Faris Ahmed

The epidemiological association of altitude with chronic kidney disease: Evidence of protective effect

Aims:  We sought to determine the association between living at high altitudes and the estimated glomerular filtration rate (eGFR) and also to determine the prevalence of end‐stage renal disease (ESRD) at various altitudes.

Asymmetric dimethylarginine and whole blood viscosity in renal failure

BACKGROUND Renal failure is a disease with accelerated atherosclerosis beginning with endothelial cell dysfunction. Factors affecting endothelial cell dysfunction include whole blood viscosity (WBV) and asymmetric dimethylarginine (ADMA). The relationship in controls and renal failure was determined. METHODS 51 subjects, 20 controls, 11 renal transplant recipients, 10 chronic kidney disease and 10 end-stage renal disease patients had blood samples drawn for WBV, Hematocrit, and ADMA. WBV was measured at various shear rates from 10 s(-1) to 780 s(-1) at 37 °C. Hematocrit using CritSpin, and ADMA was assayed using an ELISA method. The significance between groups was compared by boxplots and analysis of variance. Linear relationships were shown by regression lines and correlation coefficients. RESULTS ADMA was elevated in all groups with renal failure when compared to controls (p < 0.05). Control subjects showed a positive correlation between ADMA and WBV, while those who received a renal transplant had a negative correlation (p < 0.05). The difference in ADMA comparing pre-dialysis to post-dialysis conditions was positive (p < 0.05). CONCLUSIONS The positive relationship between WBV and ADMA in controls is a novel finding and allows for comparison with other groups. This relationship is dramatically altered in renal failure.

Estimation of Daily Proteinuria in Patients with Multiple Myeloma by Using the Protein-to-Creatinine Ratio in Random Urine Samples

discarded because they were found to be incomplete [8] . Due to the difficulties involved in obtaining a complete sample, results are often inaccurate and unreliable [9, 10] . Moreover, laboratory manipulation of specimens is costly and relatively time-consuming [11–13] . The use of the random (‘spot’) protein-to-creatinine (Pr/Cr) ratio has proven to be a valid alternative in estimating the daily proteinuria [14, 15] . If one assumes that protein and creatinine excretion remain constant throughout the day, then variations in the concentration of excreted protein are due to fluctuations in the amount of water excreted, which can vary based on diet, degree of physical activity, and body temperature. The ratio was developed to correct for these variations, and several studies have validated its use as a predictor of 24-hour urine protein excretion [8, 9, 12, 16–21] . Since 2002, the National Kidney Foundation’s Kidney Disease Outcomes Quality Initiative guidelines have stated that the Pr/Cr ratio in an untimed urine specimen should replace protein excretion in a 24-hour collection as the preferred method for measuring proteinuria [22] . The Pr/Cr ratio has been shown to be a valid estimator of daily protein excretion in a variety of conditions associated with significant proteinuria, including chronic kidney disease [12] , lupus [8] , and diabetes melUrine proteins in multiple myeloma (MM) include not only monoclonal light chains (‘Bence-Jones’ proteins) but also albumin, which can be excreted in large amounts, sometimes in the nephrotic range. A daily excretion

Light chain podocytopathy mimicking recurrent focal segmental glomerulosclerosis

Kidney injury related to paraproteinemia is common and typically occurs after the fourth decade of life in association with an underlying plasma cell dyscrasia or other lymphoproliferative disease. Kidney transplantation in paraprotein‐related kidney disease can be successful in conjunction with treatment of the underlying hematopoietic process; however, when hematologic response to therapy is not achieved, recurrent kidney injury is frequently seen. We describe a young male patient who presented at the age of 23 years with end‐stage kidney disease thought to be secondary to focal segmental glomerulosclerosis; this patient ultimately received two kidney allografts. He experienced recurrent proteinuria in both kidneys, with a biopsy from his second allograft showing kappa‐restricted crystalline light chain podocytopathy, which was identified in both his native and first allograft kidneys upon retrospective review. Recurrent light chain podocytopathy has not been previously reported but poses a diagnostic challenge as it can mimic focal segmental glomerulosclerosis, particularly in young patients in whom paraprotein‐related kidney injury is usually not suspected.

De novo immune complex deposition in kidney allografts: a series of 32 patients

Immune complex deposition in kidney allografts can include both recurrent and de novo processes. Recurrent glomerulonephritis is a well-recognized phenomenon and has been shown to be a common cause of allograft failure. De novo immune complex-mediated disease remains relatively poorly characterized, likely owing to the less frequent use of immunofluorescence and electron microscopy in the transplant setting. We performed a retrospective review of kidney allograft biopsies showing glomerular immune complex deposition. Cases with de novo deposits were identified and further organized into two groups depending on whether the immune complex deposition could be clinically and/or histologically classified. Thirty-two patients with de novo immune complex deposition were identified over a 7-year period. A broad range of immune complex-mediated injuries were observed, the majority (63%) of which could be readily classified either clinically or histologically. These included cases of membranous glomerulonephropathy, IgA nephropathy, infection-related glomerulonephritis and glomerulonephritis related to an underlying autoimmune process. A smaller subset of patients (37%) demonstrated immune complex deposition that was difficult to histologically or clinically classify. These patients typically showed mild mesangial immune complex deposition with co-dominant IgG and IgM staining by immunofluorescence microscopy. The presence of concurrent antibody-mediated rejection and donor-specific antibody positivity was significantly higher in the unclassifiable group. The significance of these deposits and their possible relationship to allograft rejection deserves further investigation.

Acute renal failure in a renal transplant patient

Accreditation and Designation Statement This activity has been planned and implemented in accordance with the accreditation requirements and policies of the Accreditation Council for Continuing Medical Education (ACCME) through the joint providership of Blackwell Futura Media Services, the American Society of Transplant Surgeons, and the American Society of Transplantation. Blackwell Futura Media Services is accredited by the ACCME to provide continuing medical education for physicians. Blackwell Futura Media Services designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM. Physicians should only claim credit commensurate with the extent of their participation in the activity.