Changes in the potassium, ammonium and calcium cation levels in the oral fluid after a low-dose oral pharyngeal provocative test in patients with apple allergy

Matsko E.F., Novikov D.K., Fadeeev V.I.

Vitebsk State Medical University, Vitebsk, Belarus

Aim. Assessment of the value of the potassium (K+), ammonium (NH4+) and calcium (Ca2+) cations levels changes in the oral fluid (OF) after a low-dose oral-pharyngeal provocative test (LOFPT) in patients with apple allergy.

Materials and methods. 21 patients with food allergy to apples and 10 clinically healthy volunteers were underwent the LOFPT with freshly prepared apple juice at a concentration of 5 PNU/ml. The K+, NH4+ and Ca2+ cations levels in the OF before and after provocation were determined by capillary electrophoresis.

Results. In patients with apple allergy, the mean K+ level in the OF before the challenge with juice was M=45.7[37.8;53.7] mg/l, after - Me=60.6(54.6;69.0) mg/l (p=0.0001). The K+ level in the OF in healthy people before provocation was M=47.2[41.0;53.5] mg/l, after - it slightly decreased - M=47.0[37.5;56.5] mg/l (p=0.9). The mean NH4+ level in the OF among patients before the test was Me=14.98(10.1;29.1) mg/l, after that it significantly decreased Me=12.9(6.7;16.4) mg/l (p=0.039). In the control, the average NH4+ level before the provocation was Me=9.0 (6.7;10.0) mg/l, and 40 minutes after - M=6.9[3.6;10.2] mg/l, (p=0.17). The average Ca2+ level in the OF in patients before provocation - M=1.09[0.9;1.3] mg/l, after provocation - Me=1.31(1.1; 1.4) mg/l (p=0.31). The Ca2+ cations level in healthy people before the test was M=1.15 [0.9; 1.4] mg/l, and 40 minutes after - Me=0.96 (0.9;1.1) mg/l (p=0.37).

Conclusions. In 81% of patients with food allergy to apples, after the LOFPT with apple juice (5 PNU/ml), the K+ cations level increase in the OF was observed, which indicates hypersensitivity to apples (p=0.0001). In these patients, after provocation, a significant NH4+ cations levels decrease was simultaneously observed (p=0.039). In patients with apple allergy after the LOFPT, the K+ ions level (p=0.02) and Ca2+ ions level (p= 0.01) was significantly higher than in healthy people. In healthy people, the baseline NH4+ cations level was significantly lower than in patients with apple allergy (p=0,019).