| Abstrakt: |
Hypophosphatasia (HPP) is characterized by low activity of tissue nonspecific alkaline phosphatase (TNSALP). The enzyme replacement therapy asfotase alfa has been approved for childhood-onset forms of HPP. MicroRNAs (miRNAs) have emerged as a novel disease biomarker, with potential application in therapy monitoring. Circulating miRNAs were analyzed at baseline, months 1, 2, 4, and 16 in a 49-yr-old woman with childhood-onset HPP, chronic musculoskeletal pain, and non-traumatic fractures prior to enzyme replacement therapy. Serum RNA was extracted and sequenced using miRNeasy Mini Kit (Qiagen, Germany), RealSeq Biosciences Kit (Santa Cruz, US) together with miND spike-in control kit (TAmiRNA, Austria) and Illumina NovaSeq 6000 SP1 flow cell (San Diego, US). Brief Pain Inventory Severity and Interference scores (BPI-S/BPI-I), fatigue severity scale (FSS), Patient Global Impression of Improvement (PGI-I), Western Ontario and McMaster university hip disability and osteoarthritis outcome score (WOMAC), fibromyalgia impact questionnaire (FIQ), 6-Minute Walking Test (6-MWT), chair-rise-test (CRT), and handgrip dynamometry (HD) were performed at baseline and different timepoints during the therapy. Out of >800 screened, 84 miRNAs were selected based on differences in expression profiles between 24 HPP patients and 24 healthy controls. Six miRNAs showed a clear graphic trend and were up- or downregulated by ≥50% reads per million (rpm). These included hsa-let-7i-5p (+50%), hsa-miR-1-3p (−66.66%), hsa-miR-1294 (+63.63%), hsa-miR-206 (−85.57%), hsa-miR-375-3p (−71.43%), and hsa-miR-624-5p (+69.44%). hsa-miR-1-3p and hsa-miR-206 were identified as muscle-specific miRNAs. hsa-mir-375-3p, which negatively regulates osteogenesis, was significantly downregulated. In terms of patient-reported outcomes, BPI-S, BPI-I, FSS, PGI-I, WOMAC, and FIQ showed a reduction by −58.62%, −68.29%, −33.33%, −75.00%, −63.29%, and −43.02%, respectively. 6-MWT improved by +33.89% and CRT by −44.46%. Mean hand grip strength of the right/left hand measured by HD improved by +12.50% and + 23.53%, respectively. miRNA profile changes during the therapy with asfotase alfa, accompanying improvements in functionality tests and quality of life scores. Lay Summary: Hypophosphatasia (HPP) is a rare genetic bone disease characterized by low activity of an enzyme involved in mineralization of bony tissues, the nonspecific alkaline phosphatase (TNSALP). The enzyme replacement therapy with recombinant asfotase alfa has been approved recently. MicroRNAs (miRNAs) are small signaling molecules, which are involved in the regulation of gene expression and signaling pathways. They emerged as a novel disease biomarker, with potential application in therapy monitoring. We analyzed the levels of miRNAs of a 49-yr-old woman with childhood-onset HPP during the therapy. The patient suffered from musculoskeletal pain and non-traumatic fractures before the begin of enzyme replacement therapy. miRNAs in blood and clinical tests were performed at baseline and different timepoints. Blood levels of 6 miRNAs showed a clear graphic trend and were elevated or lowered by ≥50% units (reads per million) during the therapy. Patient-reported questionnaires showed a reduction of at least a third, reflecting clinical improvement of symptoms during the therapy. The scores of 6-MWT and CRT and hand grip also improved, signaling improvements in muscle functionality under asfotase alfa. miRNA profile changes during the therapy with asfotase alfa, accompanying improvements in functionality tests and quality of life scores. [ABSTRACT FROM AUTHOR] |
