Urinary B-cell-activating factor of the tumour necrosis factor family (BAFF) in systemic lupus erythematosus

INTRODUCTION

We examined the clinical relevance of urinary concentrations of B-cell-activating factor of the tumour necrosis factor family (BAFF) and a proliferation-inducing ligand (APRIL) in systemic lupus erythematosus (SLE).

METHODS

We quantified urinary BAFF (uBAFF) by enzyme-linked immunosorbent assay in 85 SLE, 28 primary Sjögren syndrome (pSS), 40 immunoglobulin A nephropathy (IgAN) patients and 36 healthy controls (HCs). Urinary APRIL (uAPRIL) and monocyte chemoattractant protein 1 (uMCP-1) were also quantified. Overall and renal SLE disease activity were assessed using the Systemic Lupus Erythematosus Disease Activity Index 2000.

RESULTS

uBAFF was detected in 12% (10/85) of SLE patients, but was undetectable in HCs, IgAN and pSS patients. uBAFF was detectable in 28% (5/18) of SLE patients with active nephritis vs 5/67 (7%) of those without ( p = 0.03), and uBAFF was significantly higher in active renal patients ( p = 0.02) and more likely to be detected in patients with persistently active renal disease. In comparison, uAPRIL and uMCP-1 were detected in 32% (25/77) and 46% (22/48) of SLE patients, respectively. While no difference in proportion of samples with detectable uAPRIL was observed between SLE, HCs and IgAN patients, both uAPRIL and uMCP-1 were significantly detectable in higher proportions of patients with active renal disease.

CONCLUSIONS

uBAFF was detectable in a small but a significant proportion of SLE patients but not in other groups tested, and was higher in SLE patients with active renal disease.

Gaps and barriers in health-care provision for co-morbid diabetes and chronic kidney disease: a cross-sectional study

BACKGROUND

Patients with diabetes and chronic kidney disease (CKD) are a complex subset of the growing number of patients with diabetes, due to multi-morbidity. Gaps between recommended and received care for diabetes and chronic kidney disease (CKD) are evident despite promulgation of guidelines. Here, we document gaps in tertiary health-care, and the commonest patient-reported barriers to health-care, before exploring the association between these gaps and barriers.

METHODS

This cross-sectional study recruited patients with diabetes and CKD (eGFR < 60 mL/min/1.73 m2) across 4 large hospitals. For each patient, questionnaires were completed examining clinical data, recommended care, and patient-reported barriers limiting health-care. Descriptive statistics, subgroup analyses by CKD stage and hospital, and analyses examining the relationship between health-care gaps and barriers were performed.

RESULTS

308 patients, of mean age 66.9 (SD 11.0) years, and mostly male (69.5%) and having type 2 diabetes (88.0%), participated. 49.1% had stage 3, 24.7% stage 4 and 26.3% stage 5 CKD. Gaps between recommended versus received care were evident: 31.9% of patients had an HbA1c ≥ 8%, and 39.3% had a measured blood pressure ≥ 140/90 mmHg. The commonest barriers were poor continuity of care (49.3%), inadequate understanding/education about CKD (43.5%), and feeling unwell (42.6%). However, barriers associated with a failure to receive items of recommended care were inadequate support from family and friends, conflicting advice from and poor communication amongst specialists, the effect of co-morbidities on self-management and feeling unmotivated (all p < 0.05).

CONCLUSIONS

Barriers to health-care varied across CKD stages and hospitals. Barriers associated with a deviation from recommended care were different for different items of care, suggesting that specific interventions targeting each item of care are required.

BK Virus Associated Nephropathy, a Cause of Early Renal Allograft Dysfunction: A Single Centre Study

BACKGROUND

BK virus associated nephropathy (BKVN) is an important cause of early graft dysfunction in renal transplant recipients. The present study was carried out to determine the burden of BKVN in a single renal transplant centre in Australia.

METHOD

A retrospective analysis of de novo renal transplant recipients from 2010 to 2013 was performed to identify biopsy proven BKVN. Estimated glomerular filtration rate (eGFR) was compared at baseline, at BKVN diagnosis and 3 and 12 months postdiagnosis.

RESULT

Of the 317 de novo renal transplants recipients in the study period, 20 (6.3%) developed BKVN. The mean age was 54.8 ± 13.1 years and 13 (65%) were male. The mean time from transplant to BKVN was 8.7 ± 6.7 months with 17 (85%) diagnosed within 12 months. Four recipients each were diagnosed BKVN on 3 and 12 month surveillance biopsy. Six (30%) had normal eGFR at diagnosis. Mean eGFR at diagnosis was 38.8 ± 19.2 ml/min/1.73 m2, which was significantly lower (p < 0.01) than that at baseline (50.3 ± 16.4 ml/min/1.73 m2). eGFR improved numerically at 3 and 12 months post-diagnosis, however the difference was not significant. One patient had graft failure, 19 months after diagnosis.

CONCLUSION

BKVN generally occurs in first post-transplant year and is an important cause of early graft dysfunction. Surveillance biopsy helps in detecting subclinical BKVN.

Epidemiology and blood flow surveillance of the native arteriovenous fistula: a review of the recent literature

Vascular access placement is a key management issue for hemodialysis patients. Despite being well regarded as the access of first choice, the native arteriovenous fistula (AVF) remains underutilized in the United States. The first part of this review examines recent epidemiology studies addressing patient factors associated with the use of the synthetic arteriovenous graft as opposed to the native fistula. Female gender and older age are consistently associated with a higher frequency of graft use. Diabetes, peripheral vascular disease, and body mass index were associated with graft use in some but not all of the studies. Recent evidence also suggests an independent survival advantage for patients dialyzing via native fistulae especially for infection-related mortality. The second part reviews evidence surrounding the recommendations for blood flow surveillance of the native fistula. The hemodynamic features of the native fistula are examined and differences from synthetic grafts are highlighted. Clinical studies assessing the use of blood flow surveillance to prevent the sudden thrombosis of native fistulae are reviewed. Blood flow thresholds for further investigation are yet to be determined definitely for AVF and randomized studies should be performed to assesses the impact on AVF thrombosis rates.

Erythrocyte oxidative stress in clinical management of diabetes and its cardiovascular complications

Diabetes mellitus is a chronic disease in its own right and is also regarded as a cardiovascular risk factor as well as a cardiovascular disease, due to its ability to progress to a stage of cardiovascular co-morbidity. The pathophysiology of cardiovascular complications in diabetes is reported to involve hyperglycaemia-induced oxidative stress. The erythrocyte has an array of endogenous antioxidants involved in quenching oxidant production and the exponential chain reactions in diabetes. When the erythrocyte is oxidatively stressed, as demonstrated by depleted reduced glutathione and/or increased malondialdehyde in its cell membrane, the risk of diabetes progression and its cardiovascular sequelae, including atherosclerosis and coronary artery disease, is increased. Virtually all studies that determined erythrocyte malondialdehyde and glutathione in diabetes show consistently increased and reduced levels, respectively. Furthermore, cardiovascular complications of diabetes are reported to commence at the prediabetes stage. Current coronary artery disease screening programmes based on the presence of two or more risk factors are failing to identify those with increased risk of diabetes and cardiovascular complications, thereby limiting early interventions. Screening that includes erythrocyte oxidative stress determination may provide an additional marker for both preclinical and advanced disease. In this review, a concise description of the involvement of erythrocyte oxidative stress in diabetes mellitus and its cardiovascular sequelae is presented. Antioxidant action and interaction in the erythrocyte are also described, with emphasis on why current coronary artery disease screening markers cannot be regarded as erythrocyte oxidative stress markers.

Arterial calcification and stiffness in chronic kidney disease

1. Patients with chronic kidney disease (CKD) demonstrate a high burden of vascular disease. This vascular disease is unusual by way of a preponderance of medial calcification. Further, traditional cardiovascular risk factors fail to fully explain the high cardiovascular event rate in this population. 2. The present review examines the problem of medial calcification and arterial stiffness evident in patients with CKD and explores evidence for its existence and the potential pathological process involved. Many factors are emerging as potential culprits in this disease entity, although the specific roles of components such as fetuin-A, matrix Gla protein, osteopontin and fibroblast growth factor-23 have yet to be determined. Calcium and phosphate balance remains integral to the pathological process. 3. Pulse wave velocity has proven to be a useful tool to assess and follow arterial stiffness in CKD patients and is discussed. 4. Finally, techniques aimed at reducing or reversing arterial calcification and stiffness are discussed, with as yet no definitive answers available.

Associations of hemodialysis dose and session length with mortality risk in Australian and New Zealand patients

The optimal combination of hemodialysis (HD) dose and session length remains uncertain, and previous studies have not conclusively shown session length to be an important independent determinant of patient mortality. The objective of this study was to examine associations between HD dose and session length with mortality risk using data from the Australian and New Zealand Dialysis and Transplant Registry. Analyses were performed using a prospective inception cohort comprising all incident adult patients treated by thrice-weekly maintenance HD, who commenced renal replacement therapy with HD between 1 April 1997 and 31 March 2004. In all, 6593 patients were identified, of whom 4193 had sufficient data for multivariate analyses. HD dose (single pool fractional clearance of urea, Kt/V) and session length were included in analyses as those recorded 12 months after HD inception to reduce confounding by residual renal function. The outcome examined was patient mortality. Survival analyses included Kaplan-Meier calculations of survival and Cox regression for multivariate analyses. Covariates in Cox models included patient demographics, co-morbid medical conditions at HD inception, and HD operating parameters. After adjustment for covariates and each other, Kt/V of 1.30-1.39 and session length of 4.5-4.9 h were associated with the lowest mortality risk. There was no interaction between HD dose and session length. Thus, the optimal combination for mortality appears to be Kt/V of > or = 1.3 and session length of > or = 4.5 h. These data suggest a randomized controlled trial to test these hypotheses, and support the inclusion of criteria relating to session length in definitions of adequate HD practice.

Treatment for lupus nephritis

BACKGROUND

Lupus nephritis is the renal manifestation of systemic lupus erythematosus (SLE) - a disease mainly affecting young women with substantial morbidity and mortality. It is classified by the World Health Organization (WHO) criteria I - VI based on histology. WHO Class IV is a diffuse proliferative glomerulonephritis which has the worst prognosis without treatment, with a reported 17% five year survival in the era 1953-1969. This survival was 82% in the early 1990's and continues to improve. An important factor behind this has been the use of cytotoxics such as cyclophosphamide in addition to steroids.

OBJECTIVES

To assess the benefits and harms of different treatments in biopsy-proven proliferative lupus nephritis (LN).

SEARCH STRATEGY

We searched the Cochrane Renal Group's specialised register (January 2003), the Cochrane Central Register of Randomised Controlled Trials (CENTRAL - The Cochrane Library issue 1, 2003), MEDLINE (1966 - 31 January 2003), EMBASE (1980 - 31 January 2003) and handsearched reference lists of retrieved articles.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing treatments for PLN in both adult and paediatric patients with Class III, IV, Vc, Vd lupus nephritis were included. All treatments were considered.

DATA COLLECTION AND ANALYSIS

Data was extracted and quality assessed independently by two reviewers, with differences resolved by discussion. Dichotomous outcomes are reported as relative risk (RR) and measurements on continuous scales are reported as weighted mean differences (WMD) with 95% confidence intervals. Subgroup analysis by study quality, drug type and drug route have been performed where possible to explore reasons for heterogeneity.

MAIN RESULTS

Of 920 articles identified, 25 were RCTs suitable for inclusion, which enrolled 915 patients. The majority compared cyclophosphamide or azathioprine plus steroids versus steroids alone. Cyclophosphamide plus steroids reduced the risk of doubling of serum creatinine (RR 0.59, 95% CI 0.40 to 0.88) compared to steroids alone but had no impact on mortality (RR 0.98, 95% CI 0.53 to 1.82). The risk of ovarian failure was significantly increased (RR 2.18, 95% CI 1.10 to 4.34). Azathioprine plus steroids reduced the risk of all cause mortality compared to steroids alone (RR 0.60, 95% CI 0.36 to 0.99), but did not alter renal outcomes. Neither therapy was associated with increased risk of major infection. No benefit was found with addition of plasma exchange to cyclophosphamide or azathioprine plus steroids for mortality ( RR 0.71, 95% CI 0.50 to 1.02), doubling of serum creatinine (RR 0.17, 95% CI 0.02 to 1.26) or end-stage renal failure (RR 1.24, 95% CI 0.60 to 2.57). There was also no increased risk of major infection (RR 0.69, 95% CI 0.35 to 1.37).

REVIEWER'S CONCLUSIONS

Until future RCTs of newer agents are completed, the current use of cyclophosphamide combined with steroids remains the best option to preserve renal function in proliferative LN. The smallest effective dose and shortest duration of treatment should be used to minimise gonadal toxicity, without compromising efficacy.

Randomized, placebo-controlled trial of intramuscular vitamin B12for the treatment of hyperhomocysteinaemia in dialysis patients

BACKGROUND

Plasma homocysteine is elevated in patients with end-stage renal disease (ESRD) and is a risk factor for cardiovascular disease. Folic acid has been shown to partially reduce homocysteine levels in dialysis patients. It is not known whether vitamin B12 reduces homocysteine independent of folic acid in patients who are not vitamin B12 deficient.

AIM

To determine whether 1 mg vitamin B12 lowers homocysteine in stable, chronic, haemodialysis patients independent of folic acid.

METHODS

Twenty-eight haemodialysis patients were randomized to receive three doses of 1 mg vitamin B12 or 1 mL saline placebo in a double-blind fashion at 1-month intervals. Fasting plasma total homocysteine, folic acid, red-cell folate, vitamin B12 and haemoglobin levels were determined prior to each dose and 4 weeks after the final injection. The study was powered to detect a 30% reduction in homocysteine over the 3 months.

RESULTS

Both the two groups were well matched with respect to total homocysteine levels, folic acid, red-cell folate and vitamin B12 levels. Serum vitamin B12 levels were significantly higher in the treatment group compared to placebo (217.7 pmol/L; 95% confidence interval (CI) 103.0-332.5; P < 0.001) at the end of the trial but homocysteine levels were not significantly different (3.08 micromol/L; 95% CI -4.44-10.61; P= 0.406).

CONCLUSIONS

The administration of intramuscular vitamin B12 over a 3-month period does not result in any reduction of plasma homocysteine levels in haemo-dialysis patients independent of folate status, however reductions of <30% cannot be excluded by the present study. High-dose folic acid remains the treatment of choice in reducing homocysteine, but whether this results in a reduction in cardiovascular events remains to be determined.

Development of a capture ELISA for the detection of antibodies to enteropathogenic Escherichia coli (EPEC) in rabbit flocks using intimin-specific monoclonal antibodies

A capture enzyme-linked immunosorbent assay (cELISA) was developed using intimin-specific monoclonal antibodies to detect specific antibody in rabbits that have been in contact with enteropathogenic Escherichia coli (EPEC). Sera from 121 EPEC-negative, minimum-disease-level (MDL) rabbits were used for negative controls, and sera from 25 MDL rabbits, experimentally infected with EPEC of bio-/serotype 3-/O15, for positive controls. These were used to determine a cut-off value for a positive cELISA result. The value selected gave the test a sensitivity of 80.0% and a specificity of 98.4% on an individual level. At this value, a flock level sensitivity and specificity of 79.2 and 85.2%, respectively were calculated for a flock with a prevalence of seven per cent, if 40 animals were tested, and a minimum of two reactors were obtained. The test characteristics improve with increasing prevalence. To evaluate the diagnostic potential of the cELISA, sera from 40 to 50 slaughter rabbits per flock from 25 rabbit flocks with bacteriologically determined EPEC status were tested. The results demonstrated that this test can be a useful tool to determine the EPEC status of a rabbitry, provided that it is used at regular intervals.

Women's health issues in haemodialysis patients

OBJECTIVES

To describe reproductive health issues in women with end-stage renal disease (ESRD) treated with haemodialysis.

STUDY DESIGN

Cross-sectional survey based on structured interviews.

SETTING

Nephrology units of two major metropolitan tertiary referral hospitals in Victoria and their satellite dialysis centres between 1 November 1998 to 30 June 1999.

METHODS

Women aged 20 years or over in haemodialysis programs.

OUTCOME MEASURES

Menstrual status; prevalence of menstrual and climacteric symptoms; use of gynaecological screening; and prevalence of comorbidities that may benefit from hormone replacment therapy.

RESULTS

48 women completed the survey. They were similar to the 485 women undergoing haemodialysis in Victoria in age (mean age, 55.5 years; range, 20-84 years), years on dialysis (mean age, 3.9 years; range, 1 month-17 years) and primary diagnosis. Eleven of the 15 premenopausal women reported menstrual cycles of 22-35 days, 13 reported common premenstrual symptoms, and six reported dysmenorrhoea that interfered with daily activities. Average age at menopause was 47.7 years (95% CI, 45.6-49.9 years), and six of the 31 postmenopausal women underwent menopause before 45 years. Eight had ever been prescribed hormone replacement therapy (oral in all cases). Over half the women (26) had not had a Pap smear in the last two years, and 12 of those aged over 50 (38%) had not had a mammogram in the same period.

CONCLUSION

Despite their risk of early menopause, cardiovascular disease and bone fracture, few women undergoing haemodialysis were offered hormone replacement therapy. Nor were they adequately screened for gynaecological cancers. Women's health issues seem to be neglected among haemodialysis patients.

The antihypertensive hydralazine is an efficient scavenger of acrolein

Recent work indicates the highly toxic alpha,beta-unsaturated aldehyde acrolein is formed during the peroxidation of polyunsaturated lipids, raising the possibility that it functions as a 'toxicological second messenger' during oxidative cell injury. Acrolein reacts rapidly with proteins, forming adducts that retain carbonyl groups. Damage by this route may thus contribute to the burden of carbonylated proteins in tissues. This work evaluated several amine compounds with known aldehyde-scavenging properties for their ability to attenuate protein carbonylation by acrolein. The compounds tested were: (i) the glycoxidation inhibitors, aminoguanidine and carnosine; (ii) the antihypertensive, hydralazine; and (iii) the classic carbonyl reagent, methoxyamine. Each compound attenuated carbonylation of a model protein, bovine serum albumin, during reactions with acrolein at neutral pH and 37 degrees C. However, the most efficient agent was hydralazine, which strongly suppressed carbonylation under these conditions. Study of the rate of reaction between acrolein and the various amines in a protein-free buffered system buttressed these findings, since hydralazine reacted with acrolein at rates 2-3 times faster than its reaction with the other scavengers. Hydralazine also protected isolated mouse hepatocytes against cell killing by allyl alcohol, which undergoes in situ alcohol dehydrogenase-catalysed conversion to acrolein.

Dialyzer performance in the clinic: comparison of six low-flux membranes

The aim of this study is to assess the clinical performance of 6 different low-flux dialysis membranes under steady-state conditions in terms of urea and phosphate clearances. Ten stable hemodialysis patients were examined. The following dialyzers were studied, all in 1.5- to 1.6-m2 format: cuprammonium, cellulose acetate, cellulose diacetate, hemophane, polysulfone (low-flux), and polysynthane. The following parameters were examined: urea reduction ratio, phosphate reduction ratio, "instantaneous dialyzer clearance" for urea and phosphate, and total amount of urea and phosphate removed in the dialysate over a 1-week (three dialyses) period. Although there were differences between the membranes, all produced results within a narrow range. There was no one membrane that produced superior clearances in all categories. The cellulose acetate membrane was the least satisfactory membrane. Phosphate clearances were at best one third that of urea clearances. When choosing a low-flux dialysis membrane, urea and phosphate clearances are so similar amongst different membranes that other criteria are likely to have a greater influence on the choice of membrane.

Outcome of a screening program for vancomycin-resistant enterococci in a hospital in Victoria

OBJECTIVE

To screen for faecal colonisation with vancomycin-resistant enterococci (VRE) among potentially at-risk patients.

DESIGN

Infection control screening program.

SETTING

Monash Medical Centre (a tertiary care hospital), Melbourne, Victoria, in the seven months from June 1997.

PATIENTS

Patients in the Renal, Oncology and Intensive Care (ICU) Units.

MAIN OUTCOME MEASURES

Presence of VRE in a rectal swab or faecal specimen taken at admission and at regular intervals during inpatient stay; presence of vancomycin-resistance genes (vanA, vanB and vanC) assessed by polymerase chain reaction (PCR); genetic clonality of isolates assessed by pulsed-field gel electrophoresis (PFGE).

RESULTS

574 patients (356 renal, 134 ICU and 84 oncology) were screened; 12 were colonised with VRE--nine renal inpatients, two having peritoneal dialysis or incentre haemodialysis, and one ICU patient. Nine isolates were Enterococcus faecalis (seven positive for vanB and two negative for all three resistance genes) and three were Enterococcus faecium (all positive for vanB). Eight were high-level gentamicin resistant. PFGE suggested genetic clonality between the index isolate and five other isolates from renal patients. No specific clinical practice was associated with VRE colonisation. Attempts to clear rectal carriage with oral ampicillin/amoxycillin or bacitracin were of limited success. Although antibiotic prescribing in the Renal Unit was generally consistent with defined protocols, use of vancomycin and third-generation cephalosporins has been further restricted.

CONCLUSIONS

Renal inpatients in our institution appear most at risk of VRE colonisation (4.6% overall) and therefore of VRE infection. Routine screening, especially of potentially high-risk patients, should be considered in major Australian hospitals.

Granulomatous glomerulonephritis in intravenous drug users: a report of three cases in oxycodone addicts

Various well-documented renal lesions are associated with intravenous drug use; however, intraglomerular mesangial granulomas have not been previously described. We report three patients who developed an unusual granulomatous glomerulonephritis and interstitial nephritis after intravenous injection of oxycodone, derived from suppositories. Granulomas were seen in an intraglomerular mesangial and also interstitial location. In both sites, the granulomas were associated with filamentous material, presumably derived from a component of the suppositories. This material was periodic acid-Schiff-positive, but negative with Congo red and silver stains. Ultrastructurally, the filamentous material was seen within the mesangial granulomas and also in a subendothelial location, suggesting derivation from the circulation with subsequent transport across the basement membrane and accumulation in the mesangium, where a granulomatous reaction was elicited. All patients developed a degree of renal failure; two of the patients require hemodialysis 20 and 30 months after presentation.

Total body nitrogen predicts long-term mortality in haemodialysis patients--a single-centre experience

BACKGROUND

It has been estimated that 30-50% of adult haemodialysis patients have moderate to severe malnutrition. We have previously shown that estimation of total body nitrogen, expressed as a nitrogen index (NI) by in vivo neutron activation analysis (IVNAA) is an accurate tool for estimating total body protein in dialysis patients. It is not clear whether the nitrogen index is predictive of mortality and morbidity in dialysis patients.

METHODS

We studied the long-term predictive value of nutritional assessment by IVNAA and serum albumin on mortality and morbidity (including infection episodes requiring hospital admission, ischaemic heart disease (IHD), cerebrovascular or peripheral vascular disease (PVD). Seventy-six chronic haemodialysis patients were initially studied between 1989 and 1991, with a minimum follow-up of 5 years. The mean age of the patients was 48.3 years (range 21-76). Patients were divided into two groups, group I, n = 22, had a NI < or = 0.8 (NI < or = 0.8 represents protein malnutrition) and group II, n = 54, had a NI > 0.8.

RESULTS

Fifteen patients in group II died in the follow-up period compared to nine from group I (P < 0.05), but NI < or = 0.8 did not predict vascular or infective morbidity. Serum albumins < or = 35 g/day did predict over all mortality (P < 0.05) as well as infection episodes (P < 0.001). When patients above the age of 50 years were analysed, NI did predict mortality (P < 0.05) but serum albumin did not, while the age of> 50 itself was a strong predictor of mortality (P < 0.001).

CONCLUSION

We conclude that NI < or = 0.8 is predictive of long-term mortality. This reinforces the view that low body protein stores are predictive of increased mortality in dialysis patients and that the serum albumin is predictive of mortality because of its reflection of protein stores.

Precise quantification of dialysis using continuous sampling of spent dialysate and total dialysate volume measurement

The "gold standard" method to evaluate the mass balances achieved during dialysis for a given solute remains total dialysate collection (TDC). However, since handling over 100 liter volumes is unfeasible in our current dialysis units, alternative methods have been proposed, including urea kinetic modeling, partial dialysate collection (PDC) and more recently, monitoring of dialysate urea by on-line devices. Concerned by the complexity and costs generated by these devices, we aimed to adapt the simple "gold standard" TDC method to clinical practice by diminishing the total volumes to be handled. We describe a new system based on partial dialysate collection, the continuous spent sampling of dialysate (CSSD), and present its technical validation. Further, and for the first time, we report a long-term assessment of dialysis dosage in a dialysis clinic using both the classical PDC and the new CSSD system in a group of six stable dialysis patients who were followed for a period of three years. For the CSSD technique, spent dialysate was continuously sampled by a reversed automatic infusion pump at a rate of 10 ml/hr. The piston was automatically driven by the dialysis machine: switched on when dialysis started, off when dialysis terminated and held during the by pass periods. At the same time the number of production cycles of dialysate was monitored and the total volume of dialysate was calculated by multiplying the volume of the production chamber by the number of cycles. Urea and creatinine concentrations were measured in the syringe and the masses were obtained by multiplying this concentration by the total volume. CSSD and TDC were simultaneously performed in 20 dialysis sessions. The total mass of urea removed was calculated as 58038 and 60442 mmol/session (CSSD and TDC respectively; 3.1 +/- 1.2% variation; r = 0.99; y = 0.92x -28.9; P < 0.001). The total mass of creatinine removed was 146,941,143 and 150,071,195 mumol/session (2.2 +/- 0.9% variation; r = 0.99; y = 0.99x + 263; P < 0.001). To determine the long-term clinical use of PDC and CSSD, all the dialysis sessions monitored during three consecutive summers with PDC (during 1993 and 1994) and with CSSD (1995) in six stable dialysis patients were included. The clinical study comparing PDC and CSSD showed similar urea removal: 510 +/- 59 during the first year with PDC and 516 +/- 46 mmol/dialysis session during the third year, using CSSD. Protein catabolic rate (PCR) could be calculated from total urea removal and was 1.05 +/- 0.11 and 1.05 +/- 0.09 g/kg/day with PDC and CSSD for the same periods. PCR values were clearly more stable when calculated from the daily dialysate collections than when obtained with urea kinetic modeling performed once monthly. We found that CSSD is a simple and accurate method to monitor mass balances of urea or any other solute of clinical interest. With CSSD, dialysis efficacy can be monitored at every dialysis session without the need for bleeding a patient. As it is external to the dialysis machine, it can be attached to any type of machine with a very low cost. The sample of dialysate is easy to handle, since it is already taken in a syringe that is sent directly to the laboratory. The CSSD system is currently in routine use in our unit and has demonstrated its feasibility, low cost and high clinical interest in monitoring dialysis patients.

Myricadiol and other taraxerenes from Scaevola spinescens

Scaevola spinescens R. Br. (Goodeniaceae), a West Australian semi-arid native plant, has been found to contain a number of pentacyclic triterpenoid compounds of the taraxerene type in high yield compared with other species in which these compounds are known to occur. Isolation of these molecules, which are potential lead compounds for synthetic anti-cancer drugs, was achieved by partitioning the diethyl ether-soluble fraction, of the methanol Soxhlet extract, between hexane and aqueous methanol, followed by base extraction of minor components from the methanol isolate and recrystallisation or column chromatography. The major component isolated from the extract, and main subject of this report, is the pentacyclic triterpenoid, 14-taraxerene-3,28-diol (1; myricadiol).

Total body protein status assessed by different estimates of fat-free mass in adult peritoneal dialysis patients

OBJECTIVE

To assess the usefulness of fat-free mass (FFM) as an index of total body protein (TBPr) status in continuous ambulatory peritoneal dialysis (CAPD) patients.

DESIGN

TBPr was measured by in vivo neutron activation analysis (IVNAA) and expressed as a standardised protein index (PI). FFM was estimated by dual energy X-ray absorptiometry (DXA), whole body counting of total body potassium (TBK), and creatinine kinetics (CK), and expressed as a standardised FFM index (FFMI). FFM was also determined by a criterion method based on four compartment model (4CM) which is defined as the sum of total body water determined by D2O dilution, TBPr determined by IVNAA, bone mineral determined by DXA, and glycogen estimated to be 4.4% of TBPr. Each patient was measured within a four hour period by all methods.

SETTING

Body Composition Laboratory, Monash Medical Centre.

SUBJECTS

Six male and twelve female CAPD patients (33-77 years).

RESULTS

FFMI assessed by DXA and by TBK agreed with measurements of PI on identifying the mean TBPr status of the CAPD group as significantly below a comparable normal reference population (mean Z score: PI = -1.01 (P < 0.05); FFMI by DXA = -0.50 (P < 0.05); FFMI by TBK = -1.24 (P < 0.05)). In contrast, FFMI assessed by CK did not reveal a significantly reduced TBPr status (mean Z score: -0.70 (NS)). Furthermore, significant linear correlations were noted between PI and FFMI estimated by DXA and by TBK (r = 0.57 (P < 0.05) vs r = 0.69 (P < 0.05)) however no significant correlation was observed between PI and FFMI estimated by CK (r = 0.36 (NS)). Moderate variation in FFM hydration did not compromise the ability of DXA, TBK or CK to differentiate between protein deleted, normal and enriched patients. Comparison of FFM estimates between the criterion method and either DXA, TBK or CK revealed no significant bias (+ 1.8 kg vs -2.0 kg vs +0.8 kg) and respective SEE values of 3.8 kg (8.3%), 5.9 kg (14.3%) and 9.6 kg (21.7%).

CONCLUSION

The findings of this study indicate that FFM estimated by either DXA or the whole body counting of TBK is a useful index of TBPr status in CAPD patients. However, FFM assessed by CK does not appear to be an appropriate index of TBPr status in CAPD patients.

Assessment of the nutritional state of dialysis patients

The importance of the nutritional state of our dialysis patients has been stressed for many years. Although the calculation of the protein catabolic rate has become common practice in many dialysis units, there are several problems with this measurement. In addition, the serum albumin level is subject to multiple influences making its interpretation in individual patients difficult. This paper examines a different approach to nutritional assessment-that of using longer term measures of nutrition. Several techniques for measuring body composition are explored and their use in end-stage renal disease (ESRD) examined. Total body nitrogen measurement is a gold standard technique which has been validated in renal patients, unfortunately it is not widely available. Of the alternatives, dual energy X-ray absorptiometry scanning for assessment of fat-free mass appears to be the best technique with the narrowest limits of agreement compared to gold standard techniques. Whilst bioelectrical impedance is reasonable for body water assessment, it is not reliable in ESRD patients for lean-body mass estimation.

Dialyzer reuse: interaction between dialyzer membrane, disinfectant (formalin), and blood during dialyzer reprocessing

The growing practice of dialyzer reuse in recent years is mainly based on medical and economic considerations. However, adverse reactions such as immunohemolytic anemia due to anti-Nform antibody associated with dialyzer reuse have been reported. In this study, scanning electron microscopy and cytologic staining were used to evaluate the interaction between blood components and the reprocessed synthetic dialyzer membrane (polysulfone) after disinfectant (formaldehyde) treatment. The results showed that various blood components such as fibrin and blood cells still adhered to the dialyzer membrane after reprocessing. The study also demonstrated that the adhered denatured blood components could be detached by sonication and/or simulated hemodialysis and then gain access into the circulation. The re-entry of the denatured blood components to the patients exposed to reused dialyzers may result in an enhanced immunological response which may contribute to antibody formation (such as anti-Nform antibody) with a reused hemodialyzer.

Kt/V in CAPD by different estimations of V

This study compared the measurements of total body water (TBW) by 58% body weight (TBW58%), the Watson equation (TBWWV) and bioelectric impedance (TBWBIA) with the gold standard, Deuterium oxide (TBWD2O) dilution method in twenty continuous ambulatory peritoneal dialysis (CAPD) patients. TBW volumes were highest when calculated as TBW58% (42.6 +/- 9.4 liter) and lowest when calculated from TBWWV (34.6 +/- 6.8 liter). TBWBIA underestimated TBW when compared to TBWD2O, although the difference was not statistically significant (37.1 +/- 9.8 liter and 38.8 +/- 9.3 liter, respectively). In fact, TBWBIA correlated strongly with TBWD2O (r = 0.8, P < 0.0001). These discrepancies resulted in significant differences when Kt/V week-1 derived from the four methods were compared. To determine the effect of percent fat mass on the estimation of TBW by each method, we compared TBW and Kt/V week-1 derived from the four methods in nine CAPD patients who had normal percent fat mass (Non-Obese) and 11 CAPD patients who had greater than normal % fat mass (Obese). In the Non-Obese group, there was close correlation of TBWBIA, TBWWV and TBW58% when compared with TBWD2O (r = 0.93, P < 0.001, r = 0.89, P < 0.01 and R = 0.86, P < 0.01, respectively. Also, Kt/V week-1 derived from TBWBIA, TBWWV and TBW58% correlated strongly with Kt/V week-1 from TBWD2O (r = 0.93, P < 0.0005, r = 0.83, P < 0.01 and r = 0.8, P < 0.01, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Control of post-transplant erythrocytosis by enalapril

OBJECTIVE

To assess the erythropoietin response in patients with erythrocytosis after renal transplantation who were treated with enalapril.

PATIENTS

Fourteen patients with stable renal transplants (creatinine clearance, 74.4 +/- 24.6 mL/min) and a packed cell volume of 51% or more over six months and who had no other cause for their erythrocytosis.

METHODS

Patients were treated with enalapril for six months. Serum erythropoietin levels, creatinine clearance and packed cell volume were measured before and during the study; patients were reviewed each month.

RESULTS

All patients had erythropoietin levels inappropriate for their packed cell volume. After six months' therapy with enalapril their mean erythropoietin concentration of 21.3 +/- 5.0 U/L fell to 7.4 +/- 1.3 U/L (P < 0.02) although the concentration increased in two patients. The mean packed cell volume fell from 52.7% +/- 0.5% to 44.4% +/- 1.0% (P < 0.0001). There was no change in renal function.

CONCLUSION

Low-dose enalapril controls post-transplant erythrocytosis, at least in part, by lowering serum erythropoietin levels.

Deoxyspergualin suppresses local macrophage proliferation in rat renal allograft rejection

Deoxyspergualin (DSP) is a potent immunosuppressive drug that is able to both prevent and reverse acute allograft rejection. Although there is good evidence that DSP can inhibit T and B lymphocyte responses, the effect of this drug upon monocyte function is controversial. In the current study, substantial local proliferation of inflammatory macrophages (41.6 +/- 5.5% of ED1+ cells) within acutely rejecting rat renal allografts was identified by expression of the proliferating cell nuclear antigen. Treatment of animals with DSP not only reduced macrophage accumulation within the tissue, but it also significantly inhibited local proliferation of macrophages within the graft (26.4 +/- 5.6% of ED1+ cells, P < 0.05 vs. untreated). This appeared to be, at least in part, a direct effect of DSP upon macrophages since the drug also inhibited growth of 2 monocytic cell lines (RC-2A and U937) in vitro. However, DSP treatment had no effect upon LPS-induced monocyte IL-1 beta, TNF alpha, and IL-6 mRNA and protein production, indicating that this drug is not a general inhibitor of monocyte function. In conclusion, this study has demonstrated that local proliferation of macrophages within the kidney is a prominent feature of acute allograft rejection and that inhibition of this response is one mechanism whereby DSP exerts its potent immunosuppressive actions.

The adequacy of fragmin as a single bolus dose with reused dialyzers

Thirty-four hemodialysis patients were studied in a crossover fashion to compare the effectiveness of bolus-dose Fragmin (a low molecular weight heparin) with regular heparin usage in hemodialysis. For each anticoagulant, 3 dialyzes were studied for each patient; the first sessions involved a new dialyzer, and the subsequent sessions involved dialyzers reprocessed with peracetic acid. To assess the effectiveness of the anticoagulation regimens, the following were measured: the dialyzer fiber bundle volume and the instantaneous dialyzer clearances for urea (1 h into the second session). In addition, factor Xa levels were measured in 5 patients during the first and second sessions at 0 min, 30 min, and 4 h. Fiber bundle volumes were (in ml) 75.4 +/- 8.8, 73.0 +/- 8.9, and 73.5 +/- 7.6 on first, second, and third uses with Fragmin (p = ns); and 77.8 +/- 9.0, 73.4 +/- 8.1, and 73.8 +/- 8.1 with heparin (p < 0.001 second and third vs. first). Thus, there were no significant differences between Fragmin and heparin. Instantaneous dialyzer clearances were 165.8 +/- 12.6 ml/min with Fragmin and 163.8 +/- 9.8 with heparin (p = ns). Factor Xa levels were 0 predialysis, 0.81 +/- 0.17 U/ml at 30 min on first use, and 0.92 +/- 0.09 U/ml on second use (p = ns); they were 0.51 +/- 0.21 U/ml at 4 h on first use and 0.61 +/- 0.16 U/ml on second use (p = ns). Thus, bolus-dose Fragmin provided similar results to constant infusion heparin and is not deleteriously influenced by reprocessing dialyzers with peracetic acid.

Suppression of pulmonary injury in experimental 'Goodpasture's syndrome' by deoxyspergualin (DSP)

DSP is a potent immunosuppressive drug which can prevent allograft rejection and suppress acute rejection episodes. In this study, the ability of DSP to suppress pulmonary injury in experimental Goodpasture's syndrome was investigated. Passive accelerated anti-glomerular basement membrane (GBM) disease was induced in rats by priming with rabbit IgG, followed 5 days later by injection of rabbit anti-GBM serum (day 0). Groups of five animals were treated with DSP (5 mg/kg intraperitoneally per day) or saline (untreated) from day 0 until being killed on days 1, 7, 14 or 21. At day 1, both DSP-treated and untreated animals exhibited similar pulmonary haemorrhage, oedema, and prominent perivascular leucocyte infiltration. Untreated animals subsequently developed severe widespread pulmonary damage including granulomatous lesions and extensive fibrosis, which correlated with infiltration of macrophages and immune-activated (IL-2R+) mononuclear cells (P < 0.01). Tumour necrosis factor-alpha (TNF-alpha), a known mediator of acute lung damage, was produced by pulmonary mononuclear cells throughout the experimental course. In contrast, DSP treatment resolved pulmonary haemorrhage, prevented the appearance of granulomatous lesions, and resulted in a histologically normal lung structure by day 21. This improvement was associated with a marked suppression of macrophage infiltration (P < 0.001 versus untreated), accumulation of immune activated (IL-2R+) mononuclear cells (P < 0.01 versus untreated), and TNF-alpha production (P < 0.05 versus untreated). DSP treatment also suppressed the deposition of rat anti-rabbit IgG immunoglobulin and C3 along the alveolar basement membrane (P < 0.05 versus untreated). In conclusion, DSP suppressed pulmonary injury in accelerated anti-GBM disease by acting on the local cellular immune response and the systemic humoral immune response. Further studies are warranted to determine whether this could be a useful drug for the treatment of Goodpasture's syndrome in humans.

Cells surrounding haemodialysis-associated amyloid deposits are mainly macrophages

Dialysis-related amyloidosis is a type of amyloidosis which had beta 2-microglobulin as the major protein constituent and occurs predominantly in haemodialysis patients. Its prevalence is very high with increasing time on dialysis treatment and its pathogenesis is not completely understood. While remarkable progress has been made in the identification of the components of the deposits, there are no reports characterizing the cells surrounding the amyloid fibrils. To characterize the cellular composition of the amyloid material, specimens from seven patients treated by maintenance haemodialysis were studied with immunoperoxidase labelling using monoclonal antibodies to leukocytes (CD3, CD14, CD68, CD4, CD8, CD45). The results were very reproducible for the seven deposits assessed: Of the 182 +/- 26 leukocytes/0.2 mm2 of amyloid tissue expressing the 71.5-CD45 marker (common leukocyte), 91 +/- 6% were CD68 (KP1) positive (monocyte macrophage). No CD3-positive cells (T-cell marker) were found in six of the seven patients, with only 1.6% in the remaining one. The present study shows that although amyloidosis has classically been considered as an acellular pathology, clearly there are cells surrounding amyloid fibrils. Strikingly, these cells are almost exclusively macrophages; there are no lymphocytes or granulocytes. The putative role of macrophages in the pathogenesis of beta 2-microglobulin amyloidosis remains to be established. However, the identification and quantitation of the cells surrounding the amyloid deposits may be important for subsequent studies to elucidate amyloid pathogenesis and particularly protein-cell interactions.

Suppression of experimental crescentic glomerulonephritis by deoxyspergualin

Deoxyspergualin is an immunosuppressive drug which is effective in both preventing allograft rejection and suppressing steroid-resistant acute rejection. This study was designed to determine whether deoxyspergualin could suppress the development of rapidly progressive crescentic glomerulonephritis in antigen-primed animals. Accelerated anti-glomerular basement membrane (GBM) glomerulonephritis was induced by priming rats with rabbit immunoglobulin G (IgG), followed 5 days later by an injection of rabbit anti-rat GBM serum (day 0). Groups of five animals were treated with deoxyspergualin (5 mg/kg.day) or saline by daily ip injection from day 0 until euthanasia on days 1, 7, 14, or 21. Deoxyspergualin treatment resulted in a significant suppression of renal disease. Compared with saline-treated controls, deoxyspergualin treatment reduced proteinuria, resolved hematuria, and completely prevented a fall in creatinine clearance. Deposition of rabbit IgG along the GBM was unaffected by deoxyspergualin treatment, but glomerular deposition of rat IgG and C3 was significantly reduced from day 14 onwards, which was associated with a significant reduction of circulating rat anti-rabbit IgG. Deoxyspergualin treatment also produced a dramatic improvement in renal histology. Glomerular necrosis, fibrosis, and crescent formation were markedly suppressed, whereas tubulointerstitial lesions were completely prevented. This was associated with a marked suppression of mononuclear cell infiltration and activation. In the glomerulus, macrophage infiltration was suppressed by approximately 50%, whereas accumulation of macrophages and immune-activated (interleukin-2 receptor) T cells within the interstitium was almost completely abrogated by deoxyspergualin treatment. In conclusion, deoxyspergualin was found to be effective in suppressing the development of experimental crescentic glomerulonephritis in antigen-primed animals by acting on both the local cell-mediated response within the kidney and the systemic humoral immune response. Further work is warranted to determine whether this could be a useful drug for the treatment of human proliferative glomerulonephritis.

Calcium kinetics and the long-term effects of lowering dialysate calcium concentration

The optimal dialysate calcium (Ca) content for hemodialysis has been classically fixed at 1.75 mM. However, this dialysate Ca concentration (dCa) with its positive intradialytic Ca balance combined with the use of CaCO3 as a phosphate binder may result in hypercalcemia. To prevent or treat hypercalcemia, a decrease in dCa has been proposed. In the present study both the acute and the long-term effects of lowering dCa were assessed. Additionally, given the results obtained after one year with low dCa the effectiveness of i.v. 1 alpha vitamin D3 in lowering PTH serum levels in two groups of patients dialyzed with different dCa was also studied. (a) Ca kinetics during hemodialysis (HD) and on line hemodiafiltration (HDF) were studied in a group of nine stable patients who were sequentially treated with 1.75, 1.5 and 1.25 mM dCa. Dialysate was the same but for the dCa which was lowered stepwise. Na, K, tCa, ionized Ca (iCa), proteins, phosphate and pH were measured from blood inlet and outlet and dialysate outlet at the start, one hour, two hours and after the treatments. At the same time weight, blood pressure and heart rate were recorded. The sieving of iCa was significantly different in HDF versus HD (F = 6.73; P < 0.01); intravenous infusion of 18 liters of filtered ultrapure dialysate compensated the Ca loss due to the convective component of HDF, as iCa was similar at the blood inlet in HD and HDF in the three dCa tested (F = 2.59; NS). Intradialytic iCa kinetics measured in the blood inlet were significantly different with different dCa (P < 0.001 for 1.75 mM vs. 1.5 mm and P < 0.001 for 1.5 mM vs. 1.25 mM). A significant increase in post-dialysis iCa was observed with dCa of 1.75 and 1.5 while no modification was observed with 1.25 mM dCa. (b) Regarding long-term effects of lowering dCa, seven of the nine patients acutely studied were followed for a one year period after changing from dCa = 1.5 to dCa = 1.25 mM. A control group of six patients was maintained with dCa = 1.5 for the same period of time and with the same treatment schedule but for dCa. Total Ca, phosphate and alkaline phosphatase were assessed monthly, and phosphate binders and oral vitamin D derivative doses were adapted accordingly. Intact PTH was determined quarterly. CaCO3 oral intake was more than doubled in the low dCa group. Total Ca, phosphate and ALP were similar in both groups over the assessed year.(ABSTRACT TRUNCATED AT 400 WORDS)

A call to the international nursing community: put AIDS in developing countries on the agenda

In some African countries 10%-15% of the middle class may due during the 1990s and at the present time the human infrastructure is being eroded by HIV. Over 90% of home and community care is being supervised by nursing and midwifery personnel in some developing countries. What will happen if these carers become ill or die? Peter Kerr provided a micro view of HIV disease in developing countries in 'Health care crisis in Africa', August ANJ. In this article he discusses the macro implications for developing countries as they encounter the consequences of what is likely to be the most devastating epidemic of this century.

The effects of reprocessing high-flux polysulfone dialyzers with peroxyacetic acid on beta 2-microglobulin removal in hemodiafiltration

The reuse of dialyzers is widely practiced, especially in the United States. Despite this, the effects of reuse on the efficacy of removal of solutes and more recently proteins such as beta 2-microglobulin (beta 2M) are the subject of much debate. There is considerable evidence to suggest that reuse after cleansing and sterilizing with formalin, with or without bleach, maintains dialyzer performance. In this study, we have examined peroxyacetic acid use as the cleansing and sterilizing agent using Renatron machines. We analyzed reuse in 24 patients using polysulfone membranes in a hemodiafiltration (HDF) unit over a 2-year period. The mean maximum number of uses achieved was 20.1 +/- 0.5. Several factors considered clinically to influence the number of reuses achievable (hemoglobin, white blood cell, and platelet levels, erythrocyte sedimentation rate [ESR], and fibrinogen and total protein levels) were found not to influence the maximum number of uses obtainable. We then assessed prospectively the performance of 26 polysulfone dialyzers after peroxyacetic acid reprocessing up to 20 times, particularly with regard to their ability to remove beta 2M. We report that this combination of polysulfone membranes reprocessed with peroxyacetic acid used for HDF up to 20 times exhibits a maintained high level removal of compounds beyond a molecular weight (MW) of 12,000. Any secondary membrane formation that occurs appears not to influence the subsequent removal of beta 2M. Thus, we would recommend the use of peroxyacetic acid for reprocessing dialyzers in a safe and efficacious manner.

Two new anti-rat macrophage monoclonal antibodies

There are relatively few monoclonal antibodies (MAbs) to rat monocyte/macrophages available. We describe here 2 new such antibodies. The first, 109.2, recognizes most rat monocyte/macrophages and all polymorphs. The antigen recognized by this antibody is upregulated by 15 mins exposure to PMA (Phorbol myristate acetate) but down regulated by overnight exposure to LPS (lipopolysaccharide). It is probably an adhesion molecule and is likely to represent the rat equivalent of CD11b. The second antibody, 112.1, recognizes lysozyme in rat macrophages, particularly alveolar macrophages. In addition it also recognizes lysozyme in hen, rabbit and human macrophages. It also recognizes lysozyme in other tissues such as Paneth cells and proximal renal tubular cells.

Measurement of vascular access recirculation without contralateral venous puncture

The rate of recirculation is an important variable in calculating the correct dose of dialysis delivered to a patient. Traditionally it is calculated using blood results obtained from the arterial and venous lines and from venous puncture of the opposite arm. To avoid this venipuncture, cessation of the blood pump for 1 or 2 min was attempted to mimic the systemic circulation. This technique underestimated recirculation but was statistically correlated with the result obtained by the classical method, thus it is possible to derive a formula to obtain the recirculation value without contralateral venipuncture.

Whole blood serotonin levels are markedly elevated in patients on dialytic therapy

The normal range for whole blood serotonin levels in chronic renal failure patients has not been defined. As serotonin may be implicated in platelet abnormalities, hypo- and hypertension and itch in dialysis patients, serotonin whole blood levels were measured in a group of patients with chronic renal failure and/or who were dialysis dependent. The levels were elevated in 12 patients with moderate (mean serum creatinine 335 +/- 54 mumol/l) chronic renal failure (270 +/- 46 micrograms/l) compared to 11 normals (163 +/- 17 micrograms/l, p less than 0.05; quoted normal range less than 300 micrograms/l) but did not correlate with serum creatinine levels. There was a marked elevation in serotonin levels in dialyzed patients, including those on hemodialysis (polysulfone, n = 6, 747 +/- 234 micrograms/l; cuprophane membranes, n = 6, 708 +/- 198 micrograms/l), hemodiafiltration (n = 12, 695 +/- 130 micrograms/l) and especially peritoneal dialysis (n = 6, 1,148 +/- 162 micrograms/l). All results were significant (p less than 0.01) compared to normals and compared to the nondialyzed group (p less than 0.05). The level of serotonin decreased during hemodialysis regardless of the membrane used. There was no positive correlation of serotonin levels with pruritus or hypertension, although there was a negative correlation with systolic blood pressure. The reference range for serotonin whole blood levels needs to be broadened when considering dialyzed patients.

Deoxyspergualin inhibits cytotoxic T lymphocytes but not NK or LAK cells

Deoxyspergualin (DOSP) is a new immunosuppressive agent which probably inhibits various functions of monocytes, B cells and T cells. We examined the effects of deoxyspergualin on cellular cytotoxicity, including cytotoxic T lymphocyte (CTL) mediated killer, natural killer (NK) cell and lymphokine activated killer (LAK) cell killing. Deoxyspergualin inhibited cellular cytotoxicity generated by 7 days allo-antigenic challenge; it also inhibited cell killing if added on day 6 of this 7 day culture period. The drug did not significantly inhibit NK or LAK cell killing. The inhibitory effects of deoxyspergualin, however, were dependent on the serum used in the culture medium. Normal human serum (NHS) was associated with less inhibition than fetal calf serum (FCS). Finally, interleukin 2 (IL-2) was able to prevent the inhibitory effects of deoxyspergualin on antigen-specific cytotoxicity.

The evolution of the interstitial infiltrate in rejecting rat renal allografts: with particular reference to the production of gamma-interferon

This study aimed to examine the evolution of the leucocytic infiltrate in rat renal allografts in the first 5 days of rejection. Immunohistology was used to assess the absolute numbers of infiltrating leucocytes in the rejecting allografts. The total infiltrate approximately doubled daily from day 1 through to day 4 (370 +/- 15 total leucocytes/mm2 of tissue on day 1 vs 5055 +/- 135 on day 4, p less than 0.05 for all days) and increased only a minor degree on day 5 (5485 +/- 535 leucocytes/mm2, p = n.s.). CD4 positive cells predominated until day 3, after which time CD8 positive cells greatly outnumbered CD4 positive cells (CD4:CD8 ratio day 3 1.83 vs day 5 0.53, p less than 0.05). Gamma-interferon was positive in T cells on day 2 (73% of all T cells) and was slightly positive on day 3 (5% of all T cells) but was negative on days 4 and 5. Activation markers such as IL-2Rs increased markedly from day 3. These findings favour a pivotal role for CD4 positive cells in the early phase of rejection and suggest that the early release of lymphokines by these cells is associated with the recruitment of CD8 positive cells to the allograft and the activation of those leucocytes present.

The effects of deoxyspergualin on lymphocytes and monocytes in vivo and in vitro

It has been suggested that deoxyspergualin, a new immunosuppressant, may be immunosuppressive via a purely antimonocyte action. As this appears to be unlikely, this study examines the effect of deoxyspergualin on lymphocyte and monocyte function in vivo and in vitro. It is demonstrated that deoxyspergualin inhibits human lymphocyte proliferation in response to mitogens and allogeneic stimulation. Furthermore, it is demonstrated that this inhibition occurs no matter whether the monocytes or lymphocytes are treated with the drug. The drug appears to have a more significant effect on the lymphocyte component; rhIL-2 appears partly to overcome the deoxyspergualin-induced inhibition of lymphocyte proliferation in response to allogeneic stimulation. In a rat renal transplant model, deoxyspergualin-treated animals demonstrated a moderate interstitial infiltrate in their transplant kidneys that comprised approximately 50% each of macrophages and lymphocytes. There was significantly less activation (e.g. IL-2R expression) in the treated kidney infiltrates compared to rejected controls. Thus deoxyspergualin is an agent with immunosuppressive effects on both lymphocytes and monocytes and would appear to have more marked effects on lymphocytes.

Phenotypic definition of primed T cells in human renal allografts. Use of the CD45R marker

Immunohistological studies indicate that T cells and macrophages are the major components of human kidney allograft infiltrates. Recent work has demonstrated a division of T lymphocytes into 2 subpopulations with distinct functions on the basis of their expression of the CD45R antigen (CD45R+ "naive" and CD45R- "memory" T cells). This study analyzes CD45R expression on circulating T cells and T cells infiltrating renal allografts in patients undergoing rejection and/or cyclosporine nephrotoxicity. The percentage of circulating T cells that expressed CD45R in patients with rejecting (63 +/- 4) or stable grafts (66 +/- 3) was not different from values obtained for normal donors (62 +/- 3). In contrast, the percentage of T cells expressing CD45R infiltrating rejecting grafts was 21 +/- 2 and was not affected by the stage of rejection; in patients with CsA toxicity the value was 22 +/- 6. The reduced proportion of T cells that expressed CD45R in the allograft may reflect a change in status from the naive state due to alloantigenic stimulation (which can be demonstrated in vitro) and/or a propensity of memory T cells to enter or be retained in an allograft.