Reproducibility of in-home CFRD screening using continuous glucose monitoring and mixed meal tolerance test

Background: Cystic fibrosis related diabetes (CFRD) is associated with insulin-remediable pulmonary decline, so early detection is critical. Continuous glucose monitors (CGM) have shown promise in screening but are not recommended by clinical practice guidelines. Little is known about the reproducibility of CGM results for a given patient. Methods: Twenty non-insulin treated adults and adolescents with CF placed an in-home CGM and wore it for two 14-day periods. Participants underwent a mixed meal tolerance test (MMTT) on day 5 of each 14-day period. Glycemic data from CGM 1 and CGM 2 were compared regarding published thresholds to define abnormality: percent time >140 mg/dL of ≥4.5%, percent time >140 mg/dL of >17.5%, and percent time >180 mg/dL of >3.4%. Results of the repeat MMTT were compared for peak glucose and 2-hour glucose thresholds: >140 mg/dL, >180 mg/dL, and >200 mg/dL. Results: For percent time >140 mg/dL of ≥ 4.5%, five of 20 subjects had conflicting results between CGM 1 and CGM 2. For percent time >140 mg/dL of >17.5% and >180 mg/dL of >3.4%, only one of 20 subjects had conflicting results between CGM 1 and CGM 2. On the MMTT, few participants had a 2-hour glucose >140 mg/dL. Peak glucose >140 mg/dL, 180 mg/dL, and 200 mg/dL were more common, with 10–37% of participants demonstrating disagreement between CGM 1 and CGM 2. Conclusions: Repeated in-home CGM acquisitions show reasonable reproducibility regarding the more stringent thresholds for time >140 mg/dL and >180 mg/dL. More data is needed to determine thresholds for abnormal mixed meal tolerance tests in CFRD screening

Reduced expression of NFAT-associated genes in UCB versus adult CD4plus T lymphocytes during primary stimulation

The cellular and molecular mechanisms underlying the blunted allo-responsiveness of umbilical cord blood (UCB) T cells have not been fully elucidated. Protein expression of NFATc2 (nuclear factor of activated T cells c2), a critical transcription factor necessary for up-regulation of multiple cytokines known to amplify T-cell allogeneic responses, is reduced in UCB T cells. Affymetrix oligonucleotide microarrays were used to compare gene expression of primary purified CD4+ UCB T cells to adult peripheral blood CD4+ T cells (AB) at baseline, 6, and 16 hours of primary stimulation. NFAT-regulated genes exhibited lower expression in UCB CD4+ T cells including the following: granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-{gamma} (IFN-{gamma}), tumor necrosis factor-{alpha} (TNF-{alpha}), interleukin 3 (IL-3), IL-4, IL-5, IL-13, IL-2 receptor {alpha} (IL-2R{alpha}; CD25), CD40L, and macrophage inflammatory protein 1 {alpha} (MIP-1{alpha}). Transcription factors involved in the NFAT pathway including C/EBP{beta}, JunB, and Fosl1 (Fra-1), as well as Th1- and Th2-related transcription factors STAT4 (signal transducers and activators of transcription 4), T-bet, and c-maf showed reduced expression in UCB compared with AB during primary stimulation. Reduced cytokine, chemokine, and receptor expression was also found in UCB. Gene array data were confirmed using RNase protection assays, flow cytometry, and quantitative multiplexed cytokine measurements. Reduced global expression of NFAT-associated genes, as well as cytokines and chemokines, in UCB CD4+ T cells may contribute to the decreased graft-versus-host disease (GVHD) observed after UCB transplantation

Deficient IFN-gamma Expression in Umbilical Cord Blood (UCB) T Cells Can Be Rescued by IFN-gamma-Mediated Increase in NFATc2 Expression

Regulation of nuclear factor of activated T cells-c2 (NFATc2) gene expression is not clearly defined. We previously reported reduced NFATc2 protein expression in cord blood T lymphocytes. Here we show that NFATc2 expression in T cells is dependent in part on the presence of IFN-gamma during primary stimulation, as blocking of IFN-gamma blunted NFATc2 protein and mRNA upregulation. Conversely, addition of exogenous IFN-gamma during stimulation resulted in increased expression of NFATc2 in cord blood T lymphocytes. This correlated with rescue of deficient IFN-gamma expression by cord blood T cells. Rescue of IFN-gamma expression in cord blood T cells was dependent on the presence of antigen-presenting cells, as addition of IFN-gamma during stimulation of purified cord blood T cells did not result in an increase of IFN-gamma expression, and depletion of monocytes ablated the rescue of IFN-gamma expression. Our results point to impaired function in the antigen-presenting cell population of cord blood, playing a role in the hyporesponsiveness of T cells

Clinical endpoints in the controlled human challenge model for Shigella: A call for standardization and the development of a disease severity score.

Since 1946 the controlled human infection model (CHIM) for Shigella has been used to improve understanding of disease pathogenesis, describe clinical and immunologic responses to infection and as a tool for vaccine development. As the frequency and intent for use in vaccine comparisons increases, standardization of the primary endpoint definition is necessary.Subject-level data were obtained from previously conducted experimental Shigella CHIM studies. Signs and symptoms severity were categorized consistently across all studies. Sign and symptom correlations were estimated and univariate models were utilized to describe the association between stool output and other Shigella-attributable signs and symptoms. Multiple correspondence and hierarchical clustering analyses were performed to describe the co-occurrence of signs and symptoms. A disease score is proposed based on the co-occurrence of these events.Data were obtained on 54 subjects receiving 800 to 2000 colony forming units (cfu) of S. flexneri. The median maximum 24 hour stool output was 514 ml (IQR: 300, 998 ml) with a median frequency of 6 (IQR: 4, 9). Subjects reported abdominal pain or cramps (81.5%), headache (66.7%) and anorexia (64.8%), 50.0% had a fever and 27.8% had gross blood in multiple loose stools. Multiple correspondence analyses highlighted co-occurrence of symptoms based on severity. A 3-parameter disease severity score predicted shigellosis endpoints and better differentiated disease spectrum.Dichotomous endpoints for Shigella CHIM fail to fully account for disease variability. An ordinal disease score characterizing the breadth of disease severity may enable a better characterization of shigellosis and can decrease sample size requirements. Furthermore, the disease severity score may be a useful tool for portfolio management by enabling prioritization across vaccine candidates with comparable efficacy estimates using dichotomous endpoints

Box and whisker plot of developed <i>Shigella</i> CHIM disease severity score by previously utilized dichotomous endpoints for shigellosis.

<p>Footnote: Endpoint 1 (solid line): diarrhea (≥2 loose stools ≥200 grams over 48 hours or a single loose stool ≥300 grams) OR fever (oral temperature ≥100.0°F) OR gross blood confirmed by hemoccult in ≥1 loose stool; Endpoint 2 (dashed line): severe diarrhea (≥6 loose stools in 24 hours or >800 grams of loose stool in 24 hours) OR moderate diarrhea (4–5 loose stools in 24 hours or 401–800 grams of loose stool in 24 hours) AND [fever (oral temperature >100.4°F) or with moderate enteric/constitutional symptoms (nausea, vomiting, abdominal cramps/pain, myalgia, arthralgia, rigors, tenesmus, fecal urgency)] OR gross blood confirmed by hemoccult in ≥2 loose stools in 24 hours and enteric/constitutional symptoms (nausea, vomiting, abdominal cramps/pain, myalgia, arthralgia, rigors, tenesmus, fecal urgency).</p

Studies utilized to characterize <i>Shigella</i> CHIM endpoints and to develop a disease severity score.

<p>Studies utilized to characterize <i>Shigella</i> CHIM endpoints and to develop a disease severity score.</p

Frequency (percent) of <i>Shigella</i>-attributed signs and symptoms in four CHIMs with <i>S</i>. <i>flexneri</i> 2a strain 2457T.

<p>Frequency (percent) of <i>Shigella</i>-attributed signs and symptoms in four CHIMs with <i>S</i>. <i>flexneri</i> 2a strain 2457T.</p