Three Severe Cases of Viral Infections with Post-Kidney Transplantation Successfully Confirmed by Polymerase Chain Reaction and Flow Cytometry

Viral infections in patients with post-kidney transplantation are often difficult to diagnose as well as treat. We herein report three cases with severe viral infections after kidney transplantation. All their causative pathogens could be detected promptly by polymerase chain reaction and flow cytometry during the early stages of infection. These examinations would also be of great use to monitor therapeutic responses and disease activity. It is indeed true that no specific treatment is available for most of the viral infections, but we should be aware that some infections, such as Epstein-Barr virus infection, can be treatable with prompt and specific treatment, such as rituximab

Drug efficacy against aortic dissection

Objective: Aortic dissection is a life-threatening disease. At present, the only therapeutic strategies available are surgery and antihypertensive drugs. Moreover, the molecular mechanisms underlying the onset of aortic dissection are still unclear. We established a novel aortic dissection model in mice using pharmacologically induced endothelial dysfunction. We then used the Japanese Adverse Drug Event Report database to investigate the role of pitavastatin in preventing the onset of aortic dissection. Methods and results: To induce endothelial dysfunction, Nω-nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor, was administered to C57BL/6 mice. Three weeks later, angiotensin II (Ang II) and β-aminopropionitrile (BAPN), a lysyl oxidase inhibitor, were administered with osmotic mini-pumps. False lumen formation was used as the pathological determinant of aortic dissection. The incidences of aortic dissection and death from aneurysmal rupture were significantly higher in the Nω-nitro-L-arginine methyl ester, Ang II, and BAPN (LAB) group than they were in the Ang II and BAPN (AB) group. Pitavastatin was administered orally to LAB mice. It significantly lowered the incidences of dissection and rupture. It also decreased inflammation and medial degradation, both of which were exacerbated in the LAB group. The Japanese Adverse Drug Event Report database analysis indicated that there were 113 cases of aortic dissection out of 95 090 patients (0.12%) not receiving statins but only six cases out of 16 668 patients receiving statins (0.04%) (odds ratio: 0.30; P=0.0043). Conclusion: Our results suggest that endothelial dysfunction is associated with the onset of aortic dissection and pitavastatin can help prevent this condition

Comprehensive genetic diagnosis of Japanese patients with severe proteinuria

Numerous disease-causing gene mutations have been identified in proteinuric diseases, such as nephrotic syndrome and glomerulosclerosis. This report describes the results of comprehensive genetic diagnosis of Japanese patients with severe proteinuria. In addition, the report describes the clinical characteristics of patients with monogenic disease-causing mutations. We conducted comprehensive gene screening of patients who had either congenital nephrotic syndrome, infantile nephrotic syndrome, steroid-resistant nephrotic syndrome, or focal segmental glomerular sclerosis. Using targeted next-generation sequencing, 60 podocyte-related genes were screened in 230 unrelated patients with proteinuria. A retrospective review of clinical data was conducted for these patients. We detected monogenic disease-causing mutations in 30% (69 of 230) of patients among 19 of the screened genes. Common genes with disease-causing mutations were WT1 (25%), NPHS1 (12%), INF2 (12%), TRPC6 (10%), and LAMB2 (9%). With various immunosuppressive or renoprotective therapies, remission of proteinuria in patients with unknown causative mutations was observed in 26% of patients, whereas only 5% of patients with monogenic disease-causing mutations exhibited complete remission. We assessed the genetic backgrounds of Japanese patients with severe proteinuria. The proportion of patients with gene defects was similar to that of other reports, but the disease-causing gene mutation frequency was considerably different

Congenital chloride diarrhea needs to be distinguished from Bartter and Gitelman syndrome

Pseudo-Bartter/Gitelman syndrome (p-BS/GS) encompasses a clinically heterogeneous group of inherited or acquired disorders similar to Bartter syndrome (BS) or Gitelman syndrome (GS), both renal salt-losing tubulopathies. Phenotypic overlap frequently occurs between p-BS/GS and BS/GS, which are difficult to diagnose based on their clinical presentation and require genetic tests for accurate diagnosis. In addition, p-BS/GS can occur as a result of other inherited diseases such as cystic fibrosis, autosomal dominant hypocalcemia, Dent disease, or congenital chloride diarrhea (CCD). However, the detection of the variants in genes other than known BS/GS-causing genes by conventional Sanger sequencing requires substantial time and resources. We studied 27 cases clinically diagnosed with BS/GS, but with negative genetic tests for known BS/GS genes. We conducted targeted sequencing for 22 genes including genes responsible for tubulopathies and other inherited diseases manifesting with p-BS/GS symptoms. We detected the SLC26A3 gene variants responsible for CCD in two patients. In Patient 1, we found the SLC26A3 compound heterozygous variants: c.354delC and c.1008insT. In Patient 2, we identified the compound heterozygous variants: c.877G > A, p.(Glu293Lys), and c.1008insT. Our results suggest that a comprehensive genetic screening system using targeted sequencing is useful for the diagnosis of patients with p-BS/GS with alternative genetic origins