Study of serum alanine-aminotransferase levels in blood donors in Spain.
OBJECTIVE
Serum alanine-aminotransferase (ALT) is being used as a surrogate test for preventing post-transfusion viral hepatitis. However, ALT elevation is influenced by many factors. We have studied ALT levels in 1,036 consecutive blood donors to determine their association with gender, obesity, and hepatitis virus infection markers.


METHODS
In each donation aspartate-aminotransferase (AST), lactate dehydrogenase (LDH) and gamma-glutamyl transferase (gamma GT) activity were also determined and body mass index (BMI) was calculated.


RESULTS
Five hundred seventy-nine men and 457 women donated blood; ALT activity was 25.3 +/- 14.5 IU/L (mean +/- SD) for men and 16.3 +/- 7.9 IU/L for women (p < or = 0.0005). The upper normal value for men was 56 IU/L and 34 IU/L for women. On applying this value to the study group 4.8% of the men and 2% of the women had values greater than the cutoff. Among the men with increased ALT levels, 53.5% had a BMI > 27, 7.1% also had an increased level of GGT and 7.1% had increased levels of AST and LDH. None of them were HBsAg nor anti-HCV positive. Among the women with increased ALT, 33.3% had BMI > 27, 33.3% had increased levels of LDH and AST, and 11.1% were anti-HCV positive (only 1 donor).


CONCLUSIONS
It seems clear that different cutoff values should be considered for men and women. Factors such as obesity, may account for more than 50% of the cases with increased ALT values, indicating the low specificity of the test.
Lozano
M
M
Department of Hemotherapy and Hemostasis, Hospital Clínic i Provincial, University of Barcelona, Spain. mlozano@medicina.ub.es
Cid
J
J
Bedini
J L
JL
Mazzara
R
R
Gimenez
N
N
Mas
E
E
Ballesta
A
A
Ordinas
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000410:Alanine Transaminase / Q000097:blood*; D001219:Aspartate Aminotransferases / Q000097:blood; D001782:Blood Donors; D015992:Body Mass Index; D005260:Female; D006509:Hepatitis B / Q000097:blood; D006526:Hepatitis C / Q000097:blood; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012737:Sex Factors; D013030:Spain; D005723:gamma-Glutamyltransferase / Q000097:blood
D007770:L-Lactate Dehydrogenase; D005723:gamma-Glutamyltransferase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase