N-Terminal Pro–B-Type Natriuretic Peptide in the Emergency Department: The ICON-RELOADED Study

Background

Contemporary reconsideration of diagnostic N-terminal pro–B-type natriuretic peptide (NT-proBNP) cutoffs for diagnosis of heart failure (HF) is needed.

Vitamin B6 in Primary Hyperoxaluria I: First Prospective Trial after 40 Years of Practice

Background and objectives

Primary hyperoxaluria type I (PH I) is caused by deficiency of the liver-specific enzyme alanine-glyoxylate:aminotransferase (AGT). Many mutations are known to perturb AGT protein folding. Vitamin B6 (B6) is the only specific drug available for treatment. Although B6 has been used for >40 years, controlled data on B6 efficacy are lacking. Therefore, this study investigated the absolute and relative change of urinary oxalate (Uox) excretion under increasing dosages of B6, the first prospective trial to do so.

Design, setting, participants, & measurements

B6 response was studied in 12 patients (7 male patients) with genetically confirmed PH I (3 Gly170Arg homozygous, 5 compound Gly170Arg and/or Phe152Ile heterozygous, and 4 negative for Gly170Arg and/or Phe152Ile mutations) and noncompromised renal function. Efficacy was defined as a 30% relative reduction in Uox excretion. B6 was administered orally starting at 5 mg/kg body weight per day and given in increments of 5 mg/kg every 6 weeks, up to a final dosage of 20 mg/kg per day at week 24. Uox and serum B6 levels were measured every 6 weeks.

Results

Mean relative Uox reduction was 25.5%. Uox declined from 2.09±0.55 (mean±SD) at baseline to 1.52±0.60 mmol/1.73 m² per day (P=0.01) at week 24. Serum B6 levels increased from 22.5±8.7 to 1217±776 ng/ml (P<0.001). Six patients showed a ≥30% relative reduction of Uox at week 24.

Conclusion

This first prospective trial confirmed B6 efficacy in 50% of patients (three of three homozygous, one of five heterozygous, and two of four patients negative for the Gly170Arg and/or Phe152Ile mutations). Interestingly, no complete biochemical remission was observed, even in the homozygous Gly170Arg study participants. Future trials are necessary to learn more about genotype-related B6 response and B6 metabolism.     

Postoperative impaired glucose tolerance is an early predictor of pancreas graft failure

Aims/hypothesis

The management of pancreatic transplantation is limited by a lack of clinically relevant early markers of graft dysfunction to enable intervention prior to irreversible damage. The aim of this study was to assess the OGTT as an early predictor of pancreatic graft failure.

Methods

Patients with graft failure (return to insulin dependence) were identified from a prospectively maintained clinical database. Data from OGTTs performed within 2 weeks of the transplant were retrospectively collected for 210 subjects, 42 with graft failure (21 after simultaneous pancreas–kidney transplant and 21 after isolated pancreas transplant) matched to 168 with functioning grafts. The groups were compared to assess the relationship between early OGTT result and pancreas graft failure.

Results

Mean 2 h glucose from the OGTT was significantly higher in the overall graft failure group compared with the control group (8.36 vs 6.81 mmol/l, p?=?0.014). When interpreted in combination with fasting glucose, abnormal glucose tolerance was more common in the failed graft group (50% vs 22%, p?=?0.001). In an adjusted model, abnormal glucose tolerance emerged as the most predictive independent factor for graft failure, HR 1.66 (95% CI 1.22, 2.24), p?=?0.001. These findings were consistent between the different transplant procedures performed.

Conclusions/interpretation

We conclude that early post-transplant abnormal glucose tolerance is associated with later whole organ pancreas graft failure. An OGTT performed within the first month postoperatively provides an easily measurable assessment of an independent early risk factor of pancreatic graft dysfunction.