Kidney function and quantitative histological changes in patients on long-term lithium therapy.

Area of Science:

• Nephrology
• Pharmacology
• Pathology

Background:

• Lithium is a common mood stabilizer used in long-term psychiatric treatment.
• Potential adverse effects of lithium on renal function are a significant clinical concern.

Purpose of the Study:

• To investigate the effects of long-term lithium treatment on renal function and kidney structure.
• To assess the correlation between lithium treatment duration and observed renal changes.

Main Methods:

• Studied renal function (glomerular filtration rate, concentrating ability) in 57 patients on long-term lithium.
• Analyzed 24 renal biopsy specimens using light microscopy, comparing them to an age-matched control group.
• Evaluated structural changes including glomerular sclerosis, interstitial fibrosis, fibrous tissue, and tubular atrophy.

Main Results:

• Nine percent of patients showed a moderate decrease in glomerular filtration rate (GFR).
• Seventy-five percent exhibited decreased renal concentrating ability.
• Significantly increased glomerular sclerosis and focal interstitial fibrosis were observed in lithium-treated patients compared to controls.
• No correlation was found between lithium treatment duration and GFR or structural changes.

Conclusions:

• Long-term lithium treatment is associated with impaired renal concentrating ability and structural kidney changes like glomerular sclerosis and interstitial fibrosis.
• The observed structural changes were mild, potentially due to the reduced single-dose regimen used in this study.
• No direct correlation between lithium treatment duration and the severity of renal impairment or structural damage was identified in this cohort.