Yip Boon Chong

Clinical Predictors of Non-diabetic Renal Disease and Role of Renal Biopsy in Diabetic Patients with Renal Involvement: A Single Centre Review

Background: Type 2 diabetes mellitus (T2DM) is reportedly the leading cause of end-stage renal disease (ESRD) worldwide. However, non-diabetic renal diseases (NDRD) are not uncommon among T2DM patients with renal involvement. Our study aimed to examine the prevalence of NDRD in T2DM and clinical markers for diabetic nephropathy (DN) and NDRD and to determine the role of renal biopsy in T2DM patients and its impact on clinical practice. Methods: We conducted a retrospective analysis of T2DM patients in whom renal biopsies were performed from January 2004 to March 2008 (n = 110). Results: Biopsy results were divided into three groups: group I/pure DN (62.7%), group II/isolated NDRD (18.2%), and group III/mixed lesions (19.1%). The causes of NDRD in decreasing order of frequency were acute interstitial nephritis, glomerulonephritides, hypertensive renal disease, and acute tubular necrosis. Significant clinical markers for DN are presence of diabetic retinopathy and longer duration of diabetes. For NDRD, useful clinical markers include the presence of acute renal failure and microscopic hematuria. In the DN subgroup, Indians had significantly shorter duration of diabetes on biopsy compared with Malays and Chinese. Conclusions: NDRD is prevalent in T2DM patients, and given its potentially treatable nature, renal biopsy should be considered in T2DM patients with nephropathy, especially in those with atypical features.

Pneumocystis jirovecii pneumonia 13 years post renal transplant following a recurrent cytomegalovirus infection

Pneumocystis jirovecii (formerly Pneumocystis carinii) pneumonia (PCP) is a rare but serious infection that usually occurs within a year after solid organ transplantation. PCP may occur after 1 year post transplantation, but the rate is reported to be very low. Studies have shown an association between cytomegalovirus (CMV) infection in solid organ transplant patients and an increased risk of opportunistic infection. This increased risk is thought to be a result of the immunomodulatory effects of the CMV infection. We present a case of PCP infection occurring 13 years after a renal transplantation. This occurred following a recurrent CMV infection while the patient was on low‐dose immunosuppressants.

Safety, pharmacokinetics and pharmacodynamics of AMG 811, an anti-interferon-γ monoclonal antibody, in SLE subjects without or with lupus nephritis

Objective To evaluate safety, pharmacokinetics and pharmacodynamics of anti-interferon (IFN)-γ monoclonal antibody AMG 811 in subjects with SLE without or with lupus nephritis (LN). Methods In this phase Ib, randomised, multiple-dose escalation study (NCT00818948), subjects without LN were randomised to subcutaneous AMG 811 (6, 20 or 60 mg) or placebo and subjects with LN were randomised to subcutaneous AMG 811 (20, 60 or 120 mg) or placebo every four weeks for three total doses. Outcomes included incidence of adverse events (AEs); pharmacokinetics; levels of serum proteins (CXCL-10, interleukin 18, monocyte chemotactic protein-1); changes in gene transcript profiles and clinical parameters (Safety of Estrogen in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) scores, proteinuria, anti-double-stranded DNA (anti-dsDNA) antibodies, C3 complement, C4 complement). Results Fifty-six subjects enrolled (28 SLE without LN; 28 with LN). Baseline mean SELENA-SLEDAI scores were 2.2 and 12.0 for SLE subjects without and with LN, respectively. Most subjects reported an AE; no meaningful imbalances were observed between AMG 811 and placebo. Pharmacokinetic profiles were similar and mostly dose-proportional in subjects without or with LN. AMG 811 treatment reduced CXCL-10 protein levels and blood-based RNA IFN-γ Blockade Signature compared with placebo. Reductions were less pronounced and not sustained in subjects with LN, even at the highest dose tested, compared with subjects without LN. No effect on SELENA-SLEDAI scores, proteinuria, C3 or C4 complement levels, or anti-dsDNA antibodies was observed. Conclusion AMG 811 demonstrated favourable pharmacokinetics and acceptable safety profile but no evidence of clinical impact. IFN-γ-associated biomarkers decreased with AMG 811; effects were less pronounced and not sustained in LN subjects. Trial registration number NCT00818948; results.

Resolution of epoetin-induced pure red cell aplasia 2 years later, successful re-challenge with continuous erythropoiesis receptor stimulator.

Epoetin-induced pure red cell aplasia (PRCA) is most commonly associated with epoetin-a; nevertheless, its occurrence has been reported in epoetin-β and darbepoetin-a. We report a young hemodialysis patient who developed PRCA 2 years after receiving intravenous epoetin-β. Epoetin- induced PRCA was confirmed by bone marrow aspiration, associated with markedly elevated anti-erythropoietin antibody. He was treated with prednisolone and cyclophosphamide for 3 months but continued to be transfusion-dependent. 17 months after the development of PRCA, he was started on intravenous continuous erythropoiesis receptor stimulator (CERA) in view of frequent transfusions. He tolerated the CERA injection well and the hemoglobin level stabilized 7 months later. Repeat bone marrow aspiration confirmed complete resolution of PRCA with disappearance of anti-erythropoietin antibody. To date, he maintained a stable hemoglobin level and has been transfusion-independent for the past 1 year. This is the first in the literature that reported the utilization of CERA in epoetin-induced PRCA. Very low or undetectable level of anti-erythropoietin antibody might be the key to the success of re-challenge strategy in cases of epoetininduced PRCA. Thus, routine checking of anti-erythropoietin antibody before the rechallenge with an alternative erythropoietin product is highly recommended.

A Study of Dielectric Properties of Proteinuria between 0.2 GHz and 50 GHz

This paper investigates the dielectric properties of urine in normal subjects and subjects with chronic kidney disease (CKD) at microwave frequency of between 0.2 GHz and 50 GHz. The measurements were conducted using an open-ended coaxial probe at room temperature (25°C), at 30°C and at human body temperature (37°C). There were statistically significant differences in the dielectric properties of the CKD subjects compared to those of the normal subjects. Statistically significant differences in dielectric properties were observed across the temperatures for normal subjects and CKD subjects. Pearson correlation test showed the significant correlation between proteinuria and dielectric properties. The experimental data closely matched the single-pole Debye model. The relaxation dispersion and relaxation time increased with the proteinuria level, while decreasing with the temperature. As for static conductivity, it increased with proteinuria level and temperature.

Rothia dentocariosa Repeat and Relapsing Peritoneal Dialysis-Related Peritonitis: A Case Report and Literature Review

Peritonitis is well recognized as the Achilles tendon of peritoneal dialysis (PD). Reoccurrence of peritonitis due to the same organism, defined as either repeat or relapsing peritonitis under the 2005 guidelines by the International Society for Peritoneal Dialysis, often results in PD technique failure. Rothia dentocariosa, a low-virulent human oropharynx commensal, is a rarely reported pathogen in human infection, particularly infective endocarditis. R. dentocariosa PD-related peritonitis is exceedingly uncommon yet potentially results in repeat or relapsing peritonitis which requires catheter removal. We report a case of R. dentocariosa repeat and relapsing peritonitis in a PD patient who was treated successfully with antimicrobial therapy.

Prediction of chronic kidney disease using urinary dielectric properties and support vector machine

ABSTRACT In this study, we aim to classify the urinary dielectric properties of subjects with chronic kidney disease (CKD) and normal subjects, at microwave frequency between 1 GHz and 50 GHz using support vector machine (SVM). The dielectric properties of urine were measured at room temperature (25°C), 30°C and body temperature (37°C). Urinary dielectric behaviour differences were observed between respective diabetic kidney disease (DKD) and non-DKD compared to normal subjects. Two-group classifications obtained the highest accuracy of 75.91% and 70.02%, respectively, in differentiating DKD and non-DKD group from normal group. The highest classification accuracy was achieved at 63.94% for three-group classifications. The best classification accuracies were obtained at 30°C for two-group and three-group classifications.

Grossly Delayed Graft Function in a Living Related Kidney Transplant Recipient : A Case Report

Delayed graft function is a potentially challenging problem especially in cadaveric kidney transplant recipients. It adversely impacts long-term graft survival. It is rarely seen in living kidney transplants. Recovery of graft function usually occurs within a month. The chances of recovery of graft function diminish with further prolongation of delayed function. In fact, recovery of graft function after 3 months has rarely been described, we report herein recovery of graft function after 132 days of nonfunction in a living related kidney transplant.