Small intestinal injury in the graft versus host reaction: an innocent bystander phenomenon.

Marked morphological and functional damage to the small intestine occurs during the graft versus host reaction (GVHR); the structural lesion is characterized by crypt hypertrophy and villus shortening. The purpose of this study was to determine whether the intestine is injured in the GVHR as an antigenic target of the grafted immunocompetent cells or as an innocent bystander to donor-host lymphoid interaction. Implants of fetal mouse small intestine from either C57BL/6 or (C57BL/L X DBA/2)F1 (BDF1) hybrid donors were placed under the kidney capsule of adult BDF1 male mice. After 4 weeks, both groups were injected with parental C57BL/6 spleen cells, syngeneic BDF1 spleen cells, or no cells. Two weeks after injection the mice were killed and the implants were removed for histological processing and measurement of villus height and crypt depth. The villus-crypt ratio in the BDF1 implants of mice receiving C57BL/6 cells was 1.32 +/- 0.3 compared to 2.51 +/- 0.4 in controls receiving either syngeneic BDF1 cells or no cells (P less than 0.001). The villus-crypt ratio in the C57BL/6 implants of mice receiving C57BL/6 cells was 1.79 +/- 0.4 compared to 2.48 +/- 0.4 in the controls receiving either syngeneic BDF1 cells or no cells (P less than 0.001). Because the latter implant is antigenically identical to the spleen cells eliciting the GVHR, we conclude that the small bowel is injured in the GVHR as an innocent bystander to cytotoxic donor-host lymphoid interaction.

Results of nationwide screening of blood and plasma for antibodies to human T-cell lymphotrophic III virus, type III.

From April 22 to July 28, and from October 7 to November 3, 1985 the American Red Cross, the Council of Community Blood Centers, the American Association of Blood Banks, and the American Blood Resources Association provided the Food and Drug Administration with data at 2-week intervals on human T-lymphotropic virus type III (HTLV-III) test kit results at blood and plasma collection centers. Reports were received from over 150 blood collection centers that screened 2,502,829 units of blood for antibody to HTLV-III by enzyme-linked immunosorbent assay (ELISA) during nine 2-week surveillance intervals. Of these, 25,324 or 1.01 percent were initially reactive and 8443 or 0.34 percent were repeatedly reactive. The repeatedly reactive rate for women was 0.33 percent and for men 0.30 percent. Data for source plasma was collected at 275 locations and tested at eight central laboratories showed that for 2,603,652 units screened (which may represent multiple collections from the same donor) 3978 or 0.15 percent were repeatedly reactive. Screening results from both blood and plasma collection centers varied over time and among kits.