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PubMed2000

Distal myopathy in nephropathic cystinosis.

In long-standing nephropathic cystinosis complications are observed in various organs. Distal myopathy was first described in detail in 1994. The prevalence was calculated to be 24%. We studied seven patients with nephropathic cystinosis with neurophysiological techniques. Only two patients complained of a distal muscle weakness but all showed signs of myopathy on electromyography, which was more pronounced in the distal muscles. Motor and sensory nerve conduction parameters were within normal ranges. One patient with the juvenile form of nephropathic cystinosis also had myopathy. We conclude that distal myopathy can be detected in nephropathic cystinosis even in the absence of clinically overt muscle weakness. Cystine-depleting therapy with cysteamine is recommended for all patients with cystinosis, even after renal transplantation, and the effect on the myopathy should be studied.

Adolescent↗
PubMed2006

Nodular regenerative hyperplasia and severe portal hypertension in cystinosis.

BACKGROUND & AIMS: Cystinosis is a rare autosomal-recessive disorder characterized by the intralysosomal accumulation of cystine, which is responsible for widespread tissue destruction. Liver biopsy specimens of patients with cystinosis show cystine crystal formation in Kupffer cells. However, significant liver disease and portal hypertension is not a common complication of cystinosis. We report the case histories of 2 young men with poorly treated nephropathic cystinosis who developed noncirrhotic portal hypertension with evidence of nodular regenerative hyperplasia (NRH). METHODS: Liver biopsy examinations, upper and lower endoscopy with biopsy examination, imaging studies, venous pressure measurements, and laboratory investigations were used to evaluate the causes of the liver disease and portal hypertension. RESULTS: Histologic examination of liver biopsy specimens from both patients showed changes characteristic of NRH with portal hypertension documented by measurement of pressure gradients. In addition, endoscopy in the first patient showed varices and portal hypertensive gastropathy. CONCLUSIONS: NRH was confirmed by histologic examination of the liver in both patients and is the likely cause of their portal hypertension. NRH may represent a rare, late complication of cystinosis, although the mechanism remains undefined.

Adult↗
PubMed2002

Follow-up and treatment of adults with cystinosis in the Netherlands.

BACKGROUND: Cystinosis is a rare autosomal recessive disease, caused by intracellular cystine accumulation due to a defect in the lysosomal cystine carrier. Treatment with cysteamine favours the transport of cystine out of the lysosomes, diminishes organ damage, and postpones the progression of renal failure. The extra-renal deposition of cystine continues after renal transplantation, leading to later complications. The objective of this study was to evaluate the follow-up, the occurrence of late complications, the social status, and the adequacy of cysteamine treatment in adult patients with cystinosis. METHODS: The medical histories of 10 adult cystinosis patients aged 19-36 years were studied. The impairment of thyroid function, central nervous system, endocrine pancreas, and ocular manifestations, as well as treatment with cysteamine were evaluated. RESULTS: Eight patients received in total 12 renal grafts, one patient was dialysed and one received conservative treatment for chronic renal failure. Extra-renal complications were noted in six patients, loss of visual acuity in four, hypothyroidism in three, diabetes mellitus in one, cerebral atrophy and epilepsy in one, and swallowing difficulties in two patients. Ophthalmic control was not performed in two patients, thyroid function was not controlled in two and glycaemia not controlled in two patients. Seven patients received 2100-4000 mg cysteamine per day in 2 (n=2), 3 (n=1), 4 (n=3), or 6 (n=1) doses. Cystine concentration in leukocytes was measured once or twice a year in eight patients and was within the recommended range only in three patients. CONCLUSION: A high rate of extra-renal complications in adults with nephropathic cystinosis was found. Optimizing the cysteamine therapy may attenuate these complications. Better communication between paediatric and 'adult's' nephrologists is needed to improve follow-up and treatment of grown-up cystinosis patients.

Adult↗
PubMed1997

Tactile recognition in infantile nephropathic cystinosis.

Previous studies have demonstrated that individuals with cystinosis, an inherited metabolic disorder, have difficulty processing visual information, and may be selectively impaired in the ability to mentally rotate figures, despite having normal IQs and normal primary sensory function. In our novel task-the 'Black Box'-subjects identified objects solely by feeling the contours. Twenty-three subjects with cystinosis, aged 4 to 34 years, were individually matched with controls on age, sex, handedness, and test form. Subjects with cystinosis performed significantly worse in identifying objects than did controls. In addition, when only subjects over 7 years of age were included, those with cystinosis took significantly longer to correctly identify objects than did controls. Our findings suggest that individuals with cystinosis have difficulty with tactile recognition of common objects. These results support the hypothesis that a genetic disorder may have specific behavioral correlates.

Adolescent↗
PubMed1987

Lysosomal cystine transport in cystinosis variants and their parents.

Children with nephropathic cystinosis store 50 to 100 times normal amounts of free cystine in many cells and display negligible lysosomal cystine transport in their leucocytes and cultured fibroblasts. A patient with intermediate (adolescent) cystinosis exhibited a similar deficiency of egress out of fibroblast lysosome-rich granular fractions. Another individual with benign (adult) cystinosis accumulated only 2.85 nmol 1/2 cystine/mg leucocyte protein, or 20-50% of the amount stored in nephropathic cystinosis leucocytes. His leucocyte granular fractions also displayed substantial residual cystine-carrying capacity, as determined by measurement of lysosomal cystine counter-transport. We conclude that the variant forms of cystinosis represent a continuum of lysosomal cystine storage, with the varied clinical presentation depending on the amount of residual cystine-carrying capacity, genetic predispositions, and differential tissue susceptibilities.

Adult↗
PubMed2003

ACE inhibitorenalapril diminishes albuminuria in patients with cystinosis.

BACKGROUND/AIMS: Cystinosis, a rare autosomal recessive disease, manifests with renal Fanconi syndrome during the first year of life. Interstitial damage is a major cause of renal failure in patients with cystinosis. We presume that albuminuria contributes to the development of renal failure in these patients. The aim of this study was to examine whether the administration of ACE inhibitor enalapril diminishes albuminuria in patients with cystinosis. METHODS: Five patients with cystinosis aged 4 - 9 years were studied. All patients had Fanconi syndrome and were treated with cysteamine. Median creatinine clearance was 48 ml/min/1.73 m2 (range 21 - 61). The excretion of albumin and alpha1 microglobulin as well as arterial blood pressure and serum creatinine were evaluated before and at 3 months on oral administration of enalapril (0.15 mg/kg once daily). RESULTS: At 3 months on enalapril, albuminuria decreased in all patients (1,042 vs 629 mg per 24 h, p < 0.05). The median reduction of albuminuria was 43% (range: 4 - 72%, p < 0.05). Urinary excretion of alpha1 microglobulin remained constant. Systolic blood pressure decreased from median 110 - 100 mmHg (p < 0.05), while diastolic blood pressure remained stable (median 60 mmHg). Creatinine clearance decreased from median 48 - 45 ml/min/1.73 m2 (p < 0.05) and returned to previous values after discontinuation of enalapril. CONCLUSION: ACE inhibitor enalapril diminishes albuminuria in patients with cystinosis and might be used in these patients in order to slow the progression of renal insufficiency attributed to proteinuria.

Albuminuria↗
PubMed1992

[Cystinosis].

Recent progress of the study of the pathogenesis, diagnosis, and treatment of a lysosomal transport disorder, cystinosis is reviewed. Cystinosis is an autosomal recessively inherited disease that is caused by the accumulation of cystine in lysosome due to lack of the cystine transport system in lysosome. Renal transplantation has been a successful treatment for the cystinosis patients who are in the end stage renal failure, and this therapy has markedly prolonged the life span of cystinosis patients. Recently, oral cysteamine therapy has been successful in the excretion of accumulated cystine in cystinosis patients, and in improving the symptoms. Studies are now under way to see if early (within a month of life) start of cysteamine therapy would achieve the most satisfactory therapeutic effect and maintain normal renal function.

Administration, Oral↗
PubMed1987

Contrast sensitivity function in nephropathic cystinosis.

Cystinosis is a rare autosomal recessive metabolic disorder in which nonprotein cystine accumulates within most body organs due to a defect in lysosomal cystine transport. The pathognomonic ocular manifestations of cystinosis are the presence of distinctive iridescent crystals within ocular tissue and a pigmentary retinopathy. We measured spatial contrast sensitivity in seven patients with infantile-onset nephropathic cystinosis and compared their contrast sensitivity function with that measured in ten age-matched controls. Spatial contrast sensitivities in the patient group were significantly lower than those in the normal group. Loss of contrast sensitivity in the patients with nephropathic cystinosis was more pronounced at higher spatial frequencies. We speculate that this loss of contrast function is primarily a manifestation of corneal disease, with secondary contributions from retinal changes and central nervous system dysfunction.

Adolescent↗
PubMed1991

Ocular manifestations of nephropathic cystinosis. The French-Canadian experience in a genetically homogeneous population.

A large spectrum of ocular pathologic features have been described in infantile cystinosis. Reported symptoms may require corneal transplantation and therapeutic efforts to solubilize cystine crystals with hourly administration of cysteamine (mercaptamine) drops. French Canada has the highest incidence of cystinosis in the world. We studied 18 patients with cystinosis who appeared to have much milder ocular involvement than that in other reported series. No operative interventions were required. Relatively mild photophobia was the most common ocular manifestation of cystinosis.

Adolescent↗
PubMed1991

Biochemical and genetic analysis of a child with cystic fibrosis and cystinosis.

We have studied a child with cystic fibrosis (CF), nephropathic cystinosis, and manifestations of Bartter syndrome, a finding reported previously in both of these diseases (CF and cystinosis). The chance of an individual inheriting a mutant allele for both CF and cystinosis from each of his parents by independent segregation is very small. Therefore, other mechanisms of inheritance were investigated, including whether his diseases were caused by a chromosome deletion or rearrangement that caused defects in both genes, whether his phenotype was caused by a new mutation or variant of either disease, or whether both diseases were inherited together due to inheritance of 2 copies of the same chromosome from one of the parents (uniparental disomy). An investigation was made of whether having mutations for both CF and cystinosis resulted in a different phenotype for either disease and whether the child was a heterozygote rather than a homozygote for one of the mutations. The results suggest that neither disease influenced the expression of the defect in the other and that this child inherited a mutant allele for both diseases independently from each parent.

Cysteine↗
PubMed1998

A randomized clinical trial of topical cysteamine disulfide (cystamine) versus free thiol (cysteamine) in the treatment of corneal cystine crystals in cystinosis.

In nephropathic cystinosis, corneal cystine crystals cause severe photophobia and corneal erosions. Topical cysteamine dissolves these crystals, but cannot be marketed because it rapidly oxidizes to the disulfide form, cystamine, at room temperature. Since cystamine itself could be used commercially, we compared the efficacy of cystamine and cysteamine with respect to cystine crystal dissolution in a randomized, double-masked clinical trial. One eye each of 14 patients with cystinosis was randomized to either cystamine or cysteamine, 0.5%, with 0.01% benzalkonium chloride; the companion eye was treated with the alternate preparation. Corneal crystals were photographed and a density score was assigned to each slide based on 13 standard slides. After 8-20 months, 6 patients showed significant reduction of the corneal crystal score in only one eye. In each case, the improved eye was the cysteamine-treated eye. Theoretically, cysteamine should dissolve both intracellular and extracellular crystals, whereas cystamine should dissolve only intracellular crystals because it must first be reduced to the free thiol by the cytoplasmic-reducing environment. Hence, the lack of efficacy of the disulfide cystamine suggests that some corneal cystine crystals in cystinosis patients are extracellular, and that another form of stable, topical cysteamine must be developed for cystinosis patients.

Administration, Topical↗
PubMed1995

Recent advances in the treatment of cystinosis.

Cysteamine bitartrate capsules (Cystagon) have been approved by the US Food and Drug Administration for use in patients with nephropathic cystinosis. Plasma cysteamine concentrations were virtually identical at various times following ingestion of either cysteamine hydrochloride or Cystagon capsules in 24 normal control subjects. A transfer study was done with eight cystinosis patients who had been receiving either cysteamine hydrochloride or phosphocysteamine for many years. The plasma cysteamine concentration was significantly higher 2h after Cystagon and the leukocyte cystine content was significantly lower at all times after Cystagon compared to older forms of the drug. These differences are probably the result of greater patient compliance in taking the capsules compared to the older, liquid forms of the drug. A new method for following the course of renal glomerular deterioration in diseases such as cystinosis has been published recently. This method was used to re-analyse data on the efficacy of cysteamine treatment and to re-analyse new data on treating cystinosis patients with either of two doses of cysteamine (1.30 g/m2 per day and 1.95 g/m2 per day). This new method agrees well with other methods and shows that both doses of drug are equally effective in maintaining glomerular function.

Adolescent↗
PubMed1985

Cystinosis in the Federal Republic of Germany. Coordination and analysis of the data.

In our survey, 101 infants and children with cystinosis were registered in the Federal Republic of Germany. Ninety-five patients showed the infantile type of cystinosis, five the adolescent type and one possibly the adult type. The minimum incidence rate of infantile and adolescent cystinosis in the FRG was 1 patient per 179 000 live-births. In contrast to other countries, cystinotic patients were evenly distributed in the FRG. Patients with cystinosis originated more frequently from rural communities than from large cities. Before 1968 most patients died before reaching terminal renal failure, usually due to uncontrolled disturbances of water and electrolyte metabolism. Since 1976 the causes of death other than uraemia have been rare and most patients with terminal renal failure have entered a renal replacement program.

Adolescent↗
PubMed2003

Early oral cysteamine therapy for nephropathic cystinosis.

UNLABELLED: Nephropathic cystinosis is an autosomal recessive lysosomal storage disorder in which intracellular cystine accumulates due to impaired transport out of lysosomes. The clinical manifestations include renal tubular Fanconi syndrome in the 1st year of life, with hypophosphatemic rickets, hypokalemia, polyuria, dehydration and acidosis, growth retardation, hypothyroidism, photophobia, renal glomerular deterioration by 10 years of age, and late complications such as myopathy, pancreatic insufficiency, and retinal blindnesss. The cystinosis gene, CTNS, codes for cystinosin, a 367 amino acid protein with seven transmembrane domains. More than 50 CTNSmutations have been identified, but approximately 50% of Northern European patients have a 57257-bp deletion which removes the first nine exons of CTNS. The mainstay of cystinosis therapy is oral cysteamine (Cystagon). This aminothiol can lower intracellular cystine content by 95%, and has proven efficacy in delaying renal glomerular deterioration, enhancing growth, preventing hypothyroidism, and lowering muscle cystine content. Its early and diligent use is critical; in one study, for every month of treatment prior to 3 years of age, 14 months' worth of later renal function were preserved. Several examples of individual patients treated early and having preserved renal function and normal growth are available. Newborn screening using a chip containing cDNA to detect common CTNSmutations may allow diagnosis and treatment in the first weeks of life. CONCLUSIONS: Early diagnosis and treatment of nephropathic cystinosis can change the course of this disease.

Administration, Oral↗
PubMed2004

A new mutation in two siblings with cystinosis presenting with Bartter syndrome.

Nephropathic cystinosis is a severe autosomal recessive inherited metabolic disease characterized by accumulation of free cystine in lysosomes. Cystinosis can lead to renal failure and multiorgan impairment. Only five cases of cystinosis with associated Bartter syndrome are reported in the literature, and no genetic evaluation has been reported. We describe two siblings with nephropathic cystinosis presenting with features of Bartter syndrome and their genetic pattern.

Bartter Syndrome↗
PubMed2004

Exfoliated human proximal tubular cells: a model of cystinosis and Fanconi syndrome.

The renal Fanconi syndrome (FS) is characterised by generalised proximal tubular dysfunction. Cystinosis is the most common genetic cause of the FS and results from defective function of cystinosin, due to mutations of the CTNS gene leading to intralysosomal cystine accumulation. Despite these advances in our understanding of the molecular basis of cystinosis, the mechanisms of proximal tubular cell (PTC) dysfunction are still unknown. We have further characterised an in vitro model of cultured cells exfoliated in patients' urine. We cultured cells from 9 cystinosis children, 4 children with Lowe syndrome and 8 controls. PTC phenotype and homogeneity were studied by lectin staining, immunocytochemistry (using ZO-1 as an epithelial marker) and enzyme cytochemistry (using gamma-glutamyltransferase as a PTC marker). All cultured cells showed PTC phenotype. Cystinosin was stained using anti-cystinosin antibody and co-localised to the lysosomes with LAMP-2 antibody. Additionally, we have demonstrated significantly elevated intracellular cystine levels in cystinotic cell lines (13.8+/-2.3 nmol 1/2 cystine/mg protein, P <0.001) compared with controls. We believe this in vitro model will allow further investigation of cystinosis and other types of the FS.

Cells, Cultured↗
PubMed1977

Pediatric kidney transplantation for cystinosis.

In an experience of more than 700 kidney transplants, three recipients are known to have had congenital cystinosis. A cadaver kidney transplant in a 10 yr old child with nephropathic cystinosis functioned well for 7 1/2 yr before it was rejected and the graft was free of recurrent cystinosis after that interval. This prolongation of life was associated with marked accumulation of cystine in the patient's thyroid gland, presenting as a mass in the neck. If additional longevity is achieved in this patient, abnormal intracellular cystine accumulation may be expected in other host tissues. Retransplantation was carried out with the father as donor, accepting the possibility of increased cystine levels in the retransplant. This patient's age of 18 yr identifies him as one of the longest known survivors of infantile nephropathic cystinosis.

Adolescent↗
PubMed1992

Early occurrence of end-stage renal disease in a patient with infantile nephropathic cystinosis.

We report the case of a patient with infantile nephropathic cystinosis who required renal transplantation at age 30 months. Exhaustive evaluation did not identify a cause of progressive renal failure other than cystinosis. The patient's genetic lesion was allelic with those of other patients with cystinosis; fusion of this patient's fibroblasts with fibroblasts from another patient with infantile nephropathic cystinosis did not demonstrate complementation of the biochemical defect.

Clone Cells↗