Racial differences in ristocetin-induced platelet aggregation

G. R. Buchanan, C. R. Holtkamp, E. N. Levy

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Several investigators have reported defective ristoceptin-induced platelet aggregation (RIPA) in individuals whose red blood cells contain sickle haemoglobin, but the race of control subjects in these studies was not stated. therefore, maximal amplitude of RIAP was examined in 75 normal whites and blacks, 16 of whom had sickle trait defined by haemoglobin electrophoresis and sickle prep. Final restocetin concentrations in platelet rich plasma were 1.1, 1.2 and 1.5 mg/ml. Mean aggregation at 1.1 mg/ml was significantly less in blacks (mean 31%) than in whites (mean 72% (P <0.001). 60% of blacks but only 11% of whites had less than 50% RIPA at 1.1 mg/ml. RIPA was entirely absent in 19% of blacks. Differences in RIPA between black and white subjects were also present at ristocetin concentrations of 1.2 and 1.5 mg/ml but were less striking. RIPA in 25 children with homozygous sickle cell anaemia was similar to that in the normal AA and AS blacks. Differences in RIPA could not be explained by age, sex, presence of sickle haemoglobin, or medications. Addition of normal plasma or platelets did not correct reduced RIPA in seven blacks, and their plasma inhibited normal RIPA responses. Reduced platelet aggregation to low concentrations of ristocetin is a normal finding in many blacks, is not related to the presence of sickle haemoglobin, and appears to be due to a plasma inhibitor against RIPA.

Original languageEnglish (US)
Pages (from-to)455-464
Number of pages10
JournalBritish Journal of Haematology
Volume49
Issue number3
StatePublished - 1981

Fingerprint

Ristocetin
Platelet Aggregation
Sickle Hemoglobin
Platelet-Rich Plasma
Sickle Cell Anemia
Electrophoresis
Blood Platelets
Erythrocytes
Research Personnel

ASJC Scopus subject areas

  • Hematology

Cite this

Racial differences in ristocetin-induced platelet aggregation. / Buchanan, G. R.; Holtkamp, C. R.; Levy, E. N.

In: British Journal of Haematology, Vol. 49, No. 3, 1981, p. 455-464.

Research output: Contribution to journalArticle

Buchanan, G. R. ; Holtkamp, C. R. ; Levy, E. N. / Racial differences in ristocetin-induced platelet aggregation. In: British Journal of Haematology. 1981 ; Vol. 49, No. 3. pp. 455-464.
@article{79393ab121ca43de824a5dac052875fd,
title = "Racial differences in ristocetin-induced platelet aggregation",
abstract = "Several investigators have reported defective ristoceptin-induced platelet aggregation (RIPA) in individuals whose red blood cells contain sickle haemoglobin, but the race of control subjects in these studies was not stated. therefore, maximal amplitude of RIAP was examined in 75 normal whites and blacks, 16 of whom had sickle trait defined by haemoglobin electrophoresis and sickle prep. Final restocetin concentrations in platelet rich plasma were 1.1, 1.2 and 1.5 mg/ml. Mean aggregation at 1.1 mg/ml was significantly less in blacks (mean 31{\%}) than in whites (mean 72{\%} (P <0.001). 60{\%} of blacks but only 11{\%} of whites had less than 50{\%} RIPA at 1.1 mg/ml. RIPA was entirely absent in 19{\%} of blacks. Differences in RIPA between black and white subjects were also present at ristocetin concentrations of 1.2 and 1.5 mg/ml but were less striking. RIPA in 25 children with homozygous sickle cell anaemia was similar to that in the normal AA and AS blacks. Differences in RIPA could not be explained by age, sex, presence of sickle haemoglobin, or medications. Addition of normal plasma or platelets did not correct reduced RIPA in seven blacks, and their plasma inhibited normal RIPA responses. Reduced platelet aggregation to low concentrations of ristocetin is a normal finding in many blacks, is not related to the presence of sickle haemoglobin, and appears to be due to a plasma inhibitor against RIPA.",
author = "Buchanan, {G. R.} and Holtkamp, {C. R.} and Levy, {E. N.}",
year = "1981",
language = "English (US)",
volume = "49",
pages = "455--464",
journal = "British Journal of Haematology",
issn = "0007-1048",
publisher = "Wiley-Blackwell",
number = "3",

}

TY - JOUR

T1 - Racial differences in ristocetin-induced platelet aggregation

AU - Buchanan, G. R.

AU - Holtkamp, C. R.

AU - Levy, E. N.

PY - 1981

Y1 - 1981

N2 - Several investigators have reported defective ristoceptin-induced platelet aggregation (RIPA) in individuals whose red blood cells contain sickle haemoglobin, but the race of control subjects in these studies was not stated. therefore, maximal amplitude of RIAP was examined in 75 normal whites and blacks, 16 of whom had sickle trait defined by haemoglobin electrophoresis and sickle prep. Final restocetin concentrations in platelet rich plasma were 1.1, 1.2 and 1.5 mg/ml. Mean aggregation at 1.1 mg/ml was significantly less in blacks (mean 31%) than in whites (mean 72% (P <0.001). 60% of blacks but only 11% of whites had less than 50% RIPA at 1.1 mg/ml. RIPA was entirely absent in 19% of blacks. Differences in RIPA between black and white subjects were also present at ristocetin concentrations of 1.2 and 1.5 mg/ml but were less striking. RIPA in 25 children with homozygous sickle cell anaemia was similar to that in the normal AA and AS blacks. Differences in RIPA could not be explained by age, sex, presence of sickle haemoglobin, or medications. Addition of normal plasma or platelets did not correct reduced RIPA in seven blacks, and their plasma inhibited normal RIPA responses. Reduced platelet aggregation to low concentrations of ristocetin is a normal finding in many blacks, is not related to the presence of sickle haemoglobin, and appears to be due to a plasma inhibitor against RIPA.

AB - Several investigators have reported defective ristoceptin-induced platelet aggregation (RIPA) in individuals whose red blood cells contain sickle haemoglobin, but the race of control subjects in these studies was not stated. therefore, maximal amplitude of RIAP was examined in 75 normal whites and blacks, 16 of whom had sickle trait defined by haemoglobin electrophoresis and sickle prep. Final restocetin concentrations in platelet rich plasma were 1.1, 1.2 and 1.5 mg/ml. Mean aggregation at 1.1 mg/ml was significantly less in blacks (mean 31%) than in whites (mean 72% (P <0.001). 60% of blacks but only 11% of whites had less than 50% RIPA at 1.1 mg/ml. RIPA was entirely absent in 19% of blacks. Differences in RIPA between black and white subjects were also present at ristocetin concentrations of 1.2 and 1.5 mg/ml but were less striking. RIPA in 25 children with homozygous sickle cell anaemia was similar to that in the normal AA and AS blacks. Differences in RIPA could not be explained by age, sex, presence of sickle haemoglobin, or medications. Addition of normal plasma or platelets did not correct reduced RIPA in seven blacks, and their plasma inhibited normal RIPA responses. Reduced platelet aggregation to low concentrations of ristocetin is a normal finding in many blacks, is not related to the presence of sickle haemoglobin, and appears to be due to a plasma inhibitor against RIPA.

UR - http://www.scopus.com/inward/record.url?scp=0019517511&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0019517511&partnerID=8YFLogxK

M3 - Article

C2 - 6975118

AN - SCOPUS:0019517511

VL - 49

SP - 455

EP - 464

JO - British Journal of Haematology

JF - British Journal of Haematology

SN - 0007-1048

IS - 3

ER -