Urinary liver-type fatty acid-binding protein levels as a potential risk factor for renal dysfunction in male HIV-infected Japanese patients receiving antiretroviral therapy: a pilot study

Abstract

Renal dysfunction is recognized with increasing frequency among the non-infectious co-morbidities associated with human immunodeficiency virus (HIV) infection. Recently, urinary liver-type fatty acid-binding protein (L-FABP) was suggested to be a predictor of the progression of renal dysfunction in patients without HIV. However, little is known regarding the utility of urinary L-FABP as a predictor of renal dysfunction in patients with HIV. A retrospective, observational, single-centre study was conducted between July 2014 and December 2016. The primary outcome was renal dysfunction defined as decrease in estimated glomerular filtration rate to less than 60 ml/min/1.73 m. To estimate the effect of urinary L-FABP, proteinuria category, and urinary β2 microglobulin (β2MG) on the time to the first event, a log-rank test was performed. Accuracy, determined by area under the curve and calculated from receiver operating characteristic curves, was also assessed. Thirty Japanese outpatients with HIV receiving antiretroviral therapy (ART) were enrolled. The primary outcome occurred in five patients during the follow-up period. Urinary L-FABP level and proteinuria category were significantly associated with renal dysfunction (p = 0.045 and p = 0.037, respectively). In contrast, urinary β2MG level was not significantly associated with renal dysfunction (p = 0.141). Urinary L-FABP was the most accurate predictor of renal dysfunction among the three urinary parameters. In conclusion, urinary L-FABP levels in HIV patients receiving ART were more accurate for predicting renal dysfunction than proteinuria and urinary β2MG. In addition, urinary L-FABP helped to discriminate those patients with a higher risk for renal dysfunction.

Utility of urinary liver-type fatty acid-binding protein as a predictor of renal dysfunction in Japanese patients with HIV receiving tenofovir disoproxil fumarate with low urinary β2 microglobulin levels: a retrospective observational study

“…Although UL-FABP level was suggested to be a potential predictor of renal dysfunction [4], availability of UL-FABP level in patients with low Uβ2MG level remains unclear. To our knowledge, this is the first study that showed the usefulness of UL-FABP in predicting eGFR decrement in patients receiving TDF with low Uβ2MG levels.…”

“…Patients were divided into two groups according to UL-FABP levels of 4.0 μg/g creatinine based on the previous study [4]. Kaplan-Meier analysis and a log-rank test were then performed to estimate the effect of UL-FABP on time to the end points.…”

“…Liver-type fatty acid–binding protein (L-FABP) is also a tubular marker, and expressed in the proximal tubules of the human kidney and participates in fatty acid metabolism [3]. Urinary L-FABP (UL-FABP) level (≥ 4.0 μg/g creatinine) was a potential predictor of renal dysfunction in patients receiving ART in our previous pilot study [4]. However, it was not shown whether UL-FABP level was an independent risk factor for renal dysfunction or not because the pilot study was with too small a sample size to perform a multivariate analysis.…”

Decreased levels of urinary liver-type fatty acid-binding protein after switching from tenofovir disoproxil fumarate to tenofovir alafenamide: a prospective observational study

“…[8][9][10] It has been suggested that urinary levels of L-FABP may be a predictor of renal outcomes in patients with and without HIV. [11][12][13][14][15] It is unknown whether the switch from TDF to TAF improves urinary levels of L-FABP, although in clinical trials comparing TAF-and TDF-based regimens, it was demonstrated that this switch improved proteinuria and urinary levels of b2MG. [16][17][18][19][20] Thus, the primary aim of the present study was to assess the change in urinary levels of L-FABP after this change in medication.…”

“…8–10 It has been suggested that urinary levels of L-FABP may be a predictor of renal outcomes in patients with and without HIV. 11–15…”