Distinct patterns of naive, activated and memory T and B cells in blood of patients with ulcerative colitis or Crohn's disease.

Both major subcategories of inflammatory bowel disease (IBD), ulcerative colitis and Crohn's disease are characterized by infiltration of the gut wall by inflammatory effector cells and elevated biomarkers of inflammation in blood and feces. We investigated the phenotypes of circulating lymphocytes in the two types of IBD in treatment-naive pediatric patients by analysis of blood samples by flow cytometry. Multivariate analysis was used to compare the phenotypes of the blood lymphocytes of children with ulcerative colitis (n = 17) or Crohn's disease (n = 8) and non-IBD control children with gastrointestinal symptoms, but no signs of gut inflammation (n = 23). The two IBD subcategories could be distinguished based on the results from the flow cytometry panel. Ulcerative colitis was characterized by activated T cells, primarily in the CD8+ population, as judged by increased expression of human leukocyte antigen D-related (HLA-DR) and the ß1-integrins [very late antigen (VLA)] and a reduced proportion of naive (CD62L+ ) T cells, compared with the non-IBD controls. This T cell activation correlated positively with fecal and blood biomarkers of inflammation. In contrast, the patients with Crohn's disease were characterized by a reduced proportion of B cells of the memory CD27+ phenotype compared to the non-IBD controls. Both the patients with ulcerative colitis and those with Crohn's disease showed increased percentages of CD23+ B cells, which we demonstrate here as being naive B cells. The results support the notion that the two major forms of IBD may partially have different pathogenic mechanisms.

Radioimmunoassay of delta sleep-inducing peptide using an iodinated p-hydroxyphenylpropionic acid derivative as tracer.

A highly sensitive radioimmunoassay for delta sleep-inducing peptide (DSIP) has been developed. A p-hydroxyphenylpropionic acid conjugate of DSIP was used for radioiodination. Using reversed-phase high performance liquid chromatography the labelled DSIP derivative was isolated in a high yield and with a high specific activity. The assay allows measurement of DSIP-like material in body fluids with a minimum detectable concentration of 0.1 ng/ml standard DSIP (10 pg/tube).

Direct radioiodination of estradiol for a sensitive radioimmunoassay.

17 beta-estradiol (E2) was iodinated with the chloramine-T method. The 125I-labelled material was purified with thin-layer chromatography. The major fraction was applied to a radioimmunoassay with an antiserum against estradiol-6-(0-carboxymethyl)oxime-BSA. The sensitivity of the assay was comparable to assays with 3H-E2 or 125I-histamine-E2 as tracers. The working antiserum dilution (1:1 000 000) was the same with 125I-E2 and 3H-E2 but lower than that with 125I-histamine-E2. The results indicate that iodination of the A-ring of estrogens will not cause significant reduction of the immunoreactivity when combined with an antiserum to a B-ring conjugate.

Intraepithelial lymphocytes in the excurrent ducts of the testis of the domestic fowl (Gallus domesticus).

Cells considered to be lymphocytes are reported in the epithelial lining of the excurrent ducts of the testis of normal and vasoligated domestic fowl. They resemble those already reported in the rat and monkey epididymal epithelium, the human intestinal mucosa, and in the bursa of Fabricius. The cytoplasm is usually less dense than that of adjacent epithelial cells, and contains only a few organelles. The nucleus is highly heterochromatic and with no definite nucleolus. Cytoplasmic processes are found to extend from the cell in between epithelial cells. The possible role of these cells in the reproductive tract of the cockerel is discussed.