Slow Progression of Aortic Calcification Is a Potential Benefit of Pre-emptive Kidney Transplantation

PURPOSE

Pre-emptive kidney transplantation (PKT) is expected to improve graft and cardiovascular event-free survival compared with standard kidney transplantation. Aortic calcification is reported to be closely associated with renal dysfunction and cardiovascular events; however, its implication in PKT recipients remains incompletely explored. This aim of this study was to evaluate whether PKT confers a protective effect on aortic calcification, renal function, graft survival, and cardiovascular event-free survival.

METHODS

One hundred adult patients who underwent renal transplantation between January 1996 and March 2016 at Hirosaki University Hospital and Oyokyo Kidney Research Institute were included. Among them, 19 underwent PKT and 81 patients underwent pretransplant dialysis. We retrospectively compared pretransplant and post-transplant aortic calcification index (ACI), renal function (estimated glomerular filtration rate [eGFR]), and graft and cardiovascular event-free survivals between the 2 groups.

RESULTS

The median age of this cohort was 45 years. Preoperative ACI was significantly lower in PKT recipients. There were no significant differences between the 2 groups regarding postoperative eGFR, graft survival, and cardiovascular event-free survival. However, the ACI progression rate (ΔACI/y) was significantly lower in PKT recipients than in those who underwent pretransplant dialysis. Higher ACI was significantly associated with poor cardiovascular event-free survival.

CONCLUSIONS

PKT is beneficial in that it contributes to the slow progression of after transplantation. Although we could not observe significant differences in graft and cardiovascular event-free survivals between the 2 groups, slow progression of aortic calcification showed a potential to decrease cardiovascular events in PKT recipients during long-term follow-up.

Mutation of the doublecortin gene in male patients with double cortex syndrome: somatic mosaicism detected by hair root analysis

The molecular basis of double cortex syndrome was investigated in 2 male patients. Magnetic resonance imaging of the patients' heads showed diffuse subcortical band heterotopia, as is seen in female patients. We found a heterozygous mutation for Asp50Lys or Arg39Stop in both patients. Microsatellite polymorphism analysis revealed that both patients had inherited a single X chromosome from their mothers. Restriction enzyme analysis using DNA extracted from the hair roots of each patient showed four different patterns in the combination of cells carrying wild and mutant alleles, which strongly suggest somatic mosaicism. We conclude that somatic mosaic mutations in the doublecortin gene in male patients can cause subcortical band heterotopia, and that molecular analysis using hair roots is a useful method for detecting somatic mosaicism.

Molecular cloning and chromosomal assignment of the human brain-type phosphodiesterase I/nucleotide pyrophosphatase gene (PDNP2)

Phosphodiesterase I/nucleotide pyrophosphatase is a widely expressed membrane-bound enzyme that cleaves diester bonds of a variety of substrates. We have cloned brain-type cDNA for this enzyme from rat brain and designated it PD-I alpha (M. Narita, J. Goji, H. Nakamura, and K. Sano, 1994, J. Biol. Chem. 269: 28235-28242). In this study we have isolated cDNA and genomic DNA encoding human PD-I alpha. Human PD-I alpha cDNA, designated PDNP2 in HGMW nomenclature, has a 2589-nucleotide open reading frame encoding a polypeptide of 863 amino acids with a calculated M(r) of 99,034. Northern blot analysis revealed that human PD-I alpha transcript was present in brain, lung, placenta, and kidney. The database analysis showed that human PD-I alpha was identical with human autotaxin (ATX), a novel tumor motility-stimulating factor, except that human PD-I alpha lacks 156 nucleotides and 52 amino acids of human ATX. Human PD-I alpha and human ATX are likely to be alternative splicing products from the same gene. The 5' region of the human PDNP2 gene contains four putative binding sites of transcription factor Sp1 without typical TATA or CAAT boxes, and there is a potential octamer binding motif in intron 2. From the results of fluorescence in situ hybridization, the human PDNP2 gene is located at chromosome 8q24.1.