Serum concentrations of acute phase

Serum concentrations of acute phase proteins (APP) and of antioxidants have proved to be clinically useful biomarkers of pyometra in different species, including bitches, cows and mares [[11], [12], [13], [14], [15]]. Acute phase proteins are being increasingly used in both human and veterinary medicine in general health screening, as well as in diagnosis, prognosis and in monitoring progression and response to treatment of several diseases [16,17]. The APP response is a component of the innate immune reaction of the organism, and is a very fast reaction which develops before stimulation of the specific immune response, and in many cases even before the onset of clinical signs; therefore, it can be considered one of the earliest markers of disease [18]. The oxidative status of the Melittin is dependent of the balance between oxidant reactants and antioxidant defences [19]. The oxidative stress develops when oxygen and nitrogen free radicals exceed the capacity of the antioxidant defences of the organism, and was associated with different diseases in human and in veterinary medicine [15,[20], [21], [22]]. The antioxidant response of the organism can be assessed by determination of individual parameters such as total serum thiols (Thiol) and/or by determination of the total antioxidant capacity (TAC) [21,23]. Different methods have been reported for TAC determination, such as trolox equivalent antioxidant capacity (TEAC) assay, ferric reducing ability of plasma (FRAP) assay and cupric reducing antioxidant capacity (CUPRAC) assay, which provide different information because are based on different chemical reactions [23,24].
Materials and methods
Results Serum concentrations of SAA, Hp, albumin, Thiol, FRAP, CUPRAC, TEAC1 and TEAC2 of the diseased and of the control queens before ovariohysterectomy (T0) are presented in Table 1. Diseased queens presented significantly higher concentrations of SAA and Hp, and significantly lower concentrations of albumin than control queens (P < 0.001 in all cases). However, six queens of the diseased group presented at diagnosis concentrations of SAA within the laboratory's reference range (<5 μg/mL), despite presenting increased serum Hp (>3 g/L). Serum Thiol was significantly lower in queens with pyometra than in controls (P < 0.001). When TAC was evaluated, serum FRAP concentrations were significantly higher, while CUPRAC and TEAC2 were significantly lower in queens with pyometra than in controls (P < 0.05, P < 0.001, and P < 0.01, respectively). Fifteen out of the 23 queens with pyometra (65.2%) also presented an endometrial adenocarcinoma diagnosed at abdominal ultrasound and/or histopathology, including three cats with in situ carcinomas and 12 animals with papillary serous adenocarcinomas. Age of queens with pyometra without endometrial adenocarcinoma ranged from one to 11 years (mean ± SD, 6.1 ± 3.9 years), and BW ranged from 1.7 to 5.3 Kg (mean ± SD, 3.6 ± 1.2 Kg). Age of the queens with pyometra and with a concomitant endometrial adenocarcinoma ranged from two to 20 years (mean ± SD, 7.0 ± 4.9 years), and BW ranged from 2.5 to 5.0 Kg (mean ± SD, 3.5 ± 0.6 Kg). Age and weight were not significantly different between the two groups (P > 0.05 in both cases). However, queens with pyometra without endometrial adenocarcinoma and queens with pyometra and endometrial adenocarcinoma were significantly older than controls (P = 0.023 and P = 0.005, respectively); and weight of cats with pyometra and endometrial adenocarcinoma, but not of cats without adenocarcinoma, was significantly higher than of control queens (P = 0.028 and P = 0.230, respectively). Serum concentrations of SAA, Hp, albumin, Thiol, FRAP, CUPRAC, TEAC1 and TEAC2 of the groups of queens with pyometra with and without concomitant endometrial adenocarcinomas are Phase variation presented in Table 2. No statistically significant differences were detected between the two groups of animals in any of the evaluated biomarkers.