Laboratory characteristics for the clinical diagnosis of immunoglobulin G4-related disease in 28 cases with renal damage / 中华风湿病学杂志

ABSTRACT

Objective:To understand the laboratory characteristics for the diagnosis of immunoglobulin G4-related disease (IgG4-RD).Methods:The clinical data of 28 patients with IgG4-RD and renal damage (IgG4-RKD) diagnosed in our hospital from January 2017 to May 2019 were retrospectively analyzed. The correlation between serum IgG4 concentration and clinical features as well laboratory test results was analyzed. The 28 patients were divided into two groups high serum IgG4 concentration group and normal serum IgG4 concentration group. The serum creatinine value, erythrocyte sedimentation rate, IgG concentration, IgA concentration, complement C3, C4 concentration, peripheral blood eosinophils, hemoglobin, IgG4/IgG and other related parameters were compared between the two groups. SPSS 20.0 statistical software was used for analysis. The two groups of measurement parameters were compared between groups by independent sample t test, non-normal measurement parameters were compared between groups by Mann-Whitney U test analysis, and the correlation between patients' IgG4 and each detection parameter was analyzed by Spearman correlation analysis. Results:Among the 28 patients, 17 were male and 11 were female, with an average age of (62±14) years. The serum IgG4 concentration increased in 75% of the patients ( n=21), with an average value of 3.01(1.41, 7.52) g/L, the serum IgG concentration increased in 64.3% of patients ( n=18), with an average value of 18.91 (12.88, 24.88) g/L, and the complement C3 decreased in 50% of the patients ( n=14), with an average value of(0.77±0.28) g/L. IgG4 was positively correlated with IgG ( r=0.422, P=0.025), IgG4/IgG ( r=0.951, P<0.01), ESR ( r=0.543, P<0.01) and peripheral blood eosinophils ( r=0.487, P<0.01), but negatively correlated with complement C3 ( r=-0.431, P=0.022) and C4 ( r=-0.504, P<0.01) levels. There were significant differences in IgG ( Z=-2.255, P=0.023), IgG4/IgG ( Z=-3.793, P<0.01), C3 ( t=7.380, P<0.01) and ESR ( t=-2.195, P=0.037) between the elevated IgG4 group and the normal group. Conclusion:Serological characteristics of IgG4-RKD combined with clinical manifestations may be able to diagnose IgG4-RKD in early stage.