Page 195 - HIVMED_v21_i1.indb

Southern African Journal of HIV Medicine
ISSN: (Online) 2078-6751, (Print) 1608-9693
Page 1 of 15 Original Research

Evaluation of the impact of delayed centrifugation

on the diagnostic performance of serum creatinine

as a baseline measure of renal function

before antiretroviral treatment

Authors: Background: The measurement of serum creatinine is a standard requirement of the medical
Chemedzai E. Chikomba management of people living with HIV. Renal dysfunction is common, both as a complication
1
Carolyn J. Padoa 1
Donald Tanyanyiwa 2 of HIV-infection and as a result of its treatment. The detection of abnormal renal function
before the start of antiretroviral therapy will impact patient management and the outcome of
Affiliations: treatment.
1 Department of Chemical
Pathology, National Health Objectives: This study aimed to determine if a time delay in the centrifugation of serum
Laboratory Services, Faculty samples affected the creatinine level and the estimated glomerular filtration rate as recorded
of Health Science, University
of the Witwatersrand, on the analytical platforms used in the laboratory.
Johannesburg, South Africa
Methods: Twenty-two (n = 22) HIV-positive, newly diagnosed and treatment-naïve patients
2 Department of Chemical were randomly recruited from Alexandra Health Clinic, Johannesburg, South Africa. Serum
Pathology, National Health samples were centrifuged at six time intervals following receipt of the sample viz. < 4 h
Laboratory Service, Faculty (baseline), 6 h, 24 h, 48 h, 72 h and 96 h. Creatinine concentrations were measured on the Roche
of Health Science, Sefako platform utilising the enzymatic and kinetic Jaffe methods. Whole blood samples were also
Makgatho Health Sciences
University, Pretoria, analysed with the Abbott i-STAT point-of-care instrument. The estimated glomerular filtration
South Africa rate was calculated using the Cockcroft Gault, CKD–Epidemiology Collaboration and
Modified Diet and Renal Disease v3/4 equations.
Research Project Registration:
Project Number: M1711109 Results: At baseline (< 4 h) there was good agreement between the enzymatic and kinetic Jaffe
methods: bias 1.7 µmol/l. The enzymatic and i-STAT creatinine concentrations were stable
Corresponding author:
Chemedzai Chikomba, over 96 h viz. changes of 1.8% and 5.7%. However, from 24 h onwards agreement between the
[email protected] enzymatic and kinetic Jaffe methods was poor with the latter measuring 43.7 µmol/l higher
than the enzymatic method at 96 h. Creatinine concentrations measured with the kinetic Jaffe
Dates: method increased significantly in samples centrifuged after 6 h (p < 0.001, 61.7% change), and
Received: 12 Dec. 2019
Accepted: 11 Apr. 2020 resulted in a 95% decline in eGFR at 96 h as determined with the CKD–Epidemiology
Published: 16 July 2020 Collaboration equation.
Conclusion: The analysis of serum creatinine using the isotope dilution mass spectrometry
traceable kinetic Jaffe method is unreliable if performed on samples centrifuged ≥ 6 h after
collection. The raised creatinine concentration can affect clinical decisions such as renal functional
assessment, choice of antiretroviral drug or regimen, and the dose and frequency of medication.
Keywords: Kidney function; serum creatinine; antiretroviral; estimated GFR; kinetic Jaffe;
i-STAT; ROCHE.

Introduction

South Africa (SA) has one of the highest HIV infection rates in the world. In 2016, the overall
prevalence of HIV infection in SA was 12.7%. The use of antiretroviral drugs (ARVs) has slowed
1,2
the progression of the infection and increased the life expectancy of people living with HIV. 3,4,5
In SA’s public health sector, patients are started on antiretroviral treatment (ART) with
combinations of different ARV drug classes, prescribed as a single, once-a-day tablet. This has led
6
7,8
to a reduction of the pill-burden of therapy and to improved adherence. In the southern African
Read online:
Read online:
Scan this QR region the most frequently prescribed initial combination is the nucleotide reverse transcriptase
Scan this QR
code with your
code with your
smart phone or How to cite this article: Chikomba CE, Padoa CJ, Tanyanyiwa D. Evaluation of the impact of delayed centrifugation on the diagnostic
smart phone or
mobile device performance of serum creatinine as a baseline measure of renal function before antiretroviral treatment. S Afr J HIV Med. 2020;21(1),
mobile device
a1056. https://doi.org/10.4102/sajhivmed.v21i1.1056
to read online.
to read online.
Copyright: © 2020. The Authors. Licensee: AOSIS. This work is licensed under the Creative Commons Attribution License.
http://www.sajhivmed.org.za 187 Open Access