Involvement of the urinary bladder in systemic lupus erythematosus. A pathologic study

Area of Science:

• Nephrology
• Rheumatology
• Pathology

Background:

• Systemic lupus erythematosus (SLE) is a complex autoimmune disease with diverse organ involvement.
• Urinary bladder pathology in SLE is not well-characterized.
• Understanding SLE-related bladder changes may reveal shared pathogenic mechanisms with other organ systems.

Purpose of the Study:

• To investigate the prevalence and types of histologic urinary bladder changes in patients with SLE.
• To compare bladder abnormalities in SLE patients with a control group.
• To explore potential links between bladder pathology and other SLE manifestations, such as pulmonary hemorrhage.

Main Methods:

• Retrospective analysis of necropsy findings from 35 SLE patients and 30 control patients.
• Histologic examination of urinary bladder tissue for abnormalities.
• Correlation of bladder findings with clinical data, including pulmonary hemorrhage.

Main Results:

• Histologic bladder changes were identified in 16 of 35 (45.7%) SLE necropsies.
• Common findings included interstitial cystitis (11), hemorrhage (9), congestion (7), vasculitis (5), and perivenular infiltrate (4).
• Control group showed significantly fewer abnormalities (5/30), primarily hemorrhage likely due to catheters.
• SLE patients with bladder changes had a higher frequency of pulmonary hemorrhage.

Conclusions:

• Histologic urinary bladder abnormalities are frequent in SLE patients.
• Interstitial cystitis and hemorrhagic cystitis are notable findings.
• The association between bladder changes and pulmonary hemorrhage suggests a common autoimmune pathogenesis in SLE.