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SUMMARY Glomerulonephritis with organized microtubular monoclonal immunoglobulin deposits (GOMMID) and glomerulonephritis related to type I cryoglobulin are well-known but rare complications of B cell derived chronic lymphocytic leukaemia. In these disorders, monoclonal Ig have never been studied at the molecular level. We conducted a pathological and molecular analysis in a patient with chronic lymphocytic leukaemia, glomerulonephritis and a single circulating monoclonal Ig. Unusual IgG1κ kidney deposits were observed. The heavy and light chain variable region sequences of that cryoprecipitating monoclonal Ig were characterized. Light microscopy revealed glomerulonephritis typical of cryoglobulinaemia, with neutrophil and macrophage infiltration, endocapillary hyperplasia and few protein thrombi. Electron microscopic study clearly evidenced numerous subepithelial mixed granular and organized deposits with a unique microtubular organization, reminiscent of the GOMMID. The Ig molecule sequence revealed alterations of charge and hydrophobicity potentially promoting a crystal-like aggregation and the aggregation of microtubules.This description suggests that common mechanisms are involved in various forms of precipitation and/or deposition of complete Ig molecules, with a variable extent of organization and with a possible overlap between pathological patterns of either glomerulonephritis with microtubular deposits or type I cryoglobulinic glomerulonephritis. [ABSTRACT FROM AUTHOR]

Exploring AT and ATAngiotensin II Receptors in Humans The physiological effects of angiotensin II (Ang II) are mediated through specific AT and AT receptors. Tissue distribution and affinity of these receptors have been explored in binding studies, reverse transcriptase-polymerase chain reaction and in situ hybridisation. Sequencing has also demonstrated gene polymorphisms for both AT and AT receptors. Numerous potent nonpeptide antagonists of angiotensin converting enzyme or of AT receptors have been developed, thus providing a precise analysis of the physiology of the renin-angiotensin system. AT receptors are widely expressed throughout adult tissues, while AT receptors are mainly expressed in the fetus. Receptor density on the cell surface is regulated by multiple hormonal, cytokine and metabolic factors, and is thus profoundly affected by various pathological conditions, especially in the myocardium, kidney and blood vessels. To date, the precise molecular basis for these modifications has not been fully explained, although it may rely in part upon AT receptor gene polymorphisms, which could thus constitute increased risk factors for cardiovascular disease. AT and AT receptor expression is therefore influenced by both age and environmental specifications and is likely to be increased by a diet rich in salt or cholesterol, thus justifying the use of Ang II receptor antagonists in morbidity-mortality studies in high-risk patients. [ABSTRACT FROM AUTHOR]

We report two cases of acute renal failure in patients with arteriosclerosis obliterans treated by intravenous infusion of naftidrofuryl oxalate. At renal biopsy the histological lesions were identical with those found in ARF due to hyperoxaluria of other causes, revealing tubular epithelial necrosis and massive intra-tubular precipitation of calcium oxalate monohydrate (Cl) crystals. A second study was then conducted in four other patients with arteriosclerosis obliterans to evaluate serum and urinary levels of oxalate, and crystalluria during the intravenous administration of 800 mg of naftidrofuryl oxalate per day for 10 days. During the course of treatment, the serum and urinary oxalate levels were found to increase substantially, with the gradual onset of massive Cl crystalluria. These results indicate that naftidrofuryl oxalate was responsible for the acute renal failure in the first two patients. High intravenous doses of naftidrofuryl oxalate must be used cautiously, with close surveillance of renal function. [ABSTRACT FROM PUBLISHER]

Focuses on acute renal failure and hematuria in marathon runners, examining the role of glomerular bleeding in tublar injury in the risk of renal failure in runners and referencing the case report of a 46-year-old male marathon runner. Details on the symptoms the runner presented; Factors which contributed to the onset of renal failure; Information on the tests conducted on the patient; Treatment administered to the patient.

Background: IgA nephropathy (IgA-N) is the most common glomerular disease. Various genetic factors have been suspected to influence the disease, but they never have been studied in the same cohort of patients., Methods: In 125 IgA-N biopsy-proven cases, we studied by DNA techniques the allele distribution of 3 polymorphic loci: the angiotensin-converting enzyme (ACE) gene, the specific HLA-DQB1 gene and the hs1,2 enhancer of the alpha1 gene of the IgH locus. Patients were classified as progressive and non-progressive based on a creatininemia above 150 microl/ml or/and a deterioration of the clearance greater than 3 ml/min/year. We analyzed the influence of the polymorphism on the development and the progression of the disease. The control group consisted of 83 heathly subjects., Results: The frequency of HLA-DQB1*0602 was decreased in IgA-N patients (3.6% vs 10.2%, Pc = 0.04, RR = 0.36), suggesting a protective effect of this allele for IgA-N. Kaplan-Meyer analysis with the Cox-proportional hazard model revealed a shorter time between diagnosis and renal failure in patients with the B allele for the al gene hs1,2 enhancer (p = 0.04). ACE polymorphism did not influence the development or the progression of the disease., Conclusion: Genes controlling the immune response, such as HLA DQB1 and the alpha1 transcriptional enhancer gene, may influence the development and/or the progression of IgA-N nephropathy. Patients who develop an IgA-N nephropathy have a higher risk of severe evolution if they have a profile of high IgA humoral responder.

N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) is a physiological inhibitor of hematopoiesis that is maintained at stable levels in normal plasma. Its degradation in vivo and in vitro by angiotensin-converting enzyme (ACE) accounts for the high plasma concentrations of AcSDKP in patients treated with ACE inhibitors. Because ACE inhibitors can induce anemia in some patients, we measured plasma AcSDKP concentrations in 176 patients with chronic renal failure: 120 hemodialysis (HD) and 56 nondialysis (nD) patients, 39 of whom were administered ACE inhibitors. We studied the relationships between AcSDKP levels, hematologic parameters, and recombinant human erythropoietin (rHuEPO) requirements in these patients. AcSDKP levels were significantly greater in HD (10.3 +/- 3.9 pmol/mL) and nD (3.1 +/- 1.8 pmol/mL) patients not administered ACE inhibitors than controls (1.8 +/- 0.2 pmol/mL). In all patients, treatment with ACE inhibitors significantly increased these levels fourfold. HD sessions significantly decreased AcSDKP concentrations by 66% and reduced the predialysis in vitro half-life of AcSDKP (270 +/- 109 minutes) to values (182 +/- 67 minutes) not significantly different from those of controls or nD patients. Most HD patients treated with ACE inhibitors had AcSDKP levels greater than 24 pmol/mL (the greatest concentration found in other nD and HD patients). Only in this group of patients did weekly doses of rHuEPO correlate with AcSDKP levels. Our results show that renal function is essential to maintain stable AcSDKP plasma levels, and at high levels, AcSDKP acts as a uremic toxin causing partial resistance to erythropoietin and inhibiting erythropoiesis.

We studied the hs1,2 transcriptional enhancer identified downstream of the human alpha1 gene of the immunoglobulin H (IgH) locus, for which two different allelic configurations (a and b) were previously reported by Southern blotting. By using a polymerase chain reaction (PCR) method we amplified minisatellites within the hs1,2 core enhancer, with variable numbers of tandem repeats (VNTR) defining three 'PCR alleles' alpha1A, alpha1B and alpha1C (including one, two and three repeats, respectively). Five different alpha1 h1,2 genotypes were encountered in a population of 513 donors, representing 13.8, 34.5, 49.7, 1.3 and 0.6% for the AA, BB, AB, AC and BC genotypes, respectively. Luciferase assays showed that increasing the number of minisatellites increased the transcriptional strength of the alpha1 hs1,2 enhancer. Simultaneous determination of Southern blot alleles and VNTR alleles only showed a partial linkage between both types of polymorphism, altogether defining at least six different allelic forms of the 3'alpha1 region. In conclusion, the present study further demonstrates the genetic instability of the 3'alpha region, for which multiple alleles have been generated through inversions and internal deletions and/or duplications. This study also strengthens the hypothesis that the polymorphism at the IgH 3' regulatory region of the alpha1 gene could play a role in the outcome of diseases involving immunoglobulin secretion.

Background: IgA nephropathy is the most common glomerular disease. Mechanisms leading to its occurrence and controlling the evolution of the disease remain largely unknown. Various genetic factors have been found, mostly implicating immunologically relevant genes (IgH, TCR, human lymphocyte antigen, and complement loci). A regulatory region recently identified downstream, the alpha1 gene of the IgH locus, was a likely candidate for the control of IgA1 production in patients. Alleles of this region, differing by size, sequence, and orientation of the alpha1 hs1,2 transcriptional enhancer, were first identified through Southern blot hybridization., Methods: We established a polymerase chain reaction (PCR) method suitable for routine testing that amplifies minisatellites within the alpha1 hs1, 2 enhancer, with variable numbers of tandem repeats (VNTR) defining the two alleles. This assay allowed the typing of 104 patients with IgAN and 83 healthy volunteers. Results from typing of alpha1 hs1,2 alleles were compared with long-term clinical outcome in patients. Enhancer alleles were compared in a luciferase reporter gene assay., Results: The alpha1 hs1,2 alleles do not constitute a predictive factor for IgA nephropathy, since similar allelic frequencies were observed in healthy individuals and in unrelated European patients. In contrast, among patients, homozygosity for the weakest enhancer allele (AA genotype) was significantly correlated with a milder form of the disease, whereas the allele B was associated with severe evolution. The minisatellite region within the alpha1 hs1,2 enhancer carried potential transcription factor-binding sites, and its duplication increased the transcriptional strength of the alpha1 hs1, 2 allele B over that of allele A., Conclusion: Altogether, these alleles may constitute a risk factor for the prognosis of IgA nephropathy.

Objective: Several experimental and clinical studies indicate that the renin system may play a pivotal role in progressing renal disease. The combination of an angiotensin-converting enzyme inhibitor and an angiotensin receptor blocker could provide a higher degree of blockade of the renin-angiotensin system than either agent alone. Such enhanced suppression might be of benefit for patients exhibiting a progressive decline in renal function because of chronic renal disease., Methods: A pilot multinational, multicentre, randomized, active-controlled, parallel group open-label study has been conducted in a group of patients with progressive chronic renal failure (creatinine clearance 20-45 ml/min) either with or without proteinuria and hypertension. The primary aim of the study was to investigate the safety and tolerability of the combination of valsartan and benazepril. Patients were randomly assigned to one of three groups: group 1 received valsartan 160 mg once daily (n = 22); group 2 received valsartan 80 mg once daily plus benazepril 5 or 10 mg once daily (n = 42); group 3 received valsartan 160 mg once daily plus benazepril 5 or 10 mg once daily (n = 44). The study lasted for 5 weeks, and in groups 2 and 3 benazepril was added on top of valsartan after the first week of therapy with the angiotensin receptor blocker., Results: Serum creatinine increased in all three groups (mean change within a group: 11 micromol/l in group 1, P= 0.045; 9 micromol/l in group 2, P= 0.030; 15 micromol/l in group 3, P= 0.0006). Serum potassium also increased in all three groups of patients (mean change within a group: 0.28 mmol/l in group 1, P= 0.28; 0.48 mmol/l in group 2, P= 0.0008; 0.36 mmol/l in group 3, P= 0.02). After 5 weeks of treatment, the largest decrease in blood pressure was observed in group 3 (the mean change from baseline in seated diastolic blood pressure (SDBP) and seated systolic blood pressure (SSBP), respectively, were: -2.0 and -11.5 mmHg in group 1; -7.6 and -15.4 mmHg in group 2; -12.6 and -21.6 mmHg in group 3). In addition, both combination treatments resulted in the reduction of proteinuria. The total number of patients with adverse experiences were 10 (45.5%), 14 (33.3%) and 11 (25%) in groups 1,2 and 3, respectively. In six patients (5.6%) therapy was discontinued as a result of adverse experiences. Only one patient in each of the combined therapy groups withdrew from the study because of hyperkalaemia and no patients were forced to withdraw because of an increase in serum creatinine, acute renal failure or hospitalization., Conclusions: These results indicate that short-term combination of an angiotensin-converting enzyme inhibitor and an angiotensin receptor blocker is safe and well tolerated in patients with moderate chronic renal failure.

Background: On heterotopic heart graft in mice, aged 7 weeks (C3H and B57), we investigate the variations of Macrophage Colony stimulating factor serous rate. The macrophage colony stimulating factor (M-CSF) is a cytokine involved in the immune response during transplantation., Methods: Five groups were determined, group 1 with a heterotopic transplant without immunosuppressive treatment (N=24); group 2 with a heterotopic transplant and Corticoid treatment after the graft (N=29); group 3 with a heterotopic transplant and cyclosporine treatment after the graft (N=34); group 4 with an isogenic transplant (N=31) and group 5 undergoing a laparotomy (N=31). The mice are sacrificed at D4, D7, D10 or D14 and the M-CSF dosage are done by ELISA method., Results: The serous rate of M-CSF is stable in the group with an isogenic transplant or with only a laparotomy. But in the group with a heterotopic transplant the M-CSF values increase (x1.5). If we use an immunosuppressive treatment the raising of M-CSF is less important. When we have a rejection graft, the serous rate of M-CSF increases but not significantly (Mann-Whitney test)., Conclusions: We conclude M-CSF seems to be a reliable index of disorder during immune response, but is not a good marker of the rejection.

Human bone marrow stromal cells were studied for their ability to synthesize and to metabolize platelet-activating factor (PAF), a lipidic compound with potent immunoregulatory properties. When stimulated with 2 microM calcium ionophore for 60 minutes, cultures of stromal cells increased their PAF production (3.52 +/- 0.91 ng/1 x 10(6) cells) compared with controls (0.82 +/- 0.13 ng/1 x 10(6) cells). Addition of exogenous lyso PAF (100 nM) and acetyl-CoA (100 microM) during calcium ionophore stimulation did not change the PAF production. The synthesis of PAF was not influenced by the concentration of albumin in the incubation buffer. The PAF from stromal cells exhibited a hexadecyl chain at the sn-1 position of the molecule, as determined by reverse-phase HPLC. While stromal cells contained low amounts of PAF acetylhydrolase activity and did not secrete it in the culture medium, they metabolized exogenous PAF with 1-alkyl-2-acyl-glycero-phosphocholine and neutral lipids as the major metabolic products. The present results are the first to demonstrate the synthesis and metabolism of PAF by human bone marrow stromal cells. These data suggest that they might be a source of the PAF found in the human bone marrow and/or might be important in the regulation of its levels. The role of PAF on the proliferation and functions of human hematopoietic cells deserves investigation.