Thrombotic microangiopathy after renal transplantation: Current insights in de novo and recurrent disease

Table 3 Complement studies for atypical hemolytic uremic syndrome (aHUS)

Complement test	aHUS
Complement protein levels	C3, C4, FB1, C51
Complement regulatory protein levels	FH, FI, Properdin1, CD462
Complement split products	C3c1, C3d1, Bb1, sC5b-91
Complement functional assays	CH50, AH50, hemolytic assays, FH assays1
Autoantibodies	Anti-FH
Genetic screening	CFH, CFI, C3, CD46, CFB Genomic rearrangements across the FH-FHR locus (e.g., by MLPA) Sequencing of coding regions and assessment of CNV Non-complement genetic screening includes THBD and DGKE

¹Currently available only at specific laboratories; they are research and not clinically validated assays;

²CD46 is also known as MCP. Adapted from: Goodship et al[58]. AH50: Alternative pathway hemolytic assay; C3: Complement component 3; C4: Complement component 4; C5: Complement component 5; CFB: Complement factor B gene; CFH: Complement factor H gene; CFHR: Complement factor H related genes; CFI: Complement factor I gene; CH50: Classical pathway hemolytic assay; CNV: Copy number variation; DGKE gene: Diacylglycerol kinase epsilon gene; FB: Complement factor B; FH: Complement factor H; FI: Complement factor I; MLPA: Multiplex ligation-dependent probe amplification; sC5b-9: Soluble C5b-9; THBD: Thrombomodulin; aHUS: Atypical hemolytic uremic syndrome.