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As the battle against coronavirus disease 2019 pandemic continues, an increase in workload and medical expenses have been a concern to the health care system worldwide. Developing a measure that helps to conserve the health care resource is, therefore, highly desirable, and the pooling of the specimens for testing is one of the attractive strategies. Recently, we showed that saliva could be a potential alternative specimen for the detection of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) by real‐time polymerase chain reaction (RT‐PCR). In the present study, we performed the pooling of saliva specimens for testing by SARS‐CoV‐2 RT‐PCR. We showed that the saliva pool of either 5 or 10 samples, by allowing the detection of either gene in the pool at an increased cycle threshold cutoff value, further performing individual sample testing in the positive pools did not compromise the detection of SARS‐CoV‐2. Highlights: ‐ Saliva pooling does not compromise the detection of SARS‐CoV‐2 among symptomatic patients under investigation. ‐ Saliva pooling provides advantages in the ease of specimen collection and resource conservation. ‐ Saliva pooling may be useful for mass‐screening program or sentinel surveillance in resource‐limited settings. [ABSTRACT FROM AUTHOR]

Acute HIV-1 infection is characterized by high viremia and massive depletion of CD4+ T cells throughout all tissue compartments. During this time the latent viral reservoir is established but the dynamics of memory CD4+ T cell subset development, their infectability and influence on disease progression during acute HIV-1 infection has not been carefully described. We, therefore, investigated the dynamics of CD4+ T cell memory populations in the RV217 (ECHO) cohort during the acute phase of infection. Interestingly, while we found only small changes in central or effector memory compartments, we observed a profound expansion of stem-cell-like memory CD4+ T cells (SCM) (2.7-fold; P<0.0001). Furthermore, we demonstrated that the HIV-1 integration and replication preferentially take place in highly differentiated CD4+ T cells like transitional memory (TM) and effector memory (EM) CD4+ T cells, while naïve and less mature memory cells prove to be more resistant. Despite the relatively low frequency of productively infected SCM, we suggest that their quiescent phenotype, increased susceptibility to HIV-1 integration when compared to naïve cells and extensive expansion make them one of the key players in establishment and persistence of the HIV-1 reservoir. Moreover, the expansion of SCM in acute HIV-1 infection was a result of Fas upregulation on the surface of naïve CD4+ T cells. Interestingly, the upregulation of Fas receptor and expansion of SCM in acute HIV-1 infection was associated with the early viral setpoint and disease progression (rho=0.47, P=0.02, and rho=0.42, P=0.041 respectively). Taken together, our data demonstrate an expansion of SCM during early acute HIV-1 infection which is associated with disease outcome. [ABSTRACT FROM AUTHOR]

We report a case of an HIV-seronegative pregnant woman with disseminated cryptococcosis, poorly controlled during gestation. Immunological studies showed T-lymphocytopenia during gestation, but rapid recovery postpartum. T-lymphocytopenia may play a role in increased susceptibility to and severity of cryptococcal infection during pregnancy.

Background: Enumeration of CD4+ T-lymphocytes is important in the management of HIV. However, standard laboratory systems based on flow cytometry are expensive, complicated, and thus unavailable to most resource-limited settings where a low-cost and fully automated point-of-care CD4 testing system is required. In attempts to address this issue, a study was conducted to validate the Alere PIMA point-of-care CD4 test., Method: Duplicate values of the absolute number of CD4+ T-lymphocytes in 203 HIV-infected blood samples obtained using the PIMA system were compared with the two predicate single-platform FACSCount and the dual-platform FACSCan (Becton Dickinson Biosciences)., Results: The overall absolute CD4+ T-lymphocyte count obtained using the PIMA system correlated highly with the FACSCount (r = 0.957; mean bias, -54.2 cells/μL; limit of agreement, -190.9 to +82.5 cells/μL) and the FACSCan (r = 0.957; mean bias -44.0 cells/μL; limit of agreement, -179.7 to +91.6 cells/μL). Good correlation and low biases were also observed for samples with CD4+ T-lymphocyte count ranges of 0 to 200 and 0 to 350 cells/μL. Additionally, there was no significant difference in absolute CD4+ T-lymphocyte counts noted between the duplicate samples using the PIMA system., Conclusions: This new point-of-care product is a simple and reliable system and should contribute significantly to the simplification of performing CD4 testing and thus increase access for patients in resource-limited settings. The inability to obtain values for the frequency (%) of CD4+ T-lymphocyte count is one limitation of the PIMA system, the addition of which would be of value for clinical staging or monitoring in HIV-infected pediatric patients.

CD4(+) T-lymphocyte count is an important marker in management of HIV-1-infected patients. The standard single-platform (SP) flow cytometric (FCM) CD4(+) testing that uses the known reference microbeads is expensive; more affordable alternatives are therefore needed. We evaluated the use of glutaraldehyde-fixed chicken red blood cells (CRBCs) as counting beads as an alternative for enumerating CD4(+) T-lymphocyte counts in 87 HIV-1-infected patients. Linear regression analyses revealed an excellent correlation of the SP FCM using CRBCs with the standard SP bead-based FCM method (percentages, r(2) > 0.99; absolute counts, r(2) > 0.98) over the entire range including the clinically relevant range. Mean percent bias for the CRBC method was +0.35% [limits of agreement (LOA): -1.86% to +2.57%]. For absolute CD4(+) T-lymphocytes, the mean biases was -47.76 cells per microliter (LOA: -191.34 to +98.81 cells/microL) with much lower bias for CD4 T-lymphocyte counts <200 cells per microliter (LOA: -31.92 to +22.95 cells/microL). The use of CRBCs is comparable with the use of commercial microbeads. This has resulted in major cost savings to resource-limited countries where the health care system is under increasing pressure to operate cost effectively. This can greatly facilitate and ensure the success of the ongoing antiretroviral therapy program in these countries.

Enumeration of CD4+ T lymphocytes is important in management of HIV-infected patients. However, CD4 testing by current gold standard bead-based flow cytometer (FCM) system is expensive for developing countries. This study compared 2 affordable volumetric FCMs with the 3 predicate FCM systems. CD4+ T-lymphocyte counts on blood samples from 150 HIV-1-infected Thai patients were determined in parallel by 5 FCM systems: the 2 single-platform volumetric FCM systems, Guava and CyFlow(green); the 2 standard single-platform bead-based systems (2-color FACSCount and the TriTEST/TruCOUNT tube using a FACSCalibur FCM); and the dual-platform TriTEST system. Correlation and agreement were analyzed using linear regression and Bland-Altman analysis. Results from these 2 volumetric systems gave similar results and excellent correlation: R2 > 0.93; mean biases ranged from +6.3 to +24.1 cells per microliter more for the Guava. In contrast, the CyFlow(green) showed the lowest values with R2 > 0.97; mean biases ranged from -9.8 to -27.6 cells per microliter. This indicates that the absolute CD4+ T-lymphocyte counts determined by CyFlow(green) are < FACSCount < DP TriTEST < TriTEST/TruCOUNT < Guava. Although the use of these 2 volumetric FCMs could make CD4+ T-lymphocyte enumeration more affordable in resource-poor settings, variations among these systems should be considered if these are to be interchanged.