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Utility of multiple myeloma screening in Gaucher disease
Abstracts / Molecular Genetics and Metabolism 126 (2019) S17–S156
United States, bUniversity of Minnesota, Minneapolis, MN, United States, cChildren's Hospital Oakland Research Institute, Oakland, CA, United States, dSeattle Children's Hospital, Seattle, WA, United States Background: Skeletal and joint disease persists and slowly worsens in individuals with mucopolysaccharidosis type I (MPS I) despite treatment with hematopoietic cell transplantation (HCT) and/or enzyme replacement therapy (ERT). Surrogate biomarkers are crucial for efficient testing of the effects of new and adjunctive therapies on bones and joints in MPS I. Methods: As part of a 9-year observational study of individuals with MPS I, hip, and spine radiographs, and range-of-motion (ROM) were measured annually in years 7-9 and height in years 1-9. Fasting morning plasma and urine samples of inflammatory and bone biomarkers were measured by ELISAs in years 1 and 2. A novel summary score for skeletal disease (i.e. hip and spine radiographs and height Z-score standardized by age and sex) and joint disease (i.e. ROM in shoulders, elbows, and knees) were calculated. Linear regression, adjusting for age, was used to test for associations of change in biomarkers over the first year with the annualized change in summary bone and ROM score, and height Z-score over years 7-9 and 1-9 respectively. Sensitivity analyses removed biomarkers greater than 3 standard deviations from the mean. Results: The cohort included eighteen participants (MPS IH N=14, MPS IA N=4), age 5-16 years, who were 6.7±3.0 years since HCT (MPS IH) or 7.1±2.8 years since ERT initiation (MPS IA). Sensitivity analysis showed an association between increasing interleukin-6 and more rapid worsening of ROM (-31 pg/ml: 95%CI -45 to -18 pg/ml pb0.001) and between increasing urine pyridinolines (PYD) and more rapid decrease in height Zscore (-3.9e-4 nmol/mmol creatinine: 95%CI -6.8e-4 to -0.9e-4 p=0.013). Conclusions: We have identified two potential candidate surrogate biomarkers of change in skeletal or joint disease over time. Once validated, these biomarkers may prove useful in determining early efficacy of skeletal or joint directed therapies in MPS I.
doi:10.1016/j.ymgme.2018.12.302
287 Multiplex DBS enzyme assay for MPS II, IIIB, IVA, VI, VII and CLN2 via LC-MS/MS expands clinical utility of DBS enzyme testing Laura Pollard, Tim Wood, Greenwood Genetic Center, Greenwood, SC, United States Enzyme analysis is the gold standard for the diagnosis of lysosomal storage disorders (LSDs). However, enzyme analysis in leukocytes requires that whole blood samples arrive to the testing laboratory within 24-48 hours of collection, and requires a relatively large volume of blood. This is problematic for the international shipment of specimens and for testing infants. The adaptation of these enzyme assays for use in dried blood spots (DBS) has ameliorated these issues for a large number of LSDs. Initially enzyme analysis in DBS exclusively utilized 4-methylumbelliferone (4-MU) fluorogenic substrates. The limitation of this methodology is that each enzyme must be measured individually. The development of tandem mass spectrometry (MS/MS) substrates has allowed multiple
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enzyme reactions to be combined in a single reaction, increasing efficiency. We report validation results for a new 6-plex assay for the diagnosis of five Mucopolysaccharidosis (MPS) disorders (MPS II, IIIB, IVA, VI and VII) and neuronal ceroid lipofuscinosis type 2 (CLN2) in DBS using UPLC-MS/MS. Normal reference ranges were developed using a minimum of 236 DBS samples from unaffected controls or patients with an alternate diagnosis, and 100% clinical sensitivity was established using 99 samples from patients affected with one of the six disorders. Both intra-day and inter-day precision were acceptable (b 20% CV) and 6 month long term sample stability has been verified. Our laboratory can now analyze 18 enzymes in DBS (12 utilizing MS/ MS substrates and 6 utilizing 4-MU substrates) to diagnose 20 different LSDs (including Multiple Sulfatase Deficiency and Mucolipidosis II/III). Furthermore, we can now offer a 7 enzyme MPS panel in DBS, which will significantly enhance the worldwide diagnosis of MPS patients. Finally, the development of this 6-plex has significant implications for newborn screening, as FDA approved therapies are available for five of the six included conditions. doi:10.1016/j.ymgme.2018.12.303
288 Utility of multiple myeloma screening in Gaucher disease Carlos Prada, Katherine Abell, Sarah Chadwell, Laurie Bailey, Cincinnati Children's Hospital, Cincinnati, OH, United States Gaucher disease (GD) is a lysosomal storage disease characterized by deficiency of glucocerebrosidase within lysosomes, altering degradation of glycosphingolipids, which causes accumulation of glycosylceramide. Patients with GD type 1 (GD1) have an increased incidence of gammopathy (i.e., hypergammaglobulinemia, monoclonal gammopathy of undetermined significance [MGUS]), and multiple myeloma (MM) when compared to the general population. No formal evaluation of gammopathy screening has been reported in the literature. We conducted an IRB approved retrospective analysis of clinical and laboratory data, including screening for MM, in adults with GD at Cincinnati Children’s Hospital Medical Center between 2010 and 2018. During the 8-year study period, 20 adults with GD (11 females/9 males) ages 19 to 71 (mean = 51.95 years) were screened for MM using serum protein electrophoresis (SPE) and immunofixation (IFE). Of those, 10 were treated with substrate reduction therapy (SRT) and 9 with enzyme therapy (ET). We identified no patients with MM, 2 with MGUS, and 1 with persistent polyclonal gammopathy. The 2 MGUS patients were 48 and 61 yearsold, female and male respectively, with intact spleens. SPE and IFE follow-up has been stable without progression. The polyclonal gammopathy patient was a 54-year-old splenectomized male. All patients with abnormal SPE or IFE were on therapy (2 ET/ 1 SRT). Only one abnormal patient’s GBA genotype was known (p. Asn409Ser, p.Leu483Pro). Other SPE abnormalities included slight increases/decreases in albumin, protein, and beta globulin, or slight decreases in alpha 2 or gamma globulin without clinical significance. Family history of cancer was documented in 10 individuals, with no MM or blood-related malignancies reported. Our data show that as in the general population and previous GD studies, gammopathies are more common in patients greater than 50 years. These data support screening in GD1 for gammopathy greater than age 40 years.
doi:10.1016/j.ymgme.2018.12.304
United States, bUniversity of Minnesota, Minneapolis, MN, United States, cChildren's Hospital Oakland Research Institute, Oakland, CA, United States, dSeattle Children's Hospital, Seattle, WA, United States Background: Skeletal and joint disease persists and slowly worsens in individuals with mucopolysaccharidosis type I (MPS I) despite treatment with hematopoietic cell transplantation (HCT) and/or enzyme replacement therapy (ERT). Surrogate biomarkers are crucial for efficient testing of the effects of new and adjunctive therapies on bones and joints in MPS I. Methods: As part of a 9-year observational study of individuals with MPS I, hip, and spine radiographs, and range-of-motion (ROM) were measured annually in years 7-9 and height in years 1-9. Fasting morning plasma and urine samples of inflammatory and bone biomarkers were measured by ELISAs in years 1 and 2. A novel summary score for skeletal disease (i.e. hip and spine radiographs and height Z-score standardized by age and sex) and joint disease (i.e. ROM in shoulders, elbows, and knees) were calculated. Linear regression, adjusting for age, was used to test for associations of change in biomarkers over the first year with the annualized change in summary bone and ROM score, and height Z-score over years 7-9 and 1-9 respectively. Sensitivity analyses removed biomarkers greater than 3 standard deviations from the mean. Results: The cohort included eighteen participants (MPS IH N=14, MPS IA N=4), age 5-16 years, who were 6.7±3.0 years since HCT (MPS IH) or 7.1±2.8 years since ERT initiation (MPS IA). Sensitivity analysis showed an association between increasing interleukin-6 and more rapid worsening of ROM (-31 pg/ml: 95%CI -45 to -18 pg/ml pb0.001) and between increasing urine pyridinolines (PYD) and more rapid decrease in height Zscore (-3.9e-4 nmol/mmol creatinine: 95%CI -6.8e-4 to -0.9e-4 p=0.013). Conclusions: We have identified two potential candidate surrogate biomarkers of change in skeletal or joint disease over time. Once validated, these biomarkers may prove useful in determining early efficacy of skeletal or joint directed therapies in MPS I.
doi:10.1016/j.ymgme.2018.12.302
287 Multiplex DBS enzyme assay for MPS II, IIIB, IVA, VI, VII and CLN2 via LC-MS/MS expands clinical utility of DBS enzyme testing Laura Pollard, Tim Wood, Greenwood Genetic Center, Greenwood, SC, United States Enzyme analysis is the gold standard for the diagnosis of lysosomal storage disorders (LSDs). However, enzyme analysis in leukocytes requires that whole blood samples arrive to the testing laboratory within 24-48 hours of collection, and requires a relatively large volume of blood. This is problematic for the international shipment of specimens and for testing infants. The adaptation of these enzyme assays for use in dried blood spots (DBS) has ameliorated these issues for a large number of LSDs. Initially enzyme analysis in DBS exclusively utilized 4-methylumbelliferone (4-MU) fluorogenic substrates. The limitation of this methodology is that each enzyme must be measured individually. The development of tandem mass spectrometry (MS/MS) substrates has allowed multiple
S119
enzyme reactions to be combined in a single reaction, increasing efficiency. We report validation results for a new 6-plex assay for the diagnosis of five Mucopolysaccharidosis (MPS) disorders (MPS II, IIIB, IVA, VI and VII) and neuronal ceroid lipofuscinosis type 2 (CLN2) in DBS using UPLC-MS/MS. Normal reference ranges were developed using a minimum of 236 DBS samples from unaffected controls or patients with an alternate diagnosis, and 100% clinical sensitivity was established using 99 samples from patients affected with one of the six disorders. Both intra-day and inter-day precision were acceptable (b 20% CV) and 6 month long term sample stability has been verified. Our laboratory can now analyze 18 enzymes in DBS (12 utilizing MS/ MS substrates and 6 utilizing 4-MU substrates) to diagnose 20 different LSDs (including Multiple Sulfatase Deficiency and Mucolipidosis II/III). Furthermore, we can now offer a 7 enzyme MPS panel in DBS, which will significantly enhance the worldwide diagnosis of MPS patients. Finally, the development of this 6-plex has significant implications for newborn screening, as FDA approved therapies are available for five of the six included conditions. doi:10.1016/j.ymgme.2018.12.303
288 Utility of multiple myeloma screening in Gaucher disease Carlos Prada, Katherine Abell, Sarah Chadwell, Laurie Bailey, Cincinnati Children's Hospital, Cincinnati, OH, United States Gaucher disease (GD) is a lysosomal storage disease characterized by deficiency of glucocerebrosidase within lysosomes, altering degradation of glycosphingolipids, which causes accumulation of glycosylceramide. Patients with GD type 1 (GD1) have an increased incidence of gammopathy (i.e., hypergammaglobulinemia, monoclonal gammopathy of undetermined significance [MGUS]), and multiple myeloma (MM) when compared to the general population. No formal evaluation of gammopathy screening has been reported in the literature. We conducted an IRB approved retrospective analysis of clinical and laboratory data, including screening for MM, in adults with GD at Cincinnati Children’s Hospital Medical Center between 2010 and 2018. During the 8-year study period, 20 adults with GD (11 females/9 males) ages 19 to 71 (mean = 51.95 years) were screened for MM using serum protein electrophoresis (SPE) and immunofixation (IFE). Of those, 10 were treated with substrate reduction therapy (SRT) and 9 with enzyme therapy (ET). We identified no patients with MM, 2 with MGUS, and 1 with persistent polyclonal gammopathy. The 2 MGUS patients were 48 and 61 yearsold, female and male respectively, with intact spleens. SPE and IFE follow-up has been stable without progression. The polyclonal gammopathy patient was a 54-year-old splenectomized male. All patients with abnormal SPE or IFE were on therapy (2 ET/ 1 SRT). Only one abnormal patient’s GBA genotype was known (p. Asn409Ser, p.Leu483Pro). Other SPE abnormalities included slight increases/decreases in albumin, protein, and beta globulin, or slight decreases in alpha 2 or gamma globulin without clinical significance. Family history of cancer was documented in 10 individuals, with no MM or blood-related malignancies reported. Our data show that as in the general population and previous GD studies, gammopathies are more common in patients greater than 50 years. These data support screening in GD1 for gammopathy greater than age 40 years.
doi:10.1016/j.ymgme.2018.12.304