Growth characteristics in individuals with osteogenesis imperfecta in North America: results from a multicenter study.

PurposeOsteogenesis imperfecta (OI) predisposes people to recurrent fractures, bone deformities, and short stature. There is a lack of large-scale systematic studies that have investigated growth parameters in OI.MethodsUsing data from the Linked Clinical Research Centers, we compared height, growth velocity, weight, and body mass index (BMI) in 552 individuals with OI. Height, weight, and BMI were plotted on Centers for Disease Control and Prevention normative curves.ResultsIn children, the median z-scores for height in OI types I, III, and IV were -0.66, -6.91, and -2.79, respectively. Growth velocity was diminished in OI types III and IV. The median z-score for weight in children with OI type III was -4.55. The median z-scores for BMI in children with OI types I, III, and IV were 0.10, 0.91, and 0.67, respectively. Generalized linear model analyses demonstrated that the height z-score was positively correlated with the severity of the OI subtype (P < 0.001), age, bisphosphonate use, and rodding (P < 0.05).ConclusionFrom the largest cohort of individuals with OI, we provide median values for height, weight, and BMI z-scores that can aid the evaluation of overall growth in the clinic setting. This study is an important first step in the generation of OI-specific growth curves

Mechanisms of proteoglycan aggregate degradation in cytokine-stimulated cartilage

Aggrecan is one of the most important structural components of the extracellular matrix (ECM) of articular cartilage, where it contributes to the hydration of the tissue and its ability to resist compressive loads during joint movement. Increased aggrecan degradation and loss occurs in joint diseases and is thought to be mediated by enzymes such as the matrix metalloproteinases (MMPs) and aggrecanases (ADAMTS). It has also been proposed that aggrecan release from the cartilage can be mediated by a non-proteolytic mechanism which involves the degradation of hyaluronan (RA) to which the aggrecan is bound. As aggrecan degradation and loss is known to be induced by pro-inflammatory cytokines, IL-1, TNFalpha, IL-6, IL-17 and OSM were used to investigate the mechanisms involved in proteoglycan catabolism in organ cultures of bovine articular cartilage. Irrespective of the cytokine, all aggrecan fragments generated were characteristic of aggrecanase action, and no additional aggrecan-degrading enzymatic activity was detected. In the presence of OSM, more rapid aggrecan release was observed, due to both proteolysis and fragmentation of HA by hyaluronidase activity. Moreover, addition of OSM resulted in the cleavage of aggrecan at a non-canonical aggrecanase site near its carboxy-terminal globular domain. Such cleavage could be reproduced in vitro by the action of either ADAMTS-4 or ADAMTS-5. Gene expression analysis revealed that both aggrecanases were highly induced by the cytokines, and while ADAMTS-4 was the major aggrecanase to be stimulated in all conditions, ADAMTS-5 remains the predominant aggrecanase to be expressed in cartilage. Thus, the present study shows that aggrecanase activity is primarily responsible for aggrecan degradation in the early stages of cytokine stimulation, and that in the presence of OSM, aggrecanase substrate specificity can be differentially modulated and hyaluronidase-mediated RA degradation can be induced

Involving Families with Osteogenesis Imperfecta in Health Service Research: Joint Development of the OI/ECE Questionnaire.

BACKGROUND:Despite the growing interest in understanding the psycho-social impact of rare genetic diseases, few studies examine this concept and even fewer seek to obtain feedback from families who have lived the experience. The aim of this project was to involve families of children living with osteogenesis imperfecta (OI) in the development of a tool to assess the impact of OI on the lives of patients and their families. METHODS:This project used an integrated knowledge translation approach in which knowledge users (clinicians and people living with OI and their families) were consulted throughout the four steps of development, that is: content mapping, item generation, tool appraisal and pre-testing of the questionnaires. The International Classification of Functioning and Health was used as a framework for content mapping. Based on a scoping review we selected two validated tools to use as a basis for developing the questionnaire. The final parent self-report version measured six domains: experience of diagnosis; use of health services; use of social and psychological support services; expectations about tertiary specialized centers; and socio-demographic information. RESULTS:A total of 27 out of 40 families receiving care at the Shriners Hospital for Children-Canada and invited to participate in the pre-test returned the completed questionnaires. In more than two-thirds of families (69%; n = 18) OI was suspected either at or within the first 3 months after birth. Up to 46% of families consulted between 3 and 5 doctors (46%; n = 12) prior to final diagnosis. The use of services by families varied from 0 to 16 consultations, 0 to 9 exploratory examinations and 1 to 10 types of allied health services. In the 12 months prior to the study, fewer than a quarter of children had been admitted, for treatment, for hospital stays of longer than 8 hours or to an emergency department (24% and 9% respectively). Only 29% of parents received psychological support. CONCLUSION:This joint development process generated a tool, with good psychometric properties, that provides unique insight into the experiences of patients and families with OI, the psycho-social impact of the illness, and their service needs and expectations

Impact on Family.

<p>Impact on Family.</p

Feedback from families on the questionnaire (n = 18)

<p>Feedback from families on the questionnaire (n = 18)</p

Experiences while seeking care for OI.

<p>Experiences while seeking care for OI.</p

Growth characteristics in individuals with osteogenesis imperfecta in North America: results from a multicenter study

© 2018, American College of Medical Genetics and Genomics. Purpose: Osteogenesis imperfecta (OI) predisposes people to recurrent fractures, bone deformities, and short stature. There is a lack of large-scale systematic studies that have investigated growth parameters in OI. Methods: Using data from the Linked Clinical Research Centers, we compared height, growth velocity, weight, and body mass index (BMI) in 552 individuals with OI. Height, weight, and BMI were plotted on Centers for Disease Control and Prevention normative curves. Results: In children, the median z-scores for height in OI types I, III, and IV were −0.66, −6.91, and −2.79, respectively. Growth velocity was diminished in OI types III and IV. The median z-score for weight in children with OI type III was −4.55. The median z-scores for BMI in children with OI types I, III, and IV were 0.10, 0.91, and 0.67, respectively. Generalized linear model analyses demonstrated that the height z-score was positively correlated with the severity of the OI subtype (P \u3c 0.001), age, bisphosphonate use, and rodding (P \u3c 0.05). Conclusion: From the largest cohort of individuals with OI, we provide median values for height, weight, and BMI z-scores that can aid the evaluation of overall growth in the clinic setting. This study is an important first step in the generation of OI-specific growth curves

A multicenter study to evaluate pulmonary function in osteogenesis imperfecta

Pulmonary complications are a significant cause for morbidity and mortality in osteogenesis imperfecta (OI). However, to date, there have been few studies that have systematically evaluated pulmonary function in individuals with OI. We analyzed spirometry measurements, including forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1 ), in a large cohort of individuals with OI (n = 217) enrolled in a multicenter, observational study. We show that individuals with the more severe form of the disease, OI type III, have significantly reduced FVC and FEV1 which do not follow the expected trends of the normal population. We also show that "normalization" of FVC and FEV1 using general population data to generate percent predicted values underestimates the pulmonary involvement in OI. Within each subtype of OI, we used linear mixed models to find potential correlations between FEV1 and FVC with the clinical variables including mobility, bisphosphonate use, and scoliosis. Our results are an important step in understanding the extent of pulmonary involvement in individuals with OI and for developing pulmonary endpoints for use in the routine patient care as well as in the investigation of new therapies