Renal AA amyloidosis in a patient with hereditary complete complement C4 deficiency

Hereditary complete C4 deficiency has until now been reported in 30 cases only. A disturbed clearance of immune- complexes probably predisposes these individuals to systemic lupus erythematosus, other immune- complex diseases and recurrent microbial infections. We present here a 20- year- old female with hereditary complete C4 deficiency. Renal biopsy demonstrated renal AA amyloidosis. This unique case further substantiates that deficiency of classical pathway components predisposes to the development of recurrent microbial infections and that the patients may develop AA amyloidosis. Furthermore, in clinical practice, the nephrotic syndrome occurring in a patient with hereditary complete complement C4 deficiency should lead to the suspicion of renal AA amyloidosis.

Clinical significance of N-terminal Pro-B-type natriuretic peptide (NT-proBNP) in hemodialysis patients

Circulating biomarkers play a major role in the early detection of cardiovascular disease. The purpose of this study was to determine levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in hemodialysis (HD) patients and to examine the relationship of this marker to left ventricular hypertrophy and to cardiac dysfunction. Plasma NT-proBNP concentrations were measured in patients undergoing chronic HD, who did not any clinical evidence of heart failure, (n=32; mean age 43.14 +/- 12 years; sex-ratio 1.8) as well as healthy volunteers (n=32; mean age 45.84 +/- 1.9 years; sex-ratio 1). In addition, the correlation between plasma NT-proBNP concentration and parameters of echocardiography was examined. The plasma NT-proBNP levels in the HD patients were significantly higher (14422.6 +/- 13757.8 pg/mL) than those in healthy volunteers (39.21 pg/mL) (P< 10 -3 ). In addition, the area under the receiver operating characteristic curve (ROC) revealed that the cut-off level of NT-proBNP was 288 pg/mL. On univariate analysis, the plasma NT-proBNP concentrations, in patients on HD, correlated positively with age (P= 0.004; r=0.5), systolic (P= 0.046; r= 0.36) and diastolic blood pressures (P= 0.037; r= 0.37), residual diuresis (P= 0.09; r= 0.3), the left atrial diameter (LAD) (P= 0.006; r= 0.55), left ventricular mass index (LVMI) (P= 0.01; r= 0.44) and negatively with albumin (P= 0.01; r= -0.44). However, there was no correlation between plasma levels of NT-proBNP and gender, body mass index (BMI), mean period on dialysis, pulse pressure, dry weight and left ventricular dysfunction. On multivariate analysis, only age (P= 0.014, RR= 2.8) was associated with significantly increased levels of NT-proBNP. Further studies are needed to carefully assess the diagnostic accuracy and prognostic value of NT-proBNP in patients on HD.

Cardiovascular risk factors in hemodialysis and peritoneal dialysis patients

Cardiovascular diseases are a major cause of morbidity and mortality in patients with end-stage renal disease (ESRD). The aim of our investigation was the evaluation of an extensive cardiovascular profile in hemodialysis (HD) and peritoneal dialysis (PD) patients. We studied 74 patients with ESRD (38 males, 36 females), maintained either on chronic HD (n= 50) or chronic PD (n= 24) and age and sex matched 20 healthy subjects as controls. The lipid profile, homocysteine (Hcy) and C reactive protein (CRP) were measured. When compared to a healthy population, HD patients displayed a marked atherogenic profile, as attested by increased levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein-cholesterol (LDL-C), apolipoprotein A (Apo A), CRP, Hcy and lower concentrations of high-density lipoprotein-cholesterol (HDL-C), Apo B, albumin (ALB). A significant difference was noted concerning the rates of Apo B, HDL-C, TC, ALB and Hcy. Same biological disorders that those found at HD patients were noted in these PD patients. One also noted lower concentration in Apo A. there were a significant difference with the reference group concerning the rates of albumin, Apo A, HDL-Cl and Hcy. When compared to PD patients, HD patients had significantly decreased concentration of LDL-C. The peculiar metabolic changes observed in the present study confirm the marked tendency of patients with impaired renal function for developing cardiovascular diseases, irrespectively of the type of dialysis. We suggest including uremia-related risk factors in the panel for evaluation of cardiovascular risk in dialysis patients.

Avascular osteonecrosis after renal transplantation

Avascular osteonecrosis (AVN) is a serious osseous complication after renal transplantation. Its prevalence clearly decreased from 20% to 4% after introduction of cyclosporine and reduction of steroid doses. The aim of our study was to evaluate the frequency of AVN among kidney transplant recipients and to determine the risk factors by comparing them with a population without AVN. Among 326 kidney transplant recipients between June 1986 and December 2004, 15 patients developed AVN with mean age of 40.86 years, including 11 men and 4 women. Fifteen kidney transplant recipients without AVN were selected to be matched for age, gender, and date of transplantation (control group). Cases of symptomatic AVN were diagnosed by hip X-ray, radioisotope bone scan, or magnetic resonance imaging. AVN was diagnosed at a mean of 3.5 years after transplantation (range, 0.5-13 years). The main localization of AVN was the femoral head in 12 cases and the femoral condyle in 3 cases. We studied the following risk factors: the type of donor (cadaver or living donor), the duration on dialysis before transplantation, the cumulative steroid dose, the acute rejection rate, and the posttransplantation weight gain. Statistical analysis showed that the cumulative steroid dose and the acute rejection rate were higher among the AVN group than the control group (P=.04 and P=.058, respectively). The prevalence of AVN in our population is 4.6%, which is probably an underestimate since these were symptomatic cases. The reduction or early withdrawal of steroids remains the only efficient preventive treatment for AVN.

[Membranoproliferative glomerulonephritis in patients with cryoglobulinemia complicating hepatitis C virus: report of 11 cases]

BACKGROUND

Membranoproliferative glomerulonephritis in patients with cryoglobulinemia complicating hepatitis C virus have yet been reported. Although, it remains controversial, antiviral treatment seems to be able to improve the outcome of glomerulonephritis.

AIM

The objectives of the study were to analyze characteristics of this association and to report literature data and newness treatment.

METHODS

It's a retrospective study including 11 patients with membranoproliferative glomerulonephritis, hepatitis C virus and mixed cryoglobulinemia. Hepatitis C virus antibodies was identified by ELISA technique. Hepatitis C virus genotype was identified in one patient. Cryoglobulins were isolated from sera of all patients at 37 degrees Celsius.

RESULTS

Patients were 3 men and 8 women with a mean age of 51.9 +/- 15.5 years. Between the 11 patients, 7 had hypertension, 9 had nephrotic syndrome and 10 had chronic renal failure. Renal biopsy showed membranoproliferative glomerulonephritis lesions in all cases with fibrinoid thrombi in 8 cases. Six patients had chronic liver disease. Liver biopsy was performed in 4 patients, showing histological feature compatible with chronic active hepatitis in 2 cases. No patient had antiviral therapy. Renal failure was stable in 5 cases and progressed in 6 cases with end stage renal failure in 3 of them. One patient died, 4 months after diagnosis, because of severe pulmonary involvement in cryoglobulinemic vasculitis. In literature, treatment is dominated by antiviral therapy composed first by Interferon Alpha alone. Combination therapy associating Interferon and Ribavirin was recently used in renal involvement; it is clearly more effective than interferon alpha alone.

CONCLUSION

Hepatitis C virus detection should be performed when membranoproliferative glomerulonephritis is associated with cryoglobulinemia. Antiviral treatment should be more widely used in Tunisia to evaluate his effect on renal involvement