Akademik Veri Yönetim Sistemi
XXXIII. WASPaLM World Congress & XXIV. National Clinicial Biochemistry Congress, Antalya, Türkiye, 16 - 20 Ekim 2024, ss.163
Introduction: Microalbuminuria is defined as the presence of 30-300 mg of albumin in a 24-hour urine
sample. Under normal physiological conditions, daily urinary albumin excretion is below 30 mg.
Microalbuminuria is one of the earliest signs of diabetic nephropathy diagnosis. It is also used as a
marker in the risk assessment of cardiovascular disease. Microalbuminuria is evaluated by measuring
the albumin-to-creatinine ratio in a spot urine sample or by analyzing a 24-hour urine collection. Since
urinary albumin excretion follows a circadian rhythm, measuring the amount of albumin excreted over
a 24-hour period is considered the gold standard. The goal of this study is to investigate the proportion
of samples with microalbuminuria analyzed in our laboratory and determine the frequency of samples
exceeding the measurement range that require dilution.
Method: In this study, we analyzed albumin results from spot and 24-hour urine samples collected
between July 1, 2023, and July 1, 2024. The albumin levels in these samples were measured using the
immunoturbidimetric method (Cobas 702, Roche Diagnostics, Mannheim, Germany) with a
measurement range of 0.3–40 mg/dL. Samples with albumin concentrations exceeding 40 mg/dL were
automatically diluted at a 1/2 ratio. For samples exceeding 80 mg/dL, manual dilution was performed
at a 1/10 ratio. The results were then evaluated in this retrospective study.
Results: During a one-year period, a total of 6,686 urine samples were analyzed for microalbumin
levels in our laboratory. of these samples, 5,816 (86.9%) did not exceed the upper measurement limit
of 40 mg/dL and thus did not require any dilution. The remaining 870 samples (13.1%) exceeded this
upper limit. Among these, a 1/2 ratio automatically diluted 344 samples (39.5%), while additional
dilution procedures were required for the remaining 526 samples (60.5%).
Conclusion: As a tertiary healthcare facility, our hospital has admitted many patients with nephropathy.
As a result, these patients' urinary albumin levels may exceed the measurable range. Multiple analyses
are often required because of the need for high dilution ratios to obtain accurate results. This situation
reduces cost-effectiveness, prolongs the analysis process, increases workload, and may lead to
dilution-related errors. Kits capable of measuring high values of albumin in urine are necessary to
eliminate these issues and identify patients with high albuminuria.
Keywords: Albuminuria, Dilution, Immunoturbidimetric Assays, Nephropathy