Antiretroviral Therapy and Haemostatic Parameters in HIV Patients with Haemoglobin Phenotypes AS and AA

Abstract

Background: Haematological and coagulation defects have been reported in advanced HIV infection, the occurrence of the S gene is high in African Blacks. HIV infection is on the increase in Nigeria. About a quarter of Nigerians have haemoglobin phenotype HbAS. The haemostatic parameters have not been fully determined in Nigerians with haemoglobin HbAS. Aims: To determine the effects of HIV infection on haematological and haemostatic profiles of Nigerians with the sickle cell trait: haemoglobin AS (HbAS) and haemoglobin AA (HbAA). Methods: Subjects comprised of phenotype HbAS and HbAA patients who were newly diagnosed with HIV infection and those already on antiretroviral therapy (ART). Control group comprised of apparently healthy subjects with haemoglobin phenotypes AS and AA. Blood samples were analysed for haematological parameters: [haematocrit (Hct), total white cell count (WCC), platelet count (Plt)) and haemostatic parameters: [plasma fibrinogen concentration (Pfc), prothrombin time (PT) and activated partial thromboplastin time (APTT)]. All analyses were carried out using standard techniques. Quantitative assay was conducted to estimate D-dimer levels. Results: A total of 145 subjects were studied. The mean haemoglobin (Hb), and WCC were higher in HbAS than HbAA subjects with HIV infection but the differences in the mean values were not Statistically significant (p>0.5). The PT, APTT and the Pfc were significantly more prolonged in HbAS with HIV infection than in HbAS controls (p<0.0001). The haemostatic parameters were also significantly more prolonged in HbAA with HIV than HbAA HIV negative controls (p<0.0001). Elevation of D-dimer was found in 12 and 20% of HbAS and HbAA HIV positive subjects respectively. Positive D-dimer was found to be significantly associated with HIV infection (p = 0.0007) in both HbAS and HbAA subjects. Conclusion: This study has shown that Hb phenotype does not influence the effect of HIV infection on haemostatic and haematological parameters. Elevated plasma fibrinogen concentration, prolongation of APTT and presence of D-dimer, in HIV infection may suggest an inflammatory response as well as subclinical coagulapathy.