Outcomes of Autologous Hematopoietic Stem Cell Transplantation in an Overlapping Case of Advanced Systemic Sclerosis and IgG4-Related Disease

Both scleroderma and immunoglobulin G4-related disease (IgG4-RD) are systemic fibro-inflammatory diseases characterised by lymphoplasmacytic infiltrates. IgG4-RD and systemic Sclerosis (SSc) may share common pathophysiological mechanisms, but no examples of co-occurrence of the diseases have been found. Autologous haematopoietic stem cell transplantation (AHSCT) is implemented in selected rapidly progressive SSc with high risk of organ failure. However, existing guidelines are based on clinical trials that do not represent the entire patient population and exclude critically ill patients with no therapeutic alternatives. Examples of AHSCT in IgG4-RD are absent. We report the case of AHSCT in a female patient with overlapping progressive diffuse SSc and sinonasal IgG4-RD. Despite immunosuppressive therapy, IgG4-RD developed and clinically manifested shortly before AHSCT. Lacking therapeutic alternatives, after 11 years of SSc therapy, the 44-year-old successfully underwent AHSCT. The 63-month follow-up showed regression of symptoms. Only after surgical treatment (bilateral ethmoidectomy, sphenoidotomy, intranasal buccal antrostomy) the initially progressive clinical course of IgG4-RD remained indolent.