Clinical value of Cys C, Scr and Urea in the diagnosis of mycoplasma pneumoniae-associated nephritis

Yuanyuan MA; Ta HU; Qiurong CHEN

ABSTRACT

Objective:

To discuss the clinical value of cystatin C (Cys C), serum creatinine (Scr) and serum urea nitrogen (Urea) in the diagnosis of mycoplasma pneumoniae-associated nephritis (MPAN), thus to provide reference basis for MPAN diagnosis.

Methods:

From June 2015 to June 2017, 50 patients with MPAN who were treated in Women and Children Hospital of Guangdong Province were selected as observation group, and 50 healthy children who underwent physical examination in the hospital during the same period were selected as control group.The observation group was divided into group A, group B and group C according to the level of endogenous creatinine clearance rate.The serum levels of Cys C, Scr and Urea were compared between the control group and the observation group.The levels of Cys C, Scr and Urea and the abnormal rate in group A, group B and group C were compared.

Results:

In the observation group, the Cys C levels of groups A, B and C were (1.25±0.13)mg/L, (1.74±0.34)mg/L, (3.72±1.33)mg/L, respectively, the Scr levels were (150.46±21.09)μmol/L, (268.57±108.68)μmol/L, (476.66±91.25)μmol/L, respectively, the Urea levels were (8.75±1.09)mmol/L, (11.49±1.50)mmol/L and (17.68±2.92)mmol/L, respectively.In the control group, the Cys C, Scr and Urea levels were (0.74±0.23)mg/L, (56.86±42.36)mol/L, (3.43±1.33)mmol/L, respectively.Compared with the control group, the Cys C level of the observation group was higher, the differences were statistically significant ( t=20.379, 22.991, 13.128, all P<0.05). The Scr level of each group in the observation group were higher than those of the control group, the differences were statistically significant ( t=21.768, 21.423, 43.640, all P<0.05). The Urea level of each group in the observation group was higher than that of the control group, the differences were statistically significant ( t=37.501, 33.404, 46.661, all P<0.05). The levels of Cys C, Scr and Urea in group C were higher than those in group B, the differences were statistically significant ( t=9.737, 9.333, 12.389, all P<0.05). The Cys C, Scr and Urea levels in group C were higher than those in group A, the differences were statistically significant ( t=19.880, 35.753, 27.127, all P<0.05). The Cys C, Scr and Urea levels in group B were higher than those in group A, the differences were statistically significant ( t=13.207, 11.163, 11.177, all P<0.05). In the early stage of renal function injury, namely renal insufficiency compensation stage, the abnormal rate of Cys C(62.07%) was significantly higher than that of Scr and Urea(10.34%, 24.13%).

Conclusion:

The serum Cys C, Scr and Urea levels of MPAN patients are all higher than healthy people.The more severe the renal function damage is, the higher the serum Cys C, Scr and Urea levels are, which can provide clinical reference for the diagnosis, disease prediction and auxiliary diagnostic criteria of MPAN.In particular, Cys C is more important for the early diagnosis of MPAN.