Concordance of PD-L1 Expression Between Core Biopsy and Resection Specimens of Non-Small Cell Lung Cancer.

The heterogeneity of programmed death ligand 1 (PD-L1) expression in non-small cell lung carcinomas (NSCLCs) is well studied; however, the method of tissue sampling needed to obtain adequate diagnostic material has not been established. This study aimed to determine whether core needle biopsy provides sufficient tissue for accurate PD-L1 evaluation despite tumor heterogeneity. A retrospective analysis comparing tumoral expression of PD-L1 in 51 lung core biopsies to subsequent resection specimens was performed. Scoring of membranous staining was categorized as 0%, 1% to 49%, and ≥50% of tumor cells. Staining ≥50% tumoral PD-L1 expression was detected in 8/51 (15.7%) of core biopsies and 8/51 (15.7%) of resection specimens. Core biopsy and resection results were concordant in 92.2% of cases (κ, 0.70; 95% confidence interval, 0.43-0.98). Therefore, despite tumor heterogeneity, detection of tumoral PD-L1 expression in NSCLC appears to be largely concordant between core biopsies and resection specimens, with the caveat that it may be helpful to reassess resection specimens for low-level staining. These findings suggest that core biopsy may be adequate for determining PD-L1 expression in NSCLC.

Effect of urine pH and magnesium on calcium oxalate saturation.

Hypomagnesiuria is a common biochemical finding in patients with calcium oxalate (CaOx) nephrolithiasis. Clinical trials using Mg supplements as therapy against CaOx stones have shown mixed results. We tested the effect of Mg administration in healthy subjects under conditions of controlled urine pH (UpH) on urinary Ca excretion rate (UCaV) and CaOx saturation. This is a 4-phase, double blind, placebo-controlled, metabolic crossover study performed in healthy volunteers. Mg lactate (MgLact2) was used as Mg supplement. High UpH and low UpH were achieved by administration of potassium citrate (K3Citrate) and ammonium chloride (NH4Cl), respectively, with potassium balance maintained by KCl. Eight participants completed 4 phases of study. The interventions successfully modulated 24-h UpH (7.0 ± 0.4 vs. 5.7 ± 0.6 in high vs low pH phases; P<0.001). Administration of MgLact2 increased UMgV [175.8 ± 40.2 vs 93.4 ± 39.7 mg/day (7.2 ± 1.7 vs 3.8 ± 1.6 mmol/day), high vs low Mg phase; P<0.001], and increased pH both at low (5.6 ± 0.5 to 5.8 ± 0.7; P = 0.02) and high UpH (6.9 ± 0.4 to 7.0 ± 0.3; P = 0.01). At a given urine pH, Mg supplementation marginally increased UCaV, but did not alter UOxV or CaOx saturation. Provision of an alkali load significantly lowered UCaV and saturation of CaOx at any level of UMgV. Compared to changes in UMgV, changes in UpH play a more significant role in determining urine CaOx saturation in healthy subjects. Mg supplements are likely to reduce CaOx saturation if they also raise urine pH.

The impact of obesity on the presentation of primary hyperparathyroidism.

CONTEXT: Obesity has been associated with elevated serum PTH (sPTH) in the general population. Obesity may also alter the clinical presentation in patients with primary hyperparathyroidism (PHPT). OBJECTIVES: The objectives of the study were to compare the clinical presentation of obese (OB) vs nonobese (NO) PHPT patients and to assess the impact of obesity on the presentation of PHPT independent of serum calcium and PTH. PATIENTS: Consecutive PHPT patients who underwent parathyroidectomy between 2003 and 2012 by a single surgical group participated in the study. SETTING: The study was conducted at an academic medical center. DESIGN: Cross-sectional review of records of preoperative demographic, historical, laboratory, and densitometry findings and intraoperative pathological findings were compared in OB vs NO patients. MAIN OUTCOME MEASURES: The prevalence of nephrolithiasis and osteoporosis was measured. RESULTS: Two hundred forty-seven PHPT patients were included in this analysis. Fifty percent were OB and 79% were women. Mean body mass index was 25.3 ± 3.3 and 36.0 ± 5.2 kg/m(2) in the NO and OB groups, respectively. Age, gender, and race distribution was similar between the two groups. Serum calcium was similar between the groups (11.0 ± 0.7 mg/dL in NO vs 11.1 ± 0.9 mg/dL in OB, P = .13), whereas sPTH was higher in OB (151 ± 70 vs 136 ± 69 pg/mL, P = .03). The OB group exhibited higher prevalence of hypercalciuria (urine calcium > 400 mg per 24 h) (41% vs 23% in NO, P = .01) and nephrolithiasis (36% vs 21% in NO, P = .03). Despite higher sPTH, OB patients showed higher bone mineral density and a lower rate of osteoporosis (21% vs 35%, P = .05). Differences in the prevalence of hypercalciuria and osteoporosis between the groups persisted after adjustment for age, race, estimated glomerular filtration rate, gender, sPTH, and calcium. CONCLUSIONS: In PHPT patients, obesity is a risk factor for hypercalciuria and nephrolithiasis and is protective against osteoporosis. The impact of parathyroidectomy on the clinical features of obese PHPT patients merits further evaluation.