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This paper proposes a platform trial for conducting A/B tests with multiple arms and interim monitoring to investigate the impact of several factors on the expected sample size and probability of early stopping. We examined the performance of three stopping boundaries: O'Brien Fleming (OBF) stopping for either futility or difference (both), Pocock stopping for futility only, and fixed sample size design. We simulated twelve scenarios of different orders of arms based on various effect sizes, as well as considered 1 or 3 interim looks. The overall findings are summarizing in a flowchart to provide intuitive guidance for the design of the platform based on the simulation. We found that it is better to use OBF stopping for both if there is any effective variant and the trial is sufficiently powered to detect the expected effect size. If the study is underpowered to detect a difference, we recommend fixed sample size design to gather as much information as possible, however if the expected sample size is important to minimize, we recommend using Pocock boundaries with futility monitoring. Our results aimed at helping high-tech companies conduct their own studies without requiring extensive knowledge of clinical trial design and statistical methodology., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

An industry-academic collaboration was established to evaluate the choice of statistical test and study design for A/B testing in larger-scale industry experiments. Specifically, the standard approach at the industry partner was to apply a t -test for all outcomes, both continuous and binary, and to apply naïve interim monitoring strategies that had not evaluated the potential implications on operating characteristics such as power and type I error rates. Although many papers have summarized the robustness of the t -test, its performance for the A/B testing context of large-scale proportion data, with or without interim analyses, is needed. Investigating the effect of interim analyses on the robustness of the t -test is important, because interim analyses rely on a fraction of the total sample size and one should ensure that desired properties are maintained when a t -test is implemented not just at the end of the study, but for making interim decisions. Through simulation studies, the performance of the t -test, Chi-squared test, and Chi-squared test with Yate's correction when applied to binary outcomes data is evaluated. Further, interim monitoring through a naïve approach with no correction for multiple testing versus the O'Brien-Fleming boundary are considered in designs that allow early termination for futility, difference, or both. Results indicate that the t -test achieves similar power and type I error rates for binary outcomes data with the large sample sizes used in industrial A/B tests with and without interim monitoring, and naïve interim monitoring without corrections leads to poorly performing studies., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors. Published by Elsevier Inc.)

Humoral immune perturbations contribute to pathogenic outcomes in persons with HIV-1 infection (PWH). Gut barrier dysfunction in PWH is associated with microbial translocation and alterations in microbial communities (dysbiosis), and IgA, the most abundant immunoglobulin (Ig) isotype in the gut, is involved in gut homeostasis by interacting with the microbiome. We determined the impact of HIV-1 infection on the antibody repertoire in the gastrointestinal tract by comparing Ig gene utilization and somatic hypermutation (SHM) in colon biopsies from PWH ( n  = 19) versus age and sex-matched controls ( n  = 13). We correlated these Ig parameters with clinical, immunological, microbiome and virological data. Gene signatures of enhanced B cell activation were accompanied by skewed frequencies of multiple Ig Variable genes in PWH. PWH showed decreased frequencies of SHM in IgA and possibly IgG, with a substantial loss of highly mutated IgA sequences. The decline in IgA SHM in PWH correlated with gut CD4 + T cell loss and inversely correlated with mucosal inflammation and microbial translocation. Diminished gut IgA SHM in PWH was driven by transversion mutations at A or T deoxynucleotides, suggesting a defect not at the AID/APOBEC3 deamination step but at later stages of IgA SHM. These results expand our understanding of humoral immune perturbations in PWH that could have important implications in understanding mucosal immune defects in individuals with chronic HIV-1 infection. IMPORTANCE The gut is a major site of early HIV-1 replication and pathogenesis. Extensive CD4 + T cell depletion in this compartment results in a compromised epithelial barrier that facilitates the translocation of microbes into the underlying lamina propria and systemic circulation, resulting in chronic immune activation. To date, the consequences of microbial translocation on the mucosal humoral immune response (or vice versa) remains poorly integrated into the panoply of mucosal immune defects in PWH. We utilized next-generation sequencing approaches to profile the Ab repertoire and ascertain frequencies of somatic hypermutation in colon biopsies from antiretroviral therapy-naive PWH versus controls. Our findings identify perturbations in the Ab repertoire of PWH that could contribute to development or maintenance of dysbiosis. Moreover, IgA mutations significantly decreased in PWH and this was associated with adverse clinical outcomes. These data may provide insight into the mechanisms underlying impaired Ab-dependent gut homeostasis during chronic HIV-1 infection.

Objective: Sex discrepancies have been reported in chronic rhinosinusitis (CRS), but limited data exist exploring sex-specific biological processes and sinonasal quality of life., Study Design: Prospective cohort., Setting: Academic medical center., Methods: Demographics, clinical data, and sinonasal mucus were collected from patients with CRS presenting for surgical consideration over a 5-year period. A random forest model and linear regression were used to assess predictor variables for the 22-item Sino-Nasal Outcome Test (SNOT-22) and subdomains. Enzyme-linked immunosorbent assays were used to measure substance P and tryptase in a subset of mucus samples to explore biological differences by sex., Results: In total, 520 patients were studied (mean age 48.3 years, 50.9% female). Males were older (50.1 vs 46.6 years, P = .008), had more polyp disease (48.2% vs 35.5%, P = .004), and had higher mean Lund-Mackay CT score (11.3 vs 9.5, P = .004). Females had a higher overall mean SNOT-22 (40.9 vs 46.9, P = .001) and higher scores in ear/facial, psychological, and sleep domains ( P < .01). Age, objective disease measures, and sex were top predictors for total SNOT-22. Neither mucus substance P or tryptase, alone or paired with sex, correlated with total SNOT-22. Analysis of mucus biomarkers by sex revealed correlation between mucus tryptase in females with the extranasal subdomain ( P = .01)., Conclusion: Sex differences exist in CRS disease manifestations and presentation for surgical consideration. Detection of mucus (substance P and tryptase) was reliable, but in this exploratory study, we were not able to establish neurogenic or allergic inflammatory processes as a large source of differential disease features between sexes.

Objective: Mechanisms leading to anti-citrullinated protein antibody (ACPA) generation in rheumatoid arthritis (RA) are hypothesized to originate in the lung. We undertook this study to understand associations between neutrophil extracellular trap (NET) formation in the lung and local ACPA generation in subjects at risk of developing RA., Methods: Induced sputum was collected from 49 subjects at risk of developing RA, 12 patients with RA, and 18 controls. Sputum neutrophils were tested for ex vivo NET formation, and sputum-induced NET formation of control neutrophils was measured using immunofluorescence imaging. Sputum macrophages were tested for ex vivo endocytosis of apoptotic and opsonized cells. Levels of ACPA, NET remnants, and inflammatory proteins were quantified in sputum supernatant., Results: Spontaneous citrullinated histone H3 (Cit-H3)-expressing NET formation was higher in sputum neutrophils from at-risk subjects and RA patients compared to controls (median 12%, 22%, and 0%, respectively; P < 0.01). In at-risk subjects, sputum IgA ACPA correlated with the percentage of neutrophils that underwent Cit-H3+ NET formation (r = 0.49, P = 0.002) and levels of Cit-H3+ NET remnants (r = 0.70, P < 0.001). Reduced endocytic capacity of sputum macrophages was found in at-risk subjects and RA patients compared to controls. Using a mediation model, we found that sputum inflammatory proteins were associated with sputum IgA ACPA through a pathway mediated by Cit-H3+ NET remnants. Sputum-induced Cit-H3+ NET formation also correlated with sputum levels of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor in at-risk subjects, suggesting a causal relationship., Conclusion: These data support a potential mechanism for mucosal ACPA generation in subjects at risk of developing RA, whereby inflammation leads to increased citrullinated protein-expressing NETs that promote local ACPA generation., (© 2021 The Authors. Arthritis & Rheumatology published by Wiley Periodicals LLC on behalf of American College of Rheumatology.)