Objectives: To assess the value of measuring urinary corpuscular volume (UCV) with a haematology automat for determination of the glomerular or non-glomerular origin of isolated microscopic haematuria (MHi).
Material and methods: Forty-five fresh urine samples taken from 45 consecutive patients, with a median age of 59 years, consultant for MHi on urinary dip-sticks were studied with a haematology automat. After each analysis, MHi was classified into one of the following three groups: High MHi (glomerular, UCV < 50 fl), low MHi (non-glomerular, UCV > 50 fl), MHi of unknown origin (mixed UCV). A complete aetiological assessment of MHi was performed in each case.
Results: The aetiological diagnosis of MHi was established in 28 cases (62%), with a glomerular origin in 16 cases and a non-glomerular origin in 12 cases. UCV was of the glomerular (19 cases), non-glomerular (3 cases) or mixed type (6 cases). When UCV indicated a glomerular or non-glomerular origin for MHi (22/28 = 78.6%), the result was exact in 77% of cases (17/22). The sensitivity to diagnose glomerular haematuria was 100%, the specificity was 37.5%, the PPV was 73.7% and the NPV waas 100%.
Conclusion: The study of UCV can suggest the origin of MHi, but cannot confirm this origin due to its poor specificity.