title: Hemorheologic abnormalities associated with HIV infection: altered erythrocyte aggregation and deformability.
abstract: OBJECTIVE
  To investigate possible alterations of erythrocyte aggregation and deformability, which are factors that can influence blood flow, in human immunodeficiency virus (HIV)-infected individuals and to determine whether these factors are related to the severity of immunodeficiency.
  
  
  METHODS
  Laboratory evaluations were performed on 46 HIV-infected individuals and 44 HIV-negative control subjects. Current and nadir (lowest previous) CD4+ T-lymphocyte counts were identified for each subject. Erythrocyte aggregation was measured using a fully automatic erythrocyte aggregometer. Factors related to erythrocyte aggregation were also determined: erythrocyte sedimentation rate (ESR), zeta sedimentation ratio (ZSR), and plasma fibrinogen levels. Erythrocyte deformability was observed at various fluid shear stress levels, with a laser diffraction ektacytometer. Correlations were sought between each of these measures and current or nadir CD4+ T-lymphocyte counts, and each measure was compared between three subgroups based on current and nadir CD4+ T-lymphocyte counts (severely immunosuppressed, immune reconstituted, never severely immunosuppressed).
  
  
  RESULTS
  The following parameters were significantly different between HIV-infected subjects and controls: increased erythrocyte aggregation, at stasis (P < 0.001) and low shear stress (P < 0.001), increased ESR (P < 0.001), increased ZSR (P < 0.028), increased serum fibrinogen (P = 0.015), and decreased erythrocyte deformability (P < 0.001). Only erythrocyte aggregation at stasis correlated significantly with current CD4+ T-lymphocyte count (r = - 0.344, P = 0.022). None of the parameters was significantly different between HIV-infected subgroups.
  
  
  CONCLUSIONS
  Increased aggregation and decreased deformability of erythrocytes are associated with HIV-infection regardless of the severity of immunodeficiency. HIV-infected individuals may be at risk for progressive retinal microvascular damage from persistent hemorheologic abnormalities, despite immune reconstitution associated with potent antiretroviral drug therapies.
authors.affiliation: Ocular Inflammatory Disease Center, Jules Stein Eye Institute, Los Angeles, CA 90095-7003, USA.
authors.forename: Alisa
authors.initials: A
authors.lastname: Kim
authors.forename: Hajir
authors.initials: H
authors.lastname: Dadgostar
authors.forename: Gary N
authors.initials: GN
authors.lastname: Holland
authors.forename: Rosalinda
authors.initials: R
authors.lastname: Wenby
authors.forename: Fei
authors.initials: F
authors.lastname: Yu
authors.forename: Brian G
authors.initials: BG
authors.lastname: Terry
authors.forename: Herbert J
authors.initials: HJ
authors.lastname: Meiselman
mesh_terms: D000328:Adult; D001799:Blood Sedimentation; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D004903:Erythrocyte Aggregation; D004906:Erythrocyte Count; D004907:Erythrocyte Deformability; D005340:Fibrinogen / Q000032:analysis; D015658:HIV Infections / Q000097:blood* / Q000150:complications; D006801:Humans; D008875:Middle Aged; D012166:Retinal Hemorrhage / Q000097:blood* / Q000209:etiology; D012171:Retinal Vessels / Q000473:pathology; D012307:Risk Factors
chemical_list: D005340:Fibrinogen