Table 1.

Characteristics of proteins involved in the pathogenesis of TTP and atypical HUS

Protein	ADAMTS13	CFH	IF	MCP
Gene, RefSeq	NM 139026	NM 000186	NM 000204	NM 002389
Genomic size	37 kb	95 kb	63 kb	43 kb
Location	9q34	1q32	4q25	1q32
No. of exons	29	23	13	14
cDNA size	4.7 kb	4.0 kb	2.0 kb	3.4 kb
Amino acid residues (precursor)	1427	1231	583	392
Mol wt (kD)
Predicted	154	139	65.7	43.7
Observed	190	155	88	59–68 (BC1, BC2)
		43	(50 & 38)	51–58 (C1, C2)
Tissue expression	Liver (stellate cells)	Liver	Liver, EC, MNC, etc.	Kidney, fetal heart, brain, MNC, spermatozoa
Subcellular location	Plasma	Plasma	Plasma	Transmembrane protein
Plasma concentration	1 µg/mLa	3.5 mg/mL	35 µg/mL	-
Function	Cleavage of sheared VWF	Cofactor of IF ↓ alternative C3 convertase	Cleavage of C3b, C4b	Cofactor of IF Activation of Treg
Causes of deficiency	Inhibitory antibodies	Genetic mutations	Genetic Mutations	Genetic Mutations
	Genetic mutations	Autoantibody
Disorders of deficiency	TTP	MPGN*	Pyogenic infection	Atypical HUS
		Atypical HUS	Vasculitis
			Atypical HUS

HUS: hemolytic uremic syndrome; EC: endothelial cell; MNC: mononuclear cells; MPGN: membranoproliferative glomerulonephropathy; TTP: thrombotic thrombocytopenic purpura; Treg: regulatory T cells.

^aEstimated