Prognostic importance of histological and immunopathological assessment of skin and rectal biopsies in patients with GVHD.

Skin and rectal biopsies from patients with GVHD were examined histologically and immunopathologically before and after treatment for the disease. The patients were divided into two groups: those showing a good response to treatment and those showing a poor or no response. The aims of the study were to assess the possibility of predicting the response to treatment and to compare good and poor responders after treatment. The results show that there are no features on either skin or rectal biopsy that could identify those patients with early GVHD who would respond to treatment. Following treatment with steroids there was no change histologically in the grading of the skin biopsy whereas the rectal biopsy showed improvement in six of nine good responders and no improvement in the poor responders. There was an increase in infiltrating lymphocytes in both the skin and rectum of patients showing a poor response and this is most likely due to the ongoing immune reaction. The pre-treatment biopsy did not show any features that would predict this development and was therefore of no prognostic value. However, examination of skin and rectal biopsies may aid in determining whether patients are responding to the treatment given for GVHD.

Non-invasive assessment of intraluminal lipolysis using a 13CO2 breath test.

Techniques available for the study of lipase activity in the gut are unsatisfactory. Breath tests measuring labelled carbon dioxide (13CO2) may provide a useful means for this assessment. Six subjects with cystic fibrosis and pancreatic insufficiency and 10 controls received a test meal containing [13C] trioctanoin, and breath 13CO2 was measured using a dual inlet, dual detector isotope ratio mass spectrometer. Comparison of postprandial breath 13CO2 enrichment allowed complete separation between children with pancreatic insufficiency and controls. Administration of one capsule of pancreatic enzyme with the test meal resulted in an increase in 13CO2 production in all six patients, and four capsules produced a further increase in five of the six. Serial fat balance studies on four of the patients while receiving comparable doses of oral enzyme failed to demonstrate a progressive improvement in fat absorption. The [13C]trioctanoin breath test may prove a safe, non-invasive technique not only for the detection of pancreatic insufficiency, but also for the quantitative study of intraluminal lipolysis.