Dijana Jovanovic

Effects of Rapamycin on Active Heymann Nephritis

Background/Aim: The effects of rapamycin (RAPA) were examined in active Heymann nephritis (HN), an experimental model of human membranous nephropathy (MN). Current opinion on the therapy of MN is controversial, and medications used for its treatment have not yielded the expected results. Methods: In a two-part study, we examined the effects of RAPA (1.5 mg/kg/day) during the induction phase of HN and on the evolving disease. In both parts, control groups of immunized rats not treated with RAPA and control groups of unimmunized rats were observed and sacrificed concurrently with the treated groups. Results: During the induction phase no significant changes in proteinuria were observed in the group treated with RAPA, in comparison to those in the untreated group (p < 0.001). During the evolving disease RAPA significantly lowered proteinuria (p < 0.001). The characteristic pathohistologic changes and IgG depositions along the glomerular basement membrane were considerably diminished, and infiltration of CD8+ cells completely prevented. Conclusion: RAPA demonstrated beneficial effects on disease progression, given either in the induction phase or during evolving HN. It would be desirable to investigate the effect of RAPA on patients with MN.

Ten Years' Experience in Subtotal Parathyroidectomy of Hemodialysis Patients

Secondary hyperparathyroidism (SHP) is a frequent complication of long-term dialysis patients, and surgical parathyroidectomy remains necessary in patients resistant to medical therapy. The present paper reports single center results in subtotal parathyroidectomy, presenting diagnostic procedure, indications for parathyroidectomy, and postoperative course of metabolic and endocrine disorders. Forty-seven patients (25 males and 22 females), aged 25–60 years, regularly hemodialyzed between 3–23 years, have undergone parathyroidectomy at our Clinical Center during the last 10 years. The patients had plasma iPTH levels 8–45 times higher than the top normal limit, high values of alkaline phosphatase, calcemia on the upper normal level, and hyperphosphatemia. Radiographic changes characteristic for SHP were seen in all patients before parathyroidectomy, and the most common were subperiosteal resorptions (100%), bone cysts and periosteal neostosis (66%), and extraskeletal calcifications (98%). Enlarged parathyroid glands were seen by ultrasound in 62% of patients. All patients manifested pruritus and bone pain, 89% of them had myopathy, while other symptoms and signs were present in lower proportions. After parathyroidectomy, pruritus and myopathy reduced significantly, while pain in bones and joints remained. One patient had brown tumor at the maxillary bone that regressed gradually after parathyroidectomy. Significant decreases of phosphate and calcium levels were recorded in all but two patients on the very first postoperative day. Regular peroral and parenteral supplementations of calcium and vitamin D metabolites were used, but calcemia was not normalized until the end of the third week of the postoperative period. Serum alkaline phosphatase showed an increase after the surgery, thereupon a sudden and then slower decrease up to 1 year from the surgery. Plasma iPTH levels, checked on the 21st postoperative day, were close to the lower normal limit in all but two (4.3%) patients with persistent SHP, who required reoperation. In conclusion, subtotal parathyroidectomy was proved as a successful and safe treatment for patients with SHP resistant to medical therapy, and treatment was followed by improvement of clinical symptoms and metabolic disorders.

Effects of captopril on morphologic changes in kidney of spontaneously hypertensive rats with adriamycin nephropathy

Antihypertensive therapy has been shown to slow down the progression of chronic renal failure. Angiotensin converting enzyme inhibitors and calcium antagonists have been emphasized as the agents with the most protective effect. Our previous study showed that captopril slowed down renal function deterioration in the early course of adriamycin (ADR) nephropathy in spontaneously hypertensive rats (SHR). The present study was undertaken with the aim to examine morphologic changes associated with that slower renal function deterioration. Adult (24 weeks) female SHR were randomly divided into the following groups: the control group (n = 12) was given tap water to drink; the adriamycin (ADR) group (n = 25) was treated with ADR; the ADR-captopril (ADR-C) group (n = 27) was treated with ADR and thereafter with captopril (60 mg/kg/day). Rats were sacrificed at weeks 6, 12 and 18 and histologic analysis was semiquantitatively performed. In the control group the glomeruli exhibited only minor changes at the end of the study. In the ADR group slight glomerular mesangial hypercellularity appeared in the sixth week and progressed in focal and segmental sclerosis. Some glomeruli showed segmental proliferation and increased fibrular matrix of a tuft adherent to a fibrocellular crescents. In the ADR-C group, glomeruli with a slight increase of mesangial matrix were seen at the end of the sixth week, mesangial hypercellularity developed until the end of the sixth week, mesangial hypercellularity developed until the end of the 12th week and segmental glomerulosclerosis until the end of the study. Semiquantitative analysis revealed that the mean semiquantitative scores for mesangial expansion and glomerular sclerosis were significantly lower in ADR-C group than in ADR group throughout the study. We concluded that captopril slowed down mesangial expansion and reduced the development of glomerular sclerosis.

Cyclosporine versus azathioprine therapy in high-risk idiopathic membranous nephropathy patients: A 3-year prospective study.

There is no consensus regarding the modality of therapy for idiopathic membranous nephropathy (IMN), especially for patients who did not react to treatment with cytotoxic drugs. This study followed prospectively for 3-year IMN patients who did not react to Ponticelli protocol comparing effects of 2-year course of cyclosporine (CsA) with azathioprine (Aza) treatment both with small doses of prednisolone. Twenty-three patients were randomly assigned to receive either cyclosporine at 3mg/kg per day (10 patients) or azathioprine at 1.5 to 2mg/kg (13 patients). Both groups were comparable regarding age, sex and renal function, except for proteinuria, which was significantly greater in CsA group (P=0.003). Similar rate of remission of nephrotic syndrome (NS) have been noted at the end of treatment (80% CsA versus 93% Aza). During last year, follow-up relapses of NS were more frequent in Aza group (5 versus 1). A fall in proteinuria was recorded in both groups during treatment, but it rose significantly in Aza group (1.5g/day versus 3.1g/day, P=0.04) and remained unchanged in CsA group (3.9g/day versus 4.1g/day) after treatment cessation. Renal function deteriorated in Aza group (sCr 120.5 versus 269.8μmol/L; P<0.01) and was stable in CsA group. In conclusion, CsA and steroids may be a very important option in the management of high-risk IMN patients. Long-term treatment is necessary for achievement of full therapeutic effect. Treatment with Aza did not have long-term benefits particularly regarding renal function preservation.

Correlation of kidney size with kidney function and anthropometric parameters in healthy subjects and patients with chronic kidney diseases.

Abstract Background/Aim: Echosonography is a simple, noninvasive method of kidney visualization. The objective of this study was to compare the kidney echosonograpic characteristics with the kidney function and anthropometric characteristics in healthy subjects and patients with the chronic kidney disease (CKD). Methods: The study involved 49 patients (21 men; 46.02 ± 14.27 years) with CKD and the control group of 46 healthy persons (20 males; 45.45 ± 18.48 years). Physical examination, kidney echosonography and laboratory analyses including creatinine clearance (Ccr; 24 h and calculated by Cockroft--Gault (C--G) formula) were done in all persons. Results: There was no significant difference in age and sex between two groups but serum creatinine concentration was significantly higher (218.8 vs. 84.5 μmol/L) and Ccr significantly lower (66.44 vs. 94.20 mL/min, C--G) in patient group. The left kidney was larger in both groups, but the only significant difference was in kidney depth (p < 0.01). There was significant correlation between all measured kidney dimensions, volume, parenchymal thickness and serum creatinine concentration and Ccr (C--G) in patient group. In the controls, there was no significant correlation between the kidney size and function, but there was a significant correlation between the kidney width, depth, volume and patients’ age and anthropometric parameters. On the contrary, all analyzed parameters of kidney size, except volume, did not correlate significantly with the anthropometric parameters of patients. Conclusion: Kidney size of patients with CKD correlated significantly with kidney function, while correlation with anthropometric parameters, which is otherwise present in healthy subjects, was lost in patients with CKD.

Could the Level of Serum Albumin Be a Method for Assessing Malnutrition in Hemodialysis Patients

BACKGROUND Traditionally, serum albumin concentration has been used for assessing the nutrition status of hemodialysis patients despite evidence that the level is also affected by inflammation and many other underlying disorders frequently present in these individuals. The authors evaluated albumin as a nutrition parameter, comparing it with more specific anthropometric parameters. METHODS The study included a cohort of 271 patients. The analysis involved data obtained after patients entered the study (1994-2004). Anthropometric measurements included skinfolds, mid-arm circumference, mid-arm muscle circumference, percentage of body fat, body mass index, body height, and dry weight. Kt/V and normalized protein catabolic rate were also determined and laboratory analyses undertaken. RESULTS Serum albumin was only weakly correlated with mid-arm circumference (r = 0.12), mid-arm muscle circumference (r = 0.15), and fat-free mass (r = 0.12). Common factor analysis of nutrition parameters uncovered latent variables, but serum albumin was not associated strongly with them. The sensitivity of albumin in detecting malnutrition was 24%, with a specificity of 88% and a predictive value of 74%. Graphic analysis showed disagreement in albumin levels with percentage of body fat and mid-arm muscle circumference. CONCLUSION Serum albumin determination was shown to be a test with low sensitivity and specificity for evaluating malnutrition in hemodialysis patients. The values correlated weakly and showed graphic disagreement with anthropometric parameters. Therefore, methods that measure percentage of body fat and muscle mass should be used together or instead of serum albumin level for assessing the nutrition status of hemodialysis patients.

Analysis of factors influencing chronic renal failure progression

One of the most important characteristics of chronic renal failure (CRF) is its progression to end stage renal disease. CRF progression depends of many factors indicated in numerous experimental and clinical studies. The present study was undertaken with the aim to examine the role of sex, etiology of CRF, renal function at the beginning of the study, hypertension and protein intake on CRF progression. Ninety-two patients (47 female and 45 male) aged between 17 and 70, with various underlying kidney diseases and various degrees of CRF were followed for 8 years. CRF progression was expressed as Creatinine clearance (CCr) and reciprocal values of serum Creatinine (SCr) against time. CRF progression was slower in women than in men, but not significantly. Patients with diabetic nephropathy (b = 0.00006) and glomerulonephritis (b = 0.00005) had faster progression of CRF than patients with nephrosclerosis (b = 0.00002), tubulointerstitial nephritis (b = 0.00003) and polycystic kidney disease (b = 0.00003). The fastest progression of CRF was in patients with the lowest SCr values at the beginning of the study. Proper regulation of blood pressure was the most important factor in slowing down CRF progression, independently of kind of antihypertensive drugs. Neither angiotensin converting enzyme inhibitors (b = -0.00001) nor calcium channel blockers (b = -0.00002) showed better effects on CRF progression slowing down in comparison with other antihypertensive drugs (b = -0.00001). Low protein diet slowed down CRF progression, but not significantly. In conclusion, our retrospective study confirms that CRF progression depends on sex, underlying renal diseases and serum Creatinine levels at the beginning of the study. Good regulation of blood pressure and low protein diet can slow down CRF progression.

Nerve Conduction Studies and Prediction of Mortality in Hemodialysis Patients

Background. The electrophysiological aspects of uremic neuropathy have been studied extensively, but never for prediction of mortality. In order to assess the parameters of nerve conduction study (NCS) as predictors of mortality in hemodialysis patients, a post hoc analysis of a prospective observation study was made. Methods. We examined conventional electrophysiological parameters (motor nerve conduction velocity [MCV], terminal latency [TL], and F wave latency of the peroneal nerve, as well as sensory nerve conduction velocity [SCV] of the sural nerve) in 75 nondiabetic patients. Hemodialysis modality (bicarbonate dialysis and biocompatible membranes), Kt/V, comorbidity (ischemic heart disease and congestive heart failure), and clinical and laboratory parameters were also evaluated. Survival was analyzed using the Cox proportional hazard model. Results. SCV was significantly higher (t-test, p < 0.01) in the group of patients treated with polysulfone compared to those using cuprophane membranes. On the other hand, MCV significantly correlated with Kt/V (Pearson, r = 0.388; p < 0.01). Multivariate Cox regression revealed only MCV as a significant predictor of mortality in this group of hemodialysis patients (HR = 0.92; CI (0.86–0.99); p < 0.05). Conclusion. Only MCV was a significant mortality risk predictor among NCS parameters. This parameter correlates significantly with dialysis dose. SCV was related to the use of biocompatible membranes, indicating the complexity of polyneuropathy in dialysis patients.

Inflammatory markers as mortality predictors in continuous ambulatory peritoneal dialysis patients

Abstract Background/Aim: Besides peritonitis, the most common complication, indicators of chronic inflammation are also present in patients treated by peritoneal dialysis. The aim of this study was to analyze the predictive value of inflammatory parameters on mortality of continuous ambulatory peritoneal dialysis (CAPD) patients. Methods: Eighty-seven patients (57 males), aged from 30 to 85 [62.92 (10.61)] years who had been treated by a chronic program of CAPD for 3–113 months were analyzed. The basal period lasted 3 months with a follow-up of 30 months. Clinical parameters, dialysis adequacy and laboratory parameters including some inflammatory markers: serum amyloid-A (SAA), high sensitive C-reactive protein (hs-CRP), fibrinogen, erythrocyte sedimentation rate (ESR) and leukocytes were determined for each patient. Cox regression analysis selected the parameters of univariate and multivariate survival analysis. Results: During the follow-up period, 37 patients (42.5%) died. Univariate analysis selected the following potential mortality predictors (p < 0.10): age, months on CAPD, residual urine output, presence of cerebrovascular insult (CVI), KT/V, serum urea and albumin concentrations, SAA, hs-CRP, fibrinogen and ESR. In the multivariate survival analysis four models were created, each with a single inflammatory parameter. In all of these models, besides the age and CVI, inflammatory parameters were the most significant mortality predictors. When the inflammatory markers were analyzed altogether, multivariate analysis established that independent mortality predictors in this group of patients were: SAA, age and CVI. Conclusion: It may be concluded that in this studied group treated by CAPD, SAA was the most significant independent mortality predictor among the analyzed inflammatory markers.

Predictive value of echocardiography and its relation to Kt/V and anthropometric parameters in hemodialysis patients

Abstract Background: In order to evaluate the predictive value of echocardiograph parameters for mortality of hemodialysis patients and their relation to Kt/V and anthropometry, a prospective, single center study was analyzed post-hoc. Methods: This analysis encompassed 106 patients on maintenance hemodialysis monitored for 108 months from 1996 to 2004. spKt/V was calculated using the Daugirdas formula. Anthropometric measurements included mid-arm muscle measurements (MAMC) and percentage of body fat (%fat). Echocardiography included the estimations of left ventricular wall thickness, dimensions and volumes (EDV, ESV), systolic LV function (ejection fraction - EFLV, fractional shortening - VCF, stroke volume - SV) and diastolic LV function (E/A, VTI-A wave of transmitral flow velocity), left atrial diameter, as well as assessment of clinical and biochemical parameters. The Cox proportional hazard model was used to estimate predictive values of echocardiograph parameters. Results: Kt/V correlated significantly with left ventricular systolic and diastolic volumes and function, septal and posterior wall thickness and left atrium dimension. MAMC and %fat also correlated with many echocardiograph parameters. Multivariate Cox regression selected age [HR 1.07; CI (1.03–1.12); p < 0.01], albumin [HR 0.88; CI (0.79–0.97); p < 0.05] and left atrium dimension – binary [values > 4 cm were marked as “1” and others “0” – HR 3.76; CI (1.56–9.03); p < 0.01] as independent predictors of death. Conclusion: Left atrium dimension was the most important predictor of mortality among the echocardiograph parameters. Many of these parameters were related to Kt/V and anthropometric measurements and could be the combined consequence of hypervolemia and hypertension.