The significance of serum lysozyme in predicting bacterial complications in patients after kidney transplantation

Abstract

The aim of the study was to conduct a comparative analysis of serum lysozyme activity and study its innovativeness in predicting bacterial complications after kidney transplantation. Material and methods. Lysozyme activity was studied in 99 patients after kidney transplantation and 81 practically healthy volunteers. Patients depending on period after surgery were divided into five groups: group 1 – 1st day after kidney transplantation (n = 6); group 2 – 1–5 months (n = 10); group 3 – 6–12 months (n = 21); group 4 – 2–5 years (n = 30); group 5 – 6–10 years (n = 32). An analysis of the correlation between serum lysozyme level, absolute leukocyte count and creatinine content was performed. Lysozyme activity was assessed in bacterial complications, transplant dysfunction and organ rejection. Results and discussion. On the 1st day after kidney transplantation lysozyme activity was minimal – 117.95 [60.80–133.51] µg/ ml (median [lower quartile – upper quartile]) (in healthy volunteers it was 243.80 [190.76–305.69] µg/ml, p < 0,001). One month after surgery, it returned to normal (292.08 [311.66–218.48] μg/ml) and did not differ from the value of the group of practically healthy volunteers for 5 months (p = 0,17). Lysozyme activity in serum of patients after kidney transplantation had inverse moderate correlation with creatinine content (r = –0,32, p < 0,05). The threshold value for the probability of bacterial infections for serum lysozyme was > 321,4 μg/ml (p = 0,003). Creatinine level > 0,11 mmol/l predicts graft dysfunction. Conclusions. On the first day after transplantation a low level of lysozyme indicates high risk of bacterial infection. One month after surgery lysozyme returned to normal which indicates restoration of humoral component of nonspecific immune resistance. Relationship between creatinine content and lysozyme activity as well as an increase in the latter in comparison with healthy group allows to use lysozyme as an additional diagnostic criterion for acute bacterial infection and creatinine – for prognosis of graft dysfunction.