Adenosine deaminase activity in pig saliva: analytical validation of two spectrophotometric assays

Abstract

We validated 2 assays for the measurement of adenosine deaminase (ADA) activity in the saliva of pigs: the Giusti-Galanti manual method (ADA-GG) and a commercial automated assay (Diazyme Laboratories; ADA-D). Intra-assay coefficients of variation (CVs) were <7 and 9%, and interassay CVs were <12 and 5%, for ADA-GG and ADA-D, respectively. Accuracy was measured by 2 methods: recovery and linearity-under-dilution. Recovery was 82.4-106.8% for ADA-GG, and 92.8-107.9% for ADA-D. Serial dilutions showed R > 0.95 and 0.99 for ADA-GG and ADA-D, respectively. Linear regression between the methods gave R = 0.997 ( p < 0.0001), and a Bland-Altman plot showed a proportional bias of 112 IU/L (95% confidence interval of -99 to 322 IU/L) for ADA-D. No significant differences were observed between the results obtained by either method in saliva or serum. ADA activity was much higher in porcine saliva than in serum. Salivary ADA activity was significantly higher in lame pigs compared to healthy animals. However, serum ADA activity was significantly lower in lame pigs.

Characterization of total adenosine deaminase activity (ADA) and its isoenzymes in saliva and serum in health and inflammatory conditions to four different species: an analytical and clinical validation pilot study

“…In each species, a similar volume of samples obtained from 10 different animals ( ve with low and ve with high ADA2 activity) were mixed to prepare two pools of serum and two pools of saliva with different ADA2 activity. Intra-assay imprecision and linearity under dilution were evaluated in serum and saliva samples from the various species by calculating the intra-assay coe cient of variation (CV) and linear regression coe cient, following previously published protocols [26,32].…”

“…Serum tADA has also been measured in veterinary species being higher in chronic in ammation in dogs [24] and cows [25]. In contrast, in a study measuring tADA in saliva and serum of pigs with lameness, a decreased tADA activity in serum was found [26].…”

“…In humans, ADA activity was successfully measured in saliva being increased in local pathologies such as oral malignancies [29] or Sjögren's syndrome [30], and systemic pathologies such as obesity [31]. In animals, increased tADA activity in saliva has been described in bitches with pyometra [32] and pigs with lameness [26], probably due to the presence of a systemic in ammatory process. Recently, tADA has been measured in saliva from sheep, cow, and horses [33,34,35].…”

Stability of selected enzymes in saliva of pigs under different storage conditions: a pilot study

“…On the other hand, TEA, lipase or adenosine deaminase (ADA, E.C. 3.5.4.4) can increase in inflammatory conditions in pigs such as lameness [ 18 , 19 ].…”

“…Two pools of saliva with different enzymatic activities were performed: 500 µl of saliva from each healthy pig were mixed to obtain pool A with low enzymatic activities (5 m l total volume); and 500 µl of saliva from each lame pig were used to perform pool B with high enzymatic activities (3.5 m l total volume) since previous works reported higher TEA, lipase [ 18 ] and ADA activities [ 19 ] in lame pigs than in healthy ones. Pools A and B were analyzed freshly for the different enzymatic activities.…”