Inability of community-based laboratories to identify pathological casts in urine samples

Objective: To determine the accuracy of microscopic examination of urine from patients with known renal disease, performed by community-based laboratories. Design: Twenty-six urine specimens from 7 children with Alport syndrome, lupus nephritis, and IgA nephropathy were simultaneously submitted to 4 investigative sites: 2 community-based medical laboratories (laboratories A and B), and the offices of 2 nephrologists (nephrologists C and D). Participants A, B, and C were unaware of the nature of this investigation and blinded to the diagnosis associated with each specimen. Results: Twenty-six specimens from 7 children were analyzed. Pathological casts were identified in the 26 submitted specimens in the following order: 1 (4%) by laboratory A, 2 (8%) by laboratory B, 20 (77%) by nephrologist C, and 26 (100%) by nephrologist D. Four-way and 3-way (A, B, C) comparisons using the [chi square] test are significant at the P
Some community-based medical laboratories may not be able to accurately diagnose the presence of disease in urine specimens. Researchers submitted 26 urine specimens from seven children with known kidney disease to two community-based medical laboratories and to two nephrologists. The children had Alport syndrome, lupus nephritis, and IgA nephropathy. The two laboratories were only able to diagnose three of the specimens; one nephrologist diagnosed 20 (77%) and the other diagnosed all 26 specimens correctly. Primary care doctors should be able to do their own microscopic urinalysis, in case they doubt a laboratory's result.