Complement activation during CAPD.
Complement activation was monitored in 20 CAPD patients and 20 normal individuals using markers of the alternative (Bb fragment), classical (C4d fragment), common (iC3b) and terminal pathways (SC5b-9, the soluble form of the membrane attack complex, MAC), together with C3, C4 and factor B. CAPD plasma SC5b-9 was higher than normal although this was not due to increased complement activation in the plasma. The calculated cleavage for C3, C4 and factor B to iC3b, C4d and Bb respectively, due to spontaneous activation, was similar in both groups. C3, C4 and factor B in dialysate were less than 1% of plasma concentration, consistent with vascular leakage, whereas iC3b, Bb and SC5b-9 were at higher concentrations, suggesting generation in the peritoneum by the alternative pathway. 2.4% C4d is consistent with leakage of this small molecule but may indicate slight classical activation. It is concluded that complement activation occurs in the peritoneum during CAPD. MAC and the anaphylatoxins which are also generated may contribute to an increased risk of infection and other inflammatory complications.
Young
G A
GA
Renal Research Unit, General Infirmary, Leeds, UK.
Kendall
S
S
Brownjohn
A M
AM
D001769:Blood / Q000378:metabolism; D003167:Complement Activation; D003176:Complement C3 / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D011415:Complement Factor B / Q000032:analysis; D015938:Complement Membrane Attack Complex; D003170:Complement Pathway, Alternative; D003171:Complement Pathway, Classical; D003165:Complement System Proteins / Q000032:analysis; D005260:Female; D006023:Glycoproteins / Q000032:analysis; D015312:Hemodialysis Solutions / Q000737:chemistry; D006801:Humans; D008297:Male; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory; D012016:Reference Values
D003176:Complement C3; D003181:Complement C4; D015938:Complement Membrane Attack Complex; D006023:Glycoproteins; D015312:Hemodialysis Solutions; C047610:SC5b-9 protein complex; D003165:Complement System Proteins; D011415:Complement Factor B