Discovery and Validation of a Urinary Exosome mRNA Signature for the Diagnosis of Human Kidney Transplant Rejection

BackgroundDeveloping a noninvasive clinical test to accurately diagnose kidney allograft rejection is critical to improve allograft outcomes. Urinary exosomes, tiny vesicles released into the urine that carry parent cells’ proteins and nucleic acids, reflect the biologic function of the parent cells within the kidney, including immune cells. Their stability in urine makes them a potentially powerful tool for liquid biopsy and a noninvasive diagnostic biomarker for kidney-transplant rejection.MethodsUsing 192 of 220 urine samples with matched biopsy samples from 175 patients who underwent a clinically indicated kidney-transplant biopsy, we isolated urinary exosomal mRNAs and developed rejection signatures on the basis of differential gene expression. We used crossvalidation to assess the performance of the signatures on multiple data subsets.ResultsAn exosomal mRNA signature discriminated between biopsy samples from patients with all-cause rejection and those with no rejection, yielding an area under the curve (AUC) of 0.93 (95% CI, 0.87 to 0.98), which is significantly better than the current standard of care (increase in eGFR AUC of 0.57; 95% CI, 0.49 to 0.65). The exosome-based signature’s negative predictive value was 93.3% and its positive predictive value was 86.2%. Using the same approach, we identified an additional gene signature that discriminated patients with T cell–mediated rejection from those with antibody-mediated rejection (with an AUC of 0.87; 95% CI, 0.76 to 0.97). This signature’s negative predictive value was 90.6% and its positive predictive value was 77.8%.ConclusionsOur findings show that mRNA signatures derived from urinary exosomes represent a powerful and noninvasive tool to screen for kidney allograft rejection. This finding has the potential to assist clinicians in therapeutic decision making.     

Demographic changes and their financial implications

The impressive rise in the number of elderly persons (65 years and over) will continue in the next two to three decades. Urinary incontinence is a common problem in the elderly, adversely affecting medical, social, and "quality of life" aspects. The cost of urinary incontinence is substantial and is expected to escalate enormously (e.g., by 160% from 1980 to 2040). An aggressive approach toward the diagnosis and management of urinary incontinence can result in an impressive reduction in health care costs and improvement in the quality of life.     

Intravitreal drug administration with depot devices

The administration of medications by depot devices is a rapidly developing technology in ocular therapeutics. Sustained delivery of ophthalmic medications is a novel approach to treating chronic ocular conditions where systemic therapy may be accompanied by unwanted side effects and where repeated intravitreal drug administration carries significant risks. Eye diseases particularly suitable to this form of treatment include proliferative vitreoretinopathy and chronic intraocular infections such as cytomegalovirus retinitis. Liposomes, which have been extensively investigated over the last two decades, have not found any acceptable clinical application. Nonerodible polymers such as the ethylvinyl acetate/polyvinyl alcohol cup are in advanced phase III trials. The current status of microsphere development in the treatment of posterior segment disease is examined in the review and studies investigating the potential uses of the osmotic minipump are mentioned.     

Splenic abscess following blunt abdominal trauma

A rare case of splenic abscess occurring after blunt abdominal trauma in a previously healthy boy is reported. The diagnosis was made by ultrasonography. The patient recovered after splenectomy and drainage of subphrenic and intraperitoneal pus.     

Persistent transgene product in retina, optic nerve and brain after intraocular injection of rAAV.

Recombinant adeno-associated virus (rAAV) is a promising vector for retinal application as it transduces photoreceptors and retinal pigment epithelium cells efficiently and in a stable fashion. Because rAAV also transduces retinal ganglion cells, we reasoned that ocular application of rAAV might result in delivery of transgenic protein to the CNS. Here we describe high levels of green fluorescent protein (GFP) persisting at least 6 months in optic nerves and brains of mice and dogs after intravitreal delivery of rAAV-GFP. There was no clinical or histological evidence of inflammatory response although a mild humoral Th-2 response to viral capsid proteins was detected. These findings have important implications with respect to therapeutic applications of rAAV.     

Knowledge and perceptions of residents regarding case management of acute diarrhea.

The knowledge and perceptions about case management of acute diarrhea were studied amongst 330 resident doctors working in Pediatric Departments of various Medical Colleges in the country. Our observations highlight the inadequacies in the medical curriculum and deficient clinical training in the management of acute diarrhea in the teaching institutions. Knowledge of signs of dehydration was correctly perceived by only 79.8% interns, 80.9% house physicians and 81.1% postgraduate students. It was appalling to observe that despite spending 1-3 years in pediatric wards, the knowledge and perceptions of postgraduate students had not significantly improved. On the contrary, the responses of postgraduate students were poorer as compared to interns in their perceptions of use of ORT in moderate dehydration (p less than 0.005) and in presence of vomiting (p less than 0.05). Adequate thrust on diarrhea and its management during undergraduate as well as during postgraduate teaching and proper training in diarrhea case management with "hands on training" needs to be viewed as a priority in the teaching institutions.     

Unusual presentation of a giant glomus tumor

Giant glomus tumors pose a challenge to the Otologist by virtue of their location and vascularity. A vast majority of them present with tinnitus, conductive hearing loss and cranial nerve palsies. We report the case of a 16-year-old male patient who presented with sudden right-sided sensorineural hearing loss. This is an unusual presentation of a giant glomus tumor. We present the clinical features and management of this unusual case.     

Tissue repair plays pivotal role in final outcome of liver injury following chloroform and allyl alcohol binary mixture.

The objective of this study was to evaluate the interaction profile of chloroform (CHCl(3))+allyl alcohol (AA) binary mixture (BM)-induced acute hepatotoxic response. Plasma alanine aminotransferase (ALT) was measured to assess liver injury, and 3H-thymidine (3H-T) incorporation into hepatonuclear DNA was measured as an index of liver regeneration over a time course of 0-72 h. Male Sprague-Dawley (S-D) rats received single ip injection of 5-fold dose range of CHCl(3) (74, 185 and 370 mg/kg) in corn oil (maximum 0.5 ml/kg) and 7-fold dose range of AA (5, 20 and 35 mg/kg) in distilled water simultaneously. The doses for BM were selected from individual toxicity studies of CHCl(3) alone [Int. J. Toxicol. 22 (2003) 25], and AA alone [Reg. Pharmacol. Toxicol. 19 (1999) 165]. Since the highest dose of each treatment (CHCl(3)- 740 and AA- 50 mg/kg) yielded mortality due to the suppressed tissue repair followed by liver failure, this dose was omitted for BM. The levels of CHCl(3) (30-360 min) and AA (5-60 min) were quantified in blood and liver by gas chromatography (GC). The liver injury was more than additive after BM compared to CHCl(3) alone or AA alone at highest dose combination (370+35 mg/kg), which peaked at 24 h. The augmented liver injury observed with BM was consistent with the quantitation data. Though the liver injury was higher, the greater stimulation of tissue repair kept injury from progressing, and rescued the rats from hepatic failure and death. At lower dose combinations, the liver injury was no more than additive. Results of the present study suggest that liver tissue repair, in which liver tissue lost to injury is promptly replaced, plays a pivotal role in the final outcome of liver injury after exposure to BM of CHCl(3) and AA.     

Brief Clinical Report: Serum Tumor Necrosis Factor for Monitoring Response of Hepatic Veno-occlusive Disease to Pentoxiphyllin-A Case Report

Hepatic veno-occlusive disease (VOD) is the second most common cause of death after autologous bone marrow transplantation (ABMT). A patient with multiple myeloma undergoing ABMT developed classic features of hepatic VOD. He responded to treatment with pentoxiphyllin. Serum tumor necrosis factor (TNF) levels showed remarkable correlation with the severity of VOD and response to therapy.     

Occurrence of co-colonization or co-infection with vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus in a medical intensive care unit.

OBJECTIVE: To determine the occurrence of co-colonization or co-infection with VRE and MRSA among medical patients requiring intensive care. DESIGN: Prospective, single-center, observational study. SETTING: A 19-bed medical ICU in an urban teaching hospital. PATIENTS: Adult patients requiring at least 48 hours of intensive care and having at least one culture performed for microbiologic evaluation. RESULTS: Eight hundred seventy-eight consecutive patients were evaluated. Of these patients, 402 (45.8%) did not have microbiologic evidence of colonization or infection with either VRE or MRSA, 355 (40.4%) were colonized or infected with VRE, 38 (4.3%) were colonized or infected with MRSA, and 83 (9.5%) had co-colonization or co-infection with VRE and MRSA. Multiple logistic regression analysis demonstrated that increasing age, hospitalization during the preceding 6 months, and admission to a long-term-care facility were independently associated with colonization or infection due to VRE and co-colonization or co-infection with VRE and MRSA. The distributions of positive culture sites for VRE (stool, 86.7%; blood, 6.5%; urine, 4.8%; soft tissue or wound, 2.0%) and for MRSA (respiratory secretions, 34.1%; blood, 32.6%; urine, 17.1%; soft tissue or wound, 16.2%) were statistically different (P < .001). CONCLUSIONS: Co-colonization or co-infection with VRE and MRSA is common among medical patients requiring intensive care. The recent emergence of vancomycin-resistant Staphylococcus aureus and the presence of a patient population co-colonized or co-infected with VRE and MRSA support the need for aggressive infection control measures in the ICU.