Bone marrow transplantation from a human leukocyte antigen-mismatched unrelated donor in a case with C1q deficiency associated with refractory systemic lupus erythematosus

Int J Hematol. 2021 Feb;113(2):302-307. doi: 10.1007/s12185-020-03004-7. Epub 2020 Sep 30.


Human C1q deficiency is frequently associated with systemic lupus erythematosus (SLE), which requires long-term systemic corticosteroid administration. We report the case of a 12-year-old female patient with C1q deficiency presenting with intractable SLE who successfully underwent bone marrow transplantation from a human leukocyte antigen (HLA)-mismatched unrelated donor with an immunosuppressive conditioning regimen based on fludarabine, melphalan, and anti-thymocyte globulin. She developed Grade I graft-versus-host disease, but did not have any transplantation-related morbidity. Complete donor chimerism has been maintained for 2 years after transplantation, leading to the restoration of C1q levels and the resolution of SLE symptoms. Normal C1q mRNA expression was observed in CD14 + cells. Hematopoietic stem cell transplantation from an HLA-mismatched donor is a feasible treatment for patients with C1q deficiency with refractory SLE that is dependent on systemic corticosteroid treatment who do not have an HLA-matched donor.

Keywords: C1q deficiency; Hematopoietic stem cell transplantation; Systemic lupus erythematosus.

Publication types

  • Case Reports

MeSH terms

  • Bone Marrow Transplantation* / adverse effects
  • Bone Marrow Transplantation* / methods
  • Child
  • Complement C1q / deficiency*
  • Disease Management
  • Disease Susceptibility
  • Female
  • Graft vs Host Disease / drug therapy
  • Graft vs Host Disease / etiology
  • Graft vs Host Disease / prevention & control
  • HLA Antigens / genetics
  • HLA Antigens / immunology
  • Histocompatibility Testing
  • Humans
  • Lupus Erythematosus, Systemic / diagnosis
  • Lupus Erythematosus, Systemic / etiology*
  • Lupus Erythematosus, Systemic / therapy*
  • Transplantation Conditioning / methods
  • Transplantation, Homologous
  • Treatment Outcome
  • Unrelated Donors*


  • HLA Antigens
  • Complement C1q