How is the transplanted patient monitored for episodes of rejection

Usually, rejection concerns the cells of the exocrine part first, with the islets are rejected later. Therefore, monitoring of glycaemic control is not a reliable tool for the follow-up of the patient. The rejection of the pancreas only is less frequent than the rejection of both organs. In cases where the pancreas has been drained in the urinary bladder, the urinary amylase levels are monitored, which decrease when a rejection occurs; but in the case of intestinal drainage, this is not possible. The first clue is a rise of the serum creatinine. A transcutaneous biopsy of the organ and/or the duodenal graft, guided by ultrasound, or transurethral biopsy is performed and antirejection treatment is administered.

What are the pancreatic islets and how is their transplantation performed?

The pancreatic islets (or islets of Langerhans) are groups of cells that are scattered inside the pancreas and produce the pancreatic hormones - the a-cells produce glucagon, the ß-cells insulin, the d-cells somatostatin and the PP-cells the pancreatic polypeptide (Figure 29.1). The islets constitute 2-3 percent of the volume of the pancreas and number roughly one million in a pancreas. They can be isolated from the pancreas of a brain-dead donor and placed with a small intervention (usually through the portal vein, with local anaesthesia) inside the liver of the recipient. The

Preganglionic fibres (vagus n.) v

Langerhans Islet Parasympathetic

Figure 29.1. Schematic representation of the islet of Langerhans.

Preganglionic fibres (vagus n.) v

(parasympathetic n.)

Figure 29.1. Schematic representation of the islet of Langerhans.

number of the transplanted islets determines the sufficient production of insulin. For a 70 kg (154.3 lb) individual, roughly 650,000 islets are needed.

Was this article helpful?

0 0

Post a comment