HETEROGENEITY OF HEMOGLOBIN A(1D) - ASSESSMENT AND PARTIAL CHARACTERIZATION OF 2 NEW MINOR HEMOGLOBINS, A(1D3A) AND A(1D3B), INCREASED IN UREMIC AND DIABETIC-PATIENTS, RESPECTIVELY

We have separated and quantified two new minor hemoglobins named HbA(1 d3a) and HbA(1d3b). The level of HbA(1d3a) was significantly higher in uremic than in non-uremic patients (3.00 +/- 0.50% vs. 1.28 +/- 0.26% of total hemoglobin). It correlated well with carbamylated hemoglobin (r = 0.80, n = 81, p < 0.002) and with plasma urea concentration (r = 0.78, n = 81, p < 0.002). These data and the electrospray ionization mass spectrometric analysis provide strong evidence that HbA(1d3a) is an alpha-chain modified by carbamylation. The HbA(1d3a) level in diabe tic patients was found to be 1.6-fold that in non-diabetic subjects (3 .00 +/- 0.49 vs. 1.90 +/- 0.33). This was attributed to HbA(1d3) modif ied by glycation. Indeed HbA(1d3b) correlated significantly with HbA(1 c) (r = 0.71, p < 0.002) and with serum glucose level (r = 0.62, p < 0 .002). These two new minor hemoglobins may serve as complements for th e objective assessment of averaged long-term uremia and glycemia in ur emic and diabetic patients.