Cystatin C-Based Evaluation of Kidney Function of HIV-Infected Children in Benin City, Southern Nigeria

Abstract

Background. Human immunodeficiency virus (HIV) is now a confirmed risk factor for kidney disease with an increased burden in persons of African descent. Method. We measured the serum cystatin C levels of 205 ART-naive, HIV-infected children by an ELISA technique and compared them with the levels of apparently healthy children. Result. The mean ± SD serum cystatin C level of children with HIV infection was 1.01 ± 0.44 mg/L, significantly higher than the mean value in the control group, that is, 0.72 ± 0.20 mg/L (P = 0.000). The mean ± SD cystatin C-based estimated GFR of children with HIV infection was 102.7 ± 31.0 mL/min/1.73 m2, significantly lower than 126.9 ± 28.5 mL/min/1.73 m2 in the control group, (P = 0.014). A significantly higher proportion of HIV-infected children compared to controls had eGFR < 90 mL/min/1.73 m2 (21.5% versus 5.4%; P = 0.00). The prevalence of chronic kidney disease (CKD) among the HIV-infected children was 10.7%. The cystatin C-based eGFR of the HIV-infected children ≥5 years old correlated positively with their CD4 count (r = 0.23; P = 0.022). Conclusion. There is a high prevalence of CKD among HIV-infected children, requiring regular monitoring of their kidney function using a cystatin C-based method.

Cystatin C

“…The very different clinical and immunologic situation in the 2 Nigerian cohorts (low CD4 counts, naive status, black ethnicity, malnutrition and advanced HIV disease) compared with our cohort makes comparisons difficult. Mean cystatin C levels (0.87 mg/L) in our study are lower than those reported by other studies in pediatric (1.01 mg/L) 16 and adult HIV cohorts (1.03 mg/L) 38 ; most importantly, no differences in cystatin C values were found with healthy controls, as opposed to previous studies. 16,17,39,40 The optimal immunologic and clinical situation in our cohort, including renal function, probably explains these findings.…”

“…Mean cystatin C levels (0.87 mg/L) in our study are lower than those reported by other studies in pediatric (1.01 mg/L) 16 and adult HIV cohorts (1.03 mg/L) 38 ; most importantly, no differences in cystatin C values were found with healthy controls, as opposed to previous studies. 16,17,39,40 The optimal immunologic and clinical situation in our cohort, including renal function, probably explains these findings. Only 2 of 83 patients showed estimated GFR <90 and none <60 mL/min/1.73m 2 in our study; of note, both girls were receiving HAART regimens including tenofovir.…”

“…16,17 In both cases, consistently higher cystatin C levels and lower cystatin-calculated GFR were reported in HIV-infected children compared with healthy controls. The authors attribute these findings to a high rate of HIV-associated nephropathy and chronic kidney disease in their cohorts, but HIV viral load or markers of inflammation were not performed; therefore, the influence of the inflammatory status on cystatin C levels (and cystatin-calculated GFR) could not be taken into account in these studies.…”

“…Consistent with these properties, in our results, age, gender and BMI did not affect cystatin C levels as described previously. 16,17,26,27 When a renal injury occurs, cystatin C plasma levels increase. [23][24][25]27 Other conditions that may influence cystatin C values are thyroid illness, corticosteroid therapy and chronic viral infections, such as HIV infection.…”

“…14,15 Data on cystatin C in HIV-infected children are very limited. 16,17 In this study, we determined cystatin C plasma levels in a large cohort of HIV-infected children and adolescents, and how these levels correlated with markers of renal function and inflammation.…”