era. Conclusion: CD30+ ARL in this cohort represents 30% of all ARL evaluated, and presents almost exclusively as a non-germinal center phenotype and has a strong correlation with EBV. While no differences in survival were identified in this study, possible due to the small numbers of patients assessed with survival data, historically, NGC ARL have been shown to have poorer outcomes, by 20-30% in studies with da-EPOCH. As such, the need for better therapies, potentially to overcome these poor prognostic factors, should be studied further. Figure 1 Figure 1. Disclosures Reid: ADC Therapeutics: Other: Serves as Principle Investigator, Research Funding; Aptose Biosciences: Other: Serves as Principle Investigator, Research Funding; Millennium Pharmaceuticals: Other: Serves as Principle Investigator, Research Funding; Xencor: Other: Serves as Principle Investigator.

LB8. Lower SARS-CoV-2 IgG and Pseudovirus Neutralization Titers Post-mRNA Vaccination among People Living with HIV

Background Limited data are available on whether there are differences in the immune response to SARS-CoV-2 vaccination by HIV status or by mRNA vaccine type. Methods We saved residual outpatient laboratory samples of all previously mRNA-vaccinated individuals in the adult medicine clinics of a public hospital with a large outpatient HIV clinic during May 2021, and then excluded individuals with prior SARS-CoV-2 infection. We next 1:1 matched 100 PLWH to 100 outpatient HIV-negative adult medicine patients receiving care for chronic medical conditions on days since completion of second vaccination (minimum 10), sex, age +/-5 years, and the type of mRNA vaccine received. We defined a non-response as reciprocal pseudovirus neutralizing titer< 10 and anti-RBD IgG< 10 relative fluorescent units, and compared non-response by HIV status using mixed models. Results In each matched group there were 13 women; 25 received the mRNA-1273 vaccine and 75 received the BNT162b2 vaccine; the median age was 59. The median time from second vaccination was 35 days (IQR: 20–63). Among PLWH, the median CD4+ T-cell count was 511 (IQR: 351–796) and 5 individuals had HIV RNA > 200. We found 2.4-fold greater odds of pseudovirus neutralizing antibody non-response among PLWH compared to people without HIV (95% CI=1.1–5.4). Although few individuals in each group did not mount an IgG response (12 among PLWH vs. 5; p=0.08), continuous anti-RBD IgG concentrations were 43% lower among PLWH (95% CI=0.36–0.88). Among PLWH, when adjusting for age, sex, and days post-vaccination, each 100-cell increase in CD4+T-cell count was associated with 22% higher neutralizing antibody titers (GMR 1.22; 95% CI=1.09–1.37). Unsuppressed HIV RNA >200 was associated with 89% lower neutralizing antibody titers (GMR 0.11; 95% CI=0.01–0.84). Receipt of the BNT162b2 vs. mRNA-1273 vaccine was associated with 77% lower neutralizing titers (GMR 0.23; 95% CI=0.08–0.65) among PLWH. Post-mRNA Vaccination SARS-CoV-2 IgG Concentrations and Pseudovirus Neutralizing Titers by HIV Status and Vaccine Conclusion PLWH had lower than expected response to mRNA SARS-CoV-2 vaccines, with the highest non-response among those with low CD4+ counts, unsuppressed HIV RNA, and those who received the BNT162b2 vaccine. Immunization strategies to improve immune responses among PLWH should be studied, and may include booster vaccination or preference of the mRNA-1273 vaccine in this group. Disclosures Matthew A. Spinelli, MD, MAS, Nothing to disclose Monica Gandhi, MD, MPH, Nothing to disclose

996. CD4+ T-Cell Lymphopenia Associated with Frequent Plateletpheresis in Healthy Donors

Background Frequent plateletpheresis using the Time Accel leukoreduction system chamber may result in lymphopenia in healthy donors, with increased donation in the previous year associated with CD4+ T-cell count of less than 200 cells/µL. However, this finding has not been replicated and the clinical significance of plateletpheresis-associated lymphopenia remains unclear. Methods A prospective observational study of healthy plateletpheresis donors aged 18 or older who donated at least once in the previous 365 days was conducted at the Kraft Blood Center at Brigham and Women’s Hospital/Dana Farber Cancer Institute, where the Time Accel system is used exclusively. Blood was drawn immediately before plateletpheresis or at least 2 weeks after the last donation to assess for total lymphocyte and CD4+ T-cell counts. Results A total of 86 participants were enrolled: 23 had 1-5 donations, 36 had 6-19 donations, and 27 had 20-24 donations within the previous 365 days (Figure 1). For the low-, medium-, and high-frequency donation groups, the median age was 53 years (IQR 43-64), 61 years (IQR 53-68), and 61 years (IQR 55-65), respectively. The median total lymphocyte count was 1.5 (IQR 1.3-1.9), 1.2 (IQR 0.9-1.5), 0.8 (IQR 0.6-0.9) 103 cells/µL, and the median CD4+ T-cell count was 648 (IQR 531-843), 525 (IQR 348-698), and 220 (IQR 184-347) cells/µL. CD4+ T-cell counts were < 200 cells/µL in 0/23 (0%), 3/36 (8%), and 9/27 (33%) participants across the three groups. Total lymphocyte and CD4+ T-cell counts were inversely correlated with the number of platelet donations in the prior 365 days, R2 = 0.384 (Fig 2) and 0.402 (Fig 3) respectively. Conclusion Frequent plateletpheresis using Time Accel leukoreduction system chamber is associated with CD4+ T-cell lymphopenia, with counts below 200 cells/µL seen in one third of those who donated 20-24 times in the previous year. Vaccine immunogenicity studies are ongoing to evaluate the clinical significance of this finding. Disclosures Stephen R. Walsh, MDCM, Janssen Vaccines (Scientific Research Study Investigator)Regeneron (Scientific Research Study Investigator)Sanofi Pasteur (Scientific Research Study Investigator)

The host immune response of a discharged COVID-19 patient with twice reemergence of SARS-CoV-2: a case report

Background The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic. There have been reports that long-term SARS-CoV-2 RNA shedding and re-infection of COVID-19 patients existed. However, the specific mechanism, diagnosis, and treatment of COVID-19 are still unclarified. Case presentation In this case, we reported a 64-year-old patient who had a long-term course of COVID-19 for 174 days with two retests of SARS-CoV-2 RNA positive after discharging from the hospital. The patient’s serum immunoglobulin G (IgG) of SARS-CoV-2 tested positive after the initial infection. And during treatment, the CD4 + T cell count and ratio to peripheral blood mononuclear cell (PBMC) were in dynamic change. Conclusions Our results suggested that the host immune system responded with IgG production after SARS-CoV-2 infection, but was not protective enough for the patient. The reemergence of SARS-CoV-2 could be related to the cell count and proportion of CD4 + T cells in PBMC. And the increase of CD4 + T cells after treatment may help to clear the virus.

Evaluation of the expression pattern of 4 microRNAs and their correlation with cellular/viral factors in PBMCs of Long Term non-progressors and HIV infected naïve Individuals

Background: Long-term non-progressors (LTNPs) are small subsets of HIV-infected subjects that can control HIV-1 replication for several years without receiving ART. The exact mechanism of HIV-1 suppression has not yet been completely elucidated. Although the modulatory role of microRNAs (miRNAs) in HIV-1 replication has been reported, their importance in LTNPs is unclear. Objective: The aim of this cross-sectional study was to assess the expression pattern of miR-27b, -29, -150, and -221, as well as their relationship with CD4+ T-cell count, HIV-1 viral load, and nef gene expression in peripheral blood mononuclear cells (PBMCs) of untreated viremic patients and in LTNPs. Methods: MiRNAs expression levels were evaluated with real-time PCR assay using RNA isolated from PBMCs of LTNPs, HIV-1 infected naive patients, and healthy people. Moreover, CD4 T-cell count, HIV viral load, and nef gene expression were assessed. Results: The expression level of all miRNAs significantly decreased in the HIV-1 patient group compared to the control group, while the expression pattern of miRNAs in the LNTPs group was similar to that in the healthy subject group. In addition, there were significant correlations between some miRNA expression with viral load, CD4+ T-cell count, and nef gene expression. Conclusion: The significant similarity and difference of the miRNA expression pattern between LNTPs and healthy individuals as well as between elite controllers and HIV-infected patients, respectively, showed that these miRNAs could be used as diagnostic biomarkers. Further, positive and negative correlations between miRNAs expression and viral/cellular factors could justify the role of these miRNAs in HIV-1 disease monitoring.