Multicolor Flow Cytometry and Cytokine Analysis Provides Enhanced Information on Kidney Transplant Biopsies.

INTRODUCTION: Current processing of renal biopsy samples provides limited information about immune mechanisms causing kidney injury and disease activity. We used flow cytometry with transplanted kidney biopsy samples to provide more information on the immune status of the kidney. METHODS: To enhance the information available from a biopsy, we developed a technique for reducing a fraction of a renal biopsy sample to single cells for multicolor flow cytometry and quantitation of secreted cytokines present within the biopsy sample. As proof of concept, we used our technique with transplant kidney biopsy samples to provide examples of clinically relevant immune information obtainable with cytometry. RESULTS: A ratio of CD8+ to CD4+ lymphocytes greater than or equal to 1.2 in transplanted allografts is associated with rejection, even before it is apparent by microscopy. Elevated numbers of CD45 leukocytes and higher levels of interleukin (IL)-6, IL-8, and IL-10 indicate more severe injury. Antibody binding to renal microvascular endothelial cells can be measured and corresponds to antibody-mediated forms of allograft rejection. Eculizumab binding to endothelial cells suggests complement activation, which may be independent of bound antibody. We compared intrarenal leukocyte subsets and activation states to those of peripheral blood from the same donor at the time of biopsy and found significant differences; thus the need for new techniques to evaluate immune responses within the kidney. CONCLUSION: Assessment of leukocyte subsets, renal microvascular endothelial properties, and measurement of cytokines within a renal biopsy by flow cytometry enhance understanding of pathogenesis, indicate disease activity, and identify potential targets for therapy.

A case of mistaken identity: fibrillary glomerulonephritis masquerading as crescentic anti-glomerular basement membrane disease.

Fibrillary glomerulonephritis (FGN) is a rare cause of rapidly progressive glomerulonephritis (RPGN). We report a case of FGN in which the patient presented with a clinical pulmonary-renal syndrome and whose kidney biopsy showed > 90% crescents on light microscopy. Immunofluorescence microscopy showed pseudo-linear IgG and C3 staining of the glomerular capillary walls resulting in an initial diagnosis of crescentic glomerulonephritis of anti-glomerular basement membrane (anti-GBM) antibody etiology. Electron microscopy showed fibrillary deposits permeating the glomerular capillary walls, characteristic of FGN. Although dialysis dependent at presentation and anuric at discharge, the patient recovered adequate renal function and urine output to come off dialysis at 20 weeks. A follow up biopsy performed at this stage showed progression of the underlying chronic kidney disease. This is the third reported case of FGN with a clinical presentation and histologic and immunofluorescence microscopic findings that closely mimicked anti-GBM antibody mediated disease. These cases demonstrate that FGN is a rare but important consideration in the differential diagnosis of RPGN.

Migration of an intrauterine device and peritonitis in a peritoneal dialysis patient.

Peritonitis is a frequent complication of peritoneal dialysis. Infection is most commonly introduced into the peritoneal cavity through the indwelling catheter during the dialysis procedure. Occasionally peritonitis is associated with underlying abdominal pathology rather than secondary to the dialysis procedure itself. Here we present a case of polymicrobial peritonitis in a patient on automated peritoneal dialysis (APD) in the setting of uterine perforation by an intrauterine device (IUD). Clinicians involved in the care of patients on peritoneal dialysis should remain vigilant for underlying abdominal pathology in cases of complicated peritonitis.

Renal replacement therapy in congestive heart failure requiring left ventricular assist device augmentation.

"Cardiorenal syndrome" is a term used to describe a dys-regulation of the heart affecting the kidneys, or vice versa, in an acute or chronic manner (1,2). Renal impairment can range from reversible ischemic damage to renal failure requiring short- or long-term renal replacement therapy (2). Patients who require mechanical circulatory support, such as a left ventricular assist device (LVAD), as definitive treatment for congestive heart failure or as a bridge to cardiac transplantation pose a unique challenge with respect to receiving dialysis, because they experience higher rates of morbidity and mortality from infection in the post-LVAD period (3-7). Acute dialysis access can pose an increased infection risk. In this article, we present a patient who required renal replacement therapy and a LVAD for management of acute-on-chronic cardiorenal syndrome while awaiting heart transplantation. A literature review to determine whether peritoneal dialysis or hemodialysis is superior for patients with profound hemodynamic dysfunction and the need to minimize risk of infection did not offer clear guidance about which modality is superior in patients with advanced congestive heart failure. However, there is clear evidence of the superiority of peritoneal dialysis in reducing the risk of systemic infection secondary to acute dialysis access. Given the high risk of LVAD infection, we therefore conclude that, to decrease mortality secondary to systemic infection, peritoneal dialysis should strongly be considered in patients who require renal replacement therapy before or after LVAD placement.