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The paper reports a case of cystinosis with the involvement of kidneys, myocardium and liver in a female of 43. Late development of kidney failure might be due to a partial deficiency of the enzyme responsible for a cystine transport in the cell.
We report on an 8-year-old boy with infantile cystinosis. The patient died in hospital for unknown reason after cardiopulmonary arrest although resuscitation was started immediately. As opposed to other cases [1-3], neither laboratory investigations nor autopsy in out patient gave an explanation for the sudden death.
Nephropathic cystinosis is a lethal inborn error of metabolism that destroys kidney function by age 10 years. It is characterized by lysosomal cystine accumulation. How the cystine causes the phenotype is an open question. We propose that during apoptosis, permeablized lysosomes permit cystine to reach the cytosol where mixed disulfide formation occurs, augmenting apoptosis by interaction with a variety of pro-apoptotic proteins.
Cystine glutathione transhydrogenase, cystine-reductase, and glutathion reductase activities were studied in cultivated skin fibroblasts of control subjects and of three patients with cystinosis. Specific activity, pH optima, electrophoretic mobility, and kinetic parameters were described. Evidence for two isoenzyme forms of cystine-glutathione transhydrogenase was obtained. No difference was detected in activity of biochemical characteristics of these enzymes between cells of cystinotic and normal subjects.
Cystinosis is frequently presented with cystine storage in the cornea and conjunctiva, and the diagnosis can be established by slit-lamp examination. It can also be confirmed by electron microscopy of a conjunctival biopsy. The present paper reports on a 16-month-old boy with Fanconi's syndrome, in whom the slit-lamp examination did not show crystal deposits of cystine in the conjunctiva. The ultrastructural study of the conjunctival biopsy demonstrated polygonal crystals within double membrane-limited organelles located in fibroblasts. Similar crystals were subsequently found in a kidney biopsy. We therefore think that conjunctival biopsy is a valuable diagnostic tool prior to performing renal biopsy, even in cases with negative findings by ophthalmologic examination.
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.
Exposure of cultured skin fibroblast of normal, infantile nephropathic, juvenile-late-onset and adult type cystinotic patients and their corresponding obligate heterozygotes to 0.5 mmol/l of 35S cystine dimethyl ester for 30 minutes, resulted in an accumulation of cystine within the cells, and was used to look for differences in cystine clearance between the different cell types. The results suggested that all cystinotic variants are defective in their capacity to eliminate cystine to the same extent. The presented data imply that, separate clinical phenotypic variants of cystinosis, cannot be differentiated biochemically by the assay of cystine egress.
A patient affected with Debrè-De Toni-Fanconi syndrome secondary to cystinosis, has been given doses of vitamin D metabolites. This resulted in a reduced plasma 1,25(OH)2D level. This data should confirm, as it has already been noted in literature. There is a defect in renal 1 alpha hydroxylation of 25OHD. The administration of 1 alpha dihydroxycholecalciferol has brought rapid improvement to severe metabolic bone disease. There are no noticed side effects.
Renal calculi have rarely been cited as a major manifestation of cystinosis. We report a case history of a child with multiple urate calculi and a calcium oxalate stone resulting from proximal tubular dysfunction that was not associated with bicarbonate wastage.
Two children were followed for severe congenital tubulopathies: a boy presented an excessive sodium, calcium and water excretion; a girl had cystinosis and a De Toni-Debré-Fanconi syndrome. These renal defects were both associated with increased levels of plasma renin activity and aldosterone, and excessive urinary PGE1 production. They had been unresponsive to therapeutic attempts. Only indomethacin treatment was successful in reversing the biochemical abnormalities and improving the growth pattern.
The psychosocial and intellectual development of 4 boys with nephropathic cystinosis and brain atrophy documented by cranial computerized tomography was investigated by use of biographical data and psychological tests (HAWIK, Deutscher Rechtschreibtest). Inspite of the brain atrophy the patients showed low-normal intellectual capacities and mainly average school performance. There were no psychosocial abnormalities correlated to the primary metabolic disease. However, renal dwarfism led to mascotism requiring psychotherapy.
Lysosomes containing large amounts of the amino acid, cystine, were obtained from transformed, cultured, human lymphoblasts which had been exposed to cystine dimethyl ester. Lysosomal cystine efflux was greatly enhanced by exogenous ATP in cell lines from normal individuals. Cystine efflux was unresponsive to ATP in lysosomes from individuals with the disorder, cystinosis. Efflux of cystine from normal cell lysosomes was inhibited by both the ATP analog, 5-adenylylimidodiphosphate, and the proton translocator, carbonyl cyanide m-chlorophenylhydrazone. Efflux was not affected by ouabain or oligomycin. Thus, lysosomal cystine efflux is dependent upon the functioning of a proton-pump ATPase. ATPase-dependent cystine efflux appears to be aberrant in cystinotic cell lysosomes.
The purpose of presenting this case is to emphasize the importance of the slit lamp examination in patients with complex symptoms and signs of growth retardation, organomegaly, and abnormal kidney function tests. As the clinical expression varies greatly from one patient to another and in spite of extensive and expensive work-up, final diagnosis of cystinosis may be established only by careful ophthalmologic examination.
The effect of cysteamine was studied in 6 children with nephropathic cystinosis. In 3 of them an in vitro study on fibroblasts was performed. The cystine content of fibroblasts was immediately diminished (about 90% of total cystine content) as soon as the concentration of cysteamine in the medium was greater than or equal to 0,1 mmole/l. In vivo, 50 to 89 mg/kg/day of cysteamine was administered for 9 to 37 months (mean 21,3). There was no adverse reaction. In all cases a dramatic decline in leukocyte cystine level was observed (in 5 cases the level was within the range seen in clinically unaffected heterozygotes). Growth was not improved. The renal function was stabilised in 3 cases. Photophobia which was present in 4 children decreased in 2 cases or disappeared in 2 cases.
Isolated proteinuria preceding tubular dysfunction for years was the presenting laboratory sign in a patient with adolescent cystinosis, followed up to end-stage renal failure in the second decade of life. The renal biopsy showed the early characteristic features, multinucleated giant podocytes. The diagnosis was documented by slit lamp examination of the eyes and cystine determination in fibroblasts.
Cystinosis was discovered by chance in two adolescent boys who had proteinuria with minor tubular abnormalities. Renal biopsies were examined by light microscopy, electron microscopy and immunofluorescence. There were few histological changes but crystals were present in the epithelial cells of the glomerulus and occasionally in the tubules. A further unusual feature was the detection of IgA deposits in the mesangium.
In a retrospective study the overall survival time of 205 cystinotic patients of six countries was determined. The median survival time was 8.5 years. The median time for 'renal death' (age at death due to uraemia or age at starting renal replacement therapy) was 9.2 years. The youngest patient dying of renal death was 5.2 years. No sex difference in survival time was noticed. Furthermore no difference in survival time was noted between the different countries. The analysis of the overall survival curve indicates no clear differences between the infantile and adolescent types of cystinosis.
A 19-year-old girl suffering from the nephropathic form of cystinosis presented with the full clinical and biochemical picture of Fanconi's syndrome. Polyuria, polydipsia and photophobia associated with severe growth retardation and rickets were the main clinical features. The essential biochemical abnormalities consisted of hypophosphataemia, hypokalaemia and hypo-uricaemia together with a systemic acidosis and a reduced creatinine clearance rate. There was generalized amino-aciduria, glycosuria and bicarbonaturia. In addition, the fractional excretion of potassium, phosphate and uric acid was significantly increased. Slit-lamp examination of the cornea and histological examination of the conjuctiva, liver, bone marrow and kidney demonstrated cystine crystals.