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Biomedical subjects

J Pourrat

Publications and source records attributed to J Pourrat.

At least 19 recordsLinked to original sources
PubMed2002

Myeloma and monoclonal gammopathy of uncertain significance associated with acquired von Willebrand's syndrome. Seven new cases with a literature review.

OBJECTIVES: Acquired von Willebrand's syndrome (AvWS) is an uncommon complication of monoclonal gammopathy of uncertain significance (MGUS) or myeloma. We investigated clinical and laboratory test abnormalities, pathophysiological hypotheses, and treatment options in this poorly known condition. PATIENTS: Five patients with MGUS and two with myeloma who met classic criteria for acquired von Willebrand's syndrome were included in this retrospective study. RESULTS: Acquired von Willebrand's syndrome was diagnosed before the gammopathy in five of the seven patients. The severity of the bleeding events was chiefly dependent on the degree of von Willebrand's factor deficiency and on the presence or absence of gastrointestinal tract angiodysplasia. Bleeding event severity was similar in patients with nonmalignant and malignant disease. An antibody that inhibited von Willebrand's factor was detected in all seven patients. Clotting returned to normal after treatment of the malignancy in one of the two patients with myeloma. In patients with MGUS, treatment is warranted only when bleeding occurs or before surgery. Von Willebrand's factor concentrates were of limited efficacy because of their short half-life. Intravenous immunoglobulins had a longer-lasting effect (about 3 weeks); this treatment was used on a regular basis in two patients with recurrent bleeding. CONCLUSIONS: A diagnosis of von Willebrand's syndrome in adulthood should prompt a search for a monoclonal gammopathy. In patients with gammopathies, simple clotting tests ensure the diagnosis of acquired von Willebrand's syndrome.

Aged↗
PubMed2000

[Hypocomplementemic urticarial vasculitis].

BACKGROUND: Low-complement urticarial vasculitis is an uncommon condition associating urticaria, glomerulonephritis, obstructive ventilatory disorders, and anti-Ciq antibodies. CASE REPORT: We report a case in a 34-year-old woman who developed urticaria with purpura, membranoproliferative glomerulonephritis (creatinine 238 mumol/l) and bronchial obstruction with bronchectasia. Total complement and the C3 fraction were low. Anti-C1q antibodies were found in the serum and anti-DNA antibodies were negative. Aggravation of the respiratory and renal failure progressed despite corticosteroid therapy, leading to death at 4 months. DISCUSSION: Bronchial obstruction in low-complement urticarial vasculitis results from emphysema and is often life-threatening. Our case exhibited an unusual feature due to the lack of radiodetectable emphysema, the presence of bronchectasia and the rapid degradation of the respiratory function.

Adult↗
PubMed2000

[Microscopic polyangiitis].

Microscopic polyangiitis is a systemic necrotizing vasculitis affecting small vessels, without granulomata. Patients present with rapidly progressive glomerulonephritis, often associated with cutaneous, musculoskeletal, neurological or gastrointestinal involvement. Antineutrophilcytoplasmic antibodies are frequently found, most often with a perinuclear pattern and a antimyeloperoxidase specificity. Diagnosis is based on the evidence of a necrotizing glomerulonephritis, or histological vasculitis, in the absence of extravascular granulomata or sign of macroscopic polyarteritis nodosa. Corticosteroids and immunosuppressive drugs have improved the prognosis, but relapses are frequent.

Humans↗
PubMed2000

Polymorphism of the 5' untranslated region of NHE1 gene associated with type-I diabetes.

The ubiquitous form of the sodium-hydrogen exchanger, NHE1, is devoted to the regulation of intracellular pH and cell volume. In addition, NHE1 activity is stimulated by growth factors and increased NHE rates are found in both circulating and immortalized cells during diabetes or diabetic nephropathy. In this context, we searched for polymorphisms of the 5'-flanking regulatory region of NHE1 gene in subjects with type-I diabetes. We identified a C/T transition 696 bases upstream the translation initiation start site which disrupts a repeated palindromic GC sequence. The TT genotype was significantly more frequent in type-1 diabetics and may have functional importance. Genetic linkage between NHE1 and diabetes has been previously described in NOD mice strains with consequences on NHE rates. Hence, the polymorphism described hereby may act as a predisposition factor to type-I diabetes or to diabetic complications, and may be useful to investigate the genetic involvement of NHE1 in human pathophysiology.

5' Untranslated Regions↗
PubMed2000

Pharmacodynamic study of low molecular weight dermatan sulphate (Desmin) after a single subcutaneous administration in patients with renal insufficiency.

The pharmacodynamic pattern of low molecular weight dermatan sulphate (CAS 24967-94-0, Desmin-LMWDS) was studied in patients presenting chronic renal insufficiency. Three groups of six patients were defined according to their creatinine clearance: group 1, more than 50 ml/min, group 2 between 10 and 50 ml/min and group 3 lower than 10 ml/min (haemodialized patients). Desmin-LMWDS concentrations were determined with the Heptest assay and the chromogenic specific heparin cofactor II dependent anti IIa assay. In patients of group 1 affected by moderate renal insufficiency, the pharmacodynamic profiles were roughly comparable to those obtained in normal subjects. In the two other groups, the profiles were markedly modified by the renal insufficiency. The maximal concentrations were doubled and the areas under the time-activity curve were 4-fold higher in haemodialyzed (group 3) and severe renal insufficient patients (group 2) than in patients of group 1. The clearance of the anti IIa activity were 13.98 +/- 6.25 l/h; 4.12 +/- 2.64 l/h and 2.94 +/- 1.53 l/h and the half-lives were 2.79 +/- 2.60 h, 6.15 +/- 4.02 h and 11.51 +/- 6.54 h in groups 1 to 3, respectively (p < 0.05). The Desmin-LMWDS clearance was directly correlated to the creatinine clearance (r = 0.8244, n = 18, p < 0.001). Thus, as for low molecular weight heparin, renal function plays a major role in the elimination of low molecular weight dermatan sulphate.

Adult↗
PubMed2000

Adult Fanconi syndrome secondary to light chain gammopathy. Clinicopathologic heterogeneity and unusual features in 11 patients.

Fifty-seven cases of Ig light chain-associated Fanconi syndrome (FS) have been reported so far, mostly as isolated reports. The pioneering work by Maldonado and associates (35), who reviewed the first 17 cases in 1975, led to the unifying concept that patients with FS and Bence Jones proteinuria have a special form of plasma cell dyscrasia characterized by slow progression of the tumor and by prominent crystal formation in proximal tubule cells, in the absence of myeloma casts in the distal tubule. We carefully reappraised these characteristics in a series of 11 patients. Ten renal biopsy specimens were available for electron microscopy, adding to the 15 previously reported cases with ultrastructural studies. Moreover, 10 of the kappa light chains could be entirely or partially sequenced and tested for their resistance to cathepsin B, a lysosomal protease present in proximal tubule cells. Our series showed an unexpected clinicopathologic heterogeneity. Seven patients presented with the typical clinical and pathologic features of FS and low-mass myeloma or monoclonal gammopathy of undetermined significance (MGUS), in keeping with Maldonado et al's description. Crystals in bone marrow cells were detected in patients of this group, only. Three patients who presented with full-blown FS exhibited, however, the characteristic features of myeloma cast nephropathy in the setting of high-mass myeloma. One patient of this group also had numerous crystals in proximal tubule cells. The eleventh patient had complete FS with MGUS, but no crystals in proximal tubule cells even after electron microscopy. Contrasting with the clinicopathologic heterogeneity, genetic and biochemical analyses of the light chains showed a striking homogeneity. First, they all were of the kappa type. Second, 8 of 9 belonged to the V kappa I variability subgroup, which indicates that FS light chains are related by the sequence of their variable regions. Third, the 8 V kappa I light chain sequences most likely originated from only 2 germline genes, LCO2/012 and LCO8/018. Fourth, all 5 LCO2/012-derived sequences presented an unusual hydrophobic or nonpolar residue at position 30. These sequence peculiarities may account for unusual physicochemical properties of the light chains including the resistance of their variable domain V kappa to proteolysis by cathepsin B, observed in 7 of 9 patients in our series, while light chains isolated from patients with myeloma cast nephropathy are completely digested. Resistance of V kappa to proteolysis in FS patients can explain the accumulation of the light chain in the endocytotic compartment of the proximal tubule cells, leading to impairment of proximal tubule functions.

Adult↗
PubMed2000

Microscopic polyangiitis with alveolar hemorrhage. A study of 29 cases and review of the literature. Groupe d'Etudes et de Recherche sur les Maladies "Orphelines" Pulmonaires (GERM"O"P).

Microscopic polyangiitis (MPA) is a systemic small-vessel vasculitis primarily associated with necrotizing glomerulonephritis and pulmonary capillaritis. In this retrospective study of 29 patients with MPA and alveolar hemorrhage (AH), we characterized the pulmonary manifestations at presentation and assessed the short- and long-term outcome. AH was diagnosed when bronchoalveolar lavage was macroscopically bloody, or contained hemosiderin-laden macrophages, in the absence of lung infection or pulmonary edema. MPA was diagnosed when AH was associated with focal segmental necrotizing glomerulonephritis at kidney biopsy or pathologically proved small-vessel vasculitis. There were 17 women and 12 men, with a mean age of 55.8 +/- 16.7 years. The onset was rapidly progressive, but in 8 (28%) patients, symptoms preceded the diagnosis for more than 1 year. The most constant systemic findings associated with AH were glomerulonephritis in 28 (97%) patients; fever (62%); myalgia and arthralgia (52%); weight loss (45%); ear, nose, and throat symptoms (31%); and skin involvement (17%). Lung opacities were bilateral in 26 (90%) patients, most frequently involving the lower part of the lungs. Bronchoalveolar lavage, performed in 27 patients, was hemorrhagic in 25 (93%), and contained numerous siderophages in others. Most patients were severely anemic (mean hemoglobin, 8.1 +/- 1.8 g/dL). ANCA, present in 27 (93%) patients, gave a perinuclear (14), cytoplasmic (11), or mixed (1) pattern. Mean serum creatinine level was 407 +/- 415 mumol/L. Renal biopsy confirmed the presence of necrotizing glomerulonephritis in 27 patients. Patients were treated with corticosteroids (100%), cyclophosphamide (79%), plasmapheresis (24%), dialysis (28%), and mechanical ventilation (10%). The overall mortality rate was 31% (9 patients). Deaths were related to vasculitis (5 patients) or side effects of treatment (4). Deaths were more frequent in aged or mechanically ventilated patients. The 5-year survival rate was 68%. The recovery of respiratory function among survivors was clinically considered complete in 20 (69%) patients. However, 7 patients (24%) had persistent alterations on pulmonary function tests. Of the 11 patients who had relapses, 2 died from AH.

Adult↗
PubMed1997

[Inefficacy of exchange-transfusion in case of a methotrexate poisoning].

We report on a case of methotrexate (MTX) intoxication occurring in a 19-year-old man treated for a leukemia. Exchange-transfusion (ET) was performed in attempt to remove the MTX from the body. This exchange-transfusion was unable to decrease the MTX plasma concentration. This inefficacy of ET in MTX intoxication is in contradiction with previously reported recommendations. However, this result is easily explained by MTX pharmacokinetics parameters.

Acute Kidney Injury↗
PubMed1994

Treatment of polyarteritis nodosa related to hepatitis B virus with interferon-alpha and plasma exchanges.

OBJECTIVES: To test the effectiveness of and tolerance to interferon-alpha 2b (INFa2b) in association with plasma exchanges for the treatment of polyarteritis nodosa (PAN) related to hepatitis B virus (HBV). METHODS: A prospective, non blinded, multicentre trial was carried out in which patients with multisystemic HBV-related PAN were included. Each patient received the association of INFa2b and plasma exchanges. The end point of the study was control of the disease (recovery or remission) or death. RESULTS: Six patients were included in the study. Each patient had histopathological or arteriographic evidence of vasculitis and was infected with actively replicating HBV. All patients were alive at the end of the study and no longer presented clinical or laboratory evidence of systemic vasculitis. HBeAg/anti-HBeAb seroconversion was observed in four patients (66.6%) and HBsAg/anti-HBsAb in 3/6 (50%). Two patients are still being treated with INFa2b because of chronic active hepatitis. CONCLUSIONS: It is considered that this new therapeutic approach to HBV-related PAN effectively cured systemic vasculitis and was associated with control of HBV infections. Antiviral therapy may have a role to play as the first line treatment regime of virus-induced vasculitis.

Adult↗
PubMed1994

[Nodular and granulomatous form of periarteritis nodosa caused by the hepatitis B virus].

Polyarteritis nodosa (PAN) is, in rare cases, associated with subcutaneous nodules and pathology does not usually show the presence of peri and extravascular granulomas. When present in patients with hepatitis B virus (HBV) related PAN these facts demonstrate that classification of PAN is not homogeneous. CASE REPORT. A patient infected by HBV developed a PAN demonstrated by clinical symptoms and pathology. The disease was characterized by the presence of subcutaneous nodules and histologically by peri- and extra-vascular granuloma which surrounded necrosis of medium-sized vessels. Outcome was also unusual in the patient who did not respond to the association of plasma exchanges and antiviral agents and was only slightly improved by steroids and cyclophosphamide. COMMENTS. HBV-related PAN is considered to be an immune complex disorder. In the present case report granuloma were present as observed in Churg Strauss syndrome or Wegener's granulomatosis which are the consequence of other pathogenetic mechanisms as anticytoplasmic neutrophil antibodies (ANCA). This case reports underlines the heterogeneity of the PAN group of vasculitis and the probable role for various pathogenetic mechanisms.

Antiviral Agents↗
PubMed1993

Antineutrophil cytoplasm antibodies in systemic polyarteritis nodosa with and without hepatitis B virus infection and Churg-Strauss syndrome--62 patients.

OBJECTIVE: Antibodies directed against components of neutrophil cytoplasm have been detected in various systemic vasculitides and especially in Wegener's granulomatosis. In polyarteritis nodosa (PAN) and Churg-Strauss syndrome, few data are available and correlation between clinical manifestations and antineutrophil cytoplasm antibodies (ANCA) has not been established. Therefore, we tested, before treatment of vasculitis, 62 consecutive patients suffering from PAN with hepatitis B virus (HBV) markers, PAN of unknown etiology or Churg-Strauss syndrome. METHODS: Only patients with PAN and Churg-Strauss syndrome were included in the study. The diseases were histologically and/or angiographically proven. Every patient's serum was tested by an indirect immunofluorescence assay (IFA) and, in 37 cases, by an enzyme linked immunosorbent assay (ELISA). RESULTS: ANCA detected by IFA were observed in 10.7% of the patients with PAN with HBV markers, in 27.3% of the patients with PAN without HBV markers and in 66.7% of the patients with Churg-Strauss syndrome. When ELISA was performed, 11.1% of the patients with PAN associated with HBV infection, 20% of the patients with PAN without HBV markers and 55.6% of the patients with Churg-Strauss syndrome were positive. ANCA were positively correlated with asthma and purpura and negatively correlated with HBV markers. CONCLUSION: Regardless of the technique used, Churg-Strauss syndrome was associated with ANCA in about 60% of the cases while, in PAN of unknown etiology, ANCA were found in about 25% of cases. In contrast, IFA and ELISA only detected ANCA in a limited number of cases of PAN related to HBV infection. ELISA positivity in patients with PAN and Churg-Strauss syndrome was usually associated with antimyeloperoxidase antibodies. In our cases of PAN, ANCA and purpura were significantly correlated, suggesting that, in these cases, small vessels are involved and therefore macroscopic and microscopic PAN coexist. Thus it seems that ANCA are essentially present in the cases of small vessel vasculitis, as has been described, and are not a marker of pure macroscopic PAN, at least at our present level of understanding of these antibodies.

Adult↗
PubMed1993

[Microscopic polyarteritis].

Microscopic polyarteritis is an idiopathic necrotising vascularitis of the small vessels. Manifestations include diffuse alveolar haemorrhage, segmentary necrotising glomerulonephritis, and a cutaneous, articular, neurological or digestive vascularitis. The absence of a histological granulomas and medium calibre vessel involvement distinguishes Wegener's syndrome from polyarteritis nodulosa. The diagnosis is facilitated when anti-neutrophil cytoplasm antibodies are found in the serum. These auto-antibodies are suspected to be the cause based on clinical and experimental data, although this aetiology has not been confirmed. Corticosteroids, immunosuppressors and plasmapheresis can improve the prognosis of this severe and evolving affection which may be fatal.

Adrenal Cortex Hormones↗
PubMed1992

[Anti-polynuclear neutrophil cytoplasmic antibodies of the perinuclear type or p-ANCA].

Some neutrophil cytoplasmic auto-antibodies produce perinuclear immuno staining of alcohol-fixed neutrophils called P-Anca pattern. These autoantibodies show chiefly reactivity with myeloperoxidase in Elisa but other specificities have been detected (elastase, cathepsin, lactoferrin). These P-Anca anti-MPO are more frequent with renal angiitis but P-Anca (anti-MPO negative) are associated with other diseases without renal failure (rheumatoid arthritis, Gougerot-Sjogren and ulceritis colitis).

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1990

[Renal involvement in rheumatoid polyarthritis].

Urinary disorders were investigated in 162 patients with specific or standard rheumatoid disease, over a period of 5 years. 43 patients presented disturbances of the urinary laboratory tests, or 26.5 p. cent and 17 of them underwent a renal needle-biopsy. The findings were as follows: 11 isolated proteinurias, iatrogenic and reversible when the treatment in question was discontinued (gold salts, D-penicillamine), 13 microscopic hematurias, 3 isolated leucocyturias, 3 combinations hematuria-leucocyturia, 3 combinations hematuria-leucocyturia-proteinuria, 6 nephrotic syndromes including 5 of iatrogenic origin, 4 isolated renal failures. The most interesting discussion concerns microscopic hematurias. Besides the standard lesions of extra-membranous glomerulonephritis, amyloidosis and interstitial nephritis, 50 p. cent of the renal histologic examinations corresponded to lesions of mesangial glomerulonephritis. This lesion seems unrelated to long-term treatments and could be encouraged by the chronic inflammatory condition of the rheumatoid disease.

Adolescent↗