A total of 280 patients with IMN were enrolled in this study. Serum and urine
IgG levels were measured, and the relationship between
IgG levels and parameters suggestive of disease severity in these patients were explored. Patients were placed into one of three groups based on urine
protein levels.
RESULTS: Urine
IgG levels in most patients (99%) increased, while serum
IgG in 74% patients decreased. Higher urine and lower serum
IgG levels were associated with a more advanced-stage disease, based on the pathology assessment. Urine
IgG positively correlated with 24-h urinary
albumin, urinary α1- and β2-microglobulin, serum anti-
phospholipase A2 receptor (PLA2R) antibody, and erythrocyte sedimentation rate (ESR). However, urine
IgG negatively correlated with
serum albumin and the estimated glomerular filtration rate (eGFR). Serum
IgG positively correlated with
serum albumin, but negatively correlated with 24-h urine
protein,
albumin, urinary α1- and β2-microglobulin, and anti-PLA2R antibody levels. Multivariate regression analyses showed that the 24-h urine
protein, urinary α1-microglobulin, eGFR, and ESR were associated with urine
IgG levels, independent of age, sex, urinary
albumin, urinary β2-microglobulin, or serum anti-PLA2R antibody levels. In addition,
serum albumin and age were significant determinants of serum
IgG levels.
CONCLUSIONS: