Familial deficiency of a plasma factor stimulating vascular prostacyclin activity

Recurrence of hemolytic uremic syndrome after renal transplantation in children: a report of the North American Pediatric Renal Transplant Cooperative Study

BACKGROUND

Hemolytic uremic syndrome (HUS) is the cause of renal failure in 2-4% of children on dialysis. After renal transplantation, HUS can recur, but recurrence rate and risk factors are controversial.

METHODS

We reviewed the recurrence of HUS within the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) registry and used a separate questionnaire to ascertain additional clinical information.

RESULTS

Of 68 renal allografts, HUS recurred in 6 allografts (8.8%) occurring in five patients (8.2%). Four patients had atypical HUS, whereas one patient had classic HUS. HUS recurred after transplantation in 33 days or less in all but one allograft. Outcome was poor with five of six allografts lost, despite treatment with fresh-frozen plasma or plasmapheresis. Cyclosporine had no effect on outcome or HUS recurrence.

CONCLUSIONS

The risk of HUS recurrence in the allograft is 8-9% and is heightened in atypical HUS. Treatment was not effective and graft outcome was poor. Cyclosporine does not affect HUS recurrence.

Genetic studies into inherited and sporadic hemolytic uremic syndrome

Hemolytic uremic syndrome (HUS) in adults carries a high morbidity and mortality, and its cause remains unknown despite many theories. Although familial HUS is rare, it affords a unique opportunity to elucidate underlying mechanisms that may have relevance to acquired HUS. We have undertaken a genetic linkage study based on a candidate gene approach. A common area bounded by the markers D1S212 and D1S306, a distance of 26 cM located at 1q32 segregated with the disease (Z max 3.94). We demonstrate that the gene for factor H lies within the region. Subsequent mutation analysis of the factor H gene has revealed two mutations in patients with HUS. In an individual with the sporadic/relapsing form of the disease we have found a mutation comprising a deletion, subsequent frame shift and premature stop codon leading to half normal levels of serum factor H. In one of the three families there is a point mutation in exon 20 causing an arginine to glycine change, which is likely to alter structure and hence function of the factor H protein. Factor H is a major plasma protein that plays a critical regulatory role in the alternative pathway of complement activation. In light of these findings and previous reports of HUS in patients with factor H deficiency, we postulate that abnormalities of factor H may be involved in the etiology of HUS.

Recurrent diseases in the kidney transplant

Virtually all diseases affecting the native kidney recur in the kidney transplant with the exception of Alport syndrome, polycystic kidney disease, hypertension, chronic pyelonephritis, and chronic interstitial nephritis. Fortunately, in the majority of patients, recurrence of the original disease has minimal clinical impact, with only approximately 5% of all graft loss occurring as a result of recurrent disease. The primary renal diseases that commonly recur include membranoproliferative glomerulonephritis type II, IgA nephropathy, and focal and segmental glomerular sclerosis. The most common systemic disease that recurs is diabetic nephropathy. Living-related transplantation should be used with caution in patients with the hemolytic uremic syndrome, recurrent focal and segmental glomerular sclerosis, and membraneous glomerulonephritis. Fabry disease and primary hyperoxaluria type I are no longer absolute contraindications to kidney transplantation.

Circadian variation of tissue plasminogen activator and its inhibitor, von Willebrand factor antigen, and prostacyclin stimulating factor in men with ischaemic heart disease

OBJECTIVES

To determine whether plasma concentrations of tissue plasminogen activator antigen, von Willebrand factor antigen, and prostacyclin stimulating factor and plasminogen activator inhibitor activity show circadian variation in men with ischaemic heart disease.

DESIGN

Blood samples were obtained every four hours for 24 hours from 10 men with ischaemic heart disease. The men were ambulant from 08:10 until 00:00 when they went to bed and they remained in bed until 08:00 the following morning.

PATIENTS

Ten men with positive diagnostic exercise tolerance tests with no significant past history, who were not regularly taking any medical treatment except for glyceryl trinitrate.

RESULTS

There was significant circadian variation in plasminogen activator inhibitor activity (p = 0.001) (peak value 04:00 and trough value 20:00), but not in plasma concentrations of tissue plasminogen activator antigen, von Willebrand factor, or prostacyclin stimulating factor.

CONCLUSION

Men with ischaemic heart disease showed a significant circadian variation in fibrinolysis. The combination of peak values of plasminogen activator inhibitor activity and failure of plasma concentrations of tissue plasminogen activator antigen to increase in the early morning must predispose to thrombosis at this time. The circadian variation in fibrinolysis may contribute to the increased incidence of myocardial infarction in the morning.

Partial purification of serum prostacyclin stimulatory activity by heparin-agarose column; abnormality detected in diabetics

Human plasma-derived serum (PDS) stimulated the production of 6-keto-PGF1 alpha (a stable metabolite of PGI2) by cultured bovine aortic endothelial cells. The stimulation was both time- and dose-dependent. The main prostacyclin stimulatory activity (PSA) in human PDS remained biologically active after dialysis and was inhibited by the simultaneous addition of heparin. The maximum inhibition of PSA was obtained with 10 micrograms/ml heparin. PDS obtained from patients with non-insulin-dependent diabetes mellitus (NIDDM, n = 24) showed significantly less PSA than that from the control subjects (n = 11). A decrease in PSA was also found in diabetic patients using dialyzed PDS. The PSA in human PDS had a specific binding affinity to heparin-agarose and the bound PSA was eluted by a linear gradient of NaCl, which showed two major PSA peaks at 1.0 and 1.5 M NaCl. The dialyzed, mixed PDS from patients with NIDDM and the control subjects was independently applied to a heparin-agarose column and eluted by a linear gradient of NaCl. Comparing the PSA in each peak between the diabetic and the control dialyzed PDS, the PSA at 1.5 M NaCl was markedly decreased in the diabetic patients, but the PSA at 1.0 M NaCl did not change significantly. These observations suggest that the decreased PSA in human diabetic PDS may result mainly from the decrease in the activity of a specific non-dialyzed factor(s) which can bind to heparin. The decreased PSA in serum seems to be responsible in part for decreased PGI2 synthesis by the vascular wall of diabetics.

Post-transplantation outcome of patients with hemolytic-uremic syndrome: update

The outcome of renal transplantation in patients with hemolytic-uremic syndrome (HUS) is variable in reported cases. An update of the previously published series of patients from the University of Minnesota is reported. Seventeen patients with HUS received a renal transplant. Seven patients had recurrent HUS based on strict clinical and histological features and in 4 of these patients grafts were loss from recurrent HUS, with 1 patient losing three successive grafts. Three patients had histological features consistent with HUS but lacked some of the clinical features. Seven patients had no evidence of recurrent HUS post transplantation. The incidence of recurrence of HUS post transplantation in this updated report remains high (7/17 patients). There was no difference in the allografts used (living-related donor grafts were more common in all groups) or in the immunosuppression in the different groups of patients; only 1 patient with recurrent HUS received cyclosporine. The published cases of transplantation in patients with HUS show a variable recurrence rate of 0-25% in different centers with a poor graft outcome in patients with recurrence; a higher incidence of early chronic vascular rejection with decreased graft survival is also reported in patients without recurrence. Patients with HUS post renal transplant are at a variable risk of recurrence of HUS or decreased graft survival, and the factors responsible for this outcome are not known.

The organ donor

Vascularized organ transplantation is now a widely applied therapy for patients with end-stage diseases of the heart, lungs, liver, kidneys, and pancreas. A critical shortage of donor organs exists in the United States and, as a consequence, prospective transplant recipients die while waiting for a life-saving transplant. The apparent shortage of cadaver organs is, in large part, caused by the reluctance and failure of the physician and the public to promote cadaver organ donation. Educational awareness programs for both professional personnel and the public at large are needed to increase the number of potential donors and multiorgan procurements carried out. All victims of trauma with severe closed head injury or cerebrovascular catastrophe secondary to anoxia should be considered as potential organ donors and referred to the local organ procurement agency for evaluation.

Recurrence of disease following renal transplantation

The diagnosis of recurrent renal disease after transplantation is dependent on an accurate and complete diagnosis of the initial cause of renal failure and a similar determination of the cause of graft failure. To be classified as recurrent, the disease in the renal graft must be identical to that seen in the native kidneys. Recurrence of disease accounts for less than 2% of all graft failures, but the overall incidence of recurrent disease is probably 5 to 10 times more common. The most frequent cause of recurrent disease is glomerulonephritis, which was first recognized to recur soon after renal transplantation was introduced. It was then recognized that a variety of metabolic disorders would recur, but it has taken 25 years of experience for a clear picture to emerge of recurrence in most conditions. No initial cause of renal failure poses a contraindication to at least one attempt at transplantation, although with Fabry's disease and oxalosis, a special assessment of the risks for the individual recipient is warranted. In some patients, experience has shown the need for a delay in the commitment to transplantation (eg, in those with anti-glomerular basement membrane [GBM] antibody glomerulonephritis or Henoch Schonlein purpura), the need for the choice of a particular immunosuppressive regimen (eg, in hemolytic uremic syndrome [HUS]), the need for avoidance of primary nonfunction (eg, in oxalosis), and the desirability of avoiding live kidney donation (eg, in heterozygote donors in Fabry's disease, high-risk recipients with focal glomerulosclerosis, and in recipients with HUS). Probably all types of glomerulonephritis recur, but with great variation in frequency and severity. In some forms of glomerulonephritis, recurrence may be frequent and definite on histopathological criteria but may only have a minor clinical expression (eg, dense deposit disease, anti-GBM antibody glomerulonephritis, IgA nephropathy), but in others, recurrence is less predictable yet it is clearly associated with premature graft failure (eg, focal glomerulosclerosis, membranous nephropathy). A common theme emerging is that where the initial glomerulonephritis is aggressive and causes kidney failure over a short time, recurrence is more likely, and when present, it will lead to graft failure with an increased frequency. Clinical manifestations, the frequency of recurrence, and the prognosis of the graft are now identified for most conditions. Unexpected observations have included the rarity of recurrent systemic lupus erythematosus (SLE), the immediate return of heavy proteinuria in focal glomerulosclerosis, and the predictable return of dense deposit disease.(ABSTRACT TRUNCATED AT 400 WORDS)

Stimulatory activity on prostacyclin production decreases in sera from streptozotocin-induced diabetic rats

We recently reported that serum stimulatory activity on prostacyclin (PGI2) production by cultured bovine aortic endothelial cells decreased in noninsulin-dependent diabetic patients. In the present study, this activity was compared in streptozotocin-induced (STZ) diabetic rats and controls. Platelet-poor plasma-derived serum (PDS) from Wistar male rats stimulated 6-keto-PGF1 alpha production (a stable metabolite of PGI2) by cultured bovine aortic endothelial cells, rat lung fibroblasts, and rat aortic rings in a time- and dose-dependent manner. Namely, PDS from rats has a stimulatory activity on PGI2 production (PGI2 stimulatory activity; PSA). Furthermore, PSA in PDS from STZ diabetic rats (n = 12) significantly decreased as compared with that from control rats (n = 10) using three types of in vitro systems. The reduction in PDS-stimulated PGI2 production by the vascular wall may lead to platelet hyperaggregation and thrombus formation in diabetics, which is considered to be involved in the pathogenesis of diabetic macro- or microangiopathy.

Absence of plasma prostacyclin stimulating activity deficiency in hemolytic uremic syndrome

We compared the effect of plasma from 19 children with hemolytic uremic syndrome (HUS) on prostacyclin (PGI2) production by fresh rat aortic rings to the effect of plasma from 17 age- and sex-matched normal children, taking into account the PGI2 baseline aortic production (PGI2 release in presence of buffer, 21 determinations). After 10, 20, 30, 40, and 60 minutes incubation of rat aortic tissue with either plasma or buffer, the presence of PGI2 was studied by measuring by radioimmunoassay (RIA) the concentration of 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha). 6-keto-PGF1 alpha production increased with time in the two groups of plasma samples and in the presence of buffer, but 6-keto-PGF1 alpha production (ng/mg dried tissue) after 30 minutes incubation and mean 6-keto-PGF1 alpha production (slope of regression line, ng/mg/min) were significantly (P less than 0.01) lower in the presence of normal plasma compared with buffer, and significantly (P less than 0.01) higher in the presence of HUS plasma compared with normal plasma. There was no significant difference between buffer and HUS plasma. We conclude that, under our experimental conditions, normal plasma had an inhibitory activity on 6-keto-PGF1 alpha production by rat aorta. This inhibitory activity was absent in HUS plasma.

Decreased plasma prostacyclin-regenerating activities in diabetics

We assessed prostacyclin-regenerating activities (PGI2-RA) in 27 each of diabetic patients and of normal subjects by incubating plasma with "exhausted" rat aortic tissues, and compared these activities with platelet aggregability, vascular complications and the levels of fasting blood sugar (FBS) as an indicator of diabetic control. Patients' plasma showed a significantly decreased PGI2-RA when compared with normal (p less than 0.001). The activities in the patients with enhanced ADP-induced platelet aggregation in plasma or in whole blood were significantly decreased as compared with those with normal platelet functions (p less than 0.01). The patients with diabetic retinopathy showed significantly decreased PGI2-RA compared with those without this complication (p less than 0.02). A significant negative correlation was found between PGI2-RA and FBS levels before or during treatment. This abnormality found in patients' plasma appeared to be reversible and related to the degree of diabetic control. These results suggest that the decreased PGI2-RA could play a pathogenetic role together with platelet hyperaggregability in the development of microvascular and thrombotic complications in some diabetic patients.

Recovery from mitomycin C-induced hemolytic uremic syndrome. A case report

Mitomycin C (MMC) is a cytotoxic agent that may induce a hemolytic uremic syndrome (HUS) with severe renal insufficiency. Of all reported patients with terminal renal failure only two survived with chronic hemodialysis. A patient with advanced gastric cancer in complete remission, who developed MMC-induced HUS, is reported; hemodialysis was necessary because of oliguria. Hemolysis subsided, and after addition of captopril renal function recovered partially. The patient is alive 6 months after discontinuation of hemodialysis. Recently she developed brain metastases. Symptoms of hemolysis did not recur. The pathogenesis and treatment of HUS are discussed.

Efficacy of several plasma components in a young boy with chronic thrombocytopenia and hemolytic anemia who responds repeatedly to normal plasma infusions

This report describes a patient with thrombocytopenia, microangiopathic hemolytic anemia, proteinuria, and microscopic hematuria that could be transiently improved by the infusion of plasma or various plasma components. An increase in platelet count following the transfusion of normal plasma was predictable and reproducible. In therapeutic trials with commercially available plasma components, factor VIII preparations were effective for inducing an increase in the platelet count and improving hemolytic anemia, but albumin, gamma-globulin, factor IX, and fibronectin preparations were ineffective. Serum from normal donors also relieved the symptoms of this condition in our patient. Partial plasma exchange (1,000 ml/m2 of body surface area) was performed with albumin instead of normal plasma, but there was no significant effect on platelet count or anemia. Large, multimeric von Willebrand factor components of the factor VIII complex (VIII/vWF) were found in the patient's plasma when his platelet count was normal, but their levels were reduced when the platelet count was decreased. The multimers of the patient's plasma were larger than those in normal plasma, but smaller than those in normal platelet lysate. Although the pathogenesis of this disease remains unknown, we conclude that transfusions of normal plasma, serum or factor VIII concentrate provide a factor that causes significant improvement in the thrombocytopenia and hemolytic anemia. Furthermore, large VIII/vWF multimers are possibly directly involved in pathogenesis of this disease.

Hemolytic-uremic syndrome: an analysis of the natural history and prognostic features

Sixty-seven children with hemolytic-uremic syndrome (HUS) were admitted between 1974 and 1981. Of these, 52 (78%) were aged less than 3 years. All children had acute renal failure and 48 (72%) required peritoneal dialysis. The etiology in twenty cases varied from bacterial and viral infections (7 and 5 cases, respectively) to renal irradiation with chemotherapy (2) and preexisting glomerulopathy (1). 5 (7%) children died during the acute phase of the illness. Long-term follow-up (mean 3 years 3 months) of 56 cases showed that 37 children (60%) had so far experienced no functional sequelae and 8 (13%) only mild sequelae while 3 (5%) were on iterative hemodialysis, 3 had severe chronic renal failure and high blood pressure (HBP) and 5 (8%) had HBP and normal kidney function. While the recovery rate was approximately 60% in all age groups, the mortality rate and serious after-effects were twice as frequent (42%) in children over 3 years of age as in those less than 3. Renal histology (total of 37) showed 12 cases of cortical necrosis, 22 of glomerular thrombotic microangiopathy (TMA) and 3 arterial TMA. Prognosis was poor for all cases of arterial TMA and 58% of those exhibiting cortical necrosis.

Effect of Cyclosporin A on prostacyclin synthesis by vascular tissue

NZW rabbits with acute serum sickness given Cyclosporin A (CyA) 25 mg/kg/day develop glomerular capillary thrombosis similar to that seem in the haemolytic uraemic syndrome (HUS). Bone marrow recipients treated with CyA may also develop a similar renal lesion associated with a haemolytic uraemic-like syndrome. In the HUS, impaired production of prostacyclin by vascular tissue may be found and has been associated with a lack of a plasma factor which stimulates prostacyclin synthesis. We therefore examined, in six normal rabbits, treated with CyA 25 mg/kg for five days, the ability of plasma from treated and untreated rabbits to stimulate prostacyclin synthesis from normal rabbit aortic rings. Plasma from untreated rabbits produced 21.5 +/- 6.9 ng 6-keto PGF1 alpha/ml/mg wet weight aorta (mean +/- SEM). However, the ability of plasma from CyA-treated rabbits to stimulate prostacyclin production was profoundly reduced. This was apparent within 24 hours of starting and persisted for seven days after therapy was stopped: mean of values from all rabbits bled from start of therapy until seven days after therapy stopped was 3.7 +/- 0.5 ng/ml/mg. We suggest that the renal complications of CyA therapy are related to a failure of normal vascular prostacyclin synthesis due to lack of a prostacyclin-stimulating plasma factor.

Prostacyclin production by whole blood from children: impairment in the hemolytic uremic syndrome and excessive formation in chronic renal failure

The capacity of leukocytes to produce prostacyclin (PGI2) from endogenous and from platelet-derived endoperoxides was tested in whole blood. During the acute phase of the hemolytic uremic syndrome (H.U.S.), the PGI2-production was lower than the controls, whereas the blood from children with chronic renal failure produced higher amounts. Production of PGI2 by blood from children 3/12 to 6 years after the acute phase of H.U.S. was normal, as was the case with blood from their parents. Furthermore, in two H.U.S.-patients studied serially, the decreased PGI2-production capacity normalized 2 1/2 months after the acute phase.

Deficiency of a plasma factor stimulating vascular prostacyclin generation in patients with lupus nephritis and glomerular thrombi and its correction by ancrod: in-vivo and in-vitro observations

Glomerular thrombi occur frequently in active lupus nephritis. Their presence has been correlated with low platelet counts and with subsequent development of glomerular sclerosis. We have examined the plasma PGI2 generating capacity of 8 patients with active lupus nephritis with thrombi that were to undergo defibrination therapy with ancrod. PGI2 generation by these plasma samples was significantly decreased as compared both to normals and to 6 individuals with lupus nephritis and no glomerular thrombi. Significant improvement in the capacity to generate PGI2 was seen in the post-ancrod treatment plasma samples. the pathogenesis of this defect is discussed.

Accelerated prostacyclin degradation in the thrombotic thrombocytopenic purpura

Plasma prostacyclin (PGI2) degradation rate was measured in a 39-year-old man with chronic thrombotic thrombocytopenic purpura (TTP). His disease responded to plasma exchange, or plasma infusion alone, given at 3-4 week intervals. Plasmapheresis with albumin replacement had an adverse effect. PGI2 degradation rate was measured by incubation of exogenous PGI2 with plasma at 37 degrees C and recording of PGI2 activity after one, five, and fifteen min incubation by measurement of inhibition of platelet aggregation. The PGI2 degradation rate of the patient was significantly higher than that of normal subjects. The degradation rate improved after each plasma treatment and correlated well with clinical improvement. Moreover, the degradation rate of PGI2 could be corrected in vitro by the addition of normal plasma. When the patients plasma was incubated with aortic rings, PGI2 activity was reduced but the level of its inactive end product, 6-keto-PGF1 alpha, was normal. These findings indicate that our patient had normal PGI2 stimulating activity but had an abnormal rate of PGI2 degradation. Accelerated PGI2 degradation which leads to PGI2 deficiency may be important in the pathogenesis of microvascular thrombosis.