Urinary levels of early kidney injury molecules in children with vitamin B12 deficiency

The aim of this study was to investigate urine early kidney injury molecules, including human kidney injury molecule-1 (KIM-1), liver-type fatty-acid binding protein (L-FABP), N-acetyl-b-D-glucosaminidase A (NAG), and neutrophil gelatinase-associated lipocalin (NGAL) in children with vitamin B12 (cobalamin) deficiency (CD). Twelve children with vitamin B12 deficiency and 20 healthy matched controls were included. Hematologic parameters, serum urea, creatinine (Cr), electrolytes, B12 and folate levels were recorded. Estimated glomerular filtration rate (eGFR) was calculated. Urine protein, electrolytes, and urinary early markers were measured. Patients with CD had significantly higher urine electrolyte/Cr ratios (p < 0.05). Significantly higher urinary KIM-1/Cr, L-FABP/Cr, NAG/Cr and NGAL/Cr were found in CD group (p < 0.05). Significant negative correlations were found between levels of serum B12 and urinary markers in the patients (p < 0.05). Increased urinary kidney injury molecules and electrolytes in children with B12 deficiency suggest a possible subclinical renal dysfunction, which cannot be determined by conventional kidney function tests.