Survival of human parathyroid tissue xenotransplanted in nude mice after 9 to 55 months' cryopreservation.

Survival of human parathyroid tissue xenotransplanted after cryopreservation was studied. Peroperative biopsies from 26 patients were cryopreserved and xenotransplanted into nude mice after 9 to 55 months. At 8 to 12 weeks after transplantation, the morphology of the transplanted tissue was compared to that of the original tissue after thawing and before transplantation. Morphologically viable tissue was observed in 20 out of 26 nude mice (77%). Based on the morphological appearance, the parathyroid transplants were arranged into four "quality" groups. No correlation existed between the quality of the transplants and duration of storage, or between the age and sex of the patients. There was no correlation between initial clinical diagnosis or histopathological patterns (primary, secondary and tertiary hyperplasia [n=16], adenoma [n=9], one case undetermined) and transplant survival. After thawing and transplantation, all parathyroid grafts, except one, were morphologically either of the same or somewhat lower quality.

An improved method for the detection of soluble interleukin 2 receptors in liver transplant recipients by flow cytometry.

A new flow cytometric method (FCM) for detection of soluble interleukin 2 receptor (sIL-2R) in serum was established. Using this method, results from one to forty samples can be obtained in less than 2 hr as compared with 5 hr in an ELISA. Comparing over 300 sera samples tested by both methods, we found the FCM to be as specific and sensitive as the ELISA, but even more reproducible. Regression analysis of ELISAt on FCMt showed there is a strong relationship between the two assays and they mimic each other over time. We studied the daily serum levels of sIL-2R by FCM in 18 liver allograft recipients: 7 were in the stable group, 6 in the rejection group, and 5 had both rejection and infection. Low or decreasing sIL-2R levels correlated with absence of rejection. In patients with rejection episodes, a typical elevation of sIL-2R was followed by a rapid decrease of sIL-2R after successful response to rejection therapy. Patients with multiple complications displayed elevated sIL-2R levels. In conclusion, because of its rapid turnover time and accuracy, the FCM has the potential to determine the appropriate timing of post-transplant liver biopsies.

A flow cytometric method for the detection of the development of antibody to Orthoclone OKT3.

Orthoclone OKT3 is a monoclonal antibody used in the treatment of transplant rejection. The development of anti-OKT3 antibodies after therapy with this drug is a side effect which must be monitored. The current ELISA test to detect these antibodies is difficult to standardize between laboratories and does not lend itself to frequent monitoring of small numbers of samples. This prompted us to develop a new method employing flow cytometry to detect the development of anti-murine antibodies. Comparing samples tested by both techniques, we found the flow cytometric method to be more sensitive and as the ELISA methodology. This technique is adaptable to numerous serologic assays and could greatly expand the use of flow cytometry in the clinical laboratory.