Osteoimmunology in mucopolysaccharidoses type I, II, VI and VII. Immunological regulation of the osteoarticular system in the course of metabolic inflammation.

BACKGROUND: Mucopolysaccharidoses (MPSs) are rare genetic diseases caused by a deficient activity of one of the lysosomal enzymes involved in the glycosaminoglycan (GAG) breakdown pathway. These metabolic blocks lead to the accumulation of GAGs in various organs and tissues, resulting in a multisystemic clinical picture. The pathological GAG accumulation begins a cascade of interrelated responses: metabolic, inflammatory and immunological with systemic effects. Metabolic inflammation, secondary to GAG storage, is a significant cause of osteoarticular symptoms in MPS disorders. OBJECTIVE AND METHOD: The aim of this review is to present recent progress in the understanding of the role of inflammatory and immune processes in the pathophysiology of osteoarticular symptoms in MPS disorders and potential therapeutic interventions based on published reports in MPS patients and studies in animal models. RESULTS AND CONCLUSIONS: The immune and skeletal systems have a number of shared regulatory molecules and many relationships between bone disorders and aberrant immune responses in MPS can be explained by osteoimmunology. The treatment options currently available are not sufficiently effective in the prevention, inhibition and treatment of osteoarticular symptoms in MPS disease. A lot can be learnt from interactions between skeletal and immune systems in autoimmune diseases such as rheumatoid arthritis (RA) and similarities between RA and MPS point to the possibility of using the experience with RA in the treatment of MPS in the future. The use of different anti-inflammatory drugs requires further study, but it seems to be an important direction for new therapeutic options for MPS patients.

Enzyme replacement therapy for mucopolysaccharidosis II from 3 months of age: a 3-year follow-up.

AIM: We present a 3-year follow-up of a boy with mucopolysaccharidosis type II (MPS II) who had idursulfase therapy initiated at the age of 3 months and compare his clinical course to his healthy twin brother. METHODS: Detailed anthropometric features, ultrasound studies of liver and spleen volumes, echocardiography and audiological examinations, psychological tests, joint range of motion (ROM) and skeletal radiographs were monitored. RESULTS: After 3 years of treatment, the patient has not developed any clinical manifestations of MPS II. He did not develop coarse facial features, joint disease, or organomegaly, and his cardiac function remained normal. There were no pronounced signs of dysostosis multiplex on radiographs. The only difference when compared with his healthy twin brother was lower IQ (Termann-Merrill 98 vs. 118) and mild deformity of one vertebrae. CONCLUSION: Our study suggests that early initiation of enzyme replacement therapy may significantly slow or prevent the development of irreversible disease manifestations and therefore modify the natural history of MPS II.

Whole-body cryostimulation in kayaker women: a study of the effect of cryogenic temperatures on oxidative stress after the exercise.

AIM: The aim of this study was to determine the effect of whole-body cryostimulation on the activity of selected antioxidant enzymes and the concentration of lipid peroxidation products in kayaker women in the course of training. METHODS: The study was performed on the group of 9 kayaker women, who underwent two training cycles: one typical ten-day training cycle and the another ten-day cycle preceded by cryostimulation sessions twice a day. The activity of antioxidant enzymes was assayed in erythrocytes, while the concentration of lipid peroxidation products was measured both in erythrocytes and in blood plasma. RESULTS: A statistically significant increase in superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity in erythrocytes and in concentration of conjugated dienes (CD) in blood plasma and erythrocytes and thiobarbituric acid reactive substances (TBARS) in plasma was revealed in kayaker women after the first six days of training without cryostimulation. Comparing two performed training cycles, after the first six days of training preceded by cryostimulation lower SOD and GPx activity in erythrocytes was detected, as well as lower CD levels in blood plasma and erythrocytes and lower TBARS concentration in blood plasma of kayaker women than after the six days of training without cryostimulation. CONCLUSIONS: Whole-body cryostimulation improves the antioxidant capacity of organism exposed to intense exercise. Brief application of cryogenic temperatures is likely related to the activation of adaptive homeostatic mechanisms in accordance with the hormetic dose-response model.

Inborn errors of purine and pyrimidine metabolism.

Genetic disorders of purine and pyrimidine (PP) metabolism are under-reported and infrequently mentioned in the general literature, as well as in reviews dedicated to other inborn errors of metabolism. Owing to limited awareness, relatively recent recognition, as well as considerable phenotypic variation, these disorders may often be misdiagnosed or remain undiagnosed. Disorders that arise as a result of dysfunction in PP metabolism represent some of the most challenging diagnostic problems in medicine. In addition to their low prevalence rates, they also present with extremely variable signs and symptoms. They may affect any system in a variety of manners, and often mimic other, more recognizable disorders. The diagnostic problem is compounded by the fact that some biochemically affected patients are symptom-free. Rapidly evolving laboratory techniques such as high-performance liquid chromatography coupled to tandem mass spectrometry are now well established as the preferred method for detection for these defects, but currently the most important step in diagnosis consists of suspecting the disorder. Diagnosis is vital because genetic counselling can be provided and, in some cases, specific treatment can be offered that may slow or even reverse clinical symptoms. If undiagnosed, these disorders can be devastating to patients and their families, resulting in early death or institutionalization for the rest of patient's life. This article describes the current state of knowledge about inborn errors of purine and pyrimidine metabolism, focusing on the varying clinical presentations, the laboratory findings and discusses indications for selective screening for these disorders.

Hypoxanthine-guanine phosphoribosylotransferase deficiency--the spectrum of Polish mutations.

Hypoxanthine-guanine phosphoribosyltransferase (HPRT; EC 2.4.2.8) deficiency (OMIM 308000) is an inborn error of purine metabolism. The defect causes three overlapping clinical syndromes: Lesch-Nyhan disease (LND; OMIM 300322), HPRT-related hyperuricaemia with neurologic dysfunction (HRND) and hyperuricaemia alone (HRH; OMIM 300322). During the period 1977-2007, 18 patients belonging to 12 Polish families and one Latvian family with HPRT deficiency have been identified. The majority of patients had a typical LND phenotype, three patients were classified as HRH and one patient as an intermediate phenotype (HRND). Genetic analysis revealed 12 different HPRT1 mutations, five of them being unique. In two typical Lesch-Nyhan families a novel single-base substitution, c.220T>G (p.Phe74Val), and a deletion of seven nucleotides, c.395_401del7 (p.Ile132LysfsX3), were found. Another novel single-base substitution, c.295T>G (p.Phe99Val), was identified in a patient with severe partial deficiency of HPRT with neurological dysfunction. In patients belonging to the HRH group, two transitions were detected: c.481G>A (p.Ala161Thr) and c.526C>T (p.Pro176Ser). Other mutations identified in Polish patients, c.131A>G (p.Asp44Gly), c.222C>A (p.Phe74Leu), c.385-1G>A (p.Asn129_Glu134del), c.482C>A (p.Ala161Glu), c.508C>T (p.Arg170Ter) and c.569G>A (p.Gly190Glu), have been reported previously in unrelated patients and are located within one of the clusters of hot spots of the HPRT1 gene (exons 3, 7 and 8). Patients with partial phenotypes presented mutations predicted to permit some degree of residual enzyme function (single-base substitutions). All mutations, except c.508C>T (p.Arg170Ter), were found in single families only, indicating the lack of any common mutation causing HPRT deficiency in Poland.

D-ribose therapy in four Polish patients with adenylosuccinate lyase deficiency: absence of positive effect.

Deficiency of adenylosuccinate lyase (ADSL) (OMIM 103050) is an autosomal recessive disorder of the purine de novo synthesis pathway and purine nucleotide cycle, diagnosed so far in approximately 50 patients. The clinical presentation is characterized by severe neurological involvement including hypotonia, seizures, developmental delay and autistic features. Epilepsy in ADSL deficiency is frequent and occurs in approximately two-thirds of patients, beginning either early in the neonatal period or after the first year of life. At present there is no treatment of proven clinical efficacy. Despite of the increasing number of ADSL-deficient patients reported, there are only a few communications of therapeutic considerations or efforts. Among them only two showed some beneficial effects in ADSL-deficient patients. D-ribose, a simple and relatively cheap therapy, has been associated with improvement of behaviour and progressive reduction of the seizure frequency in one 13-year-old patient with ADSL deficiency. In this study we have re-examined D-ribose treatment in four ADSL-deficient patients. Assessments consisted of biochemical markers and neurological outcome. The 12-month trial of D-ribose failed to show any clinical benefit in ADSL patients with both milder and severe phenotype. D-ribose administration was accompanied by neither reduction in seizure frequency nor growth enhancement. Additionally, patients with milder type II presented the first seizure after 4 and 8 months of the D-ribose treatment. Therefore, we could not confirm a positive effect of D-ribose as previously reported.

Trial of erythropoietin treatment in a boy with glutathione synthetase deficiency.

We report a 3-year-old boy with glutathione synthetase deficiency, who in the newborn period developed severe persistent haemolytic anaemia. Treatment with erythropoietin was introduced with good clinical and haematological response.