Identification of the hemoglobin scavenger receptor/CD163 as a natural soluble protein in plasma.
The hemoglobin scavenger receptor (HbSR/CD163) is an interleukin-6- and glucocorticoid-regulated macrophage/monocyte receptor for uptake of haptoglobin-hemoglobin complexes. Moreover, there are strong indications that HbSR serves an anti-inflammatory function. Immunoprecipitation and immunoblotting enabled identification of a soluble plasma form of HbSR (sHbSR) having an electrophoretic mobility equal to that of recombinant HbSR consisting of the extracellular domain (scavenger receptor cysteine-rich 1-9). A sandwich enzyme-linked immunosorbent assay was established and used to measure the sHbSR level in 130 healthy subjects (median, 1.87 mg/L; range, 0.73-4.69 mg/L). To evaluate the sHbSR levels in conditions with increased leukocyte stimulation and proliferation, 140 patients admitted to a hematological department were screened. Several patients, with a broad spectrum of diagnoses, had a level of sHbSR above the range of healthy persons. Patients with myelomonocytic leukemias and pneumonia/sepsis exhibited the highest levels (up to 67.3 mg/L). In conclusion, sHbSR is an abundant plasma protein potentially valuable in monitoring patients with infections and myelomonocytic leukemia.
Møller
Holger Jon
HJ
Department of Clinical Biochemistry, AAS Aarhus University Hospital, Denmark. holger@aas.auh.dk
Peterslund
Niels Anker
NA
Graversen
Jonas Heilskov
JH
Moestrup
Søren Kragh
SK
D000818:Animals; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic / Q000097:blood* / Q000235:genetics; D016466:CHO Cells; D006224:Cricetinae; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015870:Gene Expression; D006242:Haptoglobins / Q000378:metabolism*; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D007163:Immunosorbent Techniques; D007948:Leukemia, Monocytic, Acute / Q000097:blood; D015470:Leukemia, Myeloid, Acute / Q000097:blood; D015479:Leukemia, Myelomonocytic, Acute / Q000097:blood; D008297:Male; D011014:Pneumonia / Q000097:blood; D011956:Receptors, Cell Surface / Q000097:blood* / Q000235:genetics; D011994:Recombinant Proteins; D012016:Reference Values; D018805:Sepsis / Q000097:blood; D012995:Solubility; D014162:Transfection; D000098902:CD163 Antigen
D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D000098902:CD163 Antigen; D006242:Haptoglobins; D006454:Hemoglobins; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins