Ochratoxin A in blood of healthy population in Zagreb.

Healthy blood donors from the city of Zagreb were checked for the presence of a nephrotoxic mycotoxin ochratoxin A (OTA) in the plasma. Samples of blood were collected in June, September, and December 1997, and March 1998, totalling 200 or 50 in each round. The concentrations of OTA were measured using high pressure liquid chromatography (HPLC) method (detection limit 0.2 ng OTA/ml of plasma). The frequency of OTA-positive samples (> 0.2 ng/ml of plasma) showed significant seasonal variation (P < 0.001). The frequency of OTA-positive samples was the highest in March (65%) and it gradually decreased towards December (12%). The high frequency of positive samples coincided with seasons favouring growth of moulds and production of toxins. The daily intake of OTA by healthy persons in Zagreb was estimated from the mean concentration of OTA in samples collected during the whole year (0.19 ng OTA/ml plasma). The estimated daily intake was 0.26 ng/kg b.w., that is, substantially below the tolerable daily intake proposed by World Health Organization (16.0 ng/kg b.w.).

[Quality control in an immunohematology laboratory in the Croatian Transfusion Service]. / Kontrola kvalitete rada u imunohematoloskim laboratorijima transfuzijskih ustanova u hrvatskoj.

In order to evaluate the testing proficiency in immunohematological laboratories in Croatia blood samples were prepared and fully examined in the Croatian Institute for Transfusion Medicine and sent to all the transfusion laboratories in the country. The laboratories were asked to perform the following tests: determination of AB0 blood group and Rh phenotype; detection and identification of irregular antibodies and crossmatches between serum and RBCs. All the laboratories (100%) accurately determined AB0 and Rh(D) negative blood groups and crossmatch between compatible serum and RBCs. In 80.65% of the laboratories, Rh(Du) blood group was accurately determined. The incompatibility between serum and Rh(Du) RBCs in crossmatch was detected in 93.55% of the laboratories. 96.77% laboratories correctly detected irregular antibodies. Only 35.48% of the laboratories accurately identified anti-D and anti-C alloantibodies in the serum, 32.26% failed to identify one of the two antibodies and 29.03% of the laboratories detected irregular antibodies but did not identify their specificity. Only 35.48% of the laboratories correctly performed all the tasks.

Variations of ochratoxin A concentration in the blood of healthy populations in some Croatian cities.

The nephrotoxic mycotoxin ochratoxin A (OTA), a common contaminant of cereals, has been implicated in the etiology of endemic nephropathy. It was also frequently found in low concentrations in blood of healthy populations in countries where endemic nephropathy is not known. However, data on regional and seasonal differences in the frequency and concentration of OTA in human blood are scarce. In June, September and December 1997, and March 1998, about 50 human blood samples were collected randomly from blood donors for blood banks in the Coatian cities of Osijek, Rijeka, Split, VaraZdin and Zagreb. OTA was measured in the total of 983 samples using an HPLC technique with fluorescent detection. The daily intake of OTA was estimated from the mean concentration found in different cities and at different times of year. Samples containing OTA above the detection limit (0.2 ng/ml of plasma) were found in populations from all Croatian cities at all collecting periods. The highest frequency (59%) of samples containing OTA above the detection limit and the highest mean concentration (0.39 ng/ml) were found in June. Both the frequency and the mean concentration were lowest in all samples in December (36% and 0.19 ng OTA/ml, respectively). Osijek was the city with the highest frequency of OTA-positive samples (81%) and the highest mean OTA concentration (0.56 ng/ml). The total mean concentration of OTA in blood of healthy population in Croatia is lower (0.30 ng/ ml) than the mean concentration in European countries as a whole (0.90 ng/ml). The estimated daily intake, calculated from the mean concentration in all blood samples, is 0.40 ng OTA/kg body weight, which is much lower than that proposed by World Health Organization as the tolerable daily intake (16.0 ng/kg body weight). Healthy populations of Croatia are exposed to low, but seasonally and regionally variable amounts of OTA.