Predicting Progressionin IgA Nephropathy

In an effort to create a model that will predictoutcome at an early time in the disease course ofIgA nephropathy, the authors analyzed the slop ofglomerular filtration rate in relation to demo-graphic, clinical, laboratory, and pathological pa-rameters examined at baseline and during follow-up. They found that mean arterial pressure andseverity of proteinuria over time are the most im-portant prognostic indicators of IgA nephropathy.

Tonsillectomy and SteroidPulse Therapy SignificantlyImpact on Clinical Remissionin Patients With IgANephropathy

Effective therapy of IgA nephropathy remains anunrealized goal. Hotta et al examined the results ofa variety of interventions on long-term outcomesof 329 patients followed in their clinic for morethan 36 months. Forty-eight percent of the pa-tients clearedallurinaryfinding, andnoneof thesepatients developed renal failure. In contrast, pa-tients who did not have a clinical remission had a21% chance of developing a 50% rise in serumcreatinine. Positive predictors for remission in-cluded lower creatinine at entry, lower initial his-tology score, tonsillectomy, and steroid therapy.

Comparison of Cross-SectionalRenal Function Measurementsin African Americans WithHypertensive Nephrosclerosisand of Primary Formulas toEstimate GlomerularFiltration Rate

Renal function measurements were obtained in1,703 African Americans with presumed hyper-

tensive nephrosclerosis who were screened forentry in the African-American Study of Hyper-tension and Kidney Disease (AASK). For Afri-can Americans in the AASK study, glomerularfiltration rate (GFR) was overestimated by the24-hour creatinine clearance and underesti-mated by the Cockcroft-Gault formula. A predic-tion formula developed in the Modification ofDiet in Renal Disease study more accurately pre-dicted GFR in the AASK patients than the abovemeasurements.

Long-Term Treatment of FocalSegmental Glomerulosclerosisin Children With CyclosporineGiven as a Single Daily Dose

Cyclosporine (CsA) has been used successfullyto treat children with focal segmental glomeru-losclerosis (FSGS) and nephrotic syndrome, butthe long-term outcome of such treatment hasnot been fully determined. Chishti et al fol-lowed 21 children treated with low-dose, once-daily CsA for 20.6 6 13.7 months. Fifty-twopercent responded to treatment with completeremission, and 24% had partial responses. Re-currence after discontinuation of therapy re-sponded to reinstitution of CsA. Side effects wereminimal and no nephrotoxicity was noted.Single daily dose CsA appears to offer an effec-tive and minimally toxic treatment in childhoodFSGS.

Tubular Phenotypic Change inProgressive TubulointerstitialFibrosis in HumanGlomerulonephritis

This study sought to provide evidence that tubu-lar epithelial cells can undergo phenotypicchange towards a fibroblast-like cell in humanglomerulonephritis. These data, although not

AJKD October 2001THIS MONTH IN AJKD

(continued)

conclusive, provide the first support for the hy-pothesis that transdifferentiation of tubular epi-thelial cells plays a role in progressive renal fibro-sis in human glomerulonephritis.

Familial Clustering of RupturedIntracranial Aneurysms inAutosomal DominantPolycystic Kidney Disease

Ruptured intracranial aneurysm (RICA) is a rarebut feared complication in autosomal dominantpolycystic kidney disease (ADPKD). Belz et alexamined a large data base of ADPKD patientsto determine if RICA occurs randomly or exhib-its familial clustering. The data demonstrate thatvascular central nervous system events are morecommon in family members with ADPKD thanin relatives without the kidney disease and thatfamilial clustering does occur.

Survival After End-Stage RenalDisease in AutosomalDominant Polycystic KidneyDisease: Contribution ofExtrarenal Complicationsto Mortality

Although survival on dialysis of the autosomaldominant polycystic kidney disease (ADPKD)population surpasses that of the general dialysispopulation, physicians have assumed that non-renal aspects of ADPKD contribute to morbidityand mortality in excess of that resulting fromthe development of end-stage renal disease(ESRD). The authors have shown a lower totalmortality rate in ADPKD ESRD patients com-pared with nondiabetic control ESRD patients.Mortality rates of extrarenal complications ex-cept for polycystic liver disease were similar orlower in ADPKD patients than in nondiabeticcontrols. In addition, mortality secondary to ex-trarenal complications was substantially lowerthan that secondary to cardiovascular or cerebro-vascular disease.

Ne-(Carboxymethyl)lysineLevels in Patients With Type 2Diabetes: Role ofRenal Function

Advanced glycation end products (AGEs) suchas Ne2(carboxymethyl)lysine (CML) have beenimplicated in the development and progressionof diabetic nephropathy. The aim of the presentstudy was to investigate AGE levels in patientswith type 2 diabetes with special regard to therole of renal impairment. No relationship couldbe found between serum AGE levels and param-eters of blood glucose control or the presence ofischemic heart disease, diabetic retinopathy, andneuropathy.

A Placebo-Controlled Trial toEvaluate ImmunomodulatoryEffects of Paricalcitol

The results of this study indicate that the poten-tial immunoprotective effects of paricalcitol (andprobably all forms of vitamin D) therapy in pa-tients not otherwise on vitamin D therapy can-not be achieved without significantly suppress-ing parathyroid hormone (PTH) levels and bonealkaline phosphatase and increasing serum cal-cium levels. Although paricalcitol has signifi-cant effects on calcium homeostasis comparedwith placebo, patients with low PTH levels areunlikely to experience the proimmune effects ofvitamin D therapy without more profound andpotentially adverse oversuppression of PTH.

Anemia: An Early Complicationof Chronic Renal Insufficiency

The authors performed a retrospective cohortstudy to identify factors associated with severeanemia (hematocrit ,30%) and to examine ane-mia management practices in chronic renal in-sufficiency (CRI). These results demonstratethat anemia begins early in the course of CRIand management of anemia is suboptimal evenamong patients under the care of nephrologists.

(continued)

Duration of Dialysis and ItsRelationship to DialysisAdequacy, AnemiaManagement, and SerumAlbumin Level

The findings of this study underscore the impor-tance of appropriate pre–end-stage renal diseasecare in ameliorating morbidity and mortality inchronicdialysispatients, especially in thefirst yearof dialytic therapy. The authors found that pa-tients on hemodialysis therapy for less than 6months were much less likely to achieve NationalKidney Foundation-DOQI guidelines for dose ofdialysis, anemia management, and serum albuminlevels thanpatientswitha longerdurationofdialy-sis. Several actionable items, includingadministra-tion of recombinant human erythropoietin predi-alysis, correction of iron deficiency, and timelyplacement of a permanent dialysis access, can re-sult in an improvement in the percentage of pa-tients newly started on hemodialysis therapy whomeet intermediate outcomes.

Extent and Sources ofGeographic Variation inMedicare End-Stage RenalDisease Expenditures

The authors determined the extent and sourcesof geographic variation in Medicare expendi-tures per end-stage renal disease (ESRD) patientyear. Compared with Medicare generally, boththe mean and standard deviation of ESRD expen-ditures were about seven times larger. The sub-stantial geographic variability in expendituresfor ESRD patients indicates the potential forimproving efficiency and quality of care.

Role of BioimpedanceSpectroscopy in Assessment ofBody Water Compartmentsin Hemodialysis Patients

Although bioimpedance spectroscopy (BIS) is arelatively new tool to assess fluid status in hemo-dialysis (HD) patients, physicians have been un-

certain about its reliability in patients with ab-normalities in fluid status. This study concludesthat agreement between BIS and tracer dilutiontechniques in the assessment of total-body wa-ter (TBW) and extracellular volume (ECW) inHD patients is unsatisfactory. However, BIS ad-equately predicted acute changes in ECW dur-ing isolated ultrafiltration and HD, in contrastto changes in TBW.

Depression and MaritalDissatisfaction in Patients WithEnd-Stage Renal Disease andin Their Spouses

Spouses of chronically ill patients are also at riskfor both psychological distress and compromisedphysical health. Dealing with a patient’s distressmay reduce the healthy spouse’s ability to providesupport to the patient, which in turn could influ-ence the level of patient depressive affect. Danekeret al (see p. 000) suggest that the patient withend-stage renal disease functions in a complexpsychosocial dyad that may be susceptible to pos-sibly harmful depression. Married couples maybenefit from interventions directed not only at thepatient but also at the spouse.

Attitudes of Patients TowardCardiopulmonaryResuscitation in theDialysis Unit

Because dialysis patients have a marked in-crease in mortality rate, end-of-life issues as-sume singular importance to the practice of ne-phrology. Unfortunately, problems may arise infollowing patients’ wishes with regard to cardio-pulmonary resuscitation (CPR) in dialysis units.Moss et al note that some dialysis units practice“universal CPR” policies, which they remind usis unethical and illegal. In a survey of dialysispatients in three states, 87% of patients werefound to favor CPR in the event of a cardiopul-monary arrest while on dialysis, but 13% of pa-tients stated they do not wish to be resuscitatedwhile on dialysis. However, the basis for thesechoices may rest on unreasonable expectations.As a group, patients want their fellow patients

(continued)

wishes to be honored. Dialysis units must iden-tify individuals who prefer no resuscitative ef-forts and honor these wishes.

Buzz in the Axilla: A NewPhysical Sign in HemodialysisForearm Graft Evaluation

A number of techniques for the monitoring ofvascular access patency have been advanced overthe last several years. Most of these involve some-what cumbersome and relatively expensive tech-nology. Agarwal and McDougal describe a newphysical exam sign, the “buzz in the Axilla,” andcorrelate the presence or absence of axillarybuzz, thrill only distal to the midarm, and ab-sence of thrill with access blood flow measure-ment. These simple physical examination find-ings would appear to allow ready detection ofproblematic grafts and remove the need for moreexpensive testing in patients with demonstratedfindings of excellent function.

A Scanning ElectronMicroscopy Analysis of aSpontaneous HemodialysisCatheter Fracture

Theauthorsdescribe thefirstcaseofanasymptom-atic spontaneous breakdown of a tunneled cuffedsilicone catheter used for long-term hemodialysistreatment. This was discovered on removal of thecatheter, leaving behind a catheter fragment in theleft lower pulmonary lobe. An extensive scanningelectron microscopy study showed accumulationof lumps of non-silicone material at the place ofthe fracture leading to severe disruption of theoriginal cross-linked elastomer structure.

Creatinine Excretion inContinuous Peritoneal Dialysis:A Systematic Error of theCockroft-Gault Formula

To assess correctly the effectiveness of perito-neal dialysis, one must have some way to esti-mate creatinine generation. Historically, the

Cockroft-Gault equation has been used for thispurpose. Tzamaloukas and Murata questionedthe accuracy of the Cockroft-Gault calculationwith regard to the effect of aging on creatininegeneration. Measurement of actual creatininegeneration in peritoneal dialysis patients of dif-ferent ages shows that the difference betweenmeasured creatinine generation and the genera-tion rate predicted by Cockroft-Gault increasesas the age of the patient increases. The actualrate of loss of creatinine excretion with age isone half of the rate predicted by the Cockroft-Gault formula. Because of this systematic, age-related error, the authors believe that the for-mula is not suitable for prediction of creatininegeneration by peritoneal dialysis patients.

Peritoneal Dialysis Fluids Witha Physiologic pH Based onEither Lactate or BicarbonateBuffer-Effects on HumanMesothelial Cells

The buffers used in peritoneal dialysis (PD) flu-ids have an impact on overall biocompatibility.Plum et al have exposed cultured human me-sothelial cells to lactate- and biocarbonate-buff-ered PD solutions at pH 5.5 and 7.4. Cells treatedwith the bicarbonate solutions showed less im-pairment of various measures of viability andfunction, although there were no differences inapoptosis or necrosis. The authors suggest thatthere are negative effects of conventional lactate-based solutions that are not linked to low pH.

Acute Oxalate NephropathyInduced by Star Fruit in Rats

Star fruit ingestion has been linked to complica-tions during uremia and may sometimes causeacute renal failure. The origin of these problemsmay be the large amounts of oxalate in the juice.To examine the connection between star fruitingestion and acute oxalate nephropathy, Fanget al treated rats with star fruit juice and thenmonitored kidney function over the next 5 days.Under conditions of severe dehydration, starfruit produced an increase in serum creatinineand acute tubular necrosis with oxalate crystals.