Extra-renal manifestations of atypical hemolytic uremic syndrome

Abstract

Atypical hemolytic uremic syndrome (aHUS) is a rare and complex disease resulting from abnormal alternative complement activation with a wide range of clinical presentations. Extra-renal manifestations of aHUS can involve many organ systems, including the peripheral and central nervous, gastrointestinal, cardiovascular, integumentary, pulmonary, as well as the eye. While some of these extra-renal manifestations occur in the acute phase of aHUS, some can also occur as long-term sequelae of unopposed complement activation. Extra-renal symptoms are observed in approximately 20% of patients with aHUS, with the incidence of specific organ system complications ranging from a few case reports to 50% of described patients. Careful monitoring for extra-renal involvement is critical in patients with aHUS, as prompt evaluation and management may decrease the risk of high morbidity and mortality associated with aHUS.

The long-acting C5 inhibitor, ravulizumab, is effective and safe in pediatric patients with atypical hemolytic uremic syndrome naïve to complement inhibitor treatment

“…Because TMA leads to the involvement of the microvasculature of other organs, aHUS can also manifest in neurological, gastrointestinal, cardiovascular and pulmonary systems. [24][25][26] Thirteen (72.5%) patients in this study had extrarenal symptoms at baseline, similar to the proportion reported in the clinical trial of ravulizumab in adult patients naïve to complement inhibitor therapy. 17 The term 'extrarenal symptoms', as applied in this trial, refers to any symptom which may be related to aHUS occurring in an organ other than the kidney; this may include symptoms related to the presence of renal failure.…”

Renal Damage in Recurrent Atypical Hemolytic Uremic Syndrome Associated with <i>C3</i> p.Ile1157Thr Gene Mutation

“…The present case showed CNS involvement, including a headache, seizure, and visual disorders, which are extremely common in aHUS patients (16). In a Turkish registry of pediatric aHUS patients, seizure and visual loss were observed in 20.7% and 2.3% of patients, respectively (17).…”

“…Magnetic resonance imaging of the brain revealed posterior reversible encephalopathy syndrome, which is sometimes observed in aHUS patients (17). The patient also presented with gastrointestinal disorders including abdominal pain and diarrhea, which are commonly involved in aHUS (16). These findings suggest that complement-mediated microvascular injuries might have occurred in multiple organs in addition to the kidney in the present patient.…”

Occlusive retinal vasculopathy with macular branch retinal artery occlusion as a leading sign of atypical hemolytic uremic syndrome – a case report

“…3b). During the later course, the patient suffered from myocardial infarction, a well known complication of aHUS [7], and underwent percutaneous transluminal coronary angioplasty with stent implantation. Due to his systemic condition he was lost for ophthalmological follow-up and returned 11 months after the last bevacizumab injection because of sudden loss of vision in his left eye.…”

“…Ocular complications in typical HUS are very rare and have been described in 4% of pediatric cases [7,8]. The prevalence is lower with aHUS, with only few cases reported in the literature, including Purtscher-like retinopathy [9][10][11], occlusive retinopathy [12] and hypertensive choroidopathy [13].…”