# Comparison of clinical features between patients with and without renal involvement in IgG4-related disease

## TL;DR

This study compares clinical features of IgG4-related disease patients with and without kidney involvement to identify risk factors and improve early diagnosis.

## Contribution

The study identifies specific clinical and laboratory features associated with renal involvement in IgG4-RD and develops a predictive nomogram model for disease relapse.

## Key findings

- Renal involvement was observed in 55.6% of IgG4-RD patients.
- Age, basophil counts, hemoglobin, and erythrocyte sedimentation rate were significantly different between groups.
- A nomogram model was developed to predict disease relapse in IgG4-RD patients.

## Abstract

The kidney is one of the organs most frequently affected in immunoglobulin G4-related disease (IgG4-RD). Early identification of IgG4-RD with renal injury by clinical features is a current challenge. There is a paucity of data regarding the clinical features of renal involvement in IgG4-RD.

Patients with the diagnosis of IgG4-RD with and without renal injury were included in the retrospective cohort study. Cox regression analyses were used to investigate the risk factors for disease relapse and to construct the nomogram model.

From December 2014 to February 2022, 54 patients with IgG4-RD were retrospectively enrolled. Renal involvement in IgG4-RD was observed in 55.6% of the patients. The differences of age and lacrimal gland accumulation were statistically significant (P < 0.001, and P = 0.034, respectively). Age was significantly higher in the kidney injury group. Regarding laboratory findings, basophil counts, hemoglobin levels, and serum cholinesterase level were significantly lower in patients with renal involvement (P = 0.033, P = 0.006 and P = 0.019). Erythrocyte sedimentation rate level was significantly higher in patients with renal involvement (P = 0.017). Seven (23.4%) patients in the kidney injury group relapsed during follow-up with mean recurrence time 9.86 ± 7.08 months. Early diagnosis plays a key role in patient outcomes. Female, elevated erythrocyte sedimentation rate level, and elevated complement component 4 are the risk factors for the disease relapse of IgG4-RD patients. Moreover, an effective nomogram model has been developed to predict disease relapse in patients with IgG4-RD.