Renal involvement in POEMS syndrome.

We describe a patient with POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes) who was found to have renal involvement with particular renal pathological findings. So far, 17 other cases, most of them from Japan, of POEMS syndrome with renal involvement, have been published. Clinical features are variable: acute renal failure with anasarca or moderate chronic renal insufficiency with mild proteinuria. This latter presentation often passes unnoticed. There is no severe hypertension, no microangiopathic hemolytic anemia. Renal biopsy shows prominent glomerular changes which are unusual and distinct from membranoproliferative glomerulonephritis (MPGN) and from glomerular thrombotic microangiopathy (TMA). Mesangial proliferation and thickening of the capillary wall with double contour on light microscopy suggest an MPGN. By immunofluorescent microscopy, no immunoglobulins or complement deposits were found. The occurrence of mesangiolytic lesions has led to the term of "mesangiolytic glomerulonephritis". The presence, on electron microscopy, of lucent subendothelial spaces could indicate TMA. But there are neither thrombi nor arteriolar changes. We are inclined to consider that the microangiopathic lesions are due to chronic injury of glomerular endothelial cells, exacerbated at outbreaks of the disease. Increased production of IL 6 could support the efficacy of corticosteroid therapy, particularly in acute clinical situations.

Renal biopsy in the elderly.

314 patients, aged 65 years or older, were biopsied because of a history of renal disease. In 203 patients, glomerular disease was diagnosed with one fourth having systemic disease and the remaining primary glomerulonephritis. 90 patients had tubulointerstitial disease, and 21 patients showed prominent vascular pathology. In a comparison with patients of younger age groups, it appeared that amyloidosis, membranous nephropathy, vasculitis and diabetes had a significantly higher incidence in the elderly. Main glomerular syndromes such as nephrotic syndrome and rapidly progressive glomerulonephritis imply to be managed appropriately. Glomerulosclerosis was found in high frequency, either as an isolated feature or associated with other lesions. Glomerulosclerosis seemed to be ischemic in origin and seems to represent a distinct entity as a cause of pathology in the elderly.

[Study of CD45 isoforms on T CD8 lymphocytes, in the peripheral blood and the graft in patients after kidney transplantation]. / Etude chez le transplanté rénal des isoformes du CD45 sur les lymphocytes T CD8, dans le sang circulant et dans le greffon.

We report characterization of CD45 isoforms expressed by CD8+ lymphocytes in peripheral blood and in the graft of 40 kidney transplanted patients who underwent kidney biopsy on the basis of clinical signs suggesting rejection. Standard histological examination of the biopsy fragments and three-color cytofluorimetric analysis of lymphocytes extracted from the same fragments by mechanical and enzymatic treatment were performed simultaneously and compared to the peripheral blood lymphocytes. In 14/40 biopsies where lymphocyte extraction succeeded, the predominant subset was CD8 (CD4/CD8 mean ratio was 0.53). Almost all CD8+ cells were activated: among these CD8+ cells, 55 percent were HLA-DR+, and 68 percent CD45RO+, i.e. of a memory cell type with cytotoxic activity. This situation resembles the in vitro observation made during mitogenic stimulation of lymphocytes by phytohemagglutinin, OKT3 or CML ("culture mixte lymphocytaire"). Beside their evident interest for the diagnosis, these data could be useful for our understanding of the physiopathology of the rejection crisis.

[Crescent: structure, evolution, pathogenesis]. / Le croissant: structure, évolution, pathogénie.

Extracapillary crescent is an elementary lesion which can be superimposed to any type of glomerulonephritis, or constitute the main lesion as in vasculitis, or appear to be idiopathic. One must oppose cellular crescent which is partially reversible, to irreversible fibrous crescent. Cellular composition of crescents has been much controversial: initially considered as having an epithelial-cell origin, then an exclusive macrophagic origin, crescents are in fact composed of epithelial cells, monocytes-macrophages and lymphocytes all together. The former are prevailing when Bowman's capsule (BC) is intact, whereas macrophages predominate when there is extensive damage of GBM and of BC. The initial event in crescent formation appear to be breaches in glomerular capillary wall, leading the deposition of fibrin within Bowman's space. The consequence is the proliferation of parietal epithelial cells and of activated macrophages followed by a production, in series, of cytokines and growth factors.

Immunofluorescence study of "non-idiopathic" renal amyloidosis.

The authors report the results of immunofluorescence (IF) studies of 17 cases of "non-idiopathic" renal biopsy-proven amyloidosis and 18 cases of various nephropathies and normal kidneys (as controls), investigated by IF by simultaneous use of antisera against routine IgG, IgM, IgA, C3, C4, Clq, beta-lipoprotein, albumin, and fibrinogen. Antisera against kappa and lambda light chains and amyloid A and amyloid P components were also used. Six of the 17 cases of amyloidosis were associated with immunocyte dyscrasia, and 11 were cases of reactive systemic amyloidosis associated with chronic infections or inflammatory and neoplastic disorders. In amyloidosis, IF deposits appeared for all antisera as homogeneous staining of mesangial nodules, and, more rarely, there was staining along the glomerular basement membranes. Overall immunoglobulins and C3 were present in 11 cases (64 per cent). Kappa and lambda light chains were demonstrated in 14 (82 per cent) and 12 (70 per cent) cases, respectively. In immunocyte dyscrasia associated with amyloidosis, immunoglobulin and light-chain deposits corresponding to a paraprotein abnormality were demonstrated in glomeruli and in tubular casts. Amyloid P component was always present in glomeruli with a bright and characteristic fluorescence, and it was frequently observed in arterioles. Amyloid A component was observed in six cases of reactive systemic amyloidosis but also in one case of immunocyte dyscrasia with amyloidosis. In view of the diversity of amyloid fibril types and their chemical nature, IF studies confirm the presence of different constituents but do not warrant any conclusion concerning the pathogenesis of this disease.

Immunofluorescence study of amyloid P-component patterns in human nephropathies.

The localization of amyloid P-component (AP) staining was studied by immunofluorescence in renal biopsies from 106 patients with various nephropathies and from 3 patients with normal kidneys. Linear staining was observed along the glomerular basement membranes (GBM) of normal kidneys. In amyloidosis, AP was always present in the glomeruli. In arteriolar walls, AP was present in numerous cases with varied intensity. No fixation was observed along tubular basement membranes. The possible modification of the permeability of GBM, related to a possible modification of the electrical charge of the filtration barrier, can be supposed.

[Are surgical renal biopsies useful for clinical prognosis in renal artery stenosis?]. / Les biopsies rénales chirurgicales dans la sténose de l'artère rénale sont-elles utiles au pronostic clinique?

The most significant results show the predominance of arteriolar lesions in the controlateral kidney, The most significant results show the predotients with unilateral renal artery stenosis. and parenchymal lesions of the kidney with stenosis in patients with atherosclerosis. These results do not seem to provide information which would alter the clinical management in any particular case.

Postpartum hemolytic uremic syndrome: a study of three cases with a review of the literature.

Three cases of postpartum hemolytic uremic syndrome (HUS) are presented. Symptoms of acute renal failure, hypertension and microangiopathic hemolytic anemia with thrombocytopenia occurred 10, 17 and 24 days after delivery. Despite early heparin therapy in all cases, one patient went into terminal renal failure needing chronic hemodialysis, with persistent hypertension which became uncontrollable requiring bilateral nephrectomy 6 months later. The second patient had diuresis one month after starting hemodialysis, but 3 months later developed malignant hypertension. Slight improvement in renal function with persistent hypertension occurred after hemodialysis for 20 months. The third patient showed complete clinical recovery after 2 months. Pathological examination of renal tissue showed the typical lesions of thrombotic microangiopathy (TMA). However, striking differences were observed in the lesion seen in early and late specimens. Early lesions could be differenciated from infancy TMA because the medium-dize arteries were more severely involved. Late lesions were variable, ranging from minor changes in glomeruli and blood vessels, via ischemic and sclerotic lesions in glomeruli with arteriolosclerosis, to the vascular and glomerular lesions seen in malignant nephrosclerosis. There was a good correlation between the renal pathology and the clinical outcome of the patients. HUS with renal TMA as a cuase of postpartum renal failure has been reported in 49 patients with a fatal outcome in 61%. The pathogenesis of the syndrome probably involves a primary endothelial damage. This causes local renal intravascular coagulation in the presence of the usual postpartum hypercoagulable state. This is shown by the presence of fibrin-fibrinogen in glomeruli and vessels, increased plasma fibrin degradation products, thrombocytopenia and lowered levels of coagulation factors. There is little hematological or pathological evidence fo disseminated intravascular coagulation or an immune-complex disease. Hypocomplementemia seen frequently is probably due to local C3 activation via the alternative pathway.