Influence of methylprednisolone on plasma homocysteine levels in cadaveric renal transplant recipients

The aim of the present study was to investigate plasma homocysteine levels in renal transplant recipients in the course of steroid-based or steroid-free immunosuppression. Data from 32 patients were retrospectively analyzed according to the steroid immunosuppressive regimen. The 20 recipients on methylprednisolone (MP) plus cyclosporine (CyA) or tacrolimus (TRL) (n = 20) showed similar creatinine levels when compared with those on calcineurin inhibitors plus mycophenolate mofetil (MMF; n = 12), (1.6 +/- 1.5 vs 1.6 +/- 0.4 mg/dL; P = NS) but significantly higher total plasma homocysteine (tHcy) levels (28.5 +/- 12.5 vs 16.3 +/- 5.5 micromol/L; P < .05). No differences of tHcy levels have been observed when patients were analyzed according to CyA- or TRL-based immunosuppression regardless of MP or MMF associations. Our data suggest that recipients, particularly those on steroid-based immunosuppression, should receive homocysteine-lowering treatment early after transplantation.

Platelet-Independent defect in hemostasis associated with sirolimus use

Sirolimus is currently used to prevent rejection of solid organ transplant, and sirolimus-eluting stents have shown promise for the prevention of coronary artery restenosis. Thrombocytopenia is a well-known adverse effect of sirolimus limiting its use. Herein we report on a patient in whom sirolimus caused a platelet-independent hemostasis defect. The patient was a 52-year-old woman who underwent renal transplant with consequent normal kidney function. The immunosuppressive regimen included basiliximab, steroids, and cyclosporine induction later shifted to sirolimus and mycophenolate due to biopsy findings of tubular necrosis on day 6 posttransplantation. At discharge the serum creatinine was 0.7 mg/dL. Four months after transplantation the patient was admitted to our hospital because of fever (37.5 degrees C to 38 degrees C), anorexia, and asthenia. Blood analysis showed: creatinine 1.7 mg/dL, Hb 9.6 g/dL, WBC 6 x 10(3)/microL, PLT 123 x 10(3)/microL, liver function tests normal, LDH 720 mU/mL, fibrinogen 628 mg/dL, d-dimer 0.42 ng/mL, FDP > 40 ng/mL, INR 1.10, PT 87%, aPTT 40 seconds. Cultures and tests for infection were negative. Serum sirolimus level was 25.9 ng/mL. The following day the serum creatinine rose to 2.3 mg/dL and diuresis fell to 20 mL/h. Multiple bleeding times (Ivy test) performed before the renal biopsy were repeatedly over 30 minutes (normal 3 to 5 minutes), despite normal platelet count and platelet function studies. There was no spontaneous aggregation and in vitro aggregation was normal (collagen, ADP, adrenalin, and ristocetin induced). Coagulation studies showed a defect in fibrin formation and a reduction of fibrinolysis. Suspension of sirolimus treatment was followed by remission of fever, improvement of renal function (serum creatinine 1.2 mg/dL), and normalization of bleeding time.

Hepatocyte growth factor/scatter factor released during peritonitis is active on mesothelial cells

Peritonitis causes mesothelial detachment that may result in persistent peritoneal denudation and fibrosis. We investigated whether hepatocyte growth factor (HGF), a scatter factor that induces detachment from substrate and fibroblastic transformation of several cell types, is produced during peritonitis and is active on mesothelial cells. We studied 18 patients on peritoneal dialysis, 9 uncomplicated, 9 with peritonitis. HGF was measured in serum, peritoneal fluid, and supernatant of peripheral blood mononuclear cells and peritoneal mononuclear cells. Primary culture of human peritoneal mesothelial cells and the human mesothelial cell line MeT-5A were conditioned with recombinant HGF, serum, and peritoneal fluid. HGF levels were significantly higher in serum and peritoneal fluid of peritonitic than uncomplicated patients. Mononuclear cells of peritonitic patients produced more HGF than cells of uncomplicated patients. Recombinant HGF, serum, and peritoneal fluid of peritonitic patients caused mesothelial cell growth, detachment, transformation from epithelial to fibroblast-like shape, overexpression of vimentin, and synthesis of type I and III collagen. In conclusion, HGF released during peritonitis causes a change in mesothelial cell phenotype and function. HGF may affect the healing process facilitating repair through mesothelial cell growth, but may contribute to peritoneal fibrosis inducing cell detachment with mesothelial denudation and collagen synthesis.

Hemodialysis prevents liver disease caused by hepatitis C virus: role of hepatocyte growth factor

Hemodialysis prevents liver disease caused by hepatitis C virus: Role of hepatocyte growth factor.

BACKGROUND

Hemodialysis increases markedly the serum levels of hepatocyte growth factor (HGF) so that regular dialysis treatment (RDT) mimics the regular administration of HGF as a drug. Therefore, we have studied the effects of dialysis-associated HGF production on the severity of liver damage caused by hepatitis C virus (HCV).

METHODS

Biochemical tests of liver function and liver biopsy were performed in 10 patients on RDT and in 11 patients without renal disease (WRD) converted to anti-HCV serum-positive test for the same time (48 +/- 4 months). The HGF serum concentration was measured by enzyme immunoassay. In patients on RDT, HGF was measured just before starting a dialysis session (T0), at 15 and 240 minutes of dialysis (T15 and T240), and 24 hours later (T24 hr).

RESULTS

Serum HGF was similar in WRD (average 0.17 ng/ml) as in RDT at T0 (0.25 ng/ml). In RDT serum HGF increased markedly at T15 and T240 (5.51 and 2.67 ng/ml, respectively, P < 0. 001 vs. WRD and T0) and was still higher than baseline at T24 hr (0. 41 ng/ml, P < 0.05). Both grade of necroinflammatory activity and stage of fibrosis were significantly lower in RDT than in WRD (both, P < 0.001). The number of apoptotic hepatocytes was also significantly reduced in patients on RDT compared with patients WRD.

CONCLUSION

These results show that HCV-related liver disease is more benign in patients on RDT. The phenomenon may depend on the marked and prolonged HGF release caused by dialysis.

Hemodialysis stimulates hepatocyte growth factor release

Studies were performed in 26 patients on regular dialysis treatment with cuprophane (CU), polymethylmetacrilate (PMMA) or cuprammonium (CAM) dialyzers. Controls were six patients with chronic renal failure but not on regular dialysis treatment (CRF) and six healthy subjects (N). Blood was collected at the start (T0), and at 15 (T15) and 240 (T240) minutes of dialysis to measure the serum hepatocyte growth factor (HGF) concentration and to study HGF production by peripheral blood mononuclear cells (PBMC) in vitro. The form of HGF (that is, inactive/monomeric, active/dimeric) present in the serum was analyzed by immunoblotting. In addition, the ability of serum to stimulate proliferation of tubular cells (HK-2) and HGF release by PBMC and fibroblasts (MRC-5) was investigated. At T0, serum HGF levels were identical to that of the controls. In patients treated with CU, serum HGF rose from 0.24 ng/ml at T0 to 7.44 ng/ml at T15, and remained high at T240. PBMC collected at T15 and T240 released significantly more HGF in vitro than those collected at T0. Serum at T15 stimulated proliferation of HK-2 cells and the release of HGF by PBMC and MRC-5 cells. The PMMA and CAM dialyzers had similar effects as the CU. These results indicate that dialysis induces a striking rise in serum HGF and a prompt circulation of factor(s) stimulating HGF release. Dialysis-activated PBMC release HGF.

[Interventional radiology in thoracic emergencies]

There are numerous clinical situations in which interventional angiography fully reveals its two-fold diagnostic and therapeutic value. The present review focuses attention on the use of such procedures in certain thoracic emergencies. Indications, diagnostic results and therapeutic advantages are examined together with possible complications. Pulmonary embolism is a serious circulatory condition that is often difficult to diagnose because of the lack of specificity of its accompanying symptoms. In these cases the role of the angiographic radiologist is often three-fold: diagnosis, therapy (possibility of carrying out locoregional thrombolysis), and prophylaxis (positioning of caval filters that prevent the migration of thrombi). Haemoptysis may arise from both the pulmonary and bronchial vessels and may be caused by various pathologies (cancer, angiodysplasia, vasculitis, aspergillosis). Angiographic study in such cases is indispensable for identifying the source of bleeding and for arresting, using embolising material, haemorrhage that it is no longer possible to control with other therapeutic modalities. Foreign bodies held in the vascular tree are in the main fragments of catheters detached accidentally or as a result of incorrect manoeuvres or for defects of construction of the material. Their removal is possible today by using, percutaneously, angiographic techniques (snare loop, basket, hook system, balloon catheters) which make it possible to hook up the fragment and remove it.