Renal Immune-related Adverse Event of Pembrolizumab Masked by Pemetrexed.

A Japanese woman in her 60s developed a kidney injury 9 weeks after treatment with pemetrexed, carboplatin, and pembrolizumab for stage IV lung adenocarcinoma. A renal biopsy showed chronic tubulointerstitial damage with minimal focal interstitial inflammation, consistent with pemetrexed-induced nephropathy; thus, pemetrexed was withdrawn. However, the kidney injury continued to worsen. A repeated biopsy showed severe acute tubulointerstitial nephritis, suggestive of a pembrolizumab-induced immune-related adverse event (irAE). The worsening after pemetrexed discontinuation suggested that the irAE had already begun, as the first biopsy showed focal inflammation. This case suggests thatcombining immune checkpoints and chemotherapy requires considering concurrent drug-induced nephrotoxicity.

Predictive correction of serum sodium concentration with formulas derived from the Edelman equation in patients with severe hyponatremia.

Severe hyponatremia can cause life-threatening cerebral edema. Treatment comprises rapid elevation of serum sodium concentration; however, overcorrection can result in osmotic demyelination. This study investigated potential factors, including predictive correction based on the Edelman equation, associated with appropriate correction in 221 patients with a serum sodium concentration ≤ 120 mEq/L who were admitted to a hospital in Nagoya, Japan. Appropriate correction was defined as an elevation in serum sodium concentration in the range of 4-10 mEq/L in the first 24 h and within 18 mEq/L in the first 48 h after the start of the correction. Appropriate corrections were made in 132 (59.7%) of the 221 patients. Multivariate analysis revealed that predictive correction with an infusate and fluid loss formula derived from the Edelman equation was associated with appropriate correction of serum sodium concentration (adjusted odds ratio, 7.84; 95% confidence interval, 2.97-20.64). Relative without its use, the predictive equation results in a lower proportion of undercorrection (14.3% vs. 48.0%, respectively) and overcorrection (1.0% vs. 12.2%, respectively). These results suggest that predictive correction of serum sodium concentrations using the formula derived from the Edelman equation can play an essential role in the appropriate management of patients with severe hyponatremia.