Differential regulation of chemokine receptors during dendritic cell maturation: a model for their trafficking properties

Upon exposure to immune or inflammatory stimuli, dendritic cells (DC) migrate from peripheral tissues to lymphoid organs, where they present Ag. CC chemokines induce chemotactic and transendothelial migration of immature DC, in vitro. Maturation of DC by CD40L, or by LPS, IL-1, and TNF, induces down-regulation of the two main CC chemokine receptors expressed by these cells, CCR1 and CCRS, and abrogates chemotaxis to their ligands. Inhibition was rapid (<1 h) and included the unrelated agent FMLP. Concomitantly, the expression of CCR7 and the migration to its ligand EBI1 ligand chemokine (ELC)/macrophage inflammatory protein (MIP)-3beta, a chemokine expressed in lymphoid organs, were strongly up-regulated, though with slower kinetics (24-48 h). Rapid inhibition of responsiveness to chemoattractants present at sites of inflammation and immune reaction may be permissive for leaving peripheral tissues. Conversely, the slower acquisition of responsiveness to ELC/MIP-3beta may guide subsequent localization of DC in lymphoid organs.

Transforming growth factor-beta, endothelin-1, and c-fos expression in necrotizing/crescentic IgA glomerulonephritis

BACKGROUND

Among our cases of IgA glomerulonephritis (IgAGN), 10% show necrotizing/extracapillary lesions involving a small percentage of glomeruli and associated with a certain degree of inflammation in absence of glomerular and interstitial scarring. In our experience, also in repeat biopsies, these cases of IgAGN have a worse prognosis probably because necrotizing/extracapillary lesions can repeat and accumulate, leading to the progression of damage. As it is well known that transforming growth factor-beta (TGF-beta) and endothelin-1 (ET-1) are key-factors in the progression of glomerulonephritis, aim of the study was to examine their expression in renal biopsies of primary IgAGN with necrotizing/crescentic lesions in complete absence of interstitial fibrosis. To obtain information about the mitogenic effect of ET-1, the expression of c-fos, whose upregulation by ET-1 has been established in culture, was also studied.

METHODS

Eighteen renal biopsies of patients with necrotizing/crescentic IgAGN were examined by immunohistochemistry with antibodies against TGF-beta, ET-1 and c-fos. The results were compared with those obtained on 22 cases of IgAGN characterized only by pure mesangial proliferation and 25 IgAGN biopsies with advanced, not active, glomerulointerstitial lesions.

RESULTS

In necrotizing/crescentic IgAGN glomerular TGF-beta appeared more positive than in cases characterized only by pure mesangial proliferation and was especially expressed on cellular crescents. In the interstitium, TGF-beta, ET-1 and c-fos were expressed by infiltrating leukocytes, tubules, and small vessels. This positivity, although similar as localization, was less diffuse than in biopsies with advanced interstitial damage, but significantly greater than in cases with pure mesangial proliferation.

CONCLUSIONS

Positivity of TGF-beta on cellular crescents is similar to that observed from other authors in different types of necrotizing/crescentic human glomerulonephritis and supports our hypothesis that this is a peculiar type of IgAGN. Moreover, interstitial expression of TGF-beta, ET-1 and c-fos in biopsies with glomerular active lesions but complete absence of interstitial fibrosis may potentially represent a signal of activation of mechanisms that induce and amplify the damage leading to further progression of the disease.

[Laparoalloplasty by the Rives' technique for the treatment of large ventral hernias. Ten-year experience]

The problems of the surgery of bulky laparoceles began to find concrete solutions with the introduction of materials of synthesis that can be used to reinforce or to substitute the abdominal wall. Despite that, the ideal prosthesis has still not been found, the Dacron (Mersilene), the Polypropylene (Marlex, Prolene) and PTFE (Goretex) are today considered the best materials for the alloplasty. The authors describe their experience in matter of bulky laparocels treated with the technique of Rives. 49 patients have been operated, using Dacron in 44 cases and Polypropylene in 5. They had no mortality and no relapse, while the most frequent complication was 6 seromas, all resolved with conservative therapy. In their series 3 infections of the subcuticular occurred more of which required the removal of the prosthesis.

Adhesion, transendothelial migration, and reverse transmigration of in vitro cultured dendritic cells

Dendritic cells (DC) are migratory cells which exhibit complex trafficking properties in vivo, involving interaction with vascular and lymphatic endothelium and extracellular matrix (ECM). The underlying mechanisms involved in these processes are still ill defined. In the present study we have investigated the ability of DC to interact in vitro with human vascular endothelial cells (EC) and ECM. DC were differentiated from monocytes by in vitro exposure to granulocyte-macrophage colony-stimulating factor and interleukin-13 for 7 days. In adhesion assays a considerable proportion of DC bound to resting EC monolayers: (17% +/- 4%, mean +/- SE of eight experiments). Adhesion to tumor necrosis factor (TNF)-activated EC was increased to 29% +/- 5% (n = 8). Binding to resting EC was strongly inhibited by anti-CD11a and CD11b, but not by CD11c monoclonal antibodies (MoAbs); on TNF-activated EC, anti-VLA-4 in concert with anti-CD18 inhibited adhesion by more than 70%. Binding to a natural ECM, derived from cultured EC, or to purified fibronectin was high: 52% +/- 6% (n = 8) involved VLA-4 and VLA-5 integrins. In a transmigration assay, 10% +/- 2% (n = 6) of input cells were able to cross the EC monolayer. Unlike adhesion, transendothelial migration was significantly reduced by anti-CD31 MoAb. The amount of DC transmigrated through a monolayer of EC was increased twofold to threefold by a defined set of C-C chemokines including RANTES, MIP1alpha, MIP5, and, to a lesser extent, by MIP1beta and MCP-3. Most importantly, in view of the trafficking pattern of these cells, a significant proportion of DC (13% +/- 4% of input cells seeded) was able to migrate across the endothelial basement membrane and, subsequently, across the endothelial barrier (reverse transmigration). The adhesion molecules and chemoattractants characterized herein are likely to underlie the complex trafficking of DC in vivo.

Electron microscopy study of genesis and dynamics of immunodeposition in IgMk-IgG cryoglobulin-induced glomerulonephritis in mice

Cryoglobulinemic glomerulonephritis is particularly frequent in type II mixed IgMk-IgG cryoglobulinemia. The typical form is a membranoproliferative glomerulonephritis with a particular monocyte infiltration. In the most severe cases, there is occlusion of the capillary lumina by the same immunoglobulin constituents of the cryoprecipitate. While it is generally accepted that the "hyaline thrombi" are endoluminal aggregates of IgG-IgM immune complexes, probably favored by high endocapillary concentration of cryoglobulins, the modality of generation has not been studied. To study the dynamic formation of such "thrombi," we reproduced an experimental model of cryoglobulinemic glomerulonephritis in mice by injecting them twice a day for 3 days with 4 mg human IgMk-IgG cryoglobulins previously solubilized at 37 degrees C. The dynamic formation of immunodeposits was studied by immunofluorescence and electron microscopy. After 1 day, only mesangial deposits were found; after 3 days, in addition to mesangial deposition, all the capillary lumina were occluded by huge electron-dense bodies. To look for and quantify the contacts between such "thrombi" and mesangial or subendothelial deposits, we obtained serial, ultrathin, 0.5-microm sections that allowed us to reconstruct the whole glomerular tuft. Within each serial section, there was continuity between hyaline thrombi and mesangial or subendothelial deposits ranging from 80% to 85% of the capillary loops. The percentage was 100% for two adjacent serial sections. In conclusion, our data demonstrate directly for the first time that hyaline thrombi follow mesangial deposits. The high percentage of contacts between thrombi and mesangial or subendothelial deposits suggests that they result from in situ build-up of true huge endoluminal immunodeposits after saturation of the clearance capacity of the mesangium.

Comparison between two prospective studies of cardiovascular disease carried out amongst renal replacement patients in UK and Italy

The data on 256 non-diabetic patients entering renal replacement therapy (RRT) in Manchester between 1 January 1983 and 31 December 1986 were compared with those on 84 non-diabetic patients entering RRT in Milan between 1 January 1983 and 31 December 1988. In each unit, patients had been studied prospectively and the findings were entered on the same database for this report. At the end of the study, 68% of patients were alive in each centre and in each 16% had died from cardiovascular disease. 11% of Manchester and 18% of the Milan patients developed angina. The data do not support the view that there is a differential risk for cardiovascular disease in the Northern and Southern parts of Europe and it may be advisable to study the matter prospectively in a larger patient cohort.

Human monocyte-derived and CD34+ cell-derived dendritic cells express functional receptors for platelet activating factor

Dendritic cells (DC) are a heterogeneous population of specialized antigen presenting cells that exhibit complex trafficking properties. DC differentiated in vitro from both peripheral monocytes and CD34+ cells expressed mRNA for platelet activating factor (PAF) receptor. Expression of PAF receptor was increased by TNF alpha, a prototypic inflammatory cytokine that induces differentiation and in vivo mobilization of DC. PAF induced in vitro directional migration of DC obtained from both precursor cells through its specific receptor. Since DC are highly motile cells, protein chemoattractants as well as bioactive phospholipids are likely to contribute to tissue localization of DC, in vivo.

Characterization of proteinuria in primary glomerulonephritides: urinary polymers of albumin

In 142 patients with primary glomerulonephritis (GN), there were polymers of albumin (PAs) in the urine samples of 87% of 15 minimal-change disease (MCD) patients, 52% of 27 focal segmental glomerulosclerosis (FSGS) patients, 51% of 47 membranous glomerulonephritis (MGN) patients, 55% of 20 membranoproliferative glomerulonephritis (MPGN) patients, and 9% of 33 immunoglobulin A nephropathy (IgAN) patients (P = 0.000). In IgAN, only three patients with nephrotic syndrome were PA positive. The PAs were significantly correlated with nephrotic syndrome (NS) (P = 0.000) and with the degree of proteinuria, ranging from 8% in patients with proteinuria less than 0.5 g/d to 58% in patients with proteinuria > or = 15.0 g/d (P = 0.001), but 40% of the nephrotic syndrome patients were PA-negative despite values of proteinuria comparable to those of PA-positive patients, suggesting that the presence of PAs is not simply related to protein loss, but probably to some other unidentified factor or lesion. For 72 patients (43 with NS) (22 FSGS, 36 MGN, and 14 MPGN patients) with normal renal function at entry (serum creatinine, 1.02 +/- 0.23 mg/dL) and a mean follow-up duration of 52 +/- 27 months, for whom PAs were determined and urinary protein characterized by sodium-dodecyl-sulphate polyacrylamide gel electrophoresis (SDS-PAGE) at the beginning of the follow-up period, the functional outcome was correlated with the patterns of proteinuria. Chronic renal failure (CRF) developed in 24% of all 72 patients, in 36% of the PA-positive patients, in 9% of the PA-negative patients (P = 0.007), in 44% of the SDS-PAGE 10-kd mixed glomerulotubular pattern patients, and in 17% of the SDS-PAGE 23-kd mixed-pattern patients (P = 0.001). The association of PAs with the 10-kd pattern enhanced the predictive value for CRF outcome: CRF developed in 62% of the PA-positive patients with the 10-kd pattern compared with 11% of the PA-negative patients with the 23-kd pattern (P = 0.0001). CRF developed in 32% of 43 patients with the nephrotic syndrome, in 48% of the PA-positive patients, and in 11% of the PA-negative patients (P = 0.037); in 50% of the 10-kd patients and in 24% of the 23-kd patients (P = 0.007); and in 70% of the PA-positive patients with the 10-kd pattern and 14% of the PA-negative patients with the 23-kd pattern (P = 0.001). In a retrospective study of 21 treated patients (11 FSGS, nine MGN, and one MPGN patient), a response to therapy with complete or partial remission was observed in 57% of all 21 patients; in 58% of patients with the nephrotic syndrome; in 88% of the PA-negative patients versus 38% of the PA-positive patients (P = 0.027); in 90% of the 23-kd patients versus 27% of the 10-kd patients (P = 0.004); and in 100% of the PA-negative patients with the 23-kd pattern versus 12% of the PA-positive patients with the 10-kd pattern (P = 0.001). In conclusion, urinary PAs are associated with GN characterized by lesions mainly localized in the glomerular capillary wall, with the presence of the nephrotic syndrome, and with the degree of proteinuria. In patients with FSGS, MGN, MPGN, and normal renal function at entry, the presence of polymers has a predictive value for CRF outcome; this value is enhanced by the contemporaneous presence of an SDS-PAGE proteinuric pattern with low molecular weight proteins up to 10-kd, which is known to be associated with diffuse tubulointerstitial lesions. Therefore, the best predictive value for either CRF outcome or for response to therapy was provided by a combination between a marker associated with the degree of proteinuria and the types of GN characterized by lesions mainly localized in the glomerular capillary wall and a marker associated with tubulointerstitial damage (SDS-PAGE mixed glomerulotubular pattern with low molecular weight proteins between 20 and 10 kd).

Characterization of nephropathy induced by immunization with high molecular weight dextran

BACKGROUND

Injection of DEAE dextran into Lewis rats can produce proteinuria and has been reported as a model of IgA nephropathy.

METHODS

Cationic diethyl aminoethyl (DEAE) dextran of molecular weight 500 kDa was injected into male Lewis rats. After a pre-immunization period of 3 weeks, the animals were divided into two groups: group 1 (n = 14) received daily i.v, injections of 3.5 mg of antigen, group 2 (n = 14) was injected with 1.5 mg three times per week for a total period of 6 weeks. I.v. treatment was initiated with gradually increasing doses of DEAE dextran in both groups for 1 week, after which the maintenance dose was reached.

RESULTS

We observed the appearance of proteinuria in a nephrotic range after 5 weeks of i.v. injections in group 1 (urinary excretion: 332 +/- 83 mg/24 h, controls: 53 +/- 14 mg/24 h). In group 2, the proteinuria was almost equal to protein excretion of healthy rats of the same weight (67 +/- 20 mg/24 h). The serum and urine creatinine were normal. By light microscopy of kidney biopsies, the presence of focal and segmental proliferation of mesangial cells after 6 weeks of i.v. injections was identified. Immunohistochemistry revealed no deposition of IgA, IgM, IgG, or C3. Using anti-ED1 antibodies, there was no evidence of interstitial infiltration of monocytes/macrophages after 6 weeks of i.v. injections. Staining for proliferating cell nuclear antigen (PCNA) did not show the presence of proliferating cells either in glomeruli or in the interstitium. Staining with FITC-WGA lectin revealed focal and segmental loss of the negative charge in the capillary wall. By electron microscopy there was deposition of dextran in the basal membrane and segmental and focal damage of the podocyte foot processes. As the chemokine RANTES may be involved in glomerular injury, we examined the kidneys of proteinuric and non-proteinuric rats for the presence of RANTES. By indirect immunofluorescence only the proteinuric rats showed RANTES deposition in the mesangium.

CONCLUSIONS

Injection of rats with DEAE dextran leads to dose-dependent proteinuria without deposition of immune complexes but with podocyte damage. This is associated with local expression of the chemokine RANTES which may play a role in proteinuria of glomerular disease.

Receptor expression and responsiveness of human dendritic cells to a defined set of CC and CXC chemokines

Dendritic cells (DC) are migratory cells that exhibit complex trafficking properties in vivo. The present study was designed to characterize receptor expression and responsiveness to chemoattractants of human DC obtained from PBMC by culture with granulocyte/macrophage-CSF and IL-13. DC expressed appreciable levels of the CCR1, CCR2, and CCR5 receptors for the CC chemokines and the chemokine receptors CXCR1, CXCR2, and CXCR4. DC increased intracellular free calcium and migrated in response to the CC chemokines MCP-3, MCP-4, RANTES, MIP-1alpha, MIP-1beta, and MIP-5/HCC2 and the CXC chemokine SDF-1. In contrast, the CC chemokines MCP-1 and eotaxin had little or no activity in the concentration range tested (up to 1 microg/ml). IL-8 and Gro-beta (CXC) and lymphotactin (C chemokines) were also inactive. DC did not respond to 5-HETE, whereas platelet-activating factor was an active agonist. Selected chemokines active on DC in terms of migration and calcium fluxes were examined for their capacity to modulate endocytosis and Ag presentation. Under conditions in which TNF-alpha was active, MCP-1, MCP-3, MIP-1alpha, and RANTES did not affect these two responses. Thus, among hemopoietic elements, DC respond to a unique set of CC and CXC chemokines, and their responsiveness is restricted to migration with no effect on Ag capture and presentation. Chemokines may play a role in the trafficking of DC under resting or stimulated conditions. Chemokine receptors expressed in DC are likely to underlie HIV infection of this cell type.

Receptor expression and responsiveness of human dendritic cells to a defined set of CC and CXC chemokines

Dendritic cells (DC) are migratory cells that exhibit complex trafficking properties in vivo. The present study was designed to characterize receptor expression and responsiveness to chemoattractants of human DC obtained from PBMC by culture with granulocyte/macrophage-CSF and IL-13. DC expressed appreciable levels of the CCR1, CCR2, and CCR5 receptors for the CC chemokines and the chemokine receptors CXCR1, CXCR2, and CXCR4. DC increased intracellular free calcium and migrated in response to the CC chemokines MCP-3, MCP-4, RANTES, MIP-1alpha, MIP-1beta, and MIP-5/HCC2 and the CXC chemokine SDF-1. In contrast, the CC chemokines MCP-1 and eotaxin had little or no activity in the concentration range tested (up to 1 microg/ml). IL-8 and Gro-beta (CXC) and lymphotactin (C chemokines) were also inactive. DC did not respond to 5-HETE, whereas platelet-activating factor was an active agonist. Selected chemokines active on DC in terms of migration and calcium fluxes were examined for their capacity to modulate endocytosis and Ag presentation. Under conditions in which TNF-alpha was active, MCP-1, MCP-3, MIP-1alpha, and RANTES did not affect these two responses. Thus, among hemopoietic elements, DC respond to a unique set of CC and CXC chemokines, and their responsiveness is restricted to migration with no effect on Ag capture and presentation. Chemokines may play a role in the trafficking of DC under resting or stimulated conditions. Chemokine receptors expressed in DC are likely to underlie HIV infection of this cell type.

Natural history. Clinical-haemodynamic correlations. Prediction of the risk of bleeding

Promoting the development of oesophageal varices and ascites, portal hypertension dominates the clinical course of cirrhosis. Varices appear in patients with portal pressure gradient above 10 mmHg and enlarge in 10-20% within 1-2 years of their detection. Bleeding occurs in patients with portal pressure gradient above 12 mmHg when the wall tension causes the rupture of varices, with an incidence of about 10% per year. Indicators of bleeding risk are portal pressure gradient, variceal pressure, large varices and liver dysfunction. Mortality per bleeding episode is 30-50%. Among survivors 60% will rebleed and 30% will die in the following year. The risk of rebleeding decreases in patients with spontaneous or treatment induced reduction of portal pressure gradient or variceal pressure. Ascites develops in almost all patients along the course of the disease. Median survival after its appearance is less than 2 years. Less than 5% of cirrhotic patients die without ascites or without a previous bleeding. Thus portal hypertension is a major determinant of survival in cirrhosis.

[Cancer of the gallbladder]

Carcinoma of the gallbladder is the most frequent neoplasia of the biliary tract with an incidence of 2.5-4.4 cases for every 100,000 inhabitants; it more often affects females and elderly patients (60-70 years). It is an extremely malignant tumour with an often fatal prognosis owing to both its site and the generally late diagnosis; the majority of patients in fact undergo surgery at an advanced stage of the disease when surgery is only palliative. At the Surgical Division of S. Massimo Hospital in Penne (PE) a total of 897 operations on the gallbladder and biliary tract were performed between 1988 and 1994, revealing 21 cases of carcinoma of the cholecyst (2.3%). Sixteen patients were female (male-female ratio 1:3.2) with a mean age of 67.8 years (range 58-83 years). These patients were divided into 5 stages according to the UICC-1992 classification: 80.9% of cases were stage 3-4. Diagnosis was performed intraoperatively in 2 patients, whereas in 3 cases cancer had been diagnosed by the anatomo-pathologist. A total of 3 simple cholecystectomies were performed, 4 were associated with hepatic resection and lymphadenectomy of the hilus and hepatoduodenal ligament; surgery was enlarged in 2 cases due to the involvement of adjacent organs. After exploratory laparotomy, palliative surgery was performed in the remaining 12 patients in the form of biliary and derivation. Four system were implanted for intra-arterial chemotherapy. The most frequently found histological type was adenocarcinoma (76.2%). The mean survival rate of patients who died was 7.6 months. Six of the operated patients are still alive, of whom only one with a follow-up of 4 years. In conclusion, the authors agree with those who consider carcinoma of the gallbladder generally fatal in view of the rarity of early diagnosis and the difficulties of performing radical therapy.

[Biliary cystadenoma. A report of 2 cases]

Two cases of cystadenoma of the biliary tract are presented. This is a rare tumor that represents less than 5% of non parasitic cysts of biliary origin. It usually occurs in middle-aged women. Ultrasound (US) and Computerized Tomography (CT) are most important for tumor diagnosis, but differential diagnosis with other cystic tumors of the liver is very difficult preoperatively. Malignant degeneration to biliary cystadenocarcinoma is documented. Surgery is always indicated and has included aspiration, sclerosis, marsupialization, internal drainage, but the complete removal of lesion with enucleation or liver resection is the treatment of choice.

[The selective use of intraoperative cholangiography in video laparoscopic cholecystectomy]

Intraoperative cholangiography, a diagnostic method through images introduced in to clinical use in 1932, has recently become a different technical support from that attributed by traditional surgery and it has got a different diagnostic meaning with the introduction of video surgery. The authors used it in 54 of 194 patients submitted to a CVL, always making use of the trans-cystic access, with a percentage of success of 82.6%. It was not possible in 8 patients due to the complete section of the cystic duct during the work (3 cases) and the impossibility of introducing the catheter (5 cases). There is still no common agreement about the opportunity to use IC daily: the authors think selective use is better preceded by a careful clinical laboratory instrumental preoperative study to find patients with the common duct stone. Besides, they are of the opinion that a rigorous surgical technique is fundamental to reduce the lesions of the VBP that there are not in their experience.

Characterization of proteinuria in primary glomerulonephritides. SDS-PAGE patterns: clinical significance and prognostic value of low molecular weight ("tubular") proteins

In 145 patients with focal segmental glomerulosclerosis (43), membranous glomerulonephritis (72), and membranoproliferative glomerulonephritis (30), 71% with normal renal function (NRF) and 63% with nephrotic syndrome (NS), the proteinuria was evaluated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and classified into four main patterns: physiological (termed 70 kd), pure glomerular (150 kd), mixed with low molecular weight (LMW) proteins as low as 23 kd (23 kd), and mixed with very LMW proteins (20 to 10 kd; termed 10 kd). The relative frequencies were 70 kd, 0.7%; 150 kd, 1.4%; 23 kd, 61%; and 10 kd, 37%. Therefore, only the two patterns characterized by LMW ("tubular") proteins were compared to determine whether they have different clinical and prognostic significance. The serum creatinine (sCr) values (P < 0.0001), the degrees of proteinuria (P = 0.007), and the tubulointerstitial damage (P = 0.015) were significantly different in the two subgroups of patients with 23-kd and 10-kd LMW proteinuria; the difference for tubulointerstitial damage was at the limit of statistical significance after Bonferroni correction. In 82 patients with NRF at entry (sCr, 1.00 +/- 0.22 mg/dL; range, 0.6 to 1.4 mg/dL) and a follow-up of 46 +/- 22 months (range, 12 to 84 months), the predictive value of the 23-kd and 10-kd SDS-PAGE patterns on functional outcome (chronic renal failure [CRF] or clinical remission) was evaluated. A total of 12.5% of 64 patients with mixed 23-kd proteinuria and 50% of 18 patients with mixed 10-kd proteinuria developed CRF. At this time, the difference between the survival curves was highly significant (P = 0.0001), as it also was after correction for NS (P = 0.0002). When the statistical analysis was limited to 69 patients with sCr < or = 1.2 mg/dL, the difference was still highly significant (P = 0.0016), as after correction for NS (P = 0.0064). Clinical remission developed in 30% of 64 patients with 23-kd proteinuria and in 33% of 18 patients with 10-kd proteinuria; this difference was not significant. In a retrospective analysis of 20 patients (13 focal segmental glomerulosclerosis and seven membranous glomerulonephritis; 10 with the 23-kd pattern and 10 with the 10-kd pattern) treated with steroids alone or with steroids and cyclophosphamide, 80% of the patients with the 23-kd pattern and 30% of the patients with the 10-kd pattern were responsive to treatment (P = 0.025). The SDS-PAGE patterns of 54 patients with NRF at entry were again evaluated after 48 +/- 22 months: 11 patients who developed clinical remission had changed from a prevalent (91%) 23-kd pattern to a prevalent physiological (55%) or glomerular (36%) pattern; eight patients who had developed CRF showed an increase from 37% to 100% of the 10-kd pattern. In 35 patients with normal and stable renal function (sCr from 1.08 +/- 0.20 mg/dL to 1.06 +/- 0.19 mg/dL) who had persistent proteinuria (20 patients) or NS (15 patients), the rate of the 10-kd pattern increased from 6% to 46% (72% in persistent NS), suggesting an impairment of tubular protein reabsorptive function even without a concomitant impairment of glomerular filtration rate, a phenomenon that can be hypothetically attributed to tubular toxicity of persistent proteinuria. The characterization of proteinuria by SDS-PAGE in primary progressive glomerulonephritis is a useful clinical tool: it can be used to identify the main pathophysiologic determinants of excretion of LMW proteins and it has a predictive value on CRF outcome in patients with NRF, reducing the unpredictability of clinical evolution. In focal segmental glomerulosclerosis and membranous glomerulonephritis, it seems to be of predictive value on responsiveness to therapy; monitoring the SDS-PAGE patterns over time may give some insights into the relationship between the persistent protein loss and the progression of the disease.

[Pulsed-wave color Doppler echography of the intrarenal vessels in patients with insulin-dependent diabetes mellitus and incipient nephropathy]

Diabetic nephropathy affects a subset of about 40% patients with Insulin-Dependent Diabetes Mellitus (IDDM); it also develops in a less defined percentage (30-50%) of patients with non Insulin-Dependent Diabetes Mellitus (NIDDM), after a period of 15-20 years. It is usually divided in 5 stages: the first 3 are characterized by renal hypertrophy and increased glomerular filtration surface area (I stage) followed by glomerular histological lesions (II stage) and early nephropathy with microalbuminuria (III stage). At these stages nephropathy is still reversible by medical treatment (ACE inhibitors) and good metabolic control. Aim of this study was to assess the usefulness of duplex sonography with Doppler wave form analysis in the evaluation of early diabetic nephropathy, in order to detected patients at risk for irreversible renal disease. Fifteen patients (10 males and 5 females) aged 28-46 years, affected by IDDM were studied; 15 healthy subjects (7 males and 8 females) aged 20-45 years composed the control group. All of them underwent duplex Doppler sonography of kidney; a scanner with a 3.5 MHz transducer (Toshiba 270 SSA) was used. All patients had renal function tests within normal range. Pulsatily Index (P.I.) and Resistive Index (R.I. of Doppler waveform were obtained at the interlobar arteries; the average value of 3 bilateral measurements was taken. Doppler sonography was done by the same authors without knowledge of the patient group (case or control). Both indexes (P.I. and R.I.) resulted to have higher values in patients with IDDM compared to controls: P.I. = 1.46 +/- 0.30 vs. 1.07 +/- 0.06, p < 0.05; R.I. = 0.77 +/- 0.09 vs 0.60 +/- 0.03, p < 0.05. Even if our data have to be confirmed by further studies, they suggest that duplex Doppler sonography may be a useful complementary test in the evaluation of diabetic nephropathy, even in the early stages.

Adhesion molecules expression in noncrescentic acute post-streptococcal glomerulonephritis

Clinicomorphological features of 11 cases of non-crescentic acute post-streptococcal glomerulonephritis (APSGN) were reviewed. Intraglomerular and interstitial leukocytes and their possible correlation with the adhesion molecules intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial-leukocyte adhesion molecule-1 (ELAM-1/E-selectin) were investigated by an immunohistochemical method. Intraglomerular leukocytes were primarily granulocytes (11.4 +/- 10 cells/glomerular cross-section) and monocytes-macrophages (13.4 +/- 19.4 cells/glomerular cross-section). The granulocytes outnumbered monocytes-macrophages in 7 of 11 specimens. The number of intraglomerular leukocytes correlated with proteinuria at the time of renal biopsy. Intraglomerular ICAM-1 staining was strongly positive in all biopsies, especially when intraglomerular monocytes-macrophages prevailed. Expression of intraglomerular VCAM-1 and E-selectin in diseased kidneys did not differ from that in normal kidneys. Interstitial leukocytes were primarily monocytes-macrophages (158.9 +/- 96.8 cells/mm2) and T lymphocytes (102.2 +/- 63.9 cells/mm2). The number of interstitial leukocytes, especially monocytes-macrophages, correlated with serum creatinine level at the time of biopsy. Interstitial ICAM-1 staining was strongly positive on tubules, peritubular capillaries, and small vessels. The tubular positivity for ICAM-1 correlated with the number of interstitial monocytes-macrophages. Interstitial VCAM-1 and E-selectin were expressed as in normal kidney tissues. The data from this study demonstrate that APSGN is characterized by the presence of both intraglomerular and interstitial leukocyte infiltration, correlating respectively with proteinuria and serum creatinine at the time of renal biopsy. Among the adhesion molecules studied, ICAM-1 seems the most involved in leukocyte recruitment, especially in that of monocytes-macrophages.

Hepatitis C virus genotype in anti-HCV-positive hemodialysed patients

We investigated the influence of hepatitis C virus (HCV) genotypes on the clinical course of HCV infection in a haemodialysis population. In June 1991, a 4 year prospective follow-up programme was implemented in 184 consecutive haemodialysis patients. Alanine aminotransferase (ALT) and gamma glutamine transferase (GGT) were performed every 2 months. When HCV antibody (Ab) (by second-generation ELISA) was positive, it was confirmed by RIBA 2 and HCV RNA amplification by PCR. The pattern of nucleotide sequence variability in the 5' non-coding region was categorized according to Simmonds' genotype classification. Risk factors including blood transfusions were evaluated. The levels of hepatic enzymes in HCV Ab-positive patients were retrospectively studied over a mean period of 11.8 years. ALT and GGT levels were assigned a score for every year of infection (0 = normal, 1 = fluctuating 2 = high levels). Fifty-two patients were HCV Ab reactive (30.4%), eight were RIBA undetermined and 44 were RIBA positive; 40 of these were HCV RNA positive (91%). Twelve patients were HCV RNA negative, suggesting that they had recovered from the infection. Four genotypes were identified: 1b [26 patients (65%)], 1a (one patient), 2 [12 patients (30%)] and 3 (one patient). The genotype distribution was not different from that found in patients with chronic hepatitis C and normal renal function of the same geographical area. Genotype 1b accounted for 75% of the cases before 1985 and an equal prevalence of the two major genotypes was observed after 1985. Patients infected with HCV subtype 1 had normal mean ALT levels, but higher levels in the follow-up period (28 +/- 15.6 IU/l) and higher ALT and GGT personal scores in the retrospective study. Genotype 1 patients had higher mean ALT levels after 6 months. HCV RNA-negative patients had lower ALT levels after 24 months. RIBA pattern could differentiate the patients. Patients with genotype 1 received a higher number of transfusions, while only 50% of HCV RNA-negative patients had been transfused. Our data suggest a worse course of HCV infection in haemodialysis patients infected with HCV subtype 1, but the severity of HCV infection can only be assessed by histology. Transaminases are only loosely correlated with severity.

[L-carnitine deficiency]

After the introduction of the carnitinemia as routine analysis in the general practice, the authors could identify a pathologic table with L-carnitine deficiency. This pathologic form seems to compromise the myocardium function, until, in the old age, it will be the cause an irremediable cardiac circulatory insufficiency.

On-line urea kinetics in haemodiafiltration

BACKGROUND

Calculation of Kt/V and assessment of nutrition have so far been dependent upon off-line urea measurements of blood or dialysate samples. Here we describe a biosensor for on-line urea measurement during haemodiafiltration. Methods. The biosensor consisted of a cartridge containing covalently linked urease placed between two conductivity cells. The biosensor was placed on the outlet line of a haemofilter in series with a dialyser in order to obtain an aliquot of plasma ultrafiltrate for on-line measurement of urea.

RESULTS

Urea nitrogen concentrations were highly correlated to the difference (Delta) in conductivity measured by the two conductivity cells both in aqueous solutions (in-vitro studies, y=-6. 676+32.12x, R2=0.998, P<0.0001) and in ultrafiltrates (ex-vivo studies, y=-637+32.01x, R2=0.98, P<0.00001). Delta conductivity was highly reproducible (% variation: ).8-5.3%) and stable (maximal % variation at 150 mg/dl after 100 min. 0.9+/-0.3 vs initial values). The intradialytic plasma water urea profile was obtained in 10 haemodialysis patients. To study recirculation, the plasma water urea profile was analysed before and 3 min after stopping the dialysate flow. The pre- and post-stopped flow ratio (1.21+/-0.1, mean+/-1 SD) was superimposable to conventional blood sampling data (opposite arm venous arterial: 1.22+/-0.11) and allowed correction for recirculation. A novel approach to urea kinetic modelling was described and used to reliably project end-dialysis and post-dialysis rebound urea concentration as early as 90 min. Projected (29.2+/-10.4 g) or measured (29.8+/-10.5 g) net urea removal was highly correlated with the amount of urea collected in the total spent dialysate (29.7+/-10.6 g) (R2=0.99, R2=0.97 respectively).

CONCLUSIONS

These results indicate that on-line, real-time analysis of urea kinetics may provide information on delivery of adequate dialysis in high-efficiency techniques.

High binding of immunoglobulin M kappa rheumatoid factor from type II cryoglobulins to cellular fibronectin: a mechanism for induction of in situ immune complex glomerulonephritis?

In our previous experimental work we suggested that the frequent nephritogenicity of type II cryoglobulins could depend on a particular affinity of the immunoglobulin (Ig) M kappa rheumatoid factor (RF) component for mesangial matrix. Since cellular fibronectin (cFN) in the human kidney is mainly represented in glomerular mesangium, we studied the binding capacity to cFN of IgM kappa RFs from type II cryoglobulins compared with other different monoclonal and polyclonal IgM and IgM RFs. We purified 13 IGM kappa from human IgM kappa/IgG cryoglobulins, eight monoclonal IgM from patients with Waldenström's macroglobulinemia, nine polyclonal IgM from normal donors, and eight polyclonal IgM RFs from patients with rheumatoid arthritis. Purified IgM were used at the same concentration in enzyme-linked immunosorbent assay (ELISA) on cFN-coated plates. All the cryoglobulin IgM showed high specific binding to cFN while IgM from Waldenström's macroglobulinemia, normal IgM, and polyclonal IgM RFs had low or absent binding. These data were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of cFN followed by Western blot analysis with purified IgM. The IgM kappa binding to cFN persisted using IgM kappa monomers, and was inhibited by cFN but not by plasma FN in a specific inhibition test. Further enzyme-linked immunosorbent assay studies showed that cryoglobulin IgM kappa RFs are still able to bind IgG in a dose-dependent manner once linked to solid-phase cFN. The data suggest that the affinity of cryoglobulin IgM kappa RFs for immobilized cFN could be involved in the particular high nephritogenicity of type II cryoglobulins and might lead to in situ immune complex formation.

HLA-DQ gene polymorphism in primary IgA nephropathy in three European populations

MHC Class II genes may contribute to susceptibility to IgA nephropathy (IgAN). We have previously identified a restriction fragment length polymorphism (RFLP) of the DQB1 region that associated with IgAN in British Caucasoids. However, another group, while demonstrating a DQB1 association, was unable to confirm our finding. MHC molecules are heterodimers consisting of an alpha and beta chain, and thus polymorphism of the DQA1 alpha chain may also be important to disease pathogenesis in IgAN. Therefore, we have determined DQA1 alleles and re-examined DQB1 alleles in British Caucasoids with IgAN using an approach that can differentiate between the common DQ alleles; we have also extended our studies to Caucasoid populations from Northern and Southern Europe, thereby addressing the possibility of variation in genetic susceptibility between populations. DNA was prepared from IgAN patients (British, N = 105; Italian, N = 71; Finnish, N = 48) and healthy controls (British, N = 111; Italian, N = 63; Finnish, N = 41). DQA1 alleles were identified by TaqI RFLP and Southern blotting; alleles that could not be fully resolved by Taq Southern blotting were identified by PCR-RFLP. DQB1 alleles were identified by polymerase chain reaction (PCR) based technique (PCR-RFLP). No consistent association of DQ alleles were found between the populations studied. In British patients a decreased frequency of DQB1*0201 was observed (P = 0.008), in Finnish patients a decreased frequency of DQB1*0602 was observed (P = 0.01), and in Italian patients no association between DQ markers and IgAn was found. These data demonstrate population variation in disease association, but no strong or consistent association in the DQ region.

Renal vasculitis

The term 'vasculitides' encompasses a group of inflammatory disorders which may affect the kidney by damaging its blood supply. Although the kidney may be affected by many types of systemic vasculitis, renal involvement is particularly frequent in some forms of systemic necrotizing vasculitis which are considered primary, such as Wegener's granulomatosis and microscopic polyarteritis, including its 'renal-limited' variant. Renal vasculitis can occur at any age, but is seen particularly frequently in middle-aged and elderly subjects, in whom clinical presentation and prognosis are significantly worse. In addition to the specific problems related to age, this review focuses on a few aspects that are still the subjects of debate: classification, the role of ANCA, renal pathology and the treatment of renal vasculitis.

Type II mixed cryoglobulinaemia, hepatitis C virus infection, and glomerulonephritis

Mixed cryoglobulins (MC) are immunoglobulins which precipitate reversibly in the cold. Type II mixed cryoglobulins are composed of a monoclonal component (usually IgMk) with rheumatoid factor (RF) activity against polyclonal IgG. In type III MC, all the components are polyclonal. The majority of MC are secondary to connective tissue diseases, infectious or lymphoproliferative disorders, hepatobiliary diseases, or immunologically mediated glomerular diseases. The aetiology of MC is not clear and cryoglobulinaemia was considered 'essential' until an association between hepatitis C virus (HCV) infection and MC was recognized. The renal pattern includes typical glomerular lesions characterized by a particular glomerular monocyte infiltration, double-contoured appearance of the glomerular basement membrane (GBM) and by the presence of intraluminal 'hyaline thrombi' due to deposition of circulating cryoglobulins. The progression of renal disease is variable: in one-third of patients remission of renal symptoms occurs, 20% of patients experienced nephritic or nephrotic flare-ups during the course of the disease. Uraemia is observed in only 10% of patients 10 years after renal disease onset, but 50% of patients had already died from cardiovascular disease, infectious liver failure, or neoplasia during those 10 years. This review analyses the pathogenic mechanisms of MC and associated GN, with particular attention to the role of HCV infection. HCV RNA is detected in most patients with MC. HCV, by infecting B cells, could trigger abnormal production of polyclonal RF in type III MC and, together with other factors, a clone selection of B cells to produce monoclonal IgMk RF in type II MC. The presence of IgMk in serum appears essential for glomerular damage to occur. Cryoglobulinaemic GN might be initiated by IgG antibody-HCV complexes binding to IgMk RF, either in situ or in circulation, nephrotoxicity being due to a particular affinity of the IgMk RF for cellular fibronectin present in the mesangial matrix. Glomerular damage can be perpetuated by the reduced effectiveness of monocytes to remove cryoglobulins.

Intraglomerular and interstitial leukocyte infiltration, adhesion molecules, and interleukin-1 alpha expression in 15 cases of antineutrophil cytoplasmic autoantibody-associated renal vasculitis

In renal biopsy specimens from 15 patients with antineutrophil cytoplasmic autoantibody (ANCA)-associated renal vasculitis, the infiltrating intraglomerular and interstitial leukocytes were localized and the adhesion molecules intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and the cytokine interleukin-1 alpha (IL-1 alpha) were studied by an immunohistochemical method. Intraglomerular leukocytes were mainly macrophages (13.46 +/- 9.29 cells/glomerular cross-section) and, to a lesser extent, T lymphocytes (4.61 +/- 2.81 cells/glomerular cross-section). Staining with VCAM-1, which was negative in the undamaged tufts, was strongly positive in necrotizing-extracapillary lesions. Staining with ICAM-1 was also present in the damaged tufts, but its pattern was more diffuse. Intraglomerular IL-1 alpha was found in all biopsy specimens. Where the Bowman's capsule was not damaged, the periglomerular infiltrating cells were macrophages (42.6 +/- 25.2 cells/glomerular cross-section) and T lymphocytes (51.06 +/- 33.0 cells/glomerular cross-section). When there was a granulomatous lesion involving the glomerulus, the number of cells per granulomatous area revealed a massive number of CD45-positive leukocytes (345.83 +/- 237.47 cells/granulomatous lesion), many of them positive for activity markers (HLA-DR, IL-2R), adhesion molecules, and IL-1 alpha. Many activated cells were also present in interstitial areas of perivascular clusters of leukocytes, in which T lymphocytes (prevalently CD4+ cells) outnumbered the macrophages (331.55 +/- 207.85 cells/0.05 mm2 area v 125.68 +/- 60.57 cells/0.05 mm2 area). Adhesion molecules and IL-1 alpha were found in both tubular and vascular areas in all biopsy specimens. Our data strongly support the involvement of both the adhesion molecules ICAM-1 and VCAM-1 in the recruitment of intraglomerular leukocytes in renal vasculitis, indicate that VCAM-1 is a very good marker of necrotizing-extracapillary damage, and suggest its crucial connection with the macrophage recruitment in these vasculitic lesions. The presence of histochemically detectable levels of IL-1 alpha in glomeruli, tubules, and vessels and on some inflammatory cells supports its involvement in the vasculitic lesions, probably by triggering a positive feedback that increases the damage.

Cross-reactive idiotypes on cryoprecipitating monoclonal IgMk rheumatoid factors

Shared idiotype specificities (CRIs) among monoclonal IgM rheumatoid factors from patients with essential mixed cryoglobulinemia have been demonstrated with the use of polyclonal antisera and have been confirmed, more recently, using monoclonal antibodies. In this paper we will summarize some of the work that has been performed in our laboratory using anti-idiotypic monoclonal antibodies. Such reagents allowed us to detect CRIs on cryoprecipitable rheumatoid factors, to detect idiotype-positive cells in bone marrow and peripheral blood, and to identify glomerular immune deposits.

Hepatitis C virus genotype in patients with essential mixed cryoglobulinaemia

We studied 54 patients with essential mixed cryoglobulinaemia (EMC), (23 males, 31 females) mean age 61 years (range 28-77). Forty-one (76%) had type II cryoglobulinaemia and 13 (24%) type III. Antibodies to HCV were detectable by second-generation ELISA in 49 patients (91%) with confirmed or indeterminate RIBA results. HCV RNA was detected by RT PCR using 5' UTR nested primers; HCV genotypes 1a, 1b, 2 and 3a were identified by genotype-specific core-region nested primers. All patients (49) with antibodies to HCV in their serum were HCV-RNA positive; 27 (55.1%) had HCV subtype 1b and 21 (42.8%) type 2. In one patient the HCV genotype could not be determined. The genotype distribution was not different from that found in patients with chronic hepatitis C without cryoglobulinaemia. However, the presence of HCV subtype 1b correlated significantly with signs of chronic hepatitis and presence of peripheral neuropathy. Severity of disease tended to be worse in patients infected with HCV subtype 1b, but this was mainly due to liver disease. HCV genotypes may influence the clinical expression and, in particular, the severity of liver involvement in patients with EMC. Extent and severity of EMC disease in general may also be affected by the different HCV genotypes. These findings may have therapeutical implications, since the different HCV genotypes respond differently to interferon treatment.

Hearing loss in short- and long-term haemodialysed patients

BACKGROUND

Hearing loss has been described in patients with chronic renal failure on regular dialysis treatment (RDT) with very different frequency, ranging from 20 to 75%; RDT does not seem to worsen hearing function for at least the first 5 years of treatment; no studies are available on patients on RDT for more than 10 years.

METHODS

We performed an audiometric evaluation in 91 patients on RDT for various periods: group I (34 patients), < 5 years; group II (32 patients), 5-10 years; group III (25 patients), > 10 years; patients with histories of chronic otitis, ototoxic drug treatment, and chronic auditory trauma were excluded; the possible correlations with some biochemical parameters (urea, creatinine, PTH) were also looked for.

RESULTS

Hearing loss was present in 77% of patients and 69.2% of ears; the percentage of patients with hypoacusia was higher in group III (84%) than in group I (76.3%) and II (71.7%), but the differences were not statistically significant. Hypoacusia was cochlear neurosensory in 61.5%, conductive in 6.5%, and mixed in 9.0% of patients; the percentage of patients with cochlear neurosensory hypoacousia was similar in the three groups (I, 61.7%; II, 59.3%; III, 64%). Hearing loss was of slight to moderate degree and not different in the three groups (I, 22.7 +/- 15 dB; II, 26.9 +/- 6.0 dB; III, 29.1 +/- 8.9 dB). There were no correlations between hearing loss and plasma creatinine and PTH values; patients with plasma urea > 200 mg/dl had higher percentage of hypoacousia (86%) than patients with plasma urea < 200 mg/dl (69%) (P = 0.06).

CONCLUSIONS

Hearing loss, mainly cochlear neurosensory in type, is present in a high percentage of patients on RDT even at the beginning of treatment, but no negative effects on hearing can be correlated with the duration of dialysis.

Blood volume modeling and refilling rate estimation in hemodialysis by continuous hemoglobin monitoring

Eleven bicarbonate hemodialyses (HD) of 6 patients under constant ultrafiltration were continuously monitored with an optical Hb-meter, considered to be a marker of blood volume (BV) changes. A theoretical model was fed experimental data for prediction of blood volume and estimation of vascular parameters, and a time course of rate of refilling was extrapolated. The adequacy of the model was very good for the time course of BV prediction (r2 = 0.85-0.95, n = 11) and for plasma protein concentration (r2 = 0.83-0.86, n = 2). Parameters estimated included (mean-DS): filtration coefficient (Cf) = 0.22 (0.16) dl/min*mmHg, transcapillary hydrostatic pressure (DP) = 17.80 (3.44) mmHg and protein concentration of the refilling fluid (Cref) = 0.45 (0.30) g/dl. In conclusion our study has shown that the model chosen fits the observed BV profile well in all cases, thus the Hb data series can be used for BV dynamic modeling and for estimation of vascular parameters.

Anti-mesangial and anti-endothelial cell antibodies in IgA mesangial nephropathy

In the present study we verified by solid phase ELISA the presence of antibodies against mesangial and endothelial cell constituents in patients with IgA-GN and Schoenlein-Henoch syndrome (SH). An antigen extract was prepared by sonication of human mesangial cell (MC) monolayers between third and fifth subculture and coated at 20 micrograms/ml on microtiter plates where sera were tested by incubation for 2 h at 37 degrees C and addition of peroxidase-conjugated anti-human IgG or IgA. In comparison to 86 normal controls, increased levels of IgG anti-MC antibodies were found in 15/84 patients with IgA-GN and 4/11 with SH. IgA antibodies were always negative. Furthermore anti-endothelial cell antibodies (AECA) were sought in the same patients and controls by ELISA as previously described. Increased levels of IgG and IgA AECA were found in 25/62 and 24/46 patients respectively. A cross-inhibition test showed that preadsorbment of positive sera for both IgG anti-MC and IgG AECA on endothelial cells in culture resulted in an inhibited binding of IgG to MC. HPLC-ELISA and Western blot analysis of the MC extract showed a significant binding of IgG from ELISA-positive sera to a protein band of 25-50 kD. Similar results were obtained by Western blot analysis of an endothelial cell extract. These results suggest the identity of the antigens recognized by IgG antibodies on endothelial cells and MC in patients with IgA-GN.

Tubulointerstitial damage in glomerular diseases: its role in the progression of renal damage

The evidence that tubular damage, interstitial infiltration, and interstitial fibrosis occur in all glomerular diseases, either immunologically or non-immunologically mediated, is reviewed on the basis of personal data and data from the literature. The proposed mechanisms linking glomerular and tubular damage to the interstitial recruitment of mononuclear leukocytes and fibroblast proliferation, with abnormal extracellular matrix production leading to interstitial fibrosis, also are analyzed. The role of persistent heavy proteinuria and exposure to proinflammatory cytokines in inducing the damage of the tubular epithelial cells, with consequent acquisition by these cells of the ability to interact as antigen-presenting cells with T lymphocytes, is especially emphasized. Finally, the importance of the tubulointerstitial damage as a marker of unfavorable prognosis in glomerular diseases is documented.

[A rare case of Meckel's diverticulum perforation]

Meckel's diverticulum is a pathology not rarely found everyday clinical medicine especially when it present with one of its complications. The specific diagnosis is a bit difficult to put because of the low sensibility and specificity of symptoms of diagnostic and instrumental techniques used. The reported case shows a rare type of complication constituted by the phlogosis of Meckel's diverticulum, itself due to an extraneous thing ingested by the patient. The authors discuss the entity of the manifestations of this pathology and highlight every aspects.

[Branchial carcinoma]

The Authors report three cases of epidermoidal carcinoma arising from a congenital cyst of the anterolateral region of the neck. This type of tumor, rarely found in daily practice, arises from a degenerate branchial tissue and differential diagnosis often includes nodal involvement from systemic neoplasias. However, diagnostic criteria of such diseases are well defined; furthermore the rarity of branchial carcinoma is opposed to the high frequency of metastatic lymph nodes deriving from tumors with similar histological aspects located in other sites which could alter the real percentage of branchial tumor manifestation.

Cryoglobulinemic glomerulonephritis: a membranoproliferative glomerulonephritis induced by hepatitis C virus

Mixed cryoglobulins (MCs) are proteins that precipitate from cooled serum, and are composed of a polyclonal immunoglobulin G (IgG) bound to another immunoglobulin that acts as an anti-IgG rheumatoid factor (RF). In type II mixed cryoglobulinemia, the antiglobulin component, usually of the IgM class, is monoclonal; it is polyclonal in type III mixed cryoglobulinemia. The majority of MCs are found in patients with connective tissue diseases, infectious or lymphoproliferative disorders, hepatobiliary diseases, or immunologically mediated glomerular diseases (secondary MCs). The etiology is not clear for 30% of all MCs, and this type of cryoglobulinemia is called "essential." There is a common clinical syndrome in types II and III essential mixed cryoglobulinemia (EMC) characterized by purpura, weakness, and arthralgia. In type II EMC only, in which an IgMk is the monoclonal RF, a membranoproliferative glomerulonephritis (MPGN) occurs with some peculiar morphologic and clinical features; this is termed "cryoglobulinemic GN." Glomerulonephritis can be differentiated from idiopathic MPGN, especially in the acute stage, which is characterized by an acute nephritic syndrome, by the following findings: (1) the presence of large deposits filling the capillary lumen that sometimes are shown to have a characteristic fibrillar or crystalloid structure by electron microscopy; (2) the extent of the exudative component consequent to the frequently massive infiltration of monocytes; (3) a more diffuse and evident thickening of the glomerular basement membrane, which has a double-contoured appearance that is mainly due to the peripheral interposition of monocytes, with less evident mesangial expansion; and (4) possibly some vasculitis in small and medium-sized renal arteries without concomitant features of segmental necrotizing GN or crescentic GN.(ABSTRACT TRUNCATED AT 250 WORDS)

SDS-PAGE patterns and polymeric albumin in proteinuria of lupus glomerulonephritis

Proteinuria was characterized by SDS-PAGE and by immunoblotting with anti-human albumin sera for the detection of urinary polymers of albumin (PA) in 40 patients with biopsy proven lupus glomerulonephritis (LN) (6 pts class III WHO, 24 pts class IV, 10 pts class V) with various clinical presentations (nephrotic syndrome with normal or impaired renal function, 14 pts; urinary abnormalities with normal or impaired renal function, 21 pts; clinical remission, 5 pts); in 25 pts, for whom the characterization of proteinuria and the renal biopsy were performed at the same time, the activity and chronicity index scores were calculated. The mixed SDS-PAGE patterns, characterized by the presence of low molecular weight proteins, were the more frequently found; the mixed patterns were significantly associated with interstitial leukocyte infiltration (p = 0.05) and glomerular sclerosis (p = 0.046) and nonsignificantly associated with higher values of serum creatinine; no SDS-PAGE pattern had predictive value on functional outcome at 36 months. Albumin polymers were present in 67% of pts; in active disease they were present in 33% of class III, in 100% of class IV and in 45% of class V WHO (p = 0.026); PA were not present in 5 pts with clinical remission (4 class IV and 1 class V WHO). The presence of PA was significantly associated with high values (> 10) of activity index (p = 0.009) and with extracapillary proliferation (p = 0.041). Serum creatinine was lower in patients without PA (Scr 1.0 +/- 0.4 mg/dl) than in those with PA (Scr 1.5 +/- 1.0 mg/dl), but the difference was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term predictors of survival in essential mixed cryoglobulinemic glomerulonephritis

We report the clinical outcome of 105 essential mixed cryoglobulinemia (EMC) patients with renal involvement collected throughout 25 years in three renal Units of Milan. The median follow-up was 72 months since renal biopsy and 131 months since the clinical onset of EMC. Patient survival was 49% at 10 years after renal biopsy. Forty-two patients died primarily from cardiovascular and liver disease or infection, whereas 15 patients developed chronic renal failure. Two patients had a complete remission of the disease while 15 had a remission only of renal signs. Thirty-one patients are alive with persistent renal and extrarenal manifestations. Anti-HCV antibodies were retrospectively detected in 34 patients and were present in 85% of them. This variable was not included in the statistical evaluation. At multivariate analysis, age older than 50 years, purpura, splenomegaly, cryocrit levels higher than 10%, C3 plasma levels lower than 54 mg/dl, and serum creatinine higher than 1.5 mg/dl were independent risk factors for death or dialysis. In conclusion, several factors may influence the outcome of patients with EMC nephritis. Markers of disease activity and an impaired renal function can herald a bad prognosis. It should be stressed, however, that only a minority of patients eventually develop renal failure, probably because in the most severe cases patients die earlier.

Comparability of the different registries on renal replacement therapy

This symposium was organized in Milano, Italy, on the occasion of the 25th advanced course of the San Carlo Hospital, to discuss and compare the various registries of renal replacement therapy throughout the world. Such comparison is difficult due to differences in (1) the structure and database of the registries, (2) the genetic background and demography of the populations studied, and (3) the health care systems of the countries in which the registries are operating. Therefore, the presentation of the data at the symposium and in the following reports was planned according to a common format, since the speakers were asked to answer a series of specific questions focused on the three above-mentioned problems. The data reported in all the following papers for the various countries are summarized in nine tables in this introductory review. Comparison of the data shows that the quantity and quality of renal replacement therapy is variable and depends to a considerable extent on the different political and socioeconomic backgrounds, with the consequent differences in the health care systems, existing in the various countries.