B. Durand-Gasselin

OBJECTIVE: To retrospectively analyze the clinical symptoms, laboratory findings, and outcomes in patients with microscopic polyangiitis (MPA) who were enrolled in various clinical trials conducted by the French Vasculitis Study Group. METHODS: A cohort of 85 patients meeting the Chapel Hill criteria for MPA participated in the study. Seventy-one of them were included in prospective therapeutic trials. Eighty-one diagnoses were biopsy proven. In the other patients, diagnosis was based on clinical findings. RESULTS: Forty-seven men and 38 women, with a mean +/- SD age of 56.8 +/- 14.6 years, met the criteria for MPA. Their main clinical symptoms were renal manifestations (78.8%), weight loss (72.9%), skin involvement (62.4%), fever (55.3%), mononeuritis multiplex (57.6%), arthralgias (50.6%), myalgias (48.2%), hypertension (34.1%), lung involvement (24.7%; alveolar hemorrhage 11.8%), and cardiac failure (17.6%). The mean +/- SD serum creatinine level before treatment was 2.59 +/- 2.96 mg/dl; 47 patients had renal insufficiency (serum creatinine > 1.36 mg/dl). Eight patients underwent dialysis at the time of diagnosis, and long-term dialysis was necessary for 10 patients. Antineutrophil cytoplasmic antibodies (ANCA) were present in 38 of 51 patients (74.5%), of whom 33 had a perinuclear staining pattern (pANCA) and 5 had a cytoplasmic pattern. Antibodies to proteinase 3 were present in 4 patients and antibodies to myeloperoxidase were detected in 31, as determined by enzyme-linked immunosorbent assay. Of the 30 patients who underwent renal and celiac angiography, 4 had microaneurysms. Of the 29 patients (34.1%) who had relapses, 8 died during or after the relapse. During followup, 28 of the 85 patients (32.9%) died. The mean +/- SD duration of followup of the group was 69.9 +/- 60.6 months. Deaths were less frequent when patients had been treated with steroids and immunosuppressive drugs (13 patients [24.1%]) than with steroids alone (15 patients [48.4%]) (P < 0.01). The 5-year survival rate was 74%. CONCLUSION: This study demonstrated that MPA is a multisystemic disease in which renal symptoms are frequent, but the disease is also associated with general symptoms, arthritis, mononeuritis multiplex, and other manifestations that are also seen in various vasculitides. The rarity of abnormal angiogram findings and the high frequency of pANCA are characteristic of MPA. In most cases, the outcome is comparable with those of other systemic vasculitides, but relapses are frequent.

Since low molecular weight heparins (LMWH) are partly eliminated by renal excretion, their pharmacodynamic profile may be modified in very elderly patients with age-related renal impairment. The aim of this prospective study was to determine whether tinzaparin (Innohep) 175 anti-Xa IU/kg administered subcutaneously once daily over 10 days does accumulate in hospital patients greater than 70 years of age. Plasma anti-Xa and anti-IIa amidolytic levels and APTT were determined prior to the first injection (day 0), and then, at peak level i.e. 5 h after the second injection (day 2) and subsequently on days 5, 7 and 10. Thirty consecutive inpatients (6 men, 24 women) requiring LMWHs at a curative dose for acute thromboembolic disease were included. Patients' characteristics (mean +/- SD) were: age 87.0+/-5.9 years (range 71-96), body weight 62.7+/-14.6 kg (range 38-90) and creatinine clearance 40.6+/-15.3 mL/min (range 20-72). The mean actual dose of tinzaparin delivered was 174.8 anti-Xa IU/kg. Since no patient had an anti-Xa activity above 1.5 IU/mL, the dose of tinzaparin remained fixed over 10 days. Anti-Xa and anti-IIa peak levels measured on day 2 were 0.66+/-0.20 IU/mL (range 0.26-1.04) and 0.33+/-0.10 IU/mL (range 0.18-0.55), respectively. Ex vivo anti-Xa/anti-IIa ratios were close to 2.1. APTT ratios (patient/control) were strongly correlated with anti-IIa activity (p <0.01). There was no progressive increase of the anti-Xa and anti-IIa activities after repeated administration of tinzaparin over the 10 day treatment period. No correlation was found between anti-Xa and anti-IIa activities and age, weight, or creatinine clearance. No major bleeding occurred during the study and only one minor haematoma at the injection site was reported. No thrombo-embolic complication or death occurred. Tinzaparin may thus be administered safely at a treatment dose (175 anti-Xa IU/kg) in older patients with age-related renal impairment. Neither dose adjustment, nor serial anti-Xa activity monitoring seems to be required in patients with creatinine clearance above 20 mL/min during the first ten day treatment.

Determining the optimal dose of warfarin for frail elderly patients is a challenging task because of the low dose requirements in such patients, the wide interindividual variability of response, and the associated risk of bleeding. The objective of this study was to address the influence of 13 common variations in eight genes on the maintenance dose of warfarin in a cohort of frail elderly inpatients. For our study, we enrolled 300 Caucasian subjects who were hospital inpatients, with a mean age of 86.7 +/- 6 years. In addition to age, genetic variants of VKORC1, CYP2C9, CYP4F2, and EPHX1 were found to be significant predictor variables for the maintenance dose of warfarin, explaining 26.6% of dose variability. Among 132 patients in whom warfarin therapy was initiated with the same low-dose regimen, we studied the relative influences of genetic and nongenetic factors. The time to first international normalized ratio (INR) > or =2 was influenced by VKORC1 and CYP2C9 genotypes (P = 0.0003 and P = 0.0016, respectively); individuals with multiple variant alleles were at highest risk for overanticoagulation (INR >4) (odds ratio, 12.8; 95% confidence interval, 2.73-60.0). In this special population of frail elderly patients with multiple comorbidities and polypharmacy, we demonstrated the main impact of genetic factors on warfarin response.

UNLABELLED: Although plasma exchanges (PE) have no added benefit in the treatment of vasculitides of the polyarteritis nodosa (PAN) group with steroids (CS) +/- cyclophosphamide (CY), this has not been demonstrated in patients presenting with glomerulonephritis (GN). We therefore reanalyzed the records of microscopic polyangiitis (MPA) or Churg-Strauss syndrome (CSS) patients presenting with GN. PATIENTS AND METHODS: Patients were included consecutively in 2 randomized trials: a) comparing CS vs CS + PE (n = 78) and b) comparing CS + pulse CY +/- PE in PAN and CSS with factors of poor prognosis (n = 62); 9-12 PE/patient were performed. RESULTS: 32 patients, 18 men and 14 women, presented with GN, 28 MPA and 4 CSS, mean age 53.2 +/- 17 years. Clinical/biological manifestations before treatment were comparable in both groups: weight loss 84.4%, fever 62.5%, mononeuritis multiplex 62.5%, purpura 28.1%, GI tract involvement 43.8%, arthritis 37.5%, asthma 12.5%, CNS manifestations 9.4%; cardiac involvement 9.4%; mean creatininemia was 303 +/- 286 mumol/l, proteinuria > 0.5 g/l or 1g/d was found in every case, microscopic hematuria in 20/32 patients, leukocyturia in 12/32. Eight out of/16 were ANCA-positive, ELISA detected anti-MPO antibodies in 5 and anti-PR3 in 3. HBV infection was never observed. After 1 year of treatment, creatininemia decreased from 374.4 +/- 352 to 290 +/- 352 mumol/l in the PE group and from 287 +/- 292 to 170 +/- 67 in the non PE group (NS). Six patients of the PE group and 2 of the non-PE group were dialyzed at onset of treatment. Four of the 6 PE patients and 1 of the 2 not treated with PE were off dialysis 1 year later. In addition 1 patient from the PE group developed a flare with renal failure and required chronic dialysis. The 5-year survival was higher in the PE group (4 deaths/19) than in the non PE group (7/13). The survival curve was 74% in the PE group vs 54% in the non-PE group (NS). CONCLUSION: This study confirms that PE have no added benefit in the treatment of GN in MPA and CSS.