Hemolytic Uremic Syndrome: A Fatal Outcome after Kidney and Liver Transplantation Performed to Correct Factor H Gene Mutation

Factor H-associated hemolytic uremic syndrome (HUS) is a genetic form of thrombotic microangiopathy characterized by deficient factor H (HF-1) levels/activity and uncontrolled complement activation. The disorder mostly leads to end-stage renal disease and often recurs after kidney transplantation. We previously demonstrated that in a child with HF-1-associated HUS a simultaneous kidney and liver transplantation restored the defective HF-1 with no recurrence of the disease in the transplanted kidney. Here we describe a second childhood case of HF-1-associated HUS treated by combined kidney and liver transplant and complicated by a fatal, primary non-function of the liver graft. Graft hypoperfusion during surgery triggered ischemia/reperfusion changes and complement activation. Conceivably, as a result of defective complement regulatory potential, massive shedding of vascular heparan sulfates was documented in the transplanted liver. This might have impaired the physiological thromboresistance of vascular endothelium ending with widespread microvascular thrombosis and infarction. This case indicates that more fundamental research is needed before combined liver and kidney transplant is considered an option for children with HF-1-associated HUS.     

Attempted treatment of factor H deficiency by liver transplantation

Complement factor H (FH) deficiency is one of the causes of atypical hemolytic uremic syndrome (HUS). Most patients with FH deficiency associated HUS progress to end-stage renal disease despite plasma therapy. Moreover, the disease invariably recurs in the graft kidney and causes graft failure. We confirmed FH deficiency in a 30-month-old boy with recurrent HUS of 2 years duration, and attempted an auxiliary partial orthotopic liver transplantation (APOLT) to overcome the sustained intractable dependency on plasma therapy. APOLT restored the plasma FH level, without HUS recurrence, for 7 months. However, thereafter he suffered from serious infectious complications associated with immunosuppression and finally died 11 months after APOLT. In conclusion, although APOLT showed clinical and laboratory improvement for some period in this patient, the final fatal outcome suggests that liver transplantation should be cautiously applied to patients with HUS associated with FH deficiency.     

Thrombotic Microangiopathy After Kidney Transplantation

Thrombotic microangiopathy (TMA) is a severe complication of kidney transplantation that often causes graft failure. TMA may occur de novo, often triggered by immunosuppressive drugs and acute antibody‐mediated rejection, or recur in patients with previous history of hemolytic uremic syndrome (HUS). Recurrent TMA is very rare in patients who had developed end‐stage renal failure following HUS caused by Shiga‐toxin producing E. scherichia coli, whereas disease recurrence is common in patients with atypical HUS (aHUS). The underlying genetic defect greatly impacts the risk of posttransplant recurrence in aHUS. Indeed recurrence is almost the rule in patients with mutations in genes encoding factor H or factor I, whereas patients with a mutation in membrane‐cofactor‐protein gene have a good transplant outcome. Prophylactic and therapeutic options for posttransplant TMA, including plasma therapy, combined kidney and liver transplantation and targeted complement inhibitors are discussed in this review.     

Complete factor H deficiency-associated atypical hemolytic uremic syndrome in a neonate

Recent advances have shown that atypical hemolytic uremic syndrome (aHUS) is a disease of complement dysregulation. Almost 50% of cases are associated with mutations in the three complement regulatory genes, factor H (HF1), membrane co-factor protein (MCP) and factor I (IF). The corresponding gene products act in concert and affect the same enzyme, alternative pathway convertase C3bBb, which initiates the alternative pathway and amplification of the complement system. Factor H (FH) deficiency-associated aHUS usually occurs in infants to middle-aged adults and only rarely in neonates. Moreover, the vast majority of patients are heterozygous for the HF1 gene mutations. We report on a case of neonatal-onset aHUS associated with complete FH deficiency due to novel compound heterozygous mutations in the HF1 gene. A 22-day-old baby girl developed acute renal failure and a remarkably low serum complement C3 level, which was rapidly followed by the development of micro-angiopathic hemolytic anemia. Western blot analysis revealed nearly zero plasma FH levels, and an HF1 gene study showed compound heterozygous mutations, C1077W/Q1139X. Renal pathology findings were compatible with glomerular involvement in HUS. The baby recovered completely after the repetitive infusion of fresh frozen plasma. During follow-up (until she was 20 months old) after the initial plasma therapy, the disease recurred three times; twice after the tapering off of plasma therapy, and once during a weekly plasma infusion. All recurrence episodes were preceded by an upper respiratory tract infection, and were successfully managed by restarting or increasing the frequency of plasma therapy.     

Successful Renal Transplantation in Factor H Autoantibody Associated HUS with CFHR1 and 3 Deficiency and CFH Variant G2850T

Factor H (CFH) autoantibodies are associated with atypical hemolytic uremic syndrome (aHUS). Peritransplantation plasma exchange therapy and intensification of immunosuppression, with adjuvant use of anti-CD20 monoclonal antibodies has recently been advocated for cases of CFH-autoantibody associated aHUS. In this report, we describe successful deceased donor renal transplantation in a case of CFH-autoantibody associated aHUS with combined CFHR1 and 3 deficiency in addition to the CFH sequence variant, (cG2850T, pGln950His). CFH-autoantibodies were detected 2 weeks prior to transplantation. Disease recurrence was not observed using basiliximab, an IL2-receptor antagonist and high-dose corticosteroids with mycophenolate mofetil. Adjuvant therapies such as Rituximab nor intensification of plasma therapy were employed. Consequently, careful consideration needs to be given to the use of additional immunosuppression in certain cases of CFH-autoantibody associated aHUS. Serial measurement of CFH-autoantibodies is required in the immediate pre- and posttransplantation period to further clarify their role as a factor in the recurrence of aHUS posttransplantation. Furthermore, delineation of the functional significance of CFH-autoantibodies is warranted in individual cases.     

Hemolytic uremic syndrome in Kuwaiti Arab children

Twenty-five children with hemolytic uremic syndrome (HUS) were diagnosed between January 1985 and January 2000 in the Pediatric Nephrology Unit at Mubarak Al-Kabeer Hospital. Fourteen patients (56%) had typical (D+) HUS whereas 11 (44%) had atypical (D–) HUS. No bacterial or viral pathogens could be isolated in the majority of cases. The atypical HUS group had more severe anemia (P=0.03), which was significantly more prolonged than in the typical HUS group (P=0.0028). There was no significant difference between the two groups in the mean maximum serum creatinine (P=0.1), blood urea nitrogen values (P=0.8) and severity of leukocytosis (P=0.4). Anuria and the need for dialysis were not significantly different between the two groups (P=0.1 and 0.05, respectively). Mortality was significantly higher in the D– HUS patients (P<0.0001). Recurrence of HUS was documented in 63.3% of the D– HUS group compared to 14.2% of the D+ HUS group (P=0.0053). Family history of HUS was reported in 72.7% of the atypical HUS group and 14.2% of the typical HUS group. There were no significant differences in chronic renal sequelae between the two groups. In conclusion, the pathogenesis of HUS in Kuwaiti children appears to be influenced by genetic factors rather than certain environmental pathogens. Atypical HUS has a higher mortality rate, a definite familial tendency and a high relapse rate. Received: 22 December 2000 / Revised: 8 August 2001 / Accepted: 8 August 2001     

Complement and the atypical hemolytic uremic syndrome in children

Over the past decade, atypical hemolytic uremic syndrome (aHUS) has been demonstrated to be a disorder of the regulation of the complement alternative pathway. Among approximately 200 children with the disease, reported in the literature, 50% had mutations of the complement regulatory proteins factor H, membrane cofactor protein (MCP) or factor I. Mutations in factor B and C3 have also been reported recently. In addition, 10% of children have factor H dysfunction due to anti-factor H antibodies. Early age at onset appears as characteristic of factor H and factor I mutated patients, while MCP-associated HUS is not observed before age 1 year. Low C3 level may occur in patients with factor H and factor I mutation, while C3 level is generally normal in MCP-mutated patients. Normal plasma factor H and factor I levels do not preclude the presence of a mutation in these genes. The worst prognosis is for factor H-mutated patients, as 60% die or reach end-stage renal disease (ESRD) within the first year after onset of the disease. Patients with mutations in MCP have a relapsing course, but no patient has ever reached ESRD in the first year of the disease. Half of the patients with factor I mutations have a rapid evolution to ESRD, but half recover. Early intensive plasmatherapy appears to have a beneficial effect, except in MCP-mutated patients. There is a high risk of graft loss for HUS recurrence or thrombosis in all groups except the MCP-mutated group. Recent success of liver–kidney transplantation combined with plasmatherapy opens this option for patients with mutations of factors synthesized in the liver. New therapies such as factor H concentrate or complement inhibitors offer hope for the future.     

Two Patients With History of STEC‐HUS,Posttransplant Recurrence and Complement Gene Mutations

Hemolytic uremic syndrome (HUS) is a disease of microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure. About 90% of cases are secondary to infections by Escherichia coli strains producing Shiga‐like toxins (STEC‐HUS), while 10% are associated with mutations in genes encoding proteins of complement system (aHUS). We describe two patients with a clinical history of STEC‐HUS, who developed end‐stage renal disease (ESRD) soon after disease onset. They received a kidney transplant but lost the graft for HUS recurrence, a complication more commonly observed in aHUS. Before planning a second renal transplantation, the two patients underwent genetic screening for aHUS‐associated mutations that revealed the presence of a heterozygous CFI mutation in patient #1 and a heterozygous MCP mutation in patient #2, and also in her mother who donated the kidney. This finding argues that the two cases originally diagnosed as STEC‐HUS had indeed aHUS triggered by STEC infection on a genetic background of impaired complement regulation. Complement gene sequencing should be performed before kidney transplantation in patients who developed ESRD following STEC‐HUS since they may be undiagnosed cases of aHUS, at risk of posttransplant recurrence. Furthermore, genetic analysis of donors is mandatory before living‐related transplantation to exclude carriers of HUS‐predisposing mutations.     

Complement Mutation-Associated De Novo Thrombotic Microangiopathy Following Kidney Transplantation

Mutations in one or more genes encoding complement-regulatory proteins predispose to atypical hemolytic uremic syndrome (aHUS) and its recurrence following kidney transplantation. We evaluated plasma complement level and performed a screening for mutations in genes encoding complement Factors H and I (CFH, CFI) and membrane cofactor protein (MCP) in 24 kidney transplant recipients experiencing de novo thrombotic microangiopathy (TMA). Six patients presented with low C3 and/or low Factor B levels suggestive complement alternative pathway. A mutation in the CFH or CFI gene was found in 7/24 patients (29%), two of whom had a mutation in both genes. On the contrary, no mutation was identified in a control kidney transplant patients group (n = 25) without TMA. Patients with or without mutations were similar with regard to clinical features. Eight out of 24 patients lost their graft within 1 year of posttransplantation including six patients with a CFH mutation or a decrease of C3 or CFB in plasma. To conclude, kidney transplant patients with de novo TMA exhibit an unexpectedly high frequency of CFH and CFI mutations. These results suggest that genetic abnormalities may represent risk factors for de novo TMA after kidney transplantation and raise the question of the best therapeutic strategy.     

Challenges in the management of infantile factor H associated hemolytic uremic syndrome

We describe a 1-year old with four episodes of recurrent hemolytic uremic syndrome (HUS). Family history suggested an autosomal dominant mode of inheritance. Factor H concentrations in the blood were normal in the affected family members. Mutation screening in the human complement factor H gene (HF-1) revealed a novel mutation in exon 23 (c.3546_3581dup36). The HF-1 gene encodes complement factor H and the mutation leads to the insertion of 12 additional amino acids after codon 1176 in factor H. The recurrent HUS responded to plasma infusions and renal function improved from a glomerular filtration rate of 21 to 50 ml/min per 1.73 m². The infusions of fresh-frozen plasma were necessary at once-weekly intervals at a dose of 40–45 ml/kg in order to maintain remission and resulted in significant hyperproteinemia. This was addressed by intermittent plasma exchange through an arterio-venous fistula. The prognosis and therapeutic dilemmas are discussed.     

Recurrence of HUS Due to CD46/MCP Mutation After Renal Transplantation: A Role for Endothelial Microchimerism

Mutations in the gene of the membrane cofactor protein (MCP/CD46), a complement regulatory protein, were recently described as a cause of hemolytic uremic syndrome (HUS). MCP is a transmembrane glycoprotein expressed in kidneys; therefore, the transplantation of a normal kidney should not be complicated by HUS recurrence. However, we report the case of a 32-year-old woman with an MCP mutation who developed a recurrence of HUS after renal transplantation. We found that she had vascular microchimerism of endothelial cells. We suggest that recurrence may be favored by vascular microchimerism, in which the mutated protein is produced in the in the kidney graft by endothelial cells originating from recipient.     

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.     

Hemolytic uremic syndrome in families — an argentinian experience

Six hundred and thirty-one patients with hemolytic uremic syndrome (HUS) were treated from 1960 to 1992; 19 (3%) were familial cases, of which 9 were classified as concomitant (including twins), 6 as non-concomitant, and 4 as recurrent. In the recurrent group there were 15 HUS episodes, 10 being concomitant in 2 patients. Prodromal diarrhea was present only in concomitant and non-concomitant cases. Patients with recurrences were sisters from a single family. Concomitant and non-concomitant cases had clinical features, course, and age similar to typical endemoepidemic forms of HUS, in which an association with verocytotoxin-producingEscherichia coli has been reported. There may be a genetic determinant in concomitant cases; these occurred outside the season during which endemoepidemic forms are typically detected. In patients with recurrent disease a genetic factor which may lead to the development of the disease when triggered by viral infections is likely.     

Complement Genes Strongly Predict Recurrence and Graft Outcome in Adult Renal Transplant Recipients with Atypical Hemolytic and Uremic Syndrome

Atypical hemolytic and uremic syndrome (aHUS) is a severe disease strongly associated with genetic abnormalities in the complement alternative pathway. In renal posttransplantation, few data are available on recurrence risk and graft outcome according to genetic background in aHUS patients. The aim of this study was to identify risk factors for recurrence and transplant outcome and, in particular, the role of complement gene abnormalities. We retrospectively studied 57 aHUS patients who had received 71 renal transplants. A mutation in complement gene was identified in 39 (68%), in factor H (CFH), factor I (CFI), membrane cofactor‐protein (MCP), C3 and factor B (CFB). At 5 years, death‐censored graft survival was 51%. Disease recurrence was associated with graft loss (p = 0.001). Mutations in complement genes were associated with higher risk of recurrence (p = 0.009). Patients with CFH or gain of function (C3, CFB) mutations had a highest risk of recurrence. M‐TOR inhibitor was associated with significant risk of recurrence (p = 0.043) but not calcineurin inhibitor immunosuppressive treatment (p = 0.29). Preemptive plasmatherapy was associated with a trend to decrease recurrence (p = 0.07). Our study highlights that characterization of complement genetic abnormalities predicts the risk of recurrence‐related graft loss and paves the way for future genetically based individualized prophylactic therapeutic strategies.     

Successful Renal Transplantation in a Patient with Atypical Hemolytic Uremic Syndrome Carrying Mutations in Both Factor I and MCP

Kidney transplantation in patients with atypical hemolytic uremic syndrome (aHUS) carrying mutations in the soluble complement regulators factor H (CFH) or factor I (CFI) is associated with elevated risk of disease recurrence and almost certain graft loss. In contrast, recurrence is unusual in patients with mutations in the membrane-associated complement regulator membrane cofactor protein (MCP) (CD46). Therefore, a panel of experts recently recommended the combined liver–kidney transplantation to minimize aHUS recurrence in patients with mutations in CFH or CFI . There was, however, very limited information regarding transplantation in patients carrying mutations in both soluble and membrane-associated complement regulators to support a recommendation. Here, we report the case of an aHUS patient with a heterozygous mutation in both CFI and MCP who received an isolated kidney transplant expressing normal MCP levels. Critically, the patient suffered from a severe antibody-mediated rejection that was successfully treated with plasmapheresis and IvIgG. Most important, despite the complement activation in the allograft, there was no evidence of thrombotic microangiopathy, suggesting that the normal MCP levels in the grafted kidney were sufficient to prevent the aHUS recurrence. Our results suggest that isolated kidney transplantation may be a good first option for care in aHUS patients carrying CFI / MCP combined heterozygous mutations.     

Successful plasma therapy in hemolytic uremic syndrome with factor H deficiency

A patient with homozygous factor H deficiency presented with hemolytic uremic syndrome (HUS) at the age of 7 months. After a 2-year period of stability, renal failure and erythrocyte fragmentation recurred between the age of 3 and 4 years. Fresh frozen plasma infusions allowed renal function to be improved and erythrocyte fragmentation to be stopped. Withdrawal of plasma therapy led to a relapse of the biological signs of HUS. Received: 18 April 2000 / Revised: 18 August 2000 / Accepted: 21 August 2000     

Association of Helicobacter pylori with thrombotic thrombocytopenic purpura and hemolytic uremic syndrome after bone marrow transplantation

Thrombotic microangiopathy (TMA) has attracted attention as a complication of bone marrow transplantation (BMT). The association of Helicobacter pylori (H. pylori) with thrombotic thrombocytopenic purpura and hemolytic uremic syndrome (TTP/HUS) after BMT was studied. Among 74 consecutive patients undergoing transplantation, six developed TTP/HUS (the TTP/HUS group) and 68 did not (controls). These six patients were compared with the other 68 patients to investigate differences of the IL-12 and 8 levels, H. pylori and various clinical characteristics. The patients who developed TTP/HUS seemed not apparently different from those who did not in background characteristics, except that they had a significantly higher H. pylori-positive rate (p < 0.05). In the TTP/HUS group, however, the levels of interleukin-12 and interleukin-8 increased significantly during the leukocyte recovery after BMT and at the onset of TTP/HUS, respectively, to 45.8 +/- 57.6 pg/mL and 274.8 +/- 65.9 pg/mL (p < 0.05 for both), when compared with their levels of 5.0 pg/mL in the control group. Thus, H. pylori may play a role in the pathogenesis of TTP/HUS after BMT, with cytokines (interleukin-8 and interleukin-12) also being involved.     

Blood pressure in the long-term follow-up of children with hemolytic uremic syndrome

The hemolytic uremic syndrome (HUS) is the most common cause of acute renal failure (ARF) in young children. Most patients recover from the acute phase of the illness but they may develop arterial hypertension (AH) after many years, even in the absence of signs of renal impairment during short-term follow-up. In this study, we performed casual blood pressure (BP) measurement, 24-h blood pressure monitoring (ABPM), and a Bruce walking treadmill study (ET) in 24 children (aged 5–15 years, 13 males, 11 females) with a history of HUS and normal renal function during follow-up (median 5.8 years, range 1.8–12.4 years). There were 22 children (91%) with prodromal diarrhea associated with HUS and 20 (83%) underwent dialysis during the acute illness. All children had normal casual BP measurement. Of 13 children (54%) with normal ABPM, 5 patients (38%) had an abnormal BP response during the ET study. There were 4 (58%) of the 7 patients with AH by ABPM (29%) and an abnormal BP response during ET. These findings suggest that ET could be a useful means of identifying children with a history of HUS that could be at risk of future AH even if they had normal renal function, casual BP, and ABPM during long-term follow-up. These results should be confirmed with a large prospective clinical study.     

Antibody Mediated Rejection Associated With Complement Factor H–Related Protein 3/1 Deficiency Successfully Treated With Eculizumab

Antibody mediated rejection (AMR) activates the classical complement pathway and can be detrimental to graft survival. AMR can be accompanied by thrombotic microangiopathy (TMA). Eculizumab, a monoclonal C5 antibody prevents induction of the terminal complement cascade (TCC) and has recently emerged as a therapeutic option for AMR. We present a highly sensitized 13‐year‐old female with end‐stage kidney disease secondary to spina bifida‐associated reflux nephropathy, who developed severe steroid‐, ATG‐ and plasmapheresis‐resistant AMR with TMA 1 week post second kidney transplant despite previous desensitization therapy with immunoglobulin infusions. Eculizumab rescue therapy resulted in a dramatic improvement in biochemical (C3; creatinine) and hematological (platelets) parameters within 6 days. The patient was proven to be deficient in complement Factor H‐related protein 3/1 (CFHR3/1), a plasma protein that regulates the complement cascade at the level of C5 conversion and has been involved in the pathogenesis of atypical hemolytic uremic syndrome caused by CFH autoantibodies (DEAP‐HUS). CFHR1 deficiency may have worsened the severe clinical progression of AMR and possibly contributed to the development of donor‐specific antibodies. Thus, screening for CFHR3/1 deficiency should be considered in patients with severe AMR associated with TMA.     

Eculizumab for Atypical Hemolytic Uremic Syndrome Recurrence in Renal Transplantation

Eculizumab (anti‐C5) has been sporadically reported as an efficient therapy for atypical hemolytic uremic syndrome (aHUS). However, the lack of series precludes any firm conclusion about the optimal use of anti‐C5 for preventing or treating aHUS posttransplant aHUS recurrence. We thoroughly studied 22 renal transplant recipients with aHUS who received off‐label therapy with anti‐C5, including 12 cases, which have not been reported yet. Nine patients, all carrying a complement genetic abnormality associated with a high risk of aHUS recurrence, received prophylactic anti‐C5 therapy to prevent posttransplant recurrence. Eight of them had a successful recurrence‐free posttransplant course and achieved a satisfactory graft function, while the remaining patient experienced early arterial thrombosis of the graft. Thirteen renal transplant recipients were given anti‐C5 for posttransplant aHUS recurrence. A complete reversal of aHUS activity was obtained in all of them. Importantly, the delay of anti‐C5 initiation after the onset of the aHUS episode inversely correlated with the degree of renal function improvement. Three patients in whom anti‐C5 was subsequently stopped experienced a relapse. Altogether these data suggest that long‐term eculizumab is highly effective for preventing and treating posttransplant aHUS recurrence. Our study also indicates that anti‐C5 should be promptly started if a recurrence occurs.