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Abstract Background Single-cell assays of immune function are increasingly used to monitor T cell responses in immunotherapy clinical trials. Standardization and validation of such assays are therefore important to interpretation of the clinical trial data. Here we assess the levels of intra-assay, inter-assay, and inter-operator precision, as well as linearity, of CD8+ T cell IFNγ-based ELISPOT and cytokine flow cytometry (CFC), as well as tetramer assays. Results Precision was measured in cryopreserved PBMC with a low, medium, or high response level to a CMV pp65 peptide or peptide mixture. Intra-assay precision was assessed using 6 replicates per assay; inter-assay precision was assessed by performing 8 assays on different days; and inter-operator precision was assessed using 3 different operators working on the same day. Percent CV values ranged from 4% to 133% depending upon the assay and response level. Linearity was measured by diluting PBMC from a high responder into PBMC from a non-responder, and yielded R2 values from 0.85 to 0.99 depending upon the assay and antigen. Conclusion These data provide target values for precision and linearity of single-cell assays for those wishing to validate these assays in their own laboratories. They also allow for comparison of the precision and linearity of ELISPOT, CFC, and tetramer across a range of response levels. There was a trend toward tetramer assays showing the highest precision, followed closely by CFC, and then ELISPOT; while all three assays had similar linearity. These findings are contingent upon the use of optimized protocols for each assay.

Abstract Background Cryopreservation of PBMC and/or overnight shipping of samples are required for many clinical trials, despite their potentially adverse effects upon immune monitoring assays such as MHC-peptide tetramer staining, cytokine flow cytometry (CFC), and ELISPOT. In this study, we compared the performance of these assays on leukapheresed PBMC shipped overnight in medium versus cryopreserved PBMC from matched donors. Results Using CMV pp65 peptide pool stimulation or pp65 HLA-A2 tetramer staining, there was significant correlation between shipped and cryopreserved samples for each assay (p ≤ 0.001). The differences in response magnitude between cryopreserved and shipped PBMC specimens were not significant for most antigens and assays. There was significant correlation between CFC and ELISPOT assay using pp65 peptide pool stimulation, in both shipped and cryopreserved samples (p ≤ 0.001). Strong correlation was observed between CFC (using HLA-A2-restricted pp65 peptide stimulation) and tetramer staining (p < 0.001). Roughly similar sensitivity and specificity were observed between the three assays and between shipped and cryopreserved samples for each assay. Conclusion We conclude that all three assays show concordant results on shipped versus cryopreserved specimens, when using a peptide-based readout. The assays are also concordant with each other in pair wise comparisons using equivalent antigen systems.

Background: Chronic lymphocytic leukemia (CLL) is the most common type of leukemia. However, published studies of CLL have either only focused on costs among individuals diagnosed with CLL without a non-CLL comparator group or focused on costs associated with specific CLL treatments. An examination of utilization and costs across different care settings provides a holistic view of utilization associated with CLL., Objective: To quantify the health care costs and resource utilization types attributable to CLL among Medicare beneficiaries and identify predictors associated with each of the economic outcomes among beneficiaries diagnosed with CLL., Methods: This retrospective study used a random 20% sample of the Medicare Chronic Conditions Data Warehouse (CCW) database covering the 2017-2019 period. The study population consisted of individuals with and without CLL. The CLL cohort and non-CLL cohort were matched using a 1:5 hard match based on baseline categorical variables. We characterized economic outcomes over 360 days across cost categories and places of services. We estimated average marginal effects using multivariable generalized linear regression models of total costs and across type of services. Total cost was compared between CLL and non-CLL cohorts using the matched sample. We used generalized linear models appropriate for the count or binary outcome to identify factors associated with various categories of health care resource utilization, such as inpatient admissions, emergency department (ED) visits, and oncologist/hematologist visits., Results: A total of 2,736 beneficiaries in the CLL cohort and 13,571 beneficiaries in the non-CLL matched cohort were identified. Compared with the non-CLL cohort, the annual cost for the CLL cohort was higher (CLL vs non-CLL, mean [SD]: $22,781 [$37,592] vs $13,901 [$24,725]), mainly driven by health care provider costs ($6,535 vs $3,915) and Part D prescription drug costs ($5,916 vs $2,556). The main categories of health care resource utilization were physician evaluation/management visits, oncologist/hematologist visits, and laboratory services. Compared with beneficiaries aged 65-74 years, beneficiaries aged 85 years or older had lower use and cost in maintenance services (ie, oncologist visits, hospital outpatient costs, and prescription drug cost) but higher use and cost in acute services (ie, ED). Compared with residency in a metropolitan area, living in a nonmetropolitan area was associated with fewer physician visits but higher ED visits and hospitalizations., Conclusions: The cooccurrence of lower utilization of routine care services, along with higher utilization of acute care services among some individuals, has implications for patient burden and warrants further study.

Background: The responsibilities of being a primary caregiver for a loved one with dementia can produce significant stress for the caregiver, leading to deleterious outcomes for the caregiver's physical and psychological health. Hence, researchers are developing eHealth interventions to provide support for caregivers. Members of our research team previously developed and tested a positive emotion regulation intervention that we delivered through videoconferencing, in which caregiver participants would meet one-on-one with a trained facilitator. Although proven effective, such delivery methods have limited scalability because they require significant resources in terms of cost and direct contact hours., Objective: This study aimed to conduct a pilot test of a socially enhanced, self-guided version of the positive emotion regulation intervention, Social Augmentation of Self-Guided Electronic Delivery of the Life Enhancing Activities for Family Caregivers (SAGE LEAF). Studies have shown that social presence or the perception of others in a virtual space is associated with enhanced learning and user satisfaction. Hence, the intervention leverages various social features (eg, discussion boards, podcasts, videos, user profiles, and social notifications) to foster a sense of social presence among participants and study team members., Methods: Usability, usefulness, feasibility, and acceptability data were collected from a pilot test in which participants (N=15) were given full access to the SAGE LEAF intervention over 6 weeks and completed preintervention and postintervention assessments (10/15, 67%). Preliminary outcome measures were also collected, with an understanding that no conclusions about efficacy could be made, because our pilot study did not have a control group and was not sufficiently powered., Results: The results suggest that SAGE LEAF is feasible, with participants viewing an average of 72% (SD 42%) of the total available intervention web pages. In addition, acceptability was found to be good, as demonstrated by participants' willingness to recommend the SAGE LEAF program to a friend or other caregiver. Applying Pearson correlational analyses, we found moderate, positive correlation between social presence scores and participants' willingness to recommend the program to others (r 9 =0.672; P=.03). We also found positive correlation between social presence scores and participants' perceptions about the overall usefulness of the intervention (r 9 =0.773; P=.009). This suggests that participants' sense of social presence may be important for the feasibility and acceptability of the program., Conclusions: In this pilot study, the SAGE LEAF intervention demonstrates potential for broad dissemination for dementia caregivers. We aim to incorporate participant feedback about how the social features may be improved in future iterations to enhance usability and to further bolster a sense of social connection among participants and study staff members. Next steps include partnering with dementia clinics and other caregiver-serving organizations across the United States to conduct a randomized controlled trial to evaluate the effectiveness of the intervention., (©Ian Kwok, Emily Gardiner Lattie, Dershung Yang, Amanda Summers, Veronika Grote, Paul Cotten, Judith Tedlie Moskowitz. Originally published in JMIR Aging (https://aging.jmir.org), 06.09.2023.)