Relationship between Helicobacter pylori Infection and Plasmacytoid and Myeloid Dendritic Cells in Peripheral Blood and Gastric Mucosa of Children.

PURPOSE: To investigate the frequency and activation status of peripheral plasmacytoid DCs (pDCs) and myeloid DCs (mDCs) as well as gastric mucosa DC subset distribution in Helicobacter pylori- (H. pylori-) infected and noninfected children. MATERIALS AND METHODS: Thirty-six children were studied; twenty-one had H. pylori. The frequencies of circulating pDCs (lineage-HLA-DR+CD123+) and mDCs (lineage-HLA-DR+CD11c+) and their activation status (CD83, CD86, and HLA-DR expression) were assessed by flow cytometry. Additionally, the densities of CD11c+, CD123+, CD83+, CD86+, and LAMP3+ cells in the gastric mucosa were determined by immunohistochemistry. RESULTS: The frequency of circulating CD83+ mDCs was higher in H. pylori-infected children than in the noninfected controls. The pDCs demonstrated upregulated HLA-DR surface expression, but no change in CD86 expression. Additionally, the densities of gastric lamina propria CD11c+ cells and epithelial pDCs were increased. There was a significant association between frequency of circulating CD83+ mDCs and gastric lamina propria mDC infiltration. CONCLUSION: This study shows that although H. pylori-infected children had an increased population of mature mDCs bearing CD83 in the peripheral blood, they lack mature CD83+ mDCs in the gastric mucosa, which may promote tolerance to local antigens rather than immunity. In addition, this may reduce excessive inflammatory activity as reported for children compared to adults.

Evaluation and Analysis of Fellow Learning and Education Curriculum in a Regional Anesthesiology and Acute Pain Medicine Fellowship: A Prospective, Observational Pilot Study.

Background: Since 2017, several regional anesthesiology and acute pain medicine fellowship programs throughout the country have developed various educational didactic curriculums to address the core medical knowledge requirements as set by the Accreditation Council for Graduate Medical Education. Given the paucity of existing literature regarding the medical knowledge acquisition of regional anesthesiology and acute pain medicine fellows, this study aimed to determine how quickly these fellows learn during their fellowship year, with a secondary aim of analyzing a new educational didactic curriculum in its goal of delivering the required medical knowledge. Methods: An 89-question, multiple-choice examination was administered to the 2020-2021 regional anesthesiology and acute pain medicine fellows at the University of Pittsburgh Medical Center during orientation and again at 4 months and 8 months into the fellowship. A secondary analysis of anonymous deidentified answers was completed. Results: Fellows averaged 64%, 74%, and 79% correct responses on the orientation, 4-month, and 8-month exams, respectively. An analysis of the orientation exam revealed that the most commonly incorrect answers stemmed from topics including lower extremity nerve blocks, truncal blocks, and neuraxial anesthesia. The 4-month exam showed overall marked improvement; however, truncal blocks remained the most missed topic. Topics with 100% correct response rates in all examinations were local anesthetic pharmacology and systemic opioids. Conclusions: The results of this study indicate that a large portion of learning occurs during the first 4 months of the fellowship and slows thereafter. Using this simple form of fellowship evaluation, changes to an educational didactic curriculum can be implemented to reach medical knowledge goals more effectively and efficiently as required by the Accreditation Council for Graduate Medical Education.

Regulatory T-cell subset distribution in children with primary hypertension is associated with hypertension severity and hypertensive target organ damage.

BACKGROUND: The relationship between circulating regulatory T-cell (Tregs) subset distribution and hypertension severity in children with primary hypertension is not known. We aimed to find out if target organ damage (TOD) in children with primary hypertension is related to defects in Tregs distribution reflected by their phenotype characteristics. METHODS: The study constituted 33 nontreated hypertensive children and 35 sex-matched and age-matched controls. Using multicolor flow cytometry technique, we assessed a distribution of the total Tregs (CD4CD25CD127) and their subsets (CD45RA-naive Tregs, CD45RA memory/activated Tregs, CD45RACD31 recent thymic emigrants Tregs and mature naive CD45RACD31 Tregs) in the whole blood. RESULTS: Hypertensive children showed decreased percentage of the total Tregs, the CD45RA-naive Tregs, the total CD31 Tregs and the recent thymic emigrants Tregs but elevation of the CD45RA memory/activated Treg and mature naive CD45RACD31 Tregs. Decreased frequency of the total Tregs, naive Tregs and CD31-bearing Treg cell subsets (CD31 total Tregs, CD45RACD31 recent thymic emigrants Tregs) negatively correlated to TOD markers, arterial stiffness and blood pressure elevation. In contrast, increased percentage of memory Tregs and CD31 Tregs subsets positively correlated to organ damage markers, arterial stiffness and blood pressure values. These changes were independent of BMI, age, sex and hsCRP. CONCLUSION: Both diagnosis of hypertension, TOD and arterial stiffness in hypertensive children were associated with decreased population of total CD4 Tregs, limited output of recent thymic emigrants Tregs, and increased pool of activated/memory Tregs. Hypertension was an independent predictor of the circulating Treg subsets distribution irrespective of hsCRP.

Loss of CD31 receptor in CD4+ and CD8+ T-cell subsets in children with primary hypertension is associated with hypertension severity and hypertensive target organ damage.

BACKGROUND: Primary hypertension is associated with still poorly known T-cell dependent immunity defects that participate in the disease development. However, the relationship between peripheral T-cell subset distribution and disease severity in humans is not known. The aim of the study was to find out if target organ damage in adolescents with primary hypertension is associated with thymus-dependent lymphocytes renewal reflected by changes in the T-cell subset phenotype characteristics. METHODS: Using seven-color flow cytometry technique, we assessed CD31, CCR7 and CD28 receptors expression in CD45RA and CD45RO bearing peripheral CD4 and CD8 T-cell subsets. The study included 32 hypertensive children/adolescents and 35 sex-matched and age-matched controls. RESULTS: Children with primary hypertension had slightly increased CD4 T-cell pool but decreased population of CD31 expressing CD4 T-cell subsets (recent thymic emigrants). Frequency of the CD4 and CD4/CD45RA+ T cells lacking CD31 correlated positively with the hypertensive organ damage markers (pulse wave velocity, central blood pressure, left ventricular mass index). Left ventricular hypertrophy was associated with decreased CD4/CD45RA:CD4/CD45RO ratio, loss of the CD31 receptor in the CD4 and CD8 T-cell subsets and increased population of effector/memory T cells bearing CD8/CD28 and CD8/CD45RA+/CCR7 phenotype. Regression analysis revealed that these associations were independent of age, sex, and BMI. CONCLUSION: The results suggest that subclinical arterial injury and left ventricular hypertrophy in adolescents with primary hypertension is associated with declined thymic function and increased pool of T cells bearing effector/memory phenotype.