1 23 Archivum Immunologiae et Therapiae Experimentalis ISSN 0004-069X Volume 62 Number 4 Arch. Immunol. Ther. Exp. (2014) 62:319-327 DOI 10.1007/s00005-014-0279-9 Hematopoietic Stem Cell Transplantation in Children with Autoimmune Connective Tissue Diseases Magdalena Witkowska, Elzbieta Smolewska & Piotr Smolewski