Urinary excretion of albumin and retinol-binding protein in lithium-treated patients: a longitudinal study

Lithium toxicity and the kidney with special focus on nephrotic syndrome associated with the acute kidney injury: A case-based systematic analysis

Despite the progress made in treating bipolar and unipolar affective disorders, lithium carbonate is still a common drug in psychiatric practice. Lithium-related renal side effects include nephrogenic diabetes insipidus, chronic tubulointerstitial nephropathy, and acute kidney injury (AKI). Nephrotic syndrome (NS) is an uncommon but severe complication of lithium treatment. We present a 49-year-old female treated with lithium carbonate due to a recurrent depressive disorder who developed NS during this therapy. NS spontaneously remitted after the drug withdrawal. Since her lithium serum levels were within the recommended values, we performed a retrospective analysis of lithium-induced NS cases trying to determine causes predisposing to the NS development, underlying histopathology, and preservation or irreversible loss of kidney function. This analysis revealed that in lithium-induced NS with AKI, lithium serum level was the key determinant of AKI development (the β coefficient = 0.8499 with a confidence interval ranging from 0.7452 to 0.9546 and p value < 0.0001). In these cases, the underlying pathology was mainly minimal change disease (MCD), which was quickly reversible upon the drug withdrawal. The development of chronic kidney disease (CKD) seemed to be associated with lithium therapy duration. However, the multiple regression analysis for CKD as the dependent variable showed that the decisive factor was focal segmental glomerulosclerosis (FSGS) as the underlying pathology (the β coefficient = 0.7866 with a confidence interval ranging from 0.600 to 0.9704 and the p value < 0.0001). Thus, we conclude that in lithium-induced NS/AKI, serum lithium levels contribute to these complications, while FSGS lesions are responsible for CKD's disease progression.

Elevated urinary ADAM12 protein levels in lithium-treated bipolar patients

ADAM (A Disintegrin And Metalloprotease)12 is a member of a family of integral membrane and secreted glycoproteins. ADAM12 has recently been detected in urine. In the present study we measured ADAM12 protein levels in urine from bipolar patients vs. healthy controls. Nineteen bipolar patients and 22 matched-control subjects were studied. Urine samples were concentrated and Western-blot analysis used to determine ADAM12 protein levels. The 92 kDa form of urine ADAM12 protein levels were highly elevated in Li-treated bipolar patients compared with normal controls. The 68 kDa form of urine ADAM12 protein levels did not differ. Future experiments are needed to explore a potential link between ADAM12 protein level elevation and lithium response.

Urinary excretion of albumin and transferrin in lithium maintenance treatment: daily versus alternate-day lithium dosing schedule

Urinary excretion of albumin and transferrin was determined by means of sensitive immunochemical methods in 40 manic-depressive patients prior to and following 6 months of daily or alternate-day lithium carbonate treatment. The median dose of lithium carbonate was 700 mg in the daily treatment group and 1200 mg in the alternate-day group, the corresponding median 12-h serum lithium concentration being 0.6 mmol l-1 and 0.7 mmol l-1, respectively. Urinary excretion of albumin and transferrin was significantly elevated in the lithium-treated patients as compared to a control group (Mann-Whitney). The change in urinary albumin:creatinine and transferrin:creatinine ratios between allocation and 6 months of treatment did not correlate significantly with the lithium dosing schedule (multiple linear regression), but did correlate with total lithium carbonate dose. In conclusion, the study provides no evidence of any difference in glomerular function (permeability) in the daily and alternate-day lithium dosing schedules, and lends no support to the hypothesis that alternate-day treatment diminishes the effect of lithium on renal function.