Search PubMed⌕ Search

Biomedical subjects

F P Schena

Publications and source records attributed to F P Schena.

At least 19 recordsLinked to original sources

Antimicrobial agents for preventing peritonitis in peritoneal dialysis patients.

BACKGROUND: Peritoneal dialysis (PD) is used as substitutive treatment of renal function in a large proportion (15-50%) of the end-stage kidney disease (ESRD) population. The major limitation is peritonitis which leads to technique failure, hospitalisation and increased mortality. Oral, nasal, topical antibiotic prophylaxis, exit-site disinfectants and other antimicrobial interventions are used to prevent peritonitis. OBJECTIVES: The objective of this systematic review of randomised controlled trials (RCTs) was to evaluate what evidence supports the use of different antimicrobial approaches to prevent peritonitis in PD. SEARCH STRATEGY: The Cochrane CENTRAL Registry (issue 1, 2004), MEDLINE (1966-May 2003), EMBASE (1988-May 2003) and reference lists were searched for RCTs of antimicrobial agents in PD. SELECTION CRITERIA: Trials of the following agents were included: antibiotics by any route (oral, nasal, topical), exit-site disinfectants (chlorhexidine, povidone iodine, soap and water), vaccines, and ultraviolet germicidal devices. DATA COLLECTION AND ANALYSIS: Two reviewers extracted data on the number of patients with one or more episodes and rates of peritonitis and exit-site/tunnel infection, catheter removal, catheter replacement, technique failure, toxicity of antibiotic treatments, all-cause mortality. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) with 95% confidence intervals (CI). MAIN RESULTS: Nineteen trials, enrolling 1949 patients met our inclusion criteria. Nasal mupirocin compared with placebo significantly reduced the exit-site and tunnel infection rate (one trial, 2716 patient months, RR 0.58, 95% CI 0.40 to 0.85) but not peritonitis rate (one trial, 2716 patient months, RR 0.84, 95% CI 0.44 to 1.60). Perioperative intravenous antibiotics compared with no treatment significantly reduced the risk of early peritonitis (four trials, 335 patients, RR 0.35, 95% CI 0.15 to 0.80) but not exit site and tunnel infection (three trials, 114 patients, RR 0.32, 95% CI 0.02 to 4.81). No intervention reduced the risk of catheter removal or replacement. REVIEWERS' CONCLUSIONS: This review demonstrates that nasal mupirocin reduces exit-site/tunnel infection but not peritonitis. Preoperative intravenous prophylaxis reduces early peritonitis but not exit-site/tunnel infection. No other antimicrobial interventions have proven efficacy. Given the large number of patients on PD and the importance of peritonitis, the lack of adequately powered RCTs to inform decision making about strategies to prevent peritonitis is striking.

Anti-Bacterial Agents↗

Catheter type, placement and insertion techniques for preventing peritonitis in peritoneal dialysis patients.

BACKGROUND: As many as 15-50% of end-stage kidney disease patients are on peritoneal dialysis (PD), but peritonitis limits its more widespread use. Several PD catheter-related interventions have been purported to reduce the risk of peritonitis in PD. OBJECTIVES: To evaluate the use of catheter-related interventions for the prevention of peritonitis in PD. SEARCH STRATEGY: The Cochrane Renal Group's specialised register (June 2004), The Cochrane CENTRAL Register of Controlled Trials (The Cochrane Library Issue 2 2004), MEDLINE (1966-April 2004), EMBASE (1988-April 2004) and reference lists were searched without language restriction SELECTION CRITERIA: Trials comparing different catheter insertion techniques, catheter types, use of immobilisation techniques or different break in periods were included. Trials of different PD sets were excluded. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. Statistical analyses were performed using a random effects model and the results expressed as relative risk (RR) with 95% confidence intervals (CI). MAIN RESULTS: Seventeen eligible trials (1089 patients) were identified, eight of surgical strategies of catheter insertion, eight of straight versus coiled catheters, one of single cuff versus double cuff catheters and one of an immobiliser device. The methodological quality was suboptimal. There were no significant differences with laparoscopy compared with laparotomy for peritonitis, the peritonitis rate, exit-site/tunnel infection or catheter removal/replacement. Standard insertion with resting but no subcutaneous burying of the catheter versus implantation and subcutaneous burying was not associated with a significant reduction in peritonitis rate, exit-site/tunnel infection rate or all-cause mortality. Midline compared to lateral insertion showed no significant difference in the risk of peritonitis or exit-site/tunnel infection. There was no significant difference in the risk of peritonitis, peritonitis rate, exit-site/tunnel infection, exit-site/tunnel infection rate or catheter removal/replacement between straight versus coiled intraperitoneal portion catheters. One trial compared single versus double cuffed catheters and showed no significant difference in the risk of peritonitis, exit-site/tunnel infection or catheter removal/replacement. One trial compared immobilisation versus no immobilisation of the PD catheter and showed no significant difference in the risk of peritonitis and exit-site/tunnel infection. No trials of different break-in periods were identified. REVIEWERS' CONCLUSIONS: No major advantages from any of the catheter-related interventions which have been purported to reduce the risk of PD peritonitis could be demonstrated in this review. The frequency and quality of available trials are suboptimal.

Catheterization↗

Experience with cyclosporine: approaching the therapeutic window for C2 levels in maintenance kidney transplant recipients.

This study was aimed to evaluate the clinical benefit of C2 monitoring in 191 stable renal transplant patients previously monitored by C0. All patients had been transplanted for at least 1 year and received cyclosporine (CsA)-based immunosuppression since the start. At the inceptions C0 levels were significantly correlated with C2 values (P<.0001). Patients with starting C2 levels >1000 ng/mL showed significantly higher levels of serum creatinine (sCr) both at inception (1.66 +/- 0.50 vs 1.44 +/- 0.41 mg/dL; P=.0021) and at the end of a 2-year follow-up (1.84 +/- 0.80 vs 1.46 +/- 0.51 mg/dL; P=.005). C2 monitoring revealed that a high percentage of patients were overexposed to CsA, mainly in the subgroup with most recent renal engraftments (12 to 24 months). The switch to C2 monitoring was associated with a slower deterioration of graft function (P=.02). Further, the mean values of C2 over a 2-year follow-up were inversely correlated with sCr at the end of follow-up (P=.0005). Finally, patients with mean threshold C2 levels above 720 ng/mL, roughly corresponding to the median value of C2, showed significantly lower levels of sCr at the end of follow-up (P=.0004). In conclusion, C2 monitoring of maintenance renal transplant patients allows one to identify a significant percentage of overexposed subjects, possibly limiting the rate of progression of chronic graft dysfunction. Target range values between 700 and 900 ng/mL appear to be associated with better long-term kidney graft function.

Creatinine↗

Medical and surgical complications after kidney transplantation from "suboptimal donors": one centre's experience.

To overcome the organ shortage, the pool of donors can be expanded to include aged donors (>55 years old) or patients with diabetes and long-standing hypertension, the so-called "suboptimal donors." Our experience on medical and surgical complications in kidney recipients from such donors and their impact on the graft and patient survival rates is reported. From January 1998 to April 2003, 276 kidney transplantation were performed: 107 from suboptimal donors (group A) and 169 from optimal ones (group B). After a mean follow-up of 26.8 months (range, 1-63 months), the 1-year graft survival rate was 89.3% and 97% for groups A and B, respectively. Medical complications were observed in 18.8% of group A and 6% of group B and surgical complications in 34.5% and 20%, respectively. In conclusion, even if the complication rate is higher among the suboptimal donor group, the patient and graft survival rates appear to be only slightly affected, therefore, validating the use of marginal donors.

Cadaver↗

Stem cells and kidney diseases.

The role of the stem cell (SC) in physiology and physiopathology has recently attracted much interest. SCs may originate from embryos, aborted fetuses, umbilical cord blood, and adult organs and tissues. In the adult, SCs were first defined in tissues with a high cell turnover, like skin and gut. Today, SCs have also been identified in tissues with no or low regenerative potential and turnover. However, the SC concept is changing rapidly: adult SCs not only reside locally in specific niches, but may also be recruited from the circulation to actively participate in the regeneration of various tissues. Furthermore, reverse differentiation has been demonstrated. In the kidney, both glomerular and tubular cells may differentiate into a range of phenotypes during the remodelling process in response to injury. The glomerular and tubulointerstitial scarring processes involve primarily interactions between infiltrating inflammatory cells and resident renal cells that culminate in loss of renal cells and their replacement by extracellular collagenous matrix. Reverse embryogenesis is a key step in renal healing and scarring: intrinsic renal cells regress to primitive/embryonic mesenchymal phenotype. In addition, it is clear that renal remodelling in health and disease involves the migration of hematopoietic SCs into the kidneys. These cells assume various glomerular and tubular epithelial phenotypes. Therefore, a better understanding of some of these key events in renal remodelling may open the way to new interventions based on their manipulations. Cell-based therapy may be a more successful strategy by providing a dynamic and individualized therapeutic approach that responds to the physiopathological condition of the patient. In fact, SCs may provide innovative methods for drug delivery, immunotherapy, tissue regenerative or replacement engineering.

Acute Kidney Injury↗

Immunosuppressive agents for treating IgA nephropathy.

BACKGROUND: IgA nephropathy (IgAN) is a world-wide disease and the cause of end-stage renal failure (ESRF) in 15 to 20% of patients within 10 years and in 30 to 40% of individuals within 20 years from the apparent onset of disease. No specific treatment has yet been established but many approaches have been investigated. OBJECTIVES: To assess the benefits and harms of immunosuppressive treatment for IgAN. SEARCH STRATEGY: We searched The Cochrane Renal Group's specialized register (May 2003), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 3, 2002) MEDLINE (1966 - September 2002), EMBASE (1988 - September 2002) and handsearched reference lists of retrieved articles and conference proceedings. SELECTION CRITERIA: Randomized controlled trials (RCTs) and quasi-RCTs comparing treatment of IgAN with immunosuppressive agents against placebo, no treatment, other immunosuppressive or non-immunosuppressive agents. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes, with 95% confidence intervals (CI). MAIN RESULTS: Thirteen eligible RCTs involving 623 patients were identified. All identified RCTs had a placebo, no treatment or warfarin/dipyridamole control group. Seven trials used steroids, three used alkylating agents/cyclosporin and three used combinations of steroids and alkylating agents/cyclosporin. No trial directly compared steroids versus alkylating agents/cyclosporin. Quality was sub-optimal. Steroids were associated with a lower risk of progression to ESRF (RR 0.44, 95% CI 0.25 to 0.80) and lower urinary protein excretion (WMD -0.49 g/24h, 95% CI -0.72 to -0.12). Urinary protein excretion was lower for patients treated with alkylating agents/cyclosporin compared to placebo/no treatment (WMD -0.94 g/24h, 95% CI -1.43 to -0.46). There was no significant reduction of urinary protein excretion with combination treatment of steroids and alkylating agents compared with placebo/no treatment. REVIEWER'S CONCLUSIONS: The optimal management of IgAN remains uncertain. The RCTs identified were small, of sub-optimal methodological quality and tended to only report favorable and surrogate outcomes without a thorough reporting of treatment harms. All outcomes favor the use of immunosuppressive interventions, with steroids appearing to be the most promising. Further study, in the form of RCTs, is necessary to ascertain which patients would benefit from these interventions, whether they are the ones with early signs of renal dysfunction or those with more advanced renal impairment.

Glomerulonephritis, IGA↗

Haemoglobin and haematocrit targets for the anaemia of chronic renal disease.

BACKGROUND: Anaemia affects 60-80% of patients with renal impairment, reduces quality of life and is a risk factor for early death. Treatment options are blood transfusion, erythropoietin (EPO) alpha or beta and darbepoetin alfa. Recently higher haemoglobin (Hb) and haematocrit targets have been widely advocated because of positive data from observational studies. However, higher targets may lead to access thrombosis and hypertension and are costly. OBJECTIVES: This review assesses the benefits and harms of low (Hb </= 100 g/L or HCT </= 30%) and high (Hb > 100 g/L or HCT > 30%) targets in pre- and post-dialysis patients receiving any treatment for anaemia. SEARCH STRATEGY: We searched The Cochrane Renal Group specialised register (September 2002), Cochrane Controlled Trials Register (The Cochrane Library, Issue 3, 2002) MEDLINE (1966 - September 2002), EMBASE (1988 - September 2002) and reference lists of retrieved articles. SELECTION CRITERIA: Randomised controlled trials (RCTs) and quasi-RCTs comparing low Hb/HCT targets (Hb</- 100 g/L) with high Hb/HCT targets (Hb > 100 g/dL) in patients with anaemia of chronic renal disease. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes, with 95% confidence intervals (95% CI). MAIN RESULTS: Fifteen trials were identified in which 2096 patients were included. Twelve trials (673 patients) compared placebo with EPO and three trials (1423 patients) compared two doses of EPO. Hb values of 100 g/L (obtained with low EPO doses) were associated with lower mortality compared to Hb values of 140 g/L or more (obtained with high EPO doses) in the population with chronic renal disease and cardiovascular impairment (two trials, 1379 patients: RR 0.82; 95% CI 0.68 to 0.99). Lower targets obtained with a placebo resulted in an increased risk for seizures (four trials, 219 patients: RR 5.25; 95% CI 1.13 to 24.34) as compared to higher targets reached with EPO treatment. Finally, there was a reduced risk for hypertensive episodes with lower Hb targets reached with a placebo as compared to higher targets reached with EPO (six trials, 387 patients: RR 0.50; 95% CI 0.33 to 0.76). Quality of life was not adequately evaluated in the studies. REVIEWER'S CONCLUSIONS: Lower Hb targets of 100 g/L were associated with a lower risk of death in the population with cardiovascular impairment and chronic renal disease as compared to Hb 140 g/L. Lower Hb targets (Hb < 100 g/L) were also significantly associated with an increased risk for seizures and a reduced risk of hypertension compared to Hb > 100 g/L. There is a need of more adequately powered, well-designed and reported trials in this area. In particular, randomised controlled trials comparing the benefits and harms of low (Hb < 100 g/L) versus intermediate (Hb 130 g/L) and high (Hb 140 g/L) targets in the pre-dialysis population with chronic renal disease are necessary. In fact, there is a large deficiency of trials in the pre-dialysis population. The new trials should focus on hard outcomes and also look at outcomes which were previously not studied adequately, such as seizures and quality of life, which is to be assessed with validated measures.

Anemia↗

Protease-activated receptor 1 and plasminogen activator inhibitor 1 expression in chronic allograft nephropathy: the role of coagulation and fibrinolysis in renal graft fibrosis.

BACKGROUND: Chronic allograft nephropathy (CAN), the major cause of renal graft failure, frequently displays extensive interstitial fibrin deposition. Little is known in regard to the cause of the altered coagulation/fibrinolysis balance and its relevance in the pathogenesis of CAN. Thrombin, present within the fibrin clots, can interact with a specific receptor, protease-activated receptor 1 (PAR-1), and modulate a variety of cell functions. On the other hand, the derangement of the fibrinolytic system may directly affect extracellular matrix (ECM) degradation. METHODS: In the present study, we investigated, by in situ hybridization, PAR-1 gene expression and the mRNA levels for tissue factor and plasminogen activator inhibitor 1 (PAI-1), two key regulatory molecules of coagulation and fibrinolysis, in 16 CAN biopsies and in 10 normal human kidney grafts. The thrombin-induced transforming growth factor beta (TGF-beta) gene and protein expression in proximal tubular cells (PTC) was investigated by Northern blotting and ELISA, respectively. RESULTS: Fibrin deposits, absent in normal grafts, were observed in the interstitial space and arterial wall of CAN. Tissue factor gene expression was not increased either at the vascular or at the interstitial level in CAN. On the contrary, PAI-1 gene expression, barely detectable in control tissue, was strikingly increased in CAN, with a distribution resembling the pattern of fibrin deposition. Note that PAI-1 gene expression was directly correlated with the degree of interstitial fibrosis. In addition, fibrin deposits were strictly associated with a marked increase of PAR-1 gene expression in endothelial cells and PTC. The tubular expression of PAR-1 was significantly higher in Banff grade II-III than in grade I. In vitro, incubation of PTC with thrombin caused a significant up-regulation of TGF-beta gene expression, followed by an increased TGF-beta release into the supernatant. Interestingly, urine from CAN patients contained significantly higher levels of TGF-beta. CONCLUSIONS: Fibrin deposits in CAN may result from the increased expression of PAI-1 and the subsequent inhibition of fibrinolysis. The reduced fibrinolysis may cause, in turn, a decreased ECM turnover. Finally, thrombin, preserved in the active form within the fibrin clots, may interact with PAR-1 highly expressed on PTC and induce an up-regulation of ECM deposition in a TGF-beta-dependent manner.

Chronic Disease↗

ACE gene polymorphism and IgA nephropathy: an ethnically homogeneous study and a meta-analysis.

BACKGROUND: Conflicting results have implicated the angiotensin-converting enzyme (ACE) D allele in the progression of renal damage in patients with IgA nephropathy (IgAN). Most of these findings have been obtained by heterogeneous studies. METHODS: We investigated the ACE insertion/deletion (I/D) gene polymorphism by polymerase chain reaction (PCR) amplification of genomic DNA in an ethnically homogeneous sample size of IgAN patients from Southern Italy. The association between ACE I/D gene polymorphism and the development of the disease was examined in 247 biopsy-proven IgAN patients and 205 healthy subjects. The association with the progression of renal damage was evaluated in 136 patients with a follow-up of > or =3 years according to the slope of the creatinine clearance against time, and in 221 patients with a follow-up of > or =1 year assessing by univariate and multivariate analyses of renal survival. These associations were further estimated in a meta-analysis of seven studies retrieved in the Medline database. The meta-analysis was performed according to the Mantel-Haenszel-Peto method when homogeneity of the studies was established using the chi(2) test by Breslow-Day. RESULTS: No difference in the ACE I/D gene distribution between patients and controls and between patients with stable and those with deteriorating renal function was found in our study. A meta-analysis performed separately for Caucasian and Asian studies showed that the ACE I/D gene polymorphism did not contribute to the genetic susceptibility of the development of IgAN (total OR 0.93, 95% CI, 0.71 to 1.23; and 0.95, 95% CI, 0.64 to 1.42, respectively) or the progression of the renal damage (total OR 1.12, 95% CI, 0.67 to 1.88; and 2.26, 95% CI, 0.75 to 6.79, respectively) in both groups. CONCLUSIONS: Our study and meta-analysis suggest caution in the interpretation of results from association studies enrolling heterogeneous populations. Further studies using new tests, which are free of the bias due to population stratification and ethnicity, are warranted.

Adolescent↗

Immunologic evaluation during the first year of life of infants born to cyclosporine-treated female kidney transplant recipients: analysis of lymphocyte subpopulations and immunoglobulin serum levels.

BACKGROUND: In rodents, CsA has been shown to affect T-cell development, giving rise to an abnormal production of mature T cells and the absence of many T-cell subsets as well as to autoimmunity. Surprisingly, only a few studies investigated the effect of the immunosuppressive drug on the immune system of the human fetus. METHODS: We examined six infants born to female kidney transplant recipients who had received cyclosporine and methylprednisolone throughout their pregnancies. Peripheral blood was obtained 1 day and 2, 4, 6, and 12 months after birth, and two-color flow cytometric immunophenotyping of lymphocytes was performed. RESULTS: Total T cells, as well as CD4+ and CD8+ T cells, were low at birth, but normalized thereafter. Among T-cell activation markers, the expression of CD25, the alpha chain of the interleukin-2 receptor, was below the normal range or low range throughout the study period, and HLA-DR expression was extremely low at birth and failed to increase up to 12 months. The number of total B cells was lower than normal at birth, but steeply increased over time. In contrast, B-cell subset bearing CD5 antigen was severely depleted throughout the first year of life. Total IgG concentration was significantly lower than in controls at 2 months, mainly because of subnormal levels of IgG1 and IgG3 subclasses, which remained in the low range up to 6 months. Finally, infants showed normal numbers of true natural killer (NK) cells (CD3-CD16+CD56+), whereas the expression of CD57 antigen, defining non-MHC-restricted cytotoxic lymphocytes, was barely detectable at birth and failed to increase over time, in both CD8+ and CD8- subsets. Of note, none of the infants had clinical evidence of an immunodeficient state. CONCLUSIONS: continuous exposure to CsA in utero seemingly impairs T-, B-, and NK-cell development and/or maturation, and most of its effects are still apparent at 1 year, which might suggest that conventional vaccinations should be delayed in these infants.

Antigens, CD↗

Tissue factor, plasminogen activator inhibitor-1, and thrombin receptor expression in human crescentic glomerulonephritis.

Glomerular fibrin deposition is a common histological feature of crescentic glomerulonephritis (CGN). Tissue factor (TF) is the most powerful activator of the coagulation system, whereas plasminogen activator inhibitor (PAI)-1 is a key modulator of the fibrinolytic pathway. Thrombin, released locally as the final step of the coagulation cascade and trapped within the fibrin clots, can induce the activation of glomerular cells, through the interaction with a specific receptor. To investigate the mechanisms underlying coagulation cascade activation and fibrin deposition and the role of this phenomenon in the pathogenesis of human CGN, TF, PAI-1, and thrombin receptor expression were studied in CGN biopsy specimens. Glomerular TF gene and protein expression were strikingly increased in CGN, in particular within the crescents and in the mesangial area, with the same distribution of fibrin deposits. Interestingly, very few infiltrating mononuclear cells were stained in TF immunohistochemistry. To better evaluate the involvement of monocytes in TF expression, TF mRNA and CD68 protein were studied by an in situ hybridization/immunohistochemistry combined technique. Only 16% of the cells expressing TF mRNA were CD68 positive. However, most of the TF signal was localized in the proximity of monocytes, suggesting that soluble mediator(s) released by these cells could induce TF expression. Indeed, interleukin-1 (IL-1), one of the main monocyte-derived cytokines, upregulated TF mRNA levels in cultured human mesangial cells in a time-dependent manner. Moreover, a striking increase in IL-1 expression was present within the cellular crescents in CGN biopsy specimens. Finally, we observed a marked upregulation of both PAI-1 and thrombin receptor mRNA levels in CGN with a pattern resembling TF and fibrin distribution. Surprisingly, thrombin receptor protein expression was strikingly downregulated in CGN, suggesting its continuous activation and degradation. In conclusion, we can hypothesize that TF and PAI-1, mainly expressed by resident cells, may play a pivotal role in the development and preservation of fibrin deposits in CGN. In addition, thrombin, released locally and accumulated within the fibrin clots, may represent a pathogenetic mediator of crescentic lesions.

Adolescent↗

Are lipid-dependent indicators of cardiovascular risk affected by renal transplantation?

Hyperlipoproteinemia has been reported to frequently occur in kidney transplanted patients, thus possibly explaining, at least in part, the increased incidence of cardiovascular disease in this population. To evaluate the impact of renal transplantation (Tx), and related immunosuppressive therapy, on plasma lipoprotein and Lp(a) profile, we selected a cohort of kidney transplanted patients (36 M/14 F; age 33.8 + 12.0 yr, range 13-62) lacking significant causes of hyperlipidemia. All patients received a triple immunosuppressive regimen and showed a stable renal function after Tx (plasma creatinine: 1.36 +/- 0.35 mg/dL). One year after Tx, we found a significant increase of total cholesterol (TC), LDL, HDL, ApoB and ApoA-I (p < 0.005), while plasma triglyceride levels remained unmodified. Lp(a) plasma levels after Tx were within the normal range and displayed a significant inverse relationship with apo(a) size. Noteworthy, LDL/HDL ratio and ApoB/ ApoA-I ratio in kidney transplanted patients were almost superimposable with those of normal controls. Specifically, LDL/HDL ratio significantly decreased in 64% of patients after Tx, due to a prevalent increase of HDL, and was associated with a moderate amelioration of plasma TG. In a multiple linear regression model, post-Tx HDL level was significantly related to recipient's age, gender, BMI and cyclosporine (CyA) trough levels (Adj-R2 = 0.35, p = 0.0002), with gender and CyA trough levels being the better predictors of HDL. In conclusion, immunosuppressive regimens, in themselves, do not appear to significantly increase the atherogenic risk related to lipoproteins. Rather, other factors can affect the lipoprotein profile and its vascular effects in renal transplant recipients.

Adolescent↗

IgA nephropathy, the most common cause of glomerulonephritis, is linked to 6q22-23.

End-stage renal disease (ESRD) is a major public health problem, affecting 1 in 1,000 individuals and with an annual death rate of 20% despite dialysis treatment. IgA nephropathy (IgAN) is the most common form of glomerulonephritis, a principal cause of ESRD worldwide; it affects up to 1.3% of the population and its pathogenesis is unknown. Kidneys of people with IgAN show deposits of IgA-containing immune complexes with proliferation of the glomerular mesangium (Fig. 1). Typical clinical features include onset before age 40 with haematuria and proteinuria (blood and protein in the urine), and episodes of gross haematuria following mucosal infections are common; 30% of patients develop progressive renal failure. Although not generally considered a hereditary disease, striking ethnic variation in prevalence and familial clustering, along with subclinical renal abnormalities among relatives of IgAN cases, have suggested a heretofore undefined genetic component. By genome-wide analysis of linkage in 30 multiplex IgAN kindreds, we demonstrate linkage of IgAN to 6q22-23 under a dominant model of transmission with incomplete penetrance, with a lod score of 5.6 and 60% of kindreds linked. These findings for the first time indicate the existence of a locus with large effect on development of IgAN and identify the chromosomal location of this disease gene.

Chromosome Mapping↗

MCP-1 and EGF renal expression and urine excretion in human congenital obstructive nephropathy.

BACKGROUND: Obstructive nephropathy is characterized at the histologic level by tubular atrophy and interstitial monocyte infiltration. The molecular mechanisms underlying these histologic changes are still poorly defined. Epidermal growth factor (EGF) produced by tubular cells seems to play a pivotal role in the modulation of tubular cell growth, while monocyte chemotactic peptide-1 (MCP-1) is a powerful and specific chemotactic and activating factor for monocytes. METHODS: Twenty-four patients with congenital ureteropelvic junction obstruction [UPJO; 10 with recurrent urinary tract infection (UTI) and 10 with no UTI] and 15 healthy children were studied. Diagnosis was made by renal ultrasound, intravenous pielography, and MAG3 scan. Urinary samples were collected before and after surgery. In 10 patients, urine was also collected directly from the affected pelvis at the time of surgery. Urinary EGF and MCP-1 levels were measured by enzyme-linked immunosorbent assay. MCP-1 and EGF gene expression were evaluated by in situ hybridization in 15 biopsies from congenital UPJO and in 10 normal kidneys. RESULTS: In normal kidneys, there was a high expression of EGF mRNA, whereas MCP-1 mRNA was undetectable. MCP-1 gene expression was strikingly increased at the tubulointerstitial level in UPJO biopsies compared with controls and was directly correlated with the extent of monocyte infiltration. In addition, UPJO kidney sections showed a marked reduction in EGF gene expression that was directly correlated with the degree of tubular damage. EGF urine concentration was significantly reduced in UPJO when compared with control and directly correlated with its renal gene expression. On the other hand, the MCP-1 urine concentration was strikingly increased in UPJO patients. It is noteworthy that a significant and inverse correlation was observed between the MCP-1 concentration in the urine collected from the obstructed pelvis and the MAG3 clearance of the obstructed kidney (r = -0.76). The presence of recurrent UTI was associated with a significantly higher MCP-1 excretion and a slight reduction in EGF urine concentration. The surgical correction of UPJO was followed by an improvement of renal function together with a significant reduction in MCP-1 excretion and a marked increase in EGF urine concentrations. Interestingly, EGF urine concentration measured before surgery was significantly correlated with the difference between the MAG3 clearance of the obstructed kidney before and after surgery. CONCLUSIONS: MCP-1 and EGF seem to be involved in the pathogenesis of tubulointerstitial damage in congenital obstructive nephropathy, and their urine excretion may represent a powerful prognostic marker in this form of renal disease.

Adolescent↗

Renal C3 synthesis in idiopathic membranous nephropathy: correlation to urinary C5b-9 excretion.

UNLABELLED: Renal C3 synthesis in idiopathic membranous nephropathy: Correlation to urinary C5b-9 excretion. BACKGROUND: Complement activation plays a central pathogenetic role in idiopathic membranous nephropathy (IMN). Urinary excretion of C5b-9 correlates to the immunologic activity of this disease. Recently, renal cortical C3 gene expression has been described in several nephropathies. METHODS: The aim of this study was to investigate the renal C3 gene expression by in situ hybridization in IMN and to correlate it with histopathologic, pathophysiologic, and immunologic (urinary C5b-9) indices of disease activity. RESULTS: C3 was expressed in 77% of 22 renal biopsies of IMN patients, mainly at the cortical tubular and glomerular parietal epithelial cell levels. C3 protein synthesis by tubular cells was demonstrated by immunofluorescence. The intensity of C3 gene expression by both glomerular and tubulointerstitial compartments correlated with the glomerular stage of disease (P = 0. 0023 and P = 0.0214, respectively). Although no correlation was found with proteinuria, serum creatinine at renal biopsy time was strongly associated with renal C3 expression. IMN patients showed a trend of increased urinary C5b-9 levels, which correlated to C3 at the tubulointerstitial level (P = 0.0143). CONCLUSION: Renal C3 production, mainly at the tubular level, may be induced by urinary excretion of C5b-9 in IMN and may have a pathogenetic role in the tubulointerstitial damage that can be associated with this disease.

Adult↗