Afshariyamchlou Sonia, Ng Michelle, Ferdjallah Asmaa, Warden Stuart J, Niziolek Paul, Alam Imranul, Polgreen Lynda E, Imel Erik A, Orchard Paul, Econs Michael J
Department of Medicine Indiana University School of Medicine Indianapolis IN USA.
Department of Pediatrics University of Minnesota Medical School Minneapolis MN USA.
JBMR Plus. 2022 Apr 29;6(6):e10616. doi: 10.1002/jbm4.10616. eCollection 2022 Jun.
The osteopetroses are a group of rare genetic diseases caused by osteoclast dysfunction or absence. The hallmark of osteopetrosis is generalized increased bone mineral density (BMD). However, the bone is fragile and fractures are common. Autosomal recessive osteopetrosis is usually a severe disorder and often life-threatening in childhood. We present male siblings with autosomal recessive osteopetrosis due to biallelic variants in who survived childhood and underwent hematopoietic stem cell transplant (HSCT) in adulthood. One sibling died of posttransplant complications. After transplant, the other sibling had improvement of multiple clinical parameters, including some decline in BMD -scores by dual-energy X-ray absorptiometry (DXA) and cessation of fractures. However, spine quantitative computed tomography 11 years after transplant demonstrated an anvil pattern of sclerosis with BMD -score of +18.3. High-resolution peripheral quantitative computed tomography (HR-pQCT) of the tibia demonstrated near complete obliteration of the marrow space combined with an unusual cortical phenotype, suggesting extensive cortical porosity at the distal tibia. This case highlights that despite successful transplantation and subsequent improvement in clinical parameters, this patient continued to have significantly elevated bone density and decreased marrow space. Transplant-associated increased cortical porosity is multifactorial and occurs in two-thirds of non-osteopetrotic patients undergoing HSCT. This finding after transplant in osteopetrosis may suggest particular sensitivity of the cortical bone to resorptive activity of transplanted osteoclasts. The case also suggests HR-pQCT may be a useful modality for imaging and assessing the therapeutic effects on bone in individuals with osteopetrosis. © 2022 The Authors. published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
骨质石化症是一组由破骨细胞功能障碍或缺失引起的罕见遗传性疾病。骨质石化症的标志是全身骨矿物质密度（BMD）增加。然而，骨骼很脆弱，骨折很常见。常染色体隐性骨质石化症通常是一种严重的疾病，在儿童期往往危及生命。我们报告了一对患有常染色体隐性骨质石化症的男性同胞，他们由于双等位基因变异在童年存活下来，并在成年后接受了造血干细胞移植（HSCT）。其中一个同胞死于移植后并发症。移植后，另一个同胞的多个临床参数有所改善，包括双能X线吸收法（DXA）测量的BMD评分有所下降以及骨折停止。然而，移植11年后的脊柱定量计算机断层扫描显示出硬化的砧骨模式，BMD评分为+18.3。胫骨的高分辨率外周定量计算机断层扫描（HR-pQCT）显示骨髓腔几乎完全闭塞，并伴有不寻常的皮质表型，提示胫骨远端存在广泛的皮质孔隙。该病例强调，尽管移植成功且临床参数随后有所改善，但该患者的骨密度仍显著升高，骨髓腔减小。移植相关的皮质孔隙增加是多因素的，发生在三分之二接受HSCT的非骨质石化症患者中。骨质石化症患者移植后的这一发现可能表明皮质骨对移植破骨细胞的吸收活性具有特殊敏感性。该病例还表明，HR-pQCT可能是一种用于成像和评估骨质石化症患者骨骼治疗效果的有用方法。© 2022作者。由Wiley Periodicals LLC代表美国骨与矿物质研究学会出版。
