Kidney transplantation and fibrinolytic split products in serum and urine

Intravesical urokinase for the management of clot retention in boys

We successfully used intravesical urokinase in 2 young boys to relieve clot retention occurring as a consequence of upper tract bleeding. Urokinase clot dissolution appears to offer a simple, minimally invasive, atraumatic solution to this infrequent problem.

Expression and localization of plasminogen activator inhibitor 1 mRNA in transplant kidneys

Fibrinolysis in renal transplant rejection has not been systematically investigated but is known to be impaired. By an in situ hybridization technique, we have studied gene expression of plasminogen activator inhibitor 1 (PAI-1) in human renal tissue showing severe acute vascular rejection (n = 8), clinically irreversible (chronic) vascular rejection (n = 3), mild vascular rejection (n = 8), parenchymal rejection (n = 4), 'normal' kidneys (n = 6), and non-rejecting kidneys (n = 6). The results showed that in 7/8 cases showing severe acute vascular rejection and in all three chronic vascular rejection cases, PAI-1 mRNA was expressed by endothelial cells of arterioles and arteries, and interstitial inflammatory cells but was not detectable in any other groups. The expression of PAI-1 was frequently associated with areas of haemorrhage. Expression of PAI-1 might be expected to promote thrombosis and ischaemia, the catastrophic consequence of severe vascular rejection. In irreversible chronic rejection, this seems to be the principal mode of action. However, our observation that there is expression of PAI-1 in areas of haemorrhage in severe acute vascular rejection may suggest an additional potentially protective role, if it were produced as a response to haemorrhage.

Decreased fibrinolytic activity in vessels and ureters of rejecting human kidneys

Plasminogen activator (PA) activity was determined with a histochemical fibrin slide technique in renal arteries, veins and ureters in 62 transplanted kidneys and again at transplantectomy in 12 transplants who later underwent irreversible rejection. At transplantation PA activity was the same whether the grafts later rejected or not. There was a significantly decreased PA activity in the vessels and ureters in rejected transplants. The role of the fibrinolytic system as a pathogenetic factor in rejected kidneys is discussed.

Extraordinary bladder clots

The patient with hematuria and clot retention who has an abnormality in urokinase-plasmin production or coagulopathy may have extraordinary clots. An understanding of the underlying disease and pathophysiology of clot formation will enable the urologist to better evaluate and treat this type of patient. Aberrations in urokinase-plasmin production or consumption occur in many disease states that may not be recognized generally.

Early detection of acute rejection in renal allografts using radioiodinated autologous fibrinogen

131I-labeled autologous fibrinogen was used to detect acute renal allograft rejection in the early postoperative period. Ratios of radioactive counts over transplanted kidneys to those over the heart increased with deposition of radioactive fibrinogen in kidneys undergoing rejection. The test was positive in all instances of acute rejection twelve to twenty-four hours prior to clinical ro biochemical changes. False-positive test results were noted in instances of perinephric hematoma, seroma, and wound abscess and in one patient with urinary tract infection. The test was negative in cases of renal failure secondary to acute tubular necrosis, uric acid nephropathy (in the absence of acute rejection), and chronic rejection. This test is simple, rapid, and practical. It can be performed at the bedside and is free from complications, particularly serum hepatitis.

[Behavior of fibrinogen-split-product-E in fibrinuria following allogeneic kidney transplantation (author's transl)]

80 urine samples from 10 kidney grafted patients were immunologically analyzed for detection of fibrin degradation products by various techniques. Split product E, which was quantitatively determined by two-dimensional immunoelectrophoresis only contributes to a minor part to fibrinuria, but increases significantly during periods of severe acute rejection also during the first 2-3 weeks, when overall fibrinuria is not a useful indicator of impending rejection. Determination of split-product E therefore seems to be a valuable diagnostic procedure.

Serum and urine fibrinogen-fibrin-related antigen (F.R.-antigen) levels in renal disease

The concentration of serum fibrinogen-fibrin-related antigen (F.R.-antigen) was measured in a group of 142 patients with various renal disorders, in 38 of whom urine F.R.-antigen was also estimated. Raised serum F.R.-antigen levels were present in 48% of the patients, with no particular preponderance in any diagnostic category apart from acute reversible intrinsic renal failure in which high levels were invariably present. Significantly-raised serum levels were also present in the patients with microangiopathic haemolytic anaemia and in those with the more severe degrees of renal impairment. Urine F.R.-antigen was increased in 34 of the 38 patients. The amount of F.R.-antigen in the urine correlated with the degree of proteinuria but not with the serum F.R.-antigen levels. The evidence relating to intravascular coagulation in renal disease is reviewed, and it is suggested that there is a high incidence of localized fibrinogen or fibrin degradation in the kidney, which is related more to factors such as the presence of uraemia and microangiopathic haemolytic anaemia rather than to the diagnostic category.

A technique for detecting rejection episodes in human transplant recipients using radioactive fibrinogen

Radioactive 125I-labelled human fibrinogen was given to 32 patients who had received renal transplants. In each case radioactivity was measured over the transplant and expressed as a percentage of the value recorded over the heart. Recipients that were experiencing rejection episodes had higher levels of radioactivity over their transplants when compared with patients who were free of rejection at the time. It is suggested that this technique could be of value in the diagnosis of rejection episodes, particularly in those recipients who remain oliguric after transplantation.