Neopterin as a surrogate marker for monitoring HIV disease progression and patient’s response to antiretroviral therapy: a case control study in Kumasi, Ghana

Surrogate markers including CD4 T cell, viral load estimation and activated immune markers have been identified as having significance in the pathogenesis and prognosis of the HIV infection. But there is limited data on the utility of serum neopterin estimation in HIV infection. This study was aimed at evaluating serum neopterin levels as a marker of predicting the progression of HIV infection and to monitor patient’s response to antiretroviral therapy. In all one hundred and ninety two (192) HIV infected patients constituting one hundred and four highly active antiretroviral therapy patients (104) and eighty eight (88) highly active antiretroviral therapy naïve patients were recruited from the HIV clinic at the Bomso specialist hospital in the Kumasi metropolis. Venous blood samples were taken and assayed for haematological parameters (Haemoglobin, White blood cell, Red blood cell, Mean cell haemoglobin, Mean cell volume, Haematocrit and Mean cell haemoglobin concentration) , Biochemical parameters (Albumin , Aspartate amino transferase, Alanine amino transferase , urea, creatinine, total protein and globulin), Immunological parameters (CD4 count and neopterin). Weight and height were also taken for the determination of body mass index. Out of the one hundred and four (104) highly active antiretroviral therapy patients, majority (57.7%) were on Tenofivir, Lamivudine and Nevirapine combination whiles only 5.8% were on Zidovudine, Lamivudine and Nevirapine combination. Although the median age of the highly active antiretroviral therapy patients (41yrs) was higher than the highly active antiretroviral therapy naïve patients (40yrs), this was statistically not significant (p=0.203). Haematological analysis also showed a significant increase (p=0.001) in haemoglobin levels in the highly active antiretroviral therapy patients (12.40g/dL) compared to the highly active antiretroviral therapy naïve patients (11.60g/dL). A correlation analysis between CD4 count and haemoglobin levels of the highly active antiretroviral therapy naïve patients showed a significant positive correlation which indicates the usefulness of haemoglobin measurement in the management of HIV infected patients. Result from the biochemical assay showed a significant difference in albumin levels (p=0.0001) in patients placed on highly active antiretroviral therapy (40.05g/L) compared to the highly active antiretroviral therapy naïve patients (34.75g/L). Serum v total protein, globulin, Aspartate amino transferase, Alanine amino transferase, urea and creatinine were significantly lower (p=0.0001) in the highly active antiretroviral therapy patients compared to the naïve highly active antiretroviral therapy patients. A statistically significant negative correlation was observed between the duration of therapy treatment and the transaminases (Aspartate amino transferase and Alanine amino transferase). Although body mass index was statistically not significant (p=0.521) between the highly active antiretroviral therapy patients and the naïve highly active antiretroviral therapy patients, patients on the highly active antiretroviral therapy had a higher body mass index (23.30kg/m2) compared to the naïve highly active antiretroviral therapy patients (22.55kg/m2). Neopterin was significantly lower (p=0.0001) in patients placed on the highly active antiretroviral therapy (26.40nmol/L) than the naïve highly active antiretroviral therapy patients (51.75nmol/L). The study also revealed a strong negative correlation between serum neopterin and CD4 count for both the highly active antiretroviral therapy patients (rho-0.99, p=0.0001) and the naïve highly active antiretroviral therapy patients (rho -0.96, p=0.0001). Serum neopterin were found to be increased as the disease progresses in the studied participants. Conclusion: Given it strong negative correlation with CD4 counts, an area under the curve of 0.99, specificity of 95.9% and sensitivity of 97.5%, neopterin may provide some prognostic information to CD4 counts used in the monitoring of patients infected with the HIV disease.

Source: KNUST