POS0222 POLYARTICULAR ARTHRITIS AND ADULT-ONSET OSTEOLYSIS CAUSED BY MUTATIONS IN THE ASAH1 GENE: FARBER DISEASE CLINICAL PRESENTATIONS IN THE CONTEXT OF A FIRST-EVER NATURAL HISTORY STUDY

Background

Farber disease is frequently misdiagnosed as polyarticular juvenile idiopathic arthritis or seronegative rheumatoid arthritis which leads to a delay in diagnosis for many patients. Farber disease is an ultra-rare lysosomal storage disease caused by mutations in the ASAH1 gene. The resulting deficiency of the acid ceramidase enzyme leads to accumulation of the pro-inflammatory and pro-apoptotic sphingolipid ceramide. Accumulation of ceramide throughout the body leads to the symptoms of Farber disease. Cardinal symptoms include joint disease (polyarticular arthritis and contractures), subcutaneous nodules, and a hoarse or weak voice due to laryngeal nodules. The phenotypic spectrum of Farber disease ranges from rapidly progressive disease causing death in infancy to moderate or slowly progressive disease with survival into late adulthood. Symptoms may vary in severity across patients and phenotypes.

Objectives

To further define the symptoms of Farber disease, including joint disease, subcutaneous nodules, dysphonia, and osteolysis, which can lead to referral to rheumatology or related specialties. To understand the clinical presentation and broad phenotypic spectrum of this rare disease to aid in clinical diagnosis and reduce diagnostic delay.

Methods

The Observational and Cross-Sectional Cohort Study of the Natural History and Phenotypic Spectrum of Farber Disease (NCT03233841) was the first systematic clinical study of the natural history of Farber disease. The study collected retrospective and prospective data on living and deceased patients, including demographics, clinical presentation, phenotype, diagnostic history, and patient reported outcomes.

Results

45 patients with Farber disease (27 living, 18 deceased) who had or had not undergone hematopoietic stem cell transplant (HSCT) were enrolled from 16 centers in 9 countries. A cohort of 24 living non-HSCT patients were followed prospectively. The patients represented the broad phenotypic spectrum of Farber disease, from rapidly progressive (severe) to slowly progressive (attenuated). In patients whose data was available for analysis, the average age of patients at enrollment was 7.2 years (range 1 to 28 years). The average age of onset of joint disease (arthritis and/or contractures) was 15 months (range 3 months to 7 years), of subcutaneous nodules was 13 months (range 3 months to 5 years), and of dysphonia was 13 months (range birth to 8 years). The average time from onset of symptoms to Farber disease diagnosis was 2 years (range <1 to 12 years). At baseline, the mean number of joints affected with active arthritis was 11.3 (range 0-36) and the mean number affected with contractures was 18 (range 0-38). 12.5% of patients were reported to have a bone disorder such as osteoporosis or osteolysis. The Child Health Assessment Questionnaire Disability Index (CHAQ) ranging from 0 (no impairment) to 3 (unable to do) was high, with mean scores of 2.62-3.00 across visits.

Conclusion

Data from the Farber disease natural history study further defined the cardinal symptoms, phenotypic spectrum, and high disease-related burden in patients with Farber disease. The large number of joints affected with arthritis or contractures reflects that patients with Farber disease are often referred to rheumatology and can be misdiagnosed with polyarticular juvenile idiopathic arthritis or seronegative rheumatoid arthritis. Demographic information and numbers of patients enrolled indicate that Farber disease is likely not as rare as previously thought. ASAH1 genetic testing for adult and pediatric patients referred to the rheumatology clinic with symptoms including polyarticular arthritis, subcutaneous nodules, dysphonia, or osteolysis, may shorten the time to diagnosis in patients with Farber disease.

Disclosure of Interests

Lothar Seefried Speakers bureau: Aceragen, Amgen, Alexion, Biomarin, Chiesi, KyowaKirin, Novartis, Theramex, and UCB, Consultant of: Amgen, Alexion, Biomarin, Chiesi, KyowaKirin, Novartis, Theramex, and UCB, Grant/research support from: Alexion, KyowaKirin and Novartis, Kathleen Crosby Employee of: Aceragen, Alexander Solyom Employee of: Aceragen

Determination of Campesterol, Stigmasterol, and Beta-Sitosterol in Saw Palmetto Raw Materials and Dietary Supplements by Gas Chromatography: Collaborative Study

An interlaboratory study was conducted to evaluate a method for the determination of campesterol, stigmasterol, and beta-sitosterol in saw palmetto raw materials and dietary supplements at levels &gt;1.00 mg/100 g based on a 23 g sample. Test samples were saponified at high temperature with ethanolic KOH solution. The unsaponifiable fraction containing phytosterols (campesterol, stigmasterol, and beta-sitosterol) was extracted with toluene. Phytosterols were derivatized to trimethylsilyl ethers and then quantified by gas chromatography with hydrogen flame ionization detection. Twelve blind duplicates, one of which was fortified, were successfully analyzed by 10 collaborators. Recoveries were obtained for the sample that was fortified. The results were 99.8, 111, and 111% for campesterol, stigmasterol, and beta-sitosterol, respectively. For repeatability, the relative standard deviation (RSDr) ranged from 3.93 to 17.3% for campesterol, 3.56 to 22.7% for stigmasterol, and 3.70 to 43.9% for beta-sitosterol. For reproducibility, the RSDR ranged from 7.97 to 22.6%, 0 to 26.7%, and 5.27 to 43.9% for campesterol, stigmasterol, and beta-sitosterol, respectively. Overall, the Study Director approved 5 materials with acceptable HorRat values for campesterol, stigmasterol, and beta-sitosterol ranging from 1.02 to 2.16.

Determination of Glucosamine in Raw Materials and Dietary Supplements Containing Glucosamine Sulfate and/or Glucosamine Hydrochloride by High-Performance Liquid Chromatography with FMOC-Su Derivatization: Collaborative Study

A collaborative study was conducted for determination of glucosamine in raw materials and dietary supplements containing glucosamine sulfate and/or glucosamine hydrochloride by high-performance liquid chromatography (HPLC) with N-(9-fluorenyl-methoxycarbonyloxy) succinimide (FMOC-Su) derivatization. Thirteen blind materials, one pair of which were duplicates, were tested by 12 collaborating laboratories. The test samples consisted of various commercial products, including tablets, capsules, drink mix, and liquids as well as raw materials, blanks, and those for spike recovery analyses. The tests with blank products and products spiked with glucosamine showed good specificity of the method. The average recoveries at spike levels of 100 and 150% of the declared amount were 99.0% with a relative standard deviation (RSD) of 2.1%, and 101% with an RSD of 2.3%, respectively. The test results between laboratories on each commercial product were reproducible with RSD values of no more than 4.0%, and the results were repeatable in the same laboratory with an average RSD of 0.7%. HorRat values ranged from 0.5 to 1.7 on both tests of spike recovery and reproducibility between laboratories on commercial products. The average determination coefficient of the calibration curves from the laboratories was 0.9995 with an RSD of 0.03%. All of the 12 collaborating laboratories succeeded in the study and none of their reported test results were outliers, partly indicating the robustness of the method. It is recommended that the method be accepted by AOAC INTERNATIONAL as Official First Action.

Autotransplantation of superior cervical ganglion to the caudate nucleus in three patients with Parkinson's disease (preliminary report)

Striatal cervical ganglionic implants have been utilized for the first time for treatment of three patients suffering from Parkinson's disease. Tissue grafts from the superior cervical ganglion have been dissected and immediately transplanted into the head of the caudate nucleus. The grafted tissue placed in a cavity of the caudate nucleus remains in contact with the cerebrospinal fluid in the lateral ventricle. Three and six months after surgery, none of the patients has had any major complications and their lower score of Unified Parkinsonism Rating Scale (UPRS) points was associated with an improvement of the signs of Parkinson's disease. Present data have provided some optimism that grafting of superior cervical ganglion is a feasible approach in Parkinson's disease.

The rhythmic properties of the motor system

The resonance properties of the motor control circuits are basic features of the motor system. From our results, it can be concluded that, when the normally existing suppression mechanism weakens, external stimuli or internal impulses may elicit oscillations in the circuits according to the resonant frequency, and tremor will appear. It seems that the resonant frequency is between 5 and 8 Hz, as demonstrated by rhythmic voluntary movement, rhythmic elicited reflex movement and rhythmic modulated voluntary movement modulated by the stimulation of the central motor system.