Clinical significance of serum free light chains combined with M-protein in patients with membranous nephropathy and monoclonal gammopathy of undetermined significance
Objective To explore the clinical significance of serum free light chains(sFLC)and M-protein in patients with membranous nephropathy(MN)and monoclonal gammopathy of undetermined significance(MGUS).Methods A prospective study design was employed.Eighty-two patients with MN treated at Yulin Hospital,First Hospital,Xi'an Jiaotong University from January 2021 to October 2023 were selected,and were divided into an MN group(53 cases)and a merge group(29 cases)according to whether they were combined with MGUS.There were 18 males and 11 females in the merge group;they were(52.64±7.33)years old.There were 33 males and 20 females in the MN group;they were(55.35±6.89)years old.The serological testing methods were used to detect the sFLC(sFLCκ and sFLCλ)and M-protein in these patients.Logistic regression analysis was used to explore their relationship with MN combined with MGUS,and the receiver operating characteristic curve(ROC)was used to test the diagnostic performance of sFLC combined with M-protein for MN combined with MGUS.t and x2 tests were applied.Results The erythrocyte sedimentation rate(ESR),serum creatinine(Scr),C-reactive protein(CRP),and blood urea nitrogen(BUN)in the merge group were higher than those in the MN group[(48.52±5.65)mm/h vs.(36.34±4.35)mm/h,(84.51±10.26)µmol/L vs.(72.65±8.25)μmol/L,(2.18±0.64)mg/L vs.(1.26±0.35)mg/L,and(6.45±1.27)mmol/L vs.(5.12±1.12)mmol/L],with statistical differences(t=10.884,5.702,8.434,and 4.902;all P＜0.05).The positive rate in the merge group was higher than that in the MN group[96.55％(28/29)vs.3.77％(2/53)],with a statistical difference(x2=69.543;P＜0.05).The level of sFLCκ and sFLCκ/λ ratio in the merge group were higher than those in the MN group[(453.51±123.57)mg/L vs.(62.84±100.25)mg/L and(15.89±2.84)vs.(1.11±0.26)];the level of sFLCλ in the merge group was lower than that in the MN group[(28.54±23.84)mg/L vs.(56.77±18.35)mg/L];there were statistical differences(t=15.520,37.791,and 5.979;all P＜0.05).The correlation analysis showed that sFLCκ and sFLCκ/λ ratio were significantly correlated with renal impairment and inflammation level,while sFLCλ had relatively weaker correlation.The logistic regression analysis indicated that sFLCκ and sFLCκ/λ ratio significantly influenced diagnosis,whereas sFLCλ had a negative impact.The ROC analysis demonstrated that sFLC combined with M-protein for the diagnosis had a sensitivity of 96.6％,a specificity of 77.4％,a Youden's index of 73.9％,and an area under the curve(AUC)of 0.933,with a 95％confidence interval(CI)of 0.884 to 0.982.Conclusions The detection of sFLC and M-protein is of significant clinical importance for the diagnosis and assessment of disease activity in patients with MN and MGUS.They are closely related to the degree of kidney function damage and can serve as important references for monitoring and assessing treatment efficacy.
Membranous nephropathyMonoclonal gammopathy of undetermined significanceSerum free light chainsM-protein
万方数据
维普
