Biomedical subjects
Publications and source records attributed to R Habib.
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Denys-Drash syndrome is a rare human condition in which severe urogenital aberrations result in renal failure, pseudohermaphroditism, and Wilms' tumor (nephroblastoma). To investigate its possible role, we have analyzed the coding exons of the Wilms' tumor suppressor gene (WT1) for germline mutations. In ten independent cases of Denys-Drash syndrome, point mutations in the zinc finger domains of one WT1 gene copy were found. Nine of these mutations are found within exon 9 (zinc finger III); the remaining mutation is in exon 8 (zinc finger II). These mutations directly affect DNA sequence recognition. In two families analyzed, the mutations were shown to arise de novo. Wilms' tumors from three individuals and one juvenile granulosa cell tumor demonstrate reduction to homozygosity for the mutated WT1 allele. Our results provide evidence of a direct role for WT1 in Denys-Drash syndrome and thus urogenital system development.
Renal biopsy specimens of 40 patients with recent-onset insulin-dependent diabetes mellitus treated with cyclosporine (CSA) for 6-29 months were examined. Cyclosporine-associated chronic vascular interstitial toxicity of moderate intensity was found in 10 patients (25%). The most prominent lesions were interstitial fibrosis and tubular atrophy. Arteriolopathy was less pronounced and glomerular damage unremarkable. A significant correlation exists between the extent of tubular atrophy and CSA trough whole blood levels. These data indicate that the development of CSA-associated chronic nephropathy is dose-dependent.
Cyclosporin A (CyA, Sandimmun) was given to 71 children with idiopathic nephrotic syndrome, 45 of whom were steroid-dependent with signs of steroid toxicity, and 23 who were steroid-resistant. Cyclosporin A was effective in 80% of the steroid-dependent patients, allowing cessation of corticosteroid treatment. However, most of these patients relapsed when CyA was tapered or withdrawn. In these patients, CyA may be required for long periods of time. Conversely, CyA was less effective in steroid-resistant patients; only 7% achieved remission with CyA alone. Cyclosporin A in association with prednisone may be an effective alternative as 8 out of 14 patients entered remission with this treatment combination. Serial renal biopsies were performed in 43 patients to evaluate the potential nephrotoxicity of the treatment. Eighteen patients developed significant tubulointerstitial lesions which were attributable to CyA nephrotoxicity. The risk of developing chronic nephrotoxicity appears to be higher in steroid-resistant patients, and was not related to the duration of treatment. Cyclosporin A nephrotoxicity can develop in patients with normal renal function.
A clinicopathologic study of 41 biopsy specimens from renal grafts transplanted at least ten years earlier showed normal findings or only mild tubulointerstitial lesions in 63% of cases. Results confirmed the good prognostic value of renal graft biopsy performed ten years after transplantation. A very close correlation was demonstrated between histologic evidence of chronic rejection (interstitial fibrosis, tubular atrophy, and fibrous endarteritis) and long-term graft outcome. Severity of interstitial fibrosis was apparently a more reliable indicator of prognosis than severity of fibrous endarteritis. Among 16 patients with a history of acute rejection, none had residual parenchymatous lesions. In contrast, among patients with major tubulointerstitial and/or vascular lesions, most had previously experienced one or several episodes of acute rejection. Evidence of allograft glomerulopathy was seen in approximately one case in four (11 patients). Among these patients, only eight had proteinuria and only four lost their graft. Among the four patients who developed recurrent membranoproliferative glomerulonephritis (type I in three cases and type II in one case), three lost the deposits previously detected by immunofluorescence, probably as a result of immunosuppressive therapy.
Clinical and biological features, histologic findings, and outcome were studied in 32 children with systemic lupus erythematosus who underwent at least two renal biopsies during the course of their disease. Results showed that renal biopsy was a useful aid for therapy in that it demonstrated the presence or absence of disease activity, but was unhelpful for predicting the long term outcome. Repeat renal biopsies proved an excellent means for monitoring the course of the nephropathy. This study showed that the various patterns of glomerulonephritis seen in SLE may exhibit changes over time, with either improvement or progression. Regression of lesions was seen mainly after treatment, whereas progression was associated with renal or extrarenal exacerbations of the disease. The absence of clinical improvement may reflect transformation to histologic forms which are unresponsive to therapy.
With the worldwide use of immunofluorescence microscopy, idiopathic IgA nephropathy (Berger's disease) has been recognized as a distinct form of primary glomerular disease. IgA nephropathy is the most common form of GN in many parts of the world. However, since the criteria for diagnosis are exclusively based on the findings of predominant IgA in the mesangium, the boundaries of this "entity" are not well delineated and it has become clear that several different clinical conditions share this common immunopathology. IgA nephropathy should, therefore be regarded as a syndrome. Schönlein-Henoch purpura (SHP) and Berger's disease represent the primary form of this syndrome. The clinical features of both diseases in children are reviewed. Although the clinical symptoms may appear different there is a close relationship between SHP and IgA nephropathy. They share the same pathology, the same pathogenesis, and they may both recur on a transplanted kidney. Moreover, both diseases can occur in a single family. When pathologic mechanisms are more defined, SHP may prove to be 1 end of a spectrum of diseases associated with microvascular immune deposits in which IgA is the predominant immunoglobulin seen, the other end being Berger's disease.
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Diffuse mesangial sclerosis (DMS) has been described as a distinct morphological pattern observed in patients presenting with a congenital or infantile nephrotic syndrome (NS) leading to end stage renal failure (ESRF) before the age of 3 years (Habib & Bois: Helv. Peadiat. Acta 28: 91-107, 1973). In recent years, we diagnosed this entity in 36 infants and we wish to report our findings which extend our previous observations. The nephropathy was discovered before 1 year of age in 26 patients. In one of these the onset was neonatal. Five additional children were between 1 and 2 years of age at onset of the disease and the remaining 5 were between 24 and 42 months old. Thirty-three patients presented with a NS often preceded by a proteinuria and associated with renal failure in 6 of them. The 3 remaining patients presented with renal failure. Thirty-one patients reached ESRF before the age of 4 years. Progression was slower in 5 patients who were respectively 5, 5, 6, 8 and 11 years old at ESRF. Thirteen patients were transplanted and none recurred their original disease. Seven patients in 4 families had similarly affected siblings. In 16 patients (6 boys and 10 girls) the nephropathy was isolated. In the remaining 20 several associated findings were noted. In 14 infants a diagnosis of Drash syndrome was made on the basis of the association of a male pseudo-hermaphroditism (PsH) and Wilms tumour (WT) in 5, of a male PsH in 5 additional infants and of a WT in 4 female patients.(ABSTRACT TRUNCATED AT 250 WORDS)
We observed an unusual glomerular disease in eight pediatric patients. Clinical features of this early, progressive renal disease included increased blood pressure in many cases, extrarenal hematologic and pulmonary symptoms, and, in one of our patients and two genetically related children, hemolytic uremic syndrome with thrombotic microangiopathy resulting in permanent renal failure. Histologic studies showed major and complex modifications of glomerular capillary walls and electron microscopy disclosed numerous bundles of fibrillar collagen within the extracellular glomerular matrix. Clinical and genetic investigations out-ruled hereditary osteo-onychodysplasia, a condition in which fibrillar collagen is found within glomerular basement membranes. In addition results of family studies were consistent with autosomal recessive transmission of this new entity.
Among the 652 consecutive renal transplants performed from January 1973 through December 1988, all graft failures within 60 days of transplantation were retrospectively analyzed. The 53 early failures were divided into four groups on the basis of pathologic findings in the removed transplant). 1) Irreversible vascular rejection (17 cases); in ten patients, this rejection occurred between the fourth and eight days and was manifested by uniform clinical features. 2) Thrombosis of the renal artery (18 cases), with several subgroups: a) early postoperative thrombosis (5 cases) with primary anuria; b) thrombosis following reoperation (6 cases) for urine leakage or occlusion; c) thrombosis with a clotting disorder,; d) and five cases of thrombosis with clinical manifestations of vascular rejection but with isolated thrombosis upon histologic examination. 3) Thrombosis of the renal vein (12 cases), with primary anuria in nine cases, and rupture of the kidney in three. 4) The last group includes six cases due to a variety of causes: one immediately non-viable -kidney, two severe, irreversible cases of tubulonephritis, one cortical necrosis secondary to circulatory collapse in the recipient, one complete necrosis of the ureter requiring removal of the transplant, and one immediate recurrence of hemolytic uremic syndrome. Among the risk factors for early failure, attention is drawn to the young age of the donor or recipient that increases the risk of thrombosis. Furthermore, the risk of vascular rejection was decreased in patients preventively treated by OKT3.
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Over a 15-year period we observed seven children (four girls, three boys) who presented within the first months of life with severe renal failure and acidosis, associated with hypertension in five patients and polyuria in four. In addition, one patient had a severe cholestatic liver disease. In two families, a similarly affected sibling had died previously. Four patients were referred with the clinical diagnosis of polycystic kidney disease because of moderate enlargement of kidneys, but renal imaging (intravenous pyelography and ultrasonography) did not confirm this diagnosis. A renal biopsy, performed in all patients, showed similar features characterized by a diffuse chronic tubulo-interstitial nephritis (TIN) and particularly by the presence of microcystic dilatation of proximal tubules and Bowman's space. Liver pathology was normal in two patients, including one with hepatomegaly. However, in the patient with cholestasis there was inflammatory portal fibrosis with mild duct proliferation. Progression of the renal disease was extremely rapid and all patients reached end-stage renal failure (ESRF) before the age of 2 years (11-22 months). Two children had successful renal transplants. Although this chronic TIN shares some features with nephronophthisis, we suggest that it represents a distinct entity both on clinical and morphological grounds. The specific clinical features of this disease are its early onset and rapid progression to ESRF. Pathologically, it differs from nephronophthisis by the absence of medullary cysts and thickened tubular basement membranes and by the presence of cortical microcysts.
Twenty-four biopsies of renal allografts, generally cadaveric, from 20 patients with cystinosis were examined by light, polarization, phase contrast, and electron microscopy. The unusual dark cells previously reported in the native kidneys and livers of patients with cystinosis were observed in 12 of the 24 biopsies. The cells were present in the interstitium in all of these 12 biopsies, in glomeruli in one biopsy, and in the tubular lumen in two biopsies. They were evident by light and electron microscopy in stained and unstained ultrathin sections, and could be discerned solely in Epon sections. The dark appearance resulted from the presence of dark, fine granular material in the cytoplasm and nucleus and in cytoplasmic inclusions. The cells were judged to be macrophages. They were present as early as 3 months following transplantation and bore no relationship to interstitial crystals or inflammation. The dark cells have two important implications: cystine storage may not be limited to lysosomes, and dark cells are a morphologic alternative to the traditional identifying configuration of cystine in tissues, namely crystals.
Within two years we have had the opportunity of observing seven leukemic children who were referred to our Pediatric Nephrology Unit for delayed renal failure following bone marrow transplantation (BMT). These children (3 to 12 years old), six with acute lymphoblastic leukemia (ALL) and one with acute non-lymphoblastic leukemia (ANLL), underwent BMT (4 autologous BMT, 3 allogeneic BMT) after the first remission in two, and after the second remission in five. Preparative regimen for BMT included cyclosphosphamide in three, cyclosphosphamide, vepeside and cytosine A in four, and a total body irradiation in a single dose of 10 grays (1000 R) in all of them. Three children were treated immediately after grafting with low dose cyclosporine for four to six months. Five to 10 months after BMT, four patients developed a hemolytic uremic syndrome with severe hypertension. The remaining three were found to have isolated renal insufficiency several months post-BMT. In the seven patients, renal biopsy showed a uniform pattern of severe glomerular involvement characterized by extensive lesions of mesangiolysis associated with severe arteriolonecrosis. A repeat biopsy performed one year later, in two patients showed severe scarring of the renal parenchyma with minor lesions of mesangiolysis. The similarity of the pathologic features observed suggests that the same mechanism might have been operative in the seven patients. It is very likely that the nephropathy is related to total body irradiation enhanced by chemotherapy. We conclude that current treatments of high risk leukemia might become a new cause of chronic renal failure. Further investigations are needed to know the exact incidence of this complication.
Renal cysts are present in a wide variety of renal diseases, including those having a dysplastic nature and those of genetic origin. Genetic counseling requires clear differentiation between these types of cysts. This concept has made the classification of Potter useless because of the confusion it introduces between inherited diseases and developmental abnormalities. According to this classification, type I corresponds to autosomal recessive polycystic kidney disease (RPKD), type II to multicystic dysplasia, type III to autosomal dominant polycystic kidney disease (DPKD), and type IV to cystic dysplasia associated with urethral obstruction. The term "polycystic kidney disease" should be reserved for two hereditary cystic diseases, RPKD and DPKD, which are clearly distinct both by their modes of inheritance and by their pathologic characteristics. Both forms of polycystic disease may occur in children, but because the recessive form is much more prevalent, it is commonly called the "infantile form," whereas dominant polycystic disease is commonly known as the "adult form." The pediatric expression of these two forms and the problems of differential diagnosis will be examined.
Twenty-four biopsies of generally cadaveric renal allografts from 20 patients with cystinosis were examined by light, polarization, phase contrast and electron microscopy. Cystine crystals, or cytoplasmic crystalline spaces compatible with cystine, were observed in interstitial cells in 23 of the 24 biopsies and in glomeruli in six. Among the six, crystalline spaces were identified by electron microscopy in cells compatible with macrophages in the mesangium in two, and, in one of the latter, dark, presumably cystine-containing cells were also present in the mesangium. On the premise that cystine-containing cells derive from the host, these findings support the thesis that in man cells of the mononuclear phagocyte system of extrarenal origin may exist in the mesangium. However, in comparison with infiltration of the interstitium, infiltration of the glomerulus by macrophages from extrarenal sources is scant, as studied under conditions of renal transplantation.