Low CR1 (C3b receptor) level on erythrocytes is associated with poor prognosis in hemodialysis patients.
BACKGROUND
Erythropoietin in patients under dialysis treatment for renal failure is low which induces anemia. Treatment with recombinant erythropoietin (rEPO) has been used routinely as a supplement treatment for these patients. Immune complexes (IC) react with complement and bind to CR1 on erythrocytes (E-CR1), and are transported to the liver and/or spleen where IC removal and degradation occurs. The erythrocytes then return to circulation where they bind to additional IC. There are some patients whose E-CR1 expression is low with chronic anemia in spite of rEPO treatment. We hypothesized that in hemodialysis (HD) patients altered host defense against infection is associated with low levels of E-CR1. We examined if low E-CR1 in dialysis patients constitutes a risk factor for reduced host defense and poor outcome.


METHODS
In 95 HD patients, E-CR1 was quantified using a monoclonal E-CR1 antibody and FACS analysis followed by clinical course studies for 5 years.


RESULTS
The patients were divided into three groups by E-CR1 level. Percent survival for the low E-CR1 group (53.3%) was significantly lower than the high E-CR1 group (86.4%) (p < 0.01). There were more hepatitis C virus-positive patients within the low E-CR1 group (27.3%) than in the high E-CR1 group (4.7%) (p < 0.05). Furthermore, 10 patients with the lowest E-CR1 levels had severe complications, notably infection at an arteriovenous fistula.


CONCLUSIONS
A reduced E-CR1 level might be a risk factor for reduced host defense and can be used as a predicting factor for poor prognosis in a HD patient.
Ohi
Hiroyuki
H
Kasukabe-Kisen Hospital, Kasukabe, Japan. ohi@h8.dion.ne.jp
Tamano
Mariko
M
Okada
Noriko
N
D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D007105:Immune Complex Diseases / Q000175:diagnosis / Q000378:metabolism / Q000401:mortality; D007676:Kidney Failure, Chronic / Q000378:metabolism / Q000401:mortality / Q000628:therapy; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D017463:Receptors, Complement 3b / Q000037:antagonists & inhibitors / Q000097:blood*; D006435:Renal Dialysis / Q000401:mortality / Q000639:trends; D012307:Risk Factors
D017463:Receptors, Complement 3b