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

Atypical hemolytic uremic syndrome post-kidney transplantation: two case reports and review of the literature

Atypical hemolytic uremic syndrome (aHUS) is a rare disorder characterized by over-activation and dysregulation of the alternative complement pathway. Its estimated prevalence is 1–2 per million. The disease is characterized by thrombotic microangiopathy, which causes anemia, thrombocytopenia, and acute renal failure. aHUS has more severe course compared to typical (infection-induced) HUS and is frequently characterized by relapses that leads to end stage renal disease. For a long time, kidney transplantation for these patients was contraindicated because of high rate of recurrence and subsequent renal graft loss. The post-kidney transplantation recurrence rate largely depends on the pathogenetic mechanisms involved. However, over the past several years, advancements in the understanding and therapeutics of aHUS have allowed successful kidney transplantation in these patients. Eculizumab, which is a complement C5 antibody that inhibits complement factor 5a and subsequent formation of the membrane-attack complex, has been used in prevention and treatment of post-transplant aHUS recurrence. In this paper, we present two new cases of aHUS patients who underwent successful kidney transplantation in our center with the use of prophylactic and maintenance eculizumab therapy that have not been published before. The purpose of reporting these two cases is to emphasize the importance of using eculizumab as a prophylactic therapy to prevent aHUS recurrence post-transplant in high-risk patients. We will also review the current understanding of the genetics of aHUS, the pathogenesis of its recurrence after kidney transplantation, and strategies for prevention and treatment of post-transplant aHUS recurrence.

Renal transplantation in HUS patients with disorders of complement regulation

Haemolytic uraemic syndrome (HUS) is the primary diagnosis of 4.5% of children on chronic renal replacement therapy. Approximately 5% of all HUS cases have an "atypical" or recurrent course. Atypical HUS is an inadequate term that applies to a heterogeneous group of conditions. We describe this group as non-diarrhoeal (D-) ), non-EHEC (EHEC - ) HUS. Patients in the non-diarrhoeal, non-EHEC, relapsing group are much more likely to exhibit severe hypertension, histological findings of arterial as well as arteriolar disease, chronic and end-stage renal failure. In general, these patients have an alarmingly high risk of graft loss from disease recurrence or thrombosis ranging from 60-100%. Family history is crucial, and where family members have relapsing disease, transplantation is a very high risk procedure (recurrence 100%). Patients with (D-)HUS need very careful consideration before transplantation, including molecular investigation of complement regulators (and von Willebrandt protease (ADAMTS13) activity, although this goes beyond the scope of this review). Guidelines are accessible under http://www.espn.ucwm.ac.uk . On no account should live related donation take place unless the risks of graft loss are understood. International collaboration to identify safer ways of transplanting these challenging patients is urgently needed.

Current status of kidney transplant: update 2003

Pediatric transplantation has seen remarkable advances over the past two decades with reduced morbidity and mortality, reduced rejection rates, and improved long-term patient and allograft survival. Infants currently have short-term patient and allograft survival rates better than any other age group; short-term allograft survival rates in CD recipients are equal to those in LD recipients. With decreased rejection, long-term allograft survival is improving dramatically. Transplantation allows for much reduced risks and improved metabolic status, growth and development, and more normal social interactions. The future of transplantation continues to be exciting, with opportunities for reduced immunosuppressive medications and their side effects, and the elusive goal of transplantation tolerance seems within reach.

Renal transplantation in patients with hemolytic uremic syndrome: high rate of recurrence and increased incidence of acute rejections

BACKGROUND

The reported outcome of renal transplantation in patients with the hemolytic uremic syndrome (HUS) varies greatly, probably related to the diverse causes of HUS. In this single-center retrospective study, we have analyzed the recurrence rate, the incidence of acute rejections, and graft survival in patients suffering from adult-onset and childhood-onset HUS.

METHODS

The medical records of 35 patients with end-stage renal disease caused by HUS, who received 50 renal allografts, were reviewed. A definite recurrence of HUS was diagnosed if both clinical and histologic signs of thrombotic microangiopathy (TMA) were present in the absence of any endovasculitis. If there were signs of mild endovasculitis, a probable recurrence was diagnosed.

RESULTS

After first renal transplantation, 0 definite and 1 (6%) probable recurrence occurred in 18 patients with childhood-onset HUS, as opposed to 7 (41%) definite and 3 (18%) probable recurrences in 17 adult-onset HUS patients (odds ratio [OR], 13.4; 95% confidence interval [CI], 1.7-105.7). In the latter patients, early use of cyclosporine A increased the risk for recurrence. The incidence of acute rejections was increased compared with matched controls (OR, 1.52; 95% CI, 1.05-2.19 for adult-onset HUS and OR, 1.88; 95% CI, 1.34-2.62 for childhood-onset HUS). One-year graft survival in adult-onset HUS was poor (29%), whereas 1-year graft survival in childhood-onset HUS was comparable to matched controls.

CONCLUSIONS

In adult-onset HUS, the recurrence rate and the incidence of acute rejections are high, resulting in a detrimental graft survival. In childhood-onset HUS, the recurrence rate is low, but the posttransplantation course is complicated by an increased incidence of acute rejections.

Fulminant recurrence of atypical hemolytic uremic syndrome during a calcineurin inhibitor-free immunosuppression regimen

Recurrence of hemolytic uremic syndrome (HUS) after kidney transplantation is frequent, occurring almost exclusively in patients with atypical HUS, which is not caused by Escherichia coli gastroenteritis and in which diarrhea is absent. Calcineurin inhibitors are associated with recurrence of HUS. In two children who underwent living donor kidney transplantation for atypical HUS, we pre-emptively employed sirolimus in a calcineurin inhibitor-free immunosuppression regimen. Both children had excellent early graft function, yet both developed severe recurrent disease and subsequently lost their grafts. Avoidance of calcineurin inhibitors did not prevent recurrence of severe HUS and graft loss. Transplantation for severe atypical HUS remains problematic.

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.

Recurrence of hemolytic-uremic syndrome in renal transplant recipients: a meta-analysis

BACKGROUND

Recurrence of hemolytic-uremic syndrome (HUS) in the allograft is associated with a very poor renal prognosis. Meta-analysis of previous trials may allow us to better estimate its real frequency, to identify risk factors for recurrence, and to predict the outcome of patients with definite recurrence.

METHODS

An exhaustive search was conducted of HUS recurrence in renal transplantation from January 1977 to June 1997 using MEDLINE.

RESULTS

Ten studies comprising 159 grafts in 127 patients were identified. The rate of recurrence was 27.8%. One-year graft survival was 76.6% in patients without recurrence and 33.3% in patients with recurrence (P<0.001). Older age at onset of HUS (16.96+/-7.6 years vs. 9.95+/-6.55 years; P<0.02), shorter mean interval between HUS and transplantation (2.51+/-2.7 years vs. 6.03+/-6.4 years; P<0.01), shorter mean interval between HUS and end-stage renal disease (0.79+/-0.39 years vs. 2.78+/-2.47 years; P<0.01), living-related donors, and the use of calcineurin inhibitors were associated with recurrence.

CONCLUSION

Risk factors for HUS recurrence in renal transplantation could be identified through this meta-analysis.

Renal transplantation in adults with autosomal recessive inheritance of hemolytic uremic syndrome

When hemolytic uremic syndrome (HUS) is occasionally inherited in an autosomal recessive mode, this occurs mainly in infants and children. We describe four families in which two adult siblings were affected with HUS in each kindred. HUS first occurred between the ages of 19 to 36 years, and the intervals between the onset of HUS in each sibling pair ranged from 6 months to 6 years. None of the patients had a typical prodrome of bloody diarrhea, and one had a recurrence of HUS before transplantation. All eight patients developed renal failure requiring dialysis and transplantation, and seven patients received kidney transplants. Donor kidneys were from parents, siblings, and cadavers. The initial renal transplants were performed from 6 months to 6 years after the onset of the syndrome. HUS recurred in six of the seven patients 2 weeks to 6.5 years after transplantation regardless of the interval between the onset of HUS and transplantation, the origin of the allograft, or the use of cyclosporin A. The only marker for autosomal recessive HUS is the occurrence of the syndrome in a second sibling several months to many years after its occurrence in the proband. In patients with the autosomal recessive form of HUS, the risk for a recurrence in an allograft is high regardless of the source of the kidney.

Heterogeneity of atypical haemolytic uraemic syndromes

Atypical, non-diarrhoea associated haemolytic uraemic syndrome (D-HUS) is a heterogeneous disorder with a generally poor outcome, although this view has now been questioned. The clinical and laboratory features of 23 children with D-HUS, representing a third of all patients with HUS seen during the last 26 years, were examined. The median age was 4.9 years (range 3 days-13.8 years). Twenty one children (91%) survived the initial phase. All patients except six infants aged < 18 months required dialysis (74%). Hypertension (43%), cardiomyopathy (43%), and cerebral convulsions (48%) were common. Nineteen (83%) children were followed up for a median period of 5.5 years (range 0.5-23.4). Only five (26%) patients, among them four infants, recovered completely. Six (32%) patients had one to 10 recurrences, including two siblings with neonatal onset, and eight (42%) developed end stage renal failure. Five children underwent cadaveric renal transplantation, with recurrence and subsequent graft failure in two. Four children died, resulting in an overall mortality of 26%. Atypical HUS is heterogeneous with regard to epidemiology, pathophysiology, and outcome. Children with a recurrent, familial, or neonatal course have worse outcomes; in contrast, infants not requiring dialysis in the acute phase have a better prognosis.

Recurrent hemolytic uremic syndrome in a renal transplant patient during pregnancy

The recurrence of the hemolytic uremic syndrome (HUS) in a renal transplant patient during pregnancy and during treatment with cyclosporin is reported. After 4 1/2 months of treatment with hemodialysis the renal function partially recovered. A monozygote twin sister has not developed HUS in spite of 2 pregnancies.

Renal allograft survival according to primary diagnosis: a report of the North American Pediatric Renal Transplant Cooperative Study

The data base of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) was used to examine the effect of primary diagnosis on the outcome of renal transplantation in children. The relative risk of graft failure for eight diagnostic groups was determined, with patients with congenital and structural anomalies of the urinary tract serving as the reference group. Covariate analysis was used to control for the effects of age, race and transfusion history in recipients of living-related donor kidneys, and for age, donor age, antilymphocyte prophylaxis, prior transplantation, prior dialysis and cold ischemia time in recipients of cadaver kidneys. In recipients of living-related donor kidneys, the lowest graft failure rates were associated with the diagnoses of cystinosis, familial nephritis and hemolytic uremic syndrome (HUS), while the highest failure rates were observed in patients with a primary diagnosis of congenital nephrotic syndrome (CNS) or focal segmental glomerulosclerosis (FSGS). In cadaver allograft recipients, the lowest graft failure rates were associated with primary diagnoses of glomerulonephritis, congenital/structural disease and cystinosis, while patients with FSGS, HUS and CNS had the highest graft failure rates. This study suggests that patients with a primary diagnosis of cystinosis have superior outcomes, while the diagnoses of FSGS and CNS carry with them the highest risks of graft failure.

The hemolytic uremic syndrome

HUS is the most common cause of acute renal failure in infants and young children and follows a diarrheal prodrome about 90% of the time. Persuasive evidence shows that virtually all of postdiarrheal cases are caused by EHEC infections, and that the great majority of cases in the United States are caused by the EHEC serotype O157:H7. Mortality is approximately 5%, and approximately 10% of survivors are left with severe sequelae. A much larger number (30%-50%) experience mild chronic renal damage. Public health strategies, including zero tolerance for fecal contamination in slaughter houses and additional public education on proper food handling and cooking, does much to decrease the prevalence of the syndrome. Efforts to further dissect the postdiarrheal pathogenic cascade should continue, and an animal model needs to be developed. Only then will researchers be positioned to develop effective intervention strategies. Preventing life-threatening extrarenal complications, especially of the CNS, is a major challenge. Idiopathic nondiarrheal HUS accounts for approximately 10% of cases and comprises a poorly understood composite of HUS subsets. Research directed toward a better understanding of these mysterious variants also is a priority for the years ahead.

Pediatric renal transplantation

Renal transplantation in children is a most rewarding treatment that dramatically changes the overall health and lifestyle of children with ESRD. Complexities in different aspects of renal transplantation in children are obvious. Optimum technical conditions and drug therapy must be provided for the success of renal transplantation. Application of recent advances in immunology and long-term care to clinical transplantation continue to improve graft and patient survival rates. Optimization of growth and development also can be improved with the use of rhGH.

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.

Non-immunological risk factors in paediatric renal transplantation

In paediatric renal transplantation, non-immunological risk factors account for about one-third of graft losses. Recurrence of original disease is observed mainly in primary hyperoxaluria and glomerulopathies such as steroid-resistant nephrotic syndrome and membranoproliferative glomerulonephritis. In both glomerulopathies, 20% of grafts are lost from recurrence. Vascular thrombosis is, in most series, the second cause of graft loss in children, particularly in young recipients or with young donors (under 5 years of age). Non-compliance with treatment is a common non-immunological factor in adolescent recipients, which may trigger a severe rejection process resulting in graft loss. The role of factors related to graft preservation and intra- and post-operative management (ischaemia time, delayed graft function) or to cytomegalovirus infection is less obvious in our series. Prevention of vascular thrombosis and of non-compliance is most important in order to improve the results of paediatric renal transplantation.

Hemolytic-uremic syndrome

HUS is one of the most common causes of acute renal failure in childhood. D+ HUS is the most common form and usually follows an episode of hemorrhagic colitis due to VTEC or S. dysenteriae type 1. The SLT elaborated by these organisms is responsible for the endothelial damage that is the initial insult in the pathogenesis of the acute renal failure. Excellent supportive care is necessary to reduce the mortality and morbidity due to HUS.

Cerebral infarct with recurrence of hemolytic-uremic syndrome in a child following renal transplantation

A white girl with a history of atypical hemolytic-uremic syndrome (HUS) and persistent microangiopathic anemia, and thrombocytopenia for 2 months after the initial presentation at age 7 months, received her first cadaveric renal transplant at age 3 years. During the first 2.5 days post transplant, she developed progressive thrombocytopenia and anemia followed by tonic-clonic seizures and loss of consciousness, secondary to a diffuse cerebral infarction of the left hemisphere. Renal histology showed evidence of glomerular microthrombi and microangiopathy. A large cerebral infarct, previously described in patients during their initial presentation with HUS, presented in our patient as part of the recurrence of the disease post renal transplantation.

Recurrent primary disease and de novo nephritis following renal transplantation

Recurrent or de novo diseases account for only 5% of graft failure in children, but have much to teach us about mechanisms. In children, almost the only metabolic disease with recurrence is type I hyperoxaluria, in which the poor long-term results of isolated renal transplantation make combined liver and renal transplantation, or even prophylactic liver transplantation before renal failure the preferable alternatives. While many forms of nephritis may show histological recurrence in allografts, it is notable that in many patients this is accompanied by no clinical manifestations or only mild disease: this is particularly so in mesangiocapillary glomerulonephritis (MCGN) type II. IgA-associated nephropathy and Henoch-Schönlein purpura. However focal segmental glomerulosclerosis and MCGN type I recur with sufficient frequency and severity to deter the use of living donors unless there is no alternative. The same is true of haemolytic-uraemic syndromes. As many as 10% of paediatric grafts may show de novo membranous nephropathy, but in the majority this is mild or not clinically evident. In contrast, the rare anti-glomerular basement membrane nephritis affecting some patients with Alport's syndrome usually results in graft failure, but occurs in only a minority of recipients with the syndrome. For all types of disease in allografts, risk factors for recurrence are poorly worked out, and attempts at treatment generally ineffective.