Urinary extracellular vesicles signature for diagnosis of kidney disease.

Congenital disorders characterized by the quantitative and qualitative reduction in the number of functional nephrons are the primary cause of chronic kidney disease (CKD) in children. We aimed to describe the alteration of urinary extracellular vesicles (uEVs) associated with decreased renal function during childhood. By nanoparticle tracking analysis and quantitative proteomics, we identified differentially expressed proteins in uEVs in bilateral renal hypoplasia, which is characterized by a congenitally reduced number of nephrons. This expression signature of uEVs reflected decreased renal function in CKD patients by congenital anomalies of the kidney and urinary tract or ciliopathy. As a proof-of-concept, we constructed a prototype ELISA system that enabled the isolation of uEVs and quantitation of expression of molecules representing the signature. The system identified decreased renal function even in its early stage. The uEVs signature could pave the way for non-invasive methods that can complement existing testing methods for diagnosing kidney diseases.

Urinary Podocyte Count as a Potential Routine Laboratory Test for Glomerular Disease: A Novel Method Using Liquid-Based Cytology and Immunoenzyme Staining.

INTRODUCTION: This study investigated whether our urinary podocyte detection method using podocalyxin (PDX) and Wilms tumor 1 (WT1) immunoenzyme staining combined with liquid-based cytology can serve as a noninvasive routine laboratory test for glomerular disease. METHODS: The presence of PDX- and WT1-positive cells was investigated in 79 patients with glomerular disease and 51 patients with nonglomerular disease. RESULTS: The frequencies and numbers of PDX- and WT1-positive cells were significantly higher in the glomerular disease group than in the nonglomerular disease group. The best cutoffs for PDX- and WT1-positive cell counts for identifying patients with glomerular disease were 3.5 (sensitivity = 67.1% and specificity = 100%) and 1.2 cells/10 mL (sensitivity = 43.0% and specificity = 100%), respectively. CONCLUSION: Because our urinary podocyte detection method using PDX immunoenzyme staining can be standardized and it detected glomerular disease with high accuracy, it can likely serve as a noninvasive routine laboratory test for various glomerular diseases.

The case of Kawasaki disease after rituximab infusion triggered by human anti-chimeric antibodies.

Rituximab (RTX) is an effective treatment for refractory nephrotic syndrome (NS), but may produce human anti-chimeric antibodies (HACA) which can cause severe infusion reaction or rituximab-induced serum sickness (RISS). RISS presents with a fever, rash, and arthralgia, which typically occurs 7-21 days after RTX infusion. On the other hand, Kawasaki disease (KD) also presents with fever and rash. There have been no reports of KD developed after RTX infusion. A 6-year-old girl with frequently relapsing NS was admitted to our hospital for fever and rash on day 7 after receiving RTX. Although it was suggestive of RISS at first, she also had conjunctival hyperemia, swelling, and erythema of the hands and feet, and a right coronary artery abnormality on echocardiography. Her symptoms met the diagnostic criteria of KD. We administered intravenous immunoglobulin (IVIg) (2 g/kg), and her symptoms resolved within a few days. The HACA titer determined using the serum collected at admission was very high. This is the first report of KD with a clinical course similar to RISS. It should be noted that a careful follow-up of coronary arteries should be performed in patients suspected of RISS.

Kidney function of Japanese children undergoing kidney transplant with preemptive therapy for cytomegalovirus infection.

BACKGROUND: Cytomegalovirus (CMV) infection is one of the major factors that affect morbidity and mortality in kidney transplant (KTx) patients. The rate of CMV seropositivity in children before KTx is lower than that in adults; therefore, pediatric KTx patients have a higher risk of CMV infection. In Japanese pediatric KTx patients, preemptive therapy for CMV infection is a main conventional therapy. This study investigated whether this preemptive treatment would affect kidney function at 2 years post-KTx. METHODS: A total of 163 patients, that is approximately half of the Japanese pediatric KTx patients nationwide, were recruited to participate in our study. We compared the values of the sequential estimated glomerular filtration rate (eGFR) at two years post-KTx and other influencing factors in CMV viremia, CMV disease, and no-infection groups. RESULTS: Cytomegalovirus infection after KTx occurred in 75 patients (46.0%), 38.7% of whom developed CMV disease. The sequential eGFR values post-KTx did not differ significantly between the three groups. CMV infection was not significantly correlated with other factors, other infections (including Epstein-Barr [EB] virus infection), acute rejection (AR), or adverse events. Only prolonged duration of total hospitalization was significantly associated with CMV infection (P = .002). In the multivariate analysis, younger age, CMV infection, and adverse effects were independently significantly related to prolonged total hospitalization. CONCLUSION: Preemptive therapy for CMV infection evidenced by viremia and disease did not significantly influence kidney function in Japanese pediatric KTx patients at two years after the operation.

Severe Complications from an Unexpectedly High Serum Mycophenolic Acid Concentration in a Patient with Renal Failure Secondary to Lupus Nephritis: A Case Report.

Mycophenolate mofetil (MMF) is used widely to treat lupus nephritis and is considered safer than other immunosuppressive drugs. Reports on severe complications related to MMF are sparse. We report a case of a patient with lupus nephritis in whom severe complications were possibly caused by MMF. The patient was a 17-year-old girl who received a diagnosis of lupus nephritis at the age of 14 years and had been taking steroid and immunosuppressive agents since then. One week after starting MMF 1 g/day instead of mizoribine owing to symptom relapse and serologic data deterioration, she presented with seizure, accompanied by leukopenia, thrombocytopenia, and renal failure. We discontinued MMF because she had extremely high serum mycophenolate acid concentration (88 µg/mL). A few weeks later, she recovered without any complications and was discharged. Although rare, clinicians should be aware that serum mycophenolate acid concentration may become extremely high in the setting of acute kidney injury. In such circumstances, they should perform serum concentration monitoring to avoid possible adverse events.

The Japanese Clinical Practice Guideline for acute kidney injury 2016.

Acute kidney injury (AKI) is a syndrome which has a broad range of etiologic factors depending on different clinical settings. Because AKI has significant impacts on prognosis in any clinical settings, early detection and intervention are necessary to improve the outcomes of AKI patients. This clinical guideline for AKI was developed by a multidisciplinary approach with nephrology, intensive care medicine, blood purification, and pediatrics. Of note, clinical practice for AKI management which was widely performed in Japan was also evaluated with comprehensive literature search.

The Japanese clinical practice guideline for acute kidney injury 2016.

Acute kidney injury (AKI) is a syndrome which has a broad range of etiologic factors depending on different clinical settings. Because AKI has significant impacts on prognosis in any clinical settings, early detection and intervention is necessary to improve the outcomes of AKI patients. This clinical guideline for AKI was developed by a multidisciplinary approach with nephrology, intensive care medicine, blood purification, and pediatrics. Of note, clinical practice for AKI management which was widely performed in Japan was also evaluated with comprehensive literature search.

Arima syndrome caused by CEP290 specific variant and accompanied with pathological cilium; clinical comparison with Joubert syndrome and its related diseases.

OBJECTIVE: Arima syndrome (AS) is a rare disease and its clinical features mimic those of Joubert syndrome or Joubert syndrome-related diseases (JSRD). Recently, we clarified the AS diagnostic criteria and its severe phenotype. However, genetic evidence of AS remains unknown. We explored causative genes of AS and compared the clinical and genetic features of AS with the other JSRD. PATIENTS AND METHODS: We performed genetic analyses of 4 AS patients of 3 families with combination of whole-exome sequencing and Sanger sequencing. Furthermore, we studied cell biology with the cultured fibroblasts of 3 AS patients. RESULTS: All patients had a specific homozygous variant (c.6012-12T>A, p.Arg2004Serfs*7) or compound heterozygous variants (c.1711+1G>A; c.6012-12T>A, p.Gly570Aspfs*19;Arg2004Serfs*7) in centrosomal protein 290 kDa (CEP290) gene. These unique variants lead to abnormal splicing and premature termination. Morphological analysis of cultured fibroblasts from AS patients revealed a marked decrease of the CEP290-positive cell number with significantly longer cilium and naked and protruded ciliary axoneme without ciliary membrane into the cytoplasm. CONCLUSION: AS resulted in cilia dysfunction from centrosome disruption. The unique variant of CEP290 could be strongly linked to AS pathology. Here, we provided AS specific genetic evidence, which steers the structure and functions of centrosome that is responsible for normal ciliogenesis. This is the first report that has demonstrated the molecular basis of Arima syndrome.

A Case of Juxtaglomerular Cell Tumor, or Reninoma, of the Kidney Treated by Retroperitoneoscopy-Assisted Nephron-Sparing Partial Nephrectomy Through a Small Pararectal Incision.

A 15-year-old girl was found to be hypertensive (230-270/140-170 mm Hg) without any subjective symptoms. Magnetic resonance imaging confirmed the presence of a well-defined 22 mm hypodense lesion in the lower pole of the left kidney, located close to the renal hilum. Plasma rennin activity was elevated (75 ng/mL/h), and reninoma was diagnosed. Retroperitoneoscopy-assisted nephron-sparing surgery was planned. The retroperitoneum was accessed through a 4 cm left pararectal upper abdominal incision. Following blunt dissection, the abdominal wall was elevated with a lifting bar and lifting retractor, inserted below the 12th rib in the anterior axillary line to create sufficient working space in the retroperitoneal cavity without the need for pneumoperitoneum. Three 5 mm trocars were introduced above the superior iliac crest for the camera and the assistant. Gerota's fascia was opened and the kidney exposed. The surgeon dissected the left kidney through the minilaparotomy incision under both direct vision and using the magnified view on the monitor, which was particularly effective for the lateral and posterior sides of the kidney. The posterior peritoneum was incised intentionally next to the diaphragm to allow further mobilization of the kidney. Diathermy was used to remove the tumor and a layer of surrounding normal parenchymal tissue at least 0.5 cm thick. The histopathologic diagnosis was reninoma. Ischemia time was 14 minutes. Postoperatively, both plasma rennin activity and blood pressure were normal (1.9 ng/mL/h and 90-110/70-80 mm Hg, respectively). After follow-up of 12 months, there is no evidence of recurrence.

[Sequential combined liver-kidney transplantation for a one-year-old boy with infantile primary hyperoxaluria type 1].

We present the case of a one-year-old male patient with infantile primary hyperoxaluria type 1 (PH1). The patient visited hospital because of growth delay and poor feeding when he was six months old, and was diagnosed as PH1 with chronic renal failure. He underwent peritoneal dialysis until receiving a living-related liver transplantation when he was seventeen months old, and after the operation, underwent hemodialysis or hemodiafiltration four times per week. Six months after the liver transplantation, his serum oxalate level decreased to around 20 micromol/l and a living-related kidney transplantation was successfully performed. Nine months have passed since the kidney transplantation, and the patient's liver and kidney functions have been good and his growth and development much better than before the sequential liver and kidney transplantation. However, his serum and urine oxalate levels remained high and he has required high dose hydration to prevent deposition of calcium oxalate crystals in his grafted kidney. The key-points for treating infantile PHI patients are summarized as follows; 1) make a precise diagnosis as soon as possible, 2) perform a combined liver-kidney transplantation successfully, 3) conduct careful monitoring of the serum and urine oxalate levels and continue adequate hydration after kidney transplantation until the serum and urine oxalate levels normalize. Furthermore, cooperation between the medical staff and the patient's family seems to be essential.