PHOTOMETRIC-DETERMINATION OF HBA(1C) CONC ENTRATION IN ROUTINE PRACTICE

This study was undertaken to evaluate the routine use of a new immunol ogical photometer to measure the concentration of HbA1c in whole blood from 155 patients. The basis of the measurement is a latex agglutinat ion reaction in which a monoclonal antibody as epitope recognizes gluc ose bound to HbA1c. The result is available within 9 min. High-pressur e liquid chromatography (HPLC) served as control method. The photomete r proved to be very precise (all coefficients of variant < 2,5%), and the values obtained agreed well with those by HPLC (y = 0.952x-0.12; r = 0,986; P < 0.001). The reference ranges for the photometrically mea sured HbA1c values (4.4-5.9%), obtained for 40 patients, agreed well w ith those by HPLC (4.6-6.2%). Interference study discovered no effect on the measured-value by anaemia, polycythaemia or high rheuma factor (n = 31). In 12 patients on dialysis the photometer recorded significa ntly lower values than HPLC (P < 0.0005). It is possible that in these cases the photometer values are more accurate because the method is n ot affected by carbamylated haemoglobin. False results were obtained b y the photometer in two patients with leucocytosis (79000 and 216000/m ul, respectively) due to chronic lymphocytic leukaemia.