Serum Adenosine Deaminase Values in Healthy People

The purpose of this study is to determine the activity of serum adenosine deaminase (ADA) in healthy people, in connection with significant differences in published reference ranges from different authors. In our study, we examined 160 healthy subjects aged 18 to 84, of whom 64 were men and 96 women. We have determined serum adenosine deaminase levels using a method based on the ability of the enzyme adenosine deaminase to catalyze the deamination of adenosine to inosine and ammonia. The catalytic concentration is determined spectrophotometrically by the rate of reduction of NADH measured at 340 nm. We found that normal serum ADA values among our healthy subjects are higher than the recommended reference range for the method we use, namely below 18 U/l. Using the percentile method, we worked out the following reference ranges: for women 14.53 - 25.73 U/l and for men 18.46 – 27.50 U/l. For women, the mean value is 21.07 U/l, and for men 21.30 U/l. At 95% CI, the serum ADA values of almost all subjects included in the study are within the recommended and other authors range of 11.50 - 25.00 U/l.