Eculizumab in atypical haemolytic-uraemic syndrome allows cessation of plasma exchange and dialysis

Atypical hemolytic uremic syndrome: Consensus of diagnosis and treatment in Taiwan

Atypical hemolytic uremic syndrome (aHUS), characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury, is a rare but life-threatening systemic disorder caused by the dysregulation of the complement pathway. Current advances in molecular analysis and pathogenesis have facilitated the establishment of diagnosis and development of effective complement blockade. Based on this recent consensus, we provide suggestions regarding the diagnosis and management of aHUS in Taiwan. The diagnosis of aHUS is made by the presence of TMA with normal ADAMTS13 activity without known secondary causes. Although only 60% of patients with aHUS have mutations in genes involving the compliment and coagulation systems, molecular analysis is suggestive for helping establish diagnosis, clarifying the underlying pathophysiology, guiding the treatment decision-making, predicting the prognosis, and deciding renal transplantation. Complement blockade, anti-C5 monoclonal antibody, is the first-line therapy for patients with aHUS. Plasma therapy should be considered for removing autoantibody in patients with atypical HUS caused by anti-CFH or complement inhibitor is unavailable.

Atypical Hemolytic Uremic Syndrome: New Challenges in the Complement Blockage Era

Atypical hemolytic uremic syndrome (aHUS) is a rare cause of thrombotic microangiopathy (TMA), characterized by microangiopathic hemolytic anemia, consumptive thrombocytopenia, and multisystem end organ involvement, most commonly affecting the kidney. Diagnosis is clinical, after exclusion of other TMA causes. Primary aHUS arises from genetic abnormalities, resulting in uncontrolled complement activity, while a variety of clinical scenarios cause secondary aHUS, including infection, pregnancy, malignancy, autoimmune disease, and medications. They can also induce a temporary complement deregulation with an overlap between both scenarios, which can make differential diagnosis difficult. Primary aHUS can be sporadic or familial and is associated with a high rate of progression to ESRD. Many aHUS patients relapse in the native or transplanted kidneys, leading to kidney failure. The introduction of eculizumab has changed the prognosis of aHUS, by inducing hematologic remission, improving or stabilizing kidney functions, and preventing graft failure. The early institution of appropriate therapy can prevent multiorgan damage, so is essential to recognize and differentiate the TMA syndromes. Eculizumab is considered now the first-line treatment, and it is recommended lifelong therapy. However, the high cost of therapy has led to make efforts to develop precise complement functional and genetic studies that help physicians to determine the appropriate duration of eculizumab therapy. Nowadays, more studies are needed to select candidates to adjustment of therapy.

Is eculizumab indicated in patients with atypical hemolytic uremic syndrome already on prolonged dialysis? A case report and review of the literature

BACKGROUND

Eculizumab has caused a revolution in the treatment and prognosis of atypical hemolytic uremic syndrome. Early initiation of treatment is recommended to increase chances of renal recovery.

CASE-DIAGNOSIS/TREATMENT

We describe a boy with atypical hemolytic uremic syndrome who started eculizumab therapy after being on dialysis for 4.5 months, with complete anuria. With treatment, he was weaned off dialysis.

CONCLUSION

We review the evidence in the literature and discuss the possible mechanism by which eculizumab induces renal recovery even in patients already on prolonged dialysis. This case report highlights the importance of a treatment trial with eculizumab, even in patients already on prolonged dialysis.

Should eculizumab be discontinued in patients with atypical hemolytic uremic syndrome?

Atypical hemolytic uremic syndrome (aHUS) is a life-threatening disorder for which prompt diagnosis and eculizumab treatment is indicated. The time for relapse and patients at risk for relapse after eculizumab discontinuation are unknown. While some authors believe there is no clinical evidence supporting eculizumab discontinuation, which may be associated with high collateral risks such as loss of renal function, other authors believe that the drug can be safely discontinued with close patient monitoring. In this editorial, we update the pros and cons for eculizumab discontinuation in aHUS.

Neonatal atypical hemolytic uremic syndrome from a factor H mutation treated with eculizumab

Background: Atypical hemolytic uremic syndrome (aHUS) results from an inherited dysregulation of the alternative complement pathway leading to thrombotic microangiopathy consisting of hemolytic anemia, thrombocytopenia, and renal injury. The complement inhibitor eculizumab is an approved treatment, but its reported use in neonates – who have an inherently high risk of infection – is limited. Case diagnosis/treatment: A 28-day-old female presented with gross hematuria and hypertension. aHUS was suspected based on anemia with schistocytes, thrombocytopenia, low C3, and acute kidney injury requiring peritoneal dialysis. A septic work-up initiated on day 2 for hypothermia and respiratory failure was negative. There was no improvement after 6 days of plasma therapy. Despite being < 6 weeks old she was vaccinated with pneumococcal-13 conjugate, meningococcal (groups C and Y) polysaccharide, and Haemophilus b tetanus toxoid conjugate vaccines and started on penicillin prophylaxis. After 1 dose of eculizumab 300 mg, dialysis was discontinued and her hematological parameters improved. Genetic testing revealed a complement factor H mutation. After 11 months of follow-up, she remains on eculizumab and penicillin without recurrence of aHUS or any infectious complications. Conclusions: Eculizumab is a safe and effective treatment option for aHUS even in neonates at high risk for infection.

Recovery of renal function after long-term dialysis and resolution of cardiomyopathy in a patient with aHUS receiving eculizumab

We present the case of a 18-month-old girl with renal and cardiac manifestations of atypical haemolytic uraemic syndrome (aHUS), and a novel complement factor H mutation. Transient haematological remission was achieved with intensive plasmapheresis, but cardiac function deteriorated and renal function was not restored. Initiation of eculizumab after 6 months of dialysis significantly improved organ function. At 43 months after presentation, haematological values had normalised and cardiac function had improved. Dialysis was discontinued after 10 months (the longest reported time in a patient with aHUS) and the estimated glomerular filtration rate had recovered to 70 mL/min/1.73 m(2). In conclusion, treatment of aHUS with eculizumab, even after long-term dialysis, can significantly improve renal function. Discontinuation of dialysis and resolution of cardiac function has implications on the potential recovery and treatment choice of such patients. Earlier initiation of eculizumab, however, might have prevented the irreversible renal sclerosis and cardiac dysfunction.

An international consensus approach to the management of atypical hemolytic uremic syndrome in children

Atypical hemolytic uremic syndrome (aHUS) emerged during the last decade as a disease largely of complement dysregulation. This advance facilitated the development of novel, rational treatment options targeting terminal complement activation, e.g., using an anti-C5 antibody (eculizumab). We review treatment and patient management issues related to this therapeutic approach. We present consensus clinical practice recommendations generated by HUS International, an international expert group of clinicians and basic scientists with a focused interest in HUS. We aim to address the following questions of high relevance to daily clinical practice: Which complement investigations should be done and when? What is the importance of anti-factor H antibody detection? Who should be treated with eculizumab? Is plasma exchange therapy still needed? When should eculizumab therapy be initiated? How and when should complement blockade be monitored? Can the approved treatment schedule be modified? What approach should be taken to kidney and/or combined liver-kidney transplantation? How should we limit the risk of meningococcal infection under complement blockade therapy? A pressing question today regards the treatment duration. We discuss the need for prospective studies to establish evidence-based criteria for the continuation or cessation of anticomplement therapy in patients with and without identified complement mutations.

An international consensus approach to the management of atypical hemolytic uremic syndrome in children

Atypical hemolytic uremic syndrome (aHUS) emerged during the last decade as a disease largely of complement dysregulation. This advance facilitated the development of novel, rational treatment options targeting terminal complement activation, e.g., using an anti-C5 antibody (eculizumab). We review treatment and patient management issues related to this therapeutic approach. We present consensus clinical practice recommendations generated by HUS International, an international expert group of clinicians and basic scientists with a focused interest in HUS. We aim to address the following questions of high relevance to daily clinical practice: Which complement investigations should be done and when? What is the importance of anti-factor H antibody detection? Who should be treated with eculizumab? Is plasma exchange therapy still needed? When should eculizumab therapy be initiated? How and when should complement blockade be monitored? Can the approved treatment schedule be modified? What approach should be taken to kidney and/or combined liver-kidney transplantation? How should we limit the risk of meningococcal infection under complement blockade therapy? A pressing question today regards the treatment duration. We discuss the need for prospective studies to establish evidence-based criteria for the continuation or cessation of anticomplement therapy in patients with and without identified complement mutations.

An update for atypical haemolytic uraemic syndrome: diagnosis and treatment. A consensus document

Haemolytic uraemic syndrome (HUS) is a clinical entity defined as the triad of nonimmune haemolytic anaemia, thrombocytopenia, and acute renal failure, in which the underlying lesions are mediated by systemic thrombotic microangiopathy (TMA). Different causes can induce the TMA process that characterizes HUS. In this document we consider atypical HUS (aHUS) a sub-type of HUS in which the TMA phenomena are the consequence of the endotelial damage in the microvasculature of the kidneys and other organs due to a disregulation of the activity of the complement system. In recent years, a variety of aHUs-related mutations have been identified in genes of the the complement system, which can explain approximately 60% of the aHUS cases, and a number of mutations and polymorphisms have been functionally characterized. These findings have stablished that aHUS is a consequence of the insufficient regulation of the activiation of the complement on cell surfaces, leading to endotelial damage mediated by C5 and the complement terminal pathway. Eculizumab is a monoclonal antibody that inhibits the activation of C5 and blocks the generation of the pro-inflammatory molecule C5a and the formation of the cell membrane attack complex. In prospective studies in patients with aHUS, the use of Eculizumab has shown a fast and sustained interruption of the TMA process and it has been associated with significative long-term improvements in renal function, the interruption of plasma therapy and important reductions in the need of dialysis. According to the existing literature and the accumulated clinical experience, the Spanish aHUS Group published a consensus document with recommendations for the treatment of aHUs (Nefrologia 2013;33[1]:27-45). In the current online version of this document, we update the aetiological classification of TMAs, the pathophysiology of aHUS, its differential diagnosis and its therapeutic management.

Timing of eculizumab therapy for C3 glomerulonephritis

Eculizumab is an anti-C5 antibody that inhibits C5 cleavage and prevents the generation of the terminal complement complex C5b-9. Eculizumab is licensed to treat paroxysmal nocturnal haemoglobinuria or atypical haemolytic uraemic syndrome (aHUS). Clinical trials are ongoing for C3 glomerulopathy. Given the unfamiliarity of physicians with these rare diseases and the variability of clinical presentation, a delayed initiation of eculizumab therapy is common. Thus, the question arises as to what extent improvement of kidney function may be expected when patients have been dialysis dependent for weeks or months already when eculizumab is initiated. Furthermore, given the high cost and potential adverse effects of eculizumab, the question arises of when to stop therapy because of futility when patients with kidney-only manifestations remain dialysis dependent. In literature reports, eculizumab was stopped as early as after 3 weeks because the patient remained dialysis dependent. In this issue of CKJ, Inman et al. report on eculizumab-induced reversal of dialysis-dependent kidney failure from C3 glomerulonephritis, illustrating both the potential benefit of eculizumab for this complement-mediated disease and the need for lengthy therapy—dialysis independency was reached after 5 months of eculizumab. Indeed, there are reports of renal function recovery when eculizumab was initiated after 4 months on dialysis and of recovery of renal function 2.0–3.5 months after initiation of eculizumab in dialysis-dependent patients with C3 glomerulopathy or aHUS.

Eculizumab in the treatment of atypical hemolytic uremic syndrome in an infant leads to cessation of peritoneal dialysis and improvement of severe hypertension

BACKGROUND

Severe hypertension (HTN) and acute kidney injury frequently associated with atypical hemolytic uremic syndrome (aHUS) were refractory to various therapies in the pre-eculizumab era. Here we report the case of a 4-month-old boy who developed aHUS presenting with undetectable C3 protein, no predisposing mutations in complement factors, and no antibodies against factor H.

METHODS

Repeated plasma infusions and nine sessions of plasmapheresis were ineffective. The patient initially required continuous hemodiafiltration and thereafter peritoneal dialysis. Despite vigorous antihypertensive treatment and improved fluid overload with dialysis, HTN persisted. His low C3 level (<20 mg/dl) suggested unrestricted complement activation. Therefore, based on the suspicion of unrestricted complement cascade in the pathogenesis, treatment with eculizumab, a human anti-C5 monoclonal antibody, was initiated with the aim of controlling disease activity.

RESULTS

Eculizumab therapy resulted in the control of severe HTN and cessation of peritoneal dialysis.

CONCLUSIONS

This infant with HTN and acute kidney injury associated with aHUS was treated successfully with eculizumab.

Atypical hemolytic uremic syndrome

Hemolytic uremic syndrome (HUS) is a triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. The atypical form of HUS is a disease characterized by complement overactivation. Inherited defects in complement genes and acquired autoantibodies against complement regulatory proteins have been described. Incomplete penetrance of mutations in all predisposing genes is reported, suggesting that a precipitating event or trigger is required to unmask the complement regulatory deficiency. The underlying genetic defect predicts the prognosis both in native kidneys and after renal transplantation. The successful trials of the complement inhibitor eculizumab in the treatment of atypical HUS will revolutionize disease management.

Complement therapy in atypical haemolytic uraemic syndrome (aHUS)

Central to the pathogenesis of atypical haemolytic uraemic syndrome (aHUS) is over-activation of the alternative pathway of complement. Inherited defects in complement genes and autoantibodies against complement regulatory proteins have been described. The use of plasma exchange to replace non-functioning complement regulators and hyper-functional complement components in addition to the removal of CFH-autoantibodies made this the ‘gold-standard’ for management of aHUS. In the last 4 years the introduction of the complement inhibitor Eculizumab has revolutionised the management of aHUS. In this review we shall discuss the available literature on treatment strategies to date.

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.

Use of eculizumab for atypical haemolytic uraemic syndrome and C3 glomerulopathies

In the past decade, a large body of evidence has accumulated in support of the critical role of dysregulation of the alternative complement pathway in atypical haemolytic uraemic syndrome (aHUS) and C3 glomerulopathies. These findings have paved the way for innovative therapeutic strategies based on complement blockade, and eculizumab, a monoclonal antibody targeting the human complement component 5, is now widely used to treat aHUS. In this article, we review 28 case reports and preliminary data from 37 patients enrolled in prospective trials of eculizumab treatment for episodes of aHUS involving either native or transplanted kidneys. Eculizumab may be considered as an optimal first-line therapy when the diagnosis of aHUS is unequivocal and this treatment has the potential to rescue renal function when administered early after onset of the disease. However, a number of important issues require further study, including the appropriate duration of treatment according to an individual's genetic background and medical history, the optimal strategy to prevent post-transplantation recurrence of aHUS and a cost-efficacy analysis. Data regarding the efficacy of eculizumab in the control of C3 glomerulopathies are more limited and less clear, but several observations suggest that eculizumab may act on the most inflammatory forms of this disorder.