PubMed Health⌕ Search

Biomedical subjects

B Mougenot

Publications and source records attributed to B Mougenot.

At least 19 recordsLinked to original sources
PubMed1997

Thrombotic microangiopathy and cytomegalovirus disease in patients infected with human immunodeficiency virus.

Thrombotic microangiopathy (TMA) can occur during the course of human immunodeficiency virus (HIV) infection. Clinical and pathological data for 29 patients with TMA and HIV infection were recorded. In a retrospective case-control study, we analyzed the link between opportunistic infections or drug therapies and TMA. Twenty-five patients (mean CD4+ cell count +/- SD, 71.9 +/- 18.3/mm3) had renal impairment, and four had neurological dysfunction. In one-half the cases, the disease was progressive with isolated fragmentation anemia appearing several months before the clinical symptoms. The diagnosis of TMA was confirmed by histological examination of kidney biopsy specimens (18 cases). Endothelial cytomegalovirus (CMV) inclusions were associated with TMA in nine of 18 cases, whereas histological examination did not detect CMV in any control specimens (P < .001). The case-control study demonstrated a link between TMA and clinical CMV infection (odds ratio, 3.9; 95% confidence interval, 1.1-14). We conclude that TMA is a late complication of HIV infection and can be associated with systemic CMV infection in this setting.

AIDS-Related Opportunistic Infections↗
PubMed1996

Different expression of the plasminogen activation system in renal thrombotic microangiopathy and the normal human kidney.

Renal thrombotic microangiopathy is characterized by glomerular and vascular thrombosis. The persistancy of fibrin deposits may result from imbalance between plasminogen activation and inhibition. In the present study, we used immunohistochemistry and in situ hybridization techniques to determine the localization of urokinase-type (u-PA) and tissue-type (t-PA) plasminogen activators, type 1 plasminogen activator inhibitor (PAI-1) and membrane receptor for u-PA (uPA-R) antigen and their sites of synthesis in renal thrombotic microangiopathy (N = 10) as compared to acute tubular necrosis (N = 5) and normal human kidneys (N = 7). We found an induction of PAI-1 and uPA-R expression in glomeruli and in arterial walls in renal thrombotic microangiopathy. In addition, the induction of uPA-R expression was also found in some tubular epithelial cells. In most case, local synthesis of PAI-1 and uPA-R was confirmed by in situ hybridization with the corresponding cDNA probes. In contrast, using similar techniques PAI-1 and uPA-R antigens and messenger RNAs could not be detected in normal kidneys. In both renal thrombotic microangiopathy and normal kidneys, t-PA mRNA was detected in large amounts in all glomeruli and in vascular endothelial cells, but t-PA antigen was only detected in a limited number of glomerular and arterial endothelial cells, whereas it was strongly expressed by all venous endothelial cells. Although u-PA antigen was found in almost all tubular sections, u-PA mRNA was only found in tubular epithelial cells in the deep cortex and the outer medulla. Our results indicate that there is an up-regulation of PAI-1 and u-PA-R expression in the glomeruli and in the arterial walls of thrombotic microangiopathy. The local release of PAI-1 could play a role in the persistancy of fibrin deposition and the further development of fibrotic lesions. Whether uPA-R plays a pathogenic role in the development of glomerular and vascular lesions, or is involved in the repair process of these lesion, remains to be elucidated.

Adult↗
PubMed1995

Sequences of V kappa L subgroup light chains in Fanconi's syndrome. Light chain V region gene usage restriction and peculiarities in myeloma-associated Fanconi's syndrome.

Certain monoclonal Ig light chains (LC) are responsible for marked disturbances of proximal tubule cell functions (Fanconi's syndrome, FS). In patients with FS, intracellular crystal-like inclusions containing LC determinants are commonly found in plasma cells, macrophages, and renal tubular cells. In an attempt at understanding the pathogenesis of myeloma-associated FS, we recently determined the first complete primary sequence of a kappa-LC (CHEB) responsible for the disease. We now report on the primary structure of three other kappa-LC of the V kappa l variability subgroup associated with FS (TRE, TRO, and DEL). After PCR amplification, cDNA encoding these LC were sequenced. CHEB, TRE, and TRO LC genes were found to be highly homologous to the same germline gene O2/O12. These patients had numerous intracellular crystals, whereas the fourth patient, DEL, had no detectable crystals. The LC from the latter patient was homologous to another germline gene, O8/O18. Comparison of these LC sequences to previously reported LC of the V kappa l subgroup allowed identification of a number of unusual amino acid substitutions in the V region that had rarely or never been previously described at the corresponding positions. Some of these unusual substitutions affect highly conserved amino acids located either in an external loop (residue 30) or in inner (residues 48 and 55) and outer (positions 63 and 72) beta-sheets that may be important for the structure and binding properties of the kappa-chains. These and several other substitutions, some of them shared with amyloidogenic kappa-LC, could induce conformational alterations and represent a determinant pathogenic factor.

Amino Acid Sequence↗
PubMed1995

Protease resistance and binding of Ig light chains in myeloma-associated tubulopathies.

Kidney tubule dysfunction and lesions are frequent complications of myeloma, related to unknown properties of the monoclonal light chain. We have analyzed protease sensitivity and binding properties of urinary light chains from four patients with Fanconi's syndrome, 12 with cast nephropathy, and four control patients without myeloma-associated tubulopathy. All light chains were normal-sized, monomeric and/or dimeric, and none was N-glycosylated. Kinetic studies of light chain digestion by pepsin and the lysosomal enzyme cathepsin B showed the generation of a protease-resistant 12 kDa fragment, corresponding to the V domain of the kappa chain in the four Fanconi's syndrome patients; in two out of four the V domain was also completely resistant to trypsin. Western and dot blots revealed similar patterns of reactivity of light chains from patients with the Fanconi's syndrome towards other light chains. Properties of cast-nephropathy light chains were more heterogeneous but clearly differed from those of Fanconi's syndrome: (i) 9 out of 12 were of the lambda-type; (ii) only four yielded a transient 12 kDa fragment after cathepsin B digestion, but all showed some resistance to proteolysis of the entire molecule or a fragment thereof to at least one protease, at variance with control light chains; (iii) they displayed various patterns of reactivity with other light chains; (iv) 7 out of 12 reacted specifically with Tamm-Horsfall protein (THP) by ELISA, in contrast with those of Fanconi's syndrome. In one patient who presented with cast nephropathy and the Fanconi's syndrome, the light chain exhibited both partial resistance of the V kappa domain to cathepsin B and the highest reactivity with THP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adjuvants, Immunologic↗
PubMed1995

Lipoprotein glomerulopathy: first case in a white European.

Since 1988, 11 cases of a new entity, 'Lipoprotein glomerulopathy' (LG), were described in Japan. Some of these reports suggested that this glomerular lipid storage is due to excess apo E associated with heterozygous E2/3 apo E isoform. We report the first case of LG in a white European with no such lipid abnormalities. Proteinuria was discovered in 1967 when he was 42. Blood pressure and renal function were normal. Family history was negative. Renal biopsy disclosed lesions which were only understood at the time of the Japanese publications. They were composed of endocapillary glomerular deposits. Staining for lipids disclosed capillary loop obstruction with lipid droplets. Electron microscopy showed confluent droplets of various sizes obstructing capillary loops. Proteinuria progressively increased. In 1974 repeat renal biopsy showed the same lipid deposits, now associated with focal-segmental glomerulosclerosis (FSGS). Several serum lipoprotein and apolipoprotein studies ruled out any specific lipid derangement. This suggested a local glomerular disorder, presumably affecting the glomerular endocapillary disposal of lipids. A third biopsy showed progressive glomerular destruction by FSGS with persistence of the lipid droplets. Renal insufficiency progressed and haemodialysis was started in 1992. This observation suggests that LG is a local glomerular, not a general lipid disorder and indicates that this disease is not restricted to Asian patients.

Adult↗
PubMed1995

Renal involvement in hematological disorders: monoclonal immunoglobulins and nephropathy.

The study of monoclonal immunoglobulin-associated nephropathies is useful for analyzing the physicochemical properties of immunoglobulin components responsible for their deposition in the kidney. Notable advances include the first description of truncated heavy-chain deposition disease, characterization of protease resistance and binding properties of immunoglobulin light chains involved in myeloma-associated Fanconi's syndrome and cast nephropathy, and identification of hepatitis C virus as a plausible causative agent of the so-called essential mixed cryoglobulinemias.

Antibodies, Monoclonal↗
PubMed1994

[Acute interstitial nephritis and streptococcal infection].

Two patients with acute renal failure and streptococcal erysipela are reported. In both cases, renal biopsy showed acute interstitial nephritis with a predominantly mononuclear infiltrate. Beta lactam antibiotic without steroid therapy was followed by complete recovery of renal function. It seems likely that some cases of AIN related to infection are erroneously attributed to antibiotic hypersensitivity.

Acute Kidney Injury↗
PubMed1993

[Tubulo-interstitial renal complications of myeloma].

Tubulo-interstitial lesions are the main causes of renal failure in patients with myeloma, and they sometimes reveal this tumour. They are mainly found in large tumoral mass myelomas and are characterized by tubular lesions and specific casts of unexplained physiopathology. Symptomatic and aetiological treatments must be instituted at an early stage to obtain the recovery, at least partial, of renal function, as observed in more than 50% of the cases. The persistence of renal failure carries a sombre prognosis, which emphasizes the importance of a preventive treatment that is too often omitted. Functional tubular disorders are frequent but seldom result in Fanconi's syndrome. A better understanding of the mechanisms underlying the nephrotoxicity of monoclonal immunoglobulins should permit to reduce the incidence of tubular lesions in myelomas.

Fanconi Syndrome↗
PubMed1993

Cutaneous vasculitis and IgA glomerulonephritis in ankylosing spondylitis.

Two patients with ankylosing spondylitis were found to have IgA nephropathy and leucocytoclastic cutaneous vasculitis. Immunofluorescence showed perivascular deposition of IgA in the skin of one patient and in the mesangium of both patients. Such an association has been reported only once before. This supports the concept of abnormal IgA immune stimulation in the pathogenesis of ankylosing spondylitis.

Glomerulonephritis, IGA↗
PubMed1993

["Idiopathic" extracapillary glomerulonephritides without immune deposits are vascularitides: clinical and serologic analysis].

To determine the spectrum of systemic diseases potentially associated with pauci-immune rapidly progressive glomerulonephritis (GN), most of which being considered as idiopathic, we have analyzed extra-renal manifestations, occurrence of extra-glomerular vasculitis and incidence and specificity of ANCAs in 40 patients selected only on histological criteria. Extra-renal symptoms were unexpectedly observed in all patients but one, and were suggestive of vasculitis in 24 of them. Extra-glomerular vasculitis was evidenced in 18 kidney biopsies and four biopsies from other organs. Among the 33 patients with suspected or established vasculitis, 13 had presumed or biopsy-proven Wegener's granulomatosis (WG), three had a macroscopic form of polyarteritis nodosa and 17 had a clinical presentation compatible with the so-called microscopic polyarteritis previously described in the british literature. An additional patient had clinical signs of WG without clinical and histological evidence of vasculitis. ANCAs were detected in 28/33 and 25/34 sera tested by IF and ELISA, respectively: 19 contained anti-myeloperoxidase (MPO) antibodies and 6 had anti-proteinase 3 (Pr3) activity. Anti-MPO and anti-Pr3 antibodies were present in all clinical subgroups but with various incidences: anti-MPO antibodies were surprisingly more often detected (6/12) than anti-Pr3 (4/12) in patients with suspected or histologically proven WG but anti-Pr3 antibodies were nonetheless 3- to 4-fold more frequent in WG than in non-WG systemic vasculitis (1/12) and necrotizing CGN without evidence of extra-renal vasculitis (1/10). These results strongly suggest that pauci-immune necrotizing CGNs belong to the broad spectrum of necrotizing vasculitides affecting glomerular capillaries. This hypothesis is also supported by the good response of patients to immunosuppressive treatments known for their efficacy in vasculitides, whereas these treatments are usually less successful in severe forms of extra-capillary GN with immune deposits.

Glomerulonephritis↗
PubMed1993

Necrotizing crescentic glomerulonephritis without significant immune deposits: a clinical and serological study.

To determine the spectrum of systemic diseases associated with pauci-immune necrotizing crescentic glomerulonephritis, we have analysed extra-renal manifestations, occurrence of extra-glomerular vasculitis and incidence and specificity of antinuclear cytoplasmic antibodies (ANCA) in 40 patients selected only on renal histological criteria. Extra-renal symptoms were unexpectedly observed in all patients but one, and were suggestive of vasculitis in 24. Extra-glomerular vasculitis was seen in 18 kidney biopsies and four biopsies from other organs. Among the 33 patients with suspected or established vasculitis, 13 had presumed or biopsy-proven Wegener's granulomatosis, three had a macroscopic form of polyarteritis nodosa and 17 could not be adequately classified. An additional patient had clinical signs of Wegener's granulomatosis without clinical and histological evidence of vasculitis. ANCAs were detected in 28 of 33 and 25 of 34 sera tested by immunofluorescence and enzyme-linked immunoassay, respectively: 19 contained anti-myeloperoxidase antibodies and six had anti-proteinase 3 activity. Anti-myeloperoxidase and anti-proteinase 3 antibodies were present in all clinical subgroups but with various frequencies: anti-myeloperoxidase antibodies were more common (six of 12) than anti-proteinase 3 (four of 12) in patients with suspected or histologically proven Wegener's granulomatosis. Anti-proteinase 3 antibodies were 3- to 4-fold more common in patients with Wegener's granulomatosis than in those with systemic vasculitis of other causes (one of 12) or necrotizing crescentic glomerulonephritis without evidence of extra-renal vasculitis (one of 10). These results strongly suggest that pauci-immune necrotizing crescentic glomerulonephritis belongs to the broad spectrum of necrotizing vasculitides affecting glomerular capillaries. This study shows substantial improvement in renal prognosis and life expectancy with aggressive immunosuppressive therapy despite the older age of the patients, dissemination of the vasculitic process and often delayed diagnosis.

Adult↗
PubMed1992

Glomerulonephritis in chronic lymphocytic leukemia and related B-cell lymphomas.

We retrospectively analyzed clinical presentation, immunopathological data and renal outcome in 13 patients with glomerulonephritis (GN) and chronic lymphocytic leukemia (CLL) or related diffuse well-differentiated lymphocytic lymphoma (WDLL) of B-cell lineage. B-cell proliferation and glomerulopathy were simultaneously diagnosed in seven of the 13 patients. Nephrotic syndrome was observed in nine patients. Serum creatinine was elevated (greater than 120 mumol/liter) in 10 patients and exceeded 400 mumol/liter in three patients. A clear cut relationship between GN and hematologic disease could be established in nine cases: five patients had MPGN caused by type I or type II cryoglobulinemia; two had MPGN or mesangial hypertrophy with circulating and deposited noncryoprecipitating monoclonal IgG K and IgM K, respectively; in the two remaining patients, monotypic IgG K glomerular deposits exhibiting fibrillary organization were observed in association with MGN or MPGN, despite the absence of circulating M-component by immunofixation. The pathophysiologic link between glomerular lesions and B-cell proliferation was further evidenced by effectiveness of specific treatment of the malignancy by chlorambucil. This drug, used in the absence of steroids, induced complete remission of nephrotic syndrome in the five patients to whom it was given. Moreover, in the five patients with creatininemia greater than 200 mumol/liter who received chemotherapy, substantial improvement in renal function was observed. These overall data demonstrate that the occurrence of GN in B-CLL and related lymphoma is not fortuitous, and testify to the paraneoplastic nature of glomerular involvement mediated by deposition and possibly processing of cryoprecipitating or noncryoprecipitating M-components.

Adult↗
PubMed1992

Nephropathy associated with infection by human immunodeficiency virus: a report on 11 cases including 6 treated with zidovudine.

The human immunodeficiency virus (HIV) was recently suggested to be involved in generating kidney lesions in HIV-associated nephropathy (HIVN). The possibility that antiretroviral agents can slow down the usually explosive evolution of HIVN to end-stage renal failure (ESRF) has not been studied in many of the series of cases published. The present work is a retrospective analysis of 11 patients with histologically proven HIVN, 6 of whom were treated with zidovudine. Seven patients (group 1) either required dialysis at the outset, when HIVN was diagnosed, or progressed very fast to ESRF within 15-45 days. Two patients of this group were treated with zidovudine, but it had no effect on kidney function. In the remaining 4 patients (group 2), HIVN progressed more slowly than in group 1. All 4 patients were treated with zidovudine at an earlier stage of the disease than ESRF. Only 1 deteriorated to ESRF in 9 months. The 3 others, who did not have ESRF, were followed up for 13, 10 and 32 months, respectively. Although this is a preliminary study, its results do suggest that zidovudine can slow down the evolution of HIVN to ESRF. They highlight the need to screen HIV-positive patients regularly for proteinuria, in order to detect HIVN by renal biopsies at an early stage of renal lesion formation.

AIDS-Associated Nephropathy↗