Single-nucleotide polymorphisms and rare mutations in factor H (FH; official name, CFH) are associated with age-related macular degeneration and atypical hemolytic uremic syndrome, a form of thrombotic microangiopathy.
Nine mutations were associated with genes known to be implicated in aHUS (CFH, CFI, CD46, CFHR5, and DGKE), while 4 and 5 mutations were detected on complement- (C8B, C9, and MASP1) and coagulation-associated (VWF and CD36) genes, respectively.
Mutations in the gene encoding for complement regulator factor H (FH) severely disrupt its normal function to protect human cells from unwanted complement activation, resulting in diseases such as atypical hemolytic uremic syndrome (aHUS). aHUS presents with severe hemolytic anemia, thrombocytopenia, and renal disease, leading to end-stage renal failure.
We present the case of a young patient at high immunological risk, with atypical haemolytic uraemic syndrome due to factor H mutation, who underwent a successful kidney transplantation with eculizumab, thymoglobulin, belatacept, mycophenolate and steroids, to date preserving excellent graft function without disease recurrence.
Although primary atypical hemolytic uremic syndrome (aHUS) is associated with abnormalities in complement genes and antibodies to complement factor H, the role of complement in secondary aHUS remains debatable.
We reported here the clinical course of aHUS patients with CFH mutations (p.Glu936Asp, Val 1197Ala) and a novel mutation (Glu927Lys) which caused previously defined aHUS.
Here we address this in a factor H mutant mouse (FH<sup>R/R</sup>) which developed complement-mediated TMA as well as macrovascular thrombosis caused by an aHUS-related factor H point mutation (mouse W1206R, corresponding to human W1183R).
We hypothesize that, in this patient, hyperoxaluria caused by the GRHPR genetic defect triggered endothelial perturbation and complement activation, which was amplified by impaired factor H regulatory activity due to the increased -CFHR1-CFHR4 copy numbers, resulting in aHUS.
Although the term aHUS was redefined to denote only complement-mediated HUS in the guide revised in 2016, the patients with TMA caused by other causes (secondary TMA) were included.
Complement factor H‑related 3 (CFHR3) belongs to the human factor H protein family and is associated with various human diseases, including nephropathy, age‑related macular degeneration and atypical hemolytic uremic syndrome.
Performing force-distance measurements with FH(D1119G), a variant lacking one of the C3b-binding sites and causing atypical hemolytic uremic syndrome, we found that it detached more uniformly and easily.
A 3-month-old male infant developed an extremely severe episode of atypical hemolytic uremic syndrome (aHUS) associated with partial deficiencies of full-length complement factor H (FH; ∼15% of infant normal) and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) (39% of normal) and autoantibodies reactive with both proteins.
Structural variation and single-nucleotide variation of the complement factor H (<i>CFH</i>) gene family underlie several complex genetic diseases, including age-related macular degeneration (AMD) and atypical hemolytic uremic syndrome (AHUS).
Atypical Hemolytic Uremic Syndrome Associated with Complement Factor H Mutation and IgA Nephropathy: A Case Report Successfully Treated with Eculizumab.
We present a teaching case of atypical hemolytic uremic syndrome in the postpartum period in a young woman who was found to have mutations of uncertain clinical significance in the complement cascade, including in C3, CFH, and CFI.
Genotype-phenotype correlations between the disease groups identified a higher frequency of protein altering alleles in short consensus repeat 20 (SCR20) of factor H (FH), and in the serine protease domain of factor I (FI) in aHUS/C3G patients.
Further, when we characterized epitope specificities and binding avidities of anti-FH autoantibodies in aHUS patients, most anti-FH autoantibodies were directed towards the FH cell-surface anchoring polyanionic binding site-containing C-terminal short conservative regions (SCRs) 17-20 with higher binding avidities than for native FH.
While early confirmation of aHUS is often not possible, except in the minority of patients in whom autoantibodies against factor H are identified, genetic testing ultimately reveals a complement-related mutation in a significant proportion of aHUS cases.
While FH is measured to diagnose and monitor therapy of patients with atypical hemolytic uremic syndrome, recent studies also implicated increased plasma levels of FHRs in disease.