Although cardiac and vascular complications have been recognized among pati
ents infected with the Human Immunodeficiency Virus-1 (HIV-1), their vascul
ar biology and rheology have not been studied. Rheology of red blood cells
(RBC) was assessed with an erythroaggregometer in 22 HIV-1 infected asympto
matic patients (pts) and 17 healthy HIV negative controls (C). All particip
ants were normotensive, nondiabetics, had normal lipid levels and had an he
matocrit ranging from 37 to 44% and hemoglobin levels greater than or equal
to 12 g/100 ml. Patients had a shorter RBC aggregation characteristic time
than controls (1.49 +/- 0.17 vs. 2.04 +/- 0.41 s, p = 0.001) and an increa
sed disaggregation shear rate (166 +/- 34.9 vs. 122 +/- 25.4 s(-1) p = 0.00
1). This hyperaggregation tendancy was associated with increased gamma -glo
bulin (18.3 +/- 3.3 vs. 13.7 +/- 1.9 g/l, p = 0.01) and fibrinogen (3.52 +/
- 0.57 vs 3.03 +/- 0.48 g/l, p = 0.003) levels and with an increased erythr
ocyte sedimentation rate (ESR) (25 +/- 14.3 vs. 12.3 +/- 7.5 mm, p = 0.02).
Even in patients with ESRs ranging within normal values (less than or equa
l to 20 mm), the aggregation characteristic time was found lower in patient
s than in controls (p = 0.004). There was no correlation between these rheo
logical changes and the CD4+ T-cell count. The 17 patients receiving an ant
iviral therapy had lower CD4+ T-cell counts than their 5 untreated counterp
arts (244.7 +/- 167 vs. 410 +/- 106/mm(3), p = 0.025), and a higher disaggr
egation shear rate (177.4 +/- 38.2 vs. 127 +/- 25.4, p = 0.01). Thus, an im
pairment of rheological characteristics is observed in asymptomatic HIV-1 i
nfected patients in association with changes in plasma proteins.