Complement activation during painful crisis in sickle cell anemia.
Previous studies documented complement activation in sickle cell disease patients and suggested that this contributes to increased risk of infection. We have demonstrated alternative pathway activation initiated by membrane phospholipid changes which occur in sickled erythrocytes. The present studies compared complement activation products in serial samples from sickle cell anemia patients at baseline and during hospitalization for painful crisis to examine the correlation between complement activation and disease activity. Plasma concentrations of Bb, C4d, and C3a were measured as well as C3 bound to erythrocytes. Patients were subdivided into those with continuous pain and those with intermittent painful episodes. In patients with intermittent pain, there was little evidence of complement activation at baseline and increased plasma concentrations of Bb and C3a during painful crisis. Elevated C3a and C4d levels were observed in patients with continuous pain regardless of hospitalization status, suggesting a continuous underlying inflammatory process in these patients.
Mold
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Department of Microbiology, University of New Mexico, Albuquerque 87131, USA.
Tamerius
J D
JD
Phillips
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G
D000208:Acute Disease; D000328:Adult; D000755:Anemia, Sickle Cell / Q000276:immunology*; D003167:Complement Activation / Q000276:immunology*; D051561:Complement C3 Convertase, Alternative Pathway; D015926:Complement C3a / Q000032:analysis; D003179:Complement C3b / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D015935:Complement C4b; D006801:Humans; D010146:Pain / Q000503:physiopathology*; D010446:Peptide Fragments / Q000032:analysis
D003181:Complement C4; D010446:Peptide Fragments; D015926:Complement C3a; D003179:Complement C3b; D015935:Complement C4b; C032261:complement C4d; D051561:Complement C3 Convertase, Alternative Pathway