L-Dopa Might Be Insufficient to Suppress Development of Prolactinomas in Dihydropteridine Reductase-Deficiency Patients.

Dihydropteridine reductase (DHPR) deficiency is a disorder that prevents regeneration of tetrahydrobiopterin (BH4), causing hyperphenylalaninemia (HPA) and low levels of neurotransmitters, including dopamine. Due to low levels of dopamine, patients present with hyperprolactinemia. Treatment consists of a phenylalanine (Phe)-restricted diet, hydroxytryptophan and levodopa (L-Dopa) supplementation, leading to a rapid normalization of prolactin (PRL) levels. We report a case of a patient with DHPR deficiency presenting with new symptomatic hyperprolactinemia and amenorrhea in adolescence despite appropriate management. The prolactinoma was confirmed with pituitary magnetic resonance imaging. The patient was started on cabergoline with rapid normalization of PRL levels and resolution of symptoms, in keeping with previous reports. Cabergoline has a stronger affinity for the D2R receptor and longer half-life than L-Dopa, leading to lactotroph apoptosis, tumor shrinkage, and rapid and maintained normalization of PRL levels, with a better side-effect profile. Patients with DHPR deficiency need to be actively monitored for symptomatic hyperprolactinemia, as L-Dopa monotherapy is insufficient to suppress PRL secretion, leading to lactotroph hypertrophy and proliferation over time and development of prolactinomas in later life.

Longitudinal Natural History of Pediatric Subjects Affected with Mucopolysaccharidosis IIIB.

OBJECTIVE: To characterize the longitudinal natural history of disease progression in pediatric subjects affected with mucopolysaccharidosis (MPS) IIIB. STUDY DESIGN: Sixty-five children with a confirmed diagnosis of MPS IIIB were enrolled into 1 of 2 natural history studies and followed for up to 4 years. Cognitive and adaptive behavior functions were analyzed in all subjects, and volumetric magnetic resonance imaging analysis of liver, spleen, and brain, as well as levels of heparan sulfate (HS) and heparan sulfate nonreducing ends (HS-NRE), were measured in a subset of subjects. RESULTS: The majority of subjects with MPS IIIB achieved an apex on both cognition and adaptive behavior age equivalent scales between age 3 and 6 years. Development quotients for both cognition and adaptive behavior follow a linear trajectory by which subjects reach a nadir with a score <25 for an age equivalent of 24 months by age 8 years on average and by 13.5 years at the latest. All tested subjects (n = 22) had HS and HS-NRE levels above the normal range in cerebrospinal fluid and plasma, along with signs of hepatomegaly. Subjects lost an average of 26 mL of brain volume (-2.7%) over 48 weeks, owing entirely to a loss of cortical gray matter (32 mL; -6.5%). CONCLUSIONS: MPS IIIB exists along a continuum based on cognitive decline and cortical gray matter atrophy. Although a few individuals with MPS IIIB have an attenuated phenotype, the majority follow predicted trajectories for both cognition and adaptive behavior. TRIAL REGISTRATION: ClinicalTrials.gov identifiers NCT02493998, NCT03227042, and NCT02754076.

Diagnosing Mitochondrial Disorders Remains Challenging in the Omics Era.

OBJECTIVE: We hypothesized that novel investigative pathways are needed to decrease diagnostic odysseys in pediatric mitochondrial disease and sought to determine the utility of clinical exome sequencing in a large cohort with suspected mitochondrial disease and to explore whether any of the traditional indicators of mitochondrial disease predict a confirmed genetic diagnosis. METHODS: We investigated a cohort of 85 pediatric patients using clinical exome sequencing and compared the results with the outcome of traditional diagnostic tests, including biochemical testing of routine parameters (lactate, alanine, and proline), neuroimaging, and muscle biopsy with histology and respiratory chain enzyme activity studies. RESULTS: We established a genetic diagnosis in 36.5% of the cohort and report 20 novel disease-causing variants (1 mitochondrial DNA). Counterintuitively, routine biochemical markers were more predictive of mitochondrial disease than more invasive and elaborate muscle studies. CONCLUSIONS: We propose using biochemical markers to support the clinical suspicion of mitochondrial disease and then apply first-line clinical exome sequencing to identify a definite diagnosis. Muscle biopsy studies should only be used in clinically urgent situations or to confirm an inconclusive genetic result. CLASSIFICATION OF EVIDENCE: This is a Class II diagnostic accuracy study showing that the combination of CSF and plasma biochemical tests plus neuroimaging could predict the presence or absence of exome sequencing confirmed mitochondrial disorders.

Acute exacerbations of COPD are associated with significant activation of matrix metalloproteinase 9 irrespectively of airway obstruction, emphysema and infection.

BACKGROUND: Acute exacerbations of chronic obstructive pulmonary disease (AE-COPD) are associated with accelerated aggravation of clinical symptoms and deterioration of pulmonary function. The mechanisms by which exacerbations may contribute to airway remodeling and declined lung function are poorly understood. In this study, we investigated if AE-COPD are associated with differential expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in bronchoalveolar lavage (BAL). METHODS: COPD patients undergoing diagnostic bronchoscopy, with either stable disease (n = 53) or AE-COPD (n = 44), matched for their demographics and lung function parameters were included in this study. Protein levels of MMP-2,-9,-12 and of TIMP-1 and -2 in BAL were measured by ELISA. Enzymatic activity of MMP-2 and -9 was assessed by gelatin zymography. RESULTS: We observed that MMP-9, TIMP-1 and TIMP-2 were significantly increased in BAL during AE-COPD. Furthermore, there was a significant negative correlation of MMP-9, TIMP-1 and TIMP-2 with FEV1% predicted and a significant positive correlation of TIMP-1 and TIMP-2 with RV% predicted in AE-COPD. None of MMPs and TIMPs correlated with DLCO% predicted, indicating that they are associated with airway remodeling leading to obstruction rather than emphysema. In AE-COPD the gelatinolytic activity of MMP-2 was increased and furthermore, MMP-9 activation was significantly up-regulated irrespective of lung function, bacterial or viral infections and smoking. CONCLUSIONS: The results of this study indicate that during AE-COPD increased expression of TIMP-1, TIMP-2, and MMP-9 and activation of MMP-9 may be persistent aggravating factors associated with airway remodeling and obstruction, suggesting a pathway connecting frequent exacerbations to lung function decline.

Moyamoya syndrome and neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) is the most prevalent autosomal dominant genetic disorder among humans. NF1 vasculopathy is a significant but underrecognized complication of the disease, affecting both arterial and venous blood vessels of all sizes. Moyamoya syndrome is a cerebral vasculopathy that is only rarely observed in association with NF1, particularly in the pediatric age range. Herein, we report of a 5-year-old female with NF1 and moyamoya syndrome and we briefly review the existing literature.

Alterations in serum MMP and TIMP concentrations following chronic heroin abuse.

UNLABELLED: Abstract Context: Although opiate abuse is known to affect matrix metalloproteinases (MMPs), data on these enzymes and their tissue inhibitors in heroin addicts are scarce. OBJECTIVE: In the present study, we determined serum concentrations of MMP-2, MMP-9, tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in heroin users, and compared them with healthy individuals. We evaluated whether 21 d of abstinence are adequate to reverse the effect of opiates and we compared seropositive with seronegative, for anti-HCV antibodies, heroin users. MATERIALS AND METHODS: Twenty-six heroin-dependent male volunteers and an equal number of healthy individuals participated in this study. ELISA was used to assess the serum levels of MMP-2, MMP-9, TIMP-1 and TIMP-2. Heroin users were assessed both upon admission and upon completion of a 21-d detoxification program. RESULTS: Serum TIMP-1 concentrations were significantly lower and the ratios MMP-2/TIMP-1, MMP-9/TIMP-1 and MMP-2/TIMP-2 were significantly higher in heroin users compared to healthy individuals. Heroin users who were seropositive had lower MMP concentrations, as well as lower MMP/TIMP ratios, compared to those who were seronegative. DISCUSSION: Our results showed that in heroin-addicted individuals, and especially those who are positive for anti-HCV antibodies, the balance between MMPs and TIMPs in serum is disrupted and this disruption cannot be restored within 21 d of abstinence. CONCLUSION: Chronic heroin abuse disrupts the balance between MMPs and TIMPs in serum and this effect is not reversible within 21 d of abstinence.

MYH9-related disorders: report on a patient of Greek origin presenting with macroscopic hematuria and presenile cataract, caused by an R1165C mutation.

Myosin heavy chain-9 (MYH9)-related disorders represent a heterogenous group of hereditary diseases caused by mutations in the gene encoding the heavy chain of nonmuscle myosin IIA. May-Hegglin anomaly and Fechtner, Sebastian, and Epstein syndromes are the four phenotypes of the disease, characterized by congenital macrothrombocytopenia and distinguished by different combinations of clinical signs that may include glomerulonephritis, sensorineural hearing loss, and presenile cataract. The spectrum of mutations responsible for the disease is wide and the existence of genotype-phenotype correlation remains a critical issue. We report the first case of an MYH9-RD in a patient of Greek origin presenting with macroscopic hematuria and presenile cataract caused by a p.R1165C mutation. The same mutation was present in the patient's father, who exhibited no extrahematological features of the disease. The p.R1165C mutation is one of the MYH9 alterations whose prognostic significance is still poorly defined. Thus, the patients described add to the limited existing data on the MYH9 mutations and their resultant phenotypes.

Developing treatment options for metachromatic leukodystrophy.

Metachromatic leukodystrophy (MLD) represents a devastating lysosomal storage disease characterized by intralysosomal accumulation of the sphingolipid sulfatide in various tissues. Three types of the disease are currently distinguished: the late-infantile, which is the most commonly observed, the juvenile and the adult type. Demyelination represents the main histopathological feature of the disorder, leading to neurological impairment with no curative treatment currently available. Nevertheless, the increased scientific interest on the disease has led to the experimental use of innovative therapeutic approaches in animal models, aiming to provide an effective therapeutic regimen for human patients, as well. This paper provides an overview of developing treatment options among patients with MLD. Apart from hematopoietic stem cell transplantation, already in use for decades, other recent data discussed includes umbilical cord blood and stem cell transplantation, enzyme replacement therapy, gene therapy and autologous hematopoietic transplantation of genetically modified stem cells. Gene therapy with oligodedroglial, neural progenitor, embryonic and microencapsulated recombinant cells represents add-on treatment options still on experimental level.

Differential expression of matrix metalloproteinases and proteoglycans in Juvenile Hyaline Fibromatosis.

BACKGROUND: Juvenile Hyaline Fibromatosis (JHF) is a rare autosomal recessive disorder, histologically characterized by the production and deposition of an unidentified hyaline material in the skin and other organs. Extracellular matrix molecules are implicated in the development of skin lesion which is debilitating and recurrent and, so far, no treatment is satisfactory. OBJECTIVE: To investigate the expression of matrix metalloproteinases (MMPs), their tissue inhibitors (TIMPs) and proteoglycans in lesional as compared to site-matched lesion-free skin tissue specimens of a JHF patient, aiming to elucidate the aetiopathological mechanisms involved in the development of JHF skin lesions. METHODS: Gelatinase activity of MMP-2 and MMP-9 was investigated by gelatine zymography. Protein levels of MMP-2, MMP-9, TIMP-1 and TIMP-2 in skin tissue extracts were measured by ELISA. Gene expression of MMPs, TIMPs and proteoglycans was examined by quantitative RT-PCR. RESULTS: JHF lesions exhibited significantly higher activity as well as elevated protein and gene expression of MMP-2 and MMP-9, as compared to lesion-free skin tissue specimens. Decorin was downregulated and aggrecan was upregulated in lesional skin, as compared to normal skin. CONCLUSION: The results presented in this study indicate that MMPs and proteoglycans may be involved in the pathogenesis of JHF and therefore these molecules may offer alternative targets for pharmacological intervention to achieve more radical and effective treatment.