Esophageal motility in systemic sclerosis before and after autologous hematopoietic cell transplantation.

INTRODUCTION: Systemic sclerosis (SSc) is associated with esophageal dysmotility. Autologous hematopoietic cell transplantation (HCT) results in improvement of skin tightness and lung function. Whether esophageal motility improves after HCT is unknown. METHODS: Esophageal motility was studied using high-resolution esophageal manometry in 21 SSc patients before and at multiple time points after autologous HCT. Median posttransplant follow-up was 2 years (range, 6 months to 5 years). RESULTS: Prior to HCT, all 21 patients had abnormal motility-10 (48%) had unmeasurable and 11 (52%) had measurable peristalsis. Manometric diagnosis in the former 10 patients was "absent contractility" and in the latter 11 patients "ineffective esophageal motility (IEM)." After HCT, among the 10 patients with absent contractility, 9 continued to have absent contractility and one demonstrated weak measurable peristalsis. Of the 11 patients with IEM, 5 experienced SSc relapse, and 2 out of these 5 patients developed absent contractility. Among the 6 non-relapsed patients, 4 continued to have IEM, and 2 developed normal motility. CONCLUSIONS: HCT appears to have no beneficial effect on motility in patients with unmeasurable peristalsis. In patients with measurable peristalsis, HCT appears to stabilize and in some normalize motility, unless relapse occurs. Key Points • In patients with systemic sclerosis, esophageal dysmotility is a significant contributor to morbidity and so far, there has been no data describing the effects of hematopoietic cell transplantation on esophageal motility. • Our work demonstrated that in patients with systemic sclerosis and unmeasurable esophageal peristalsis prehematopoietic cell transplantation, there was no measurable beneficial effect of transplantation on esophageal motility. • In patients with systemic sclerosis and measurable peristalsis prehematopoietic cell transplantation, esophageal motility stabilized, except in relapsed patients.

The cancer-associated glycan polysialic acid is dysregulated in systemic sclerosis and is associated with fibrosis.

OBJECTIVE: Systemic sclerosis (SSc) is a rare but deadly disease characterized by autoimmunity, vasculopathy, and fibrosis. Fibrotic complications associated with SSc correlate with severe morbidity and mortality. Previous studies in SSc have identified fibroblasts as the primary drivers of fibrosis; however, the mechanism(s) promoting this are not well understood. Aberrant glycosylation, particularly polysialylation (polySia), has been described as a prominent feature of aggressive cancers. Inspired by this observation, we aimed to determine if polySia is dysregulated in various forms of SSc. METHODS: All patients with SSc met the 2013 ACR/EULAR. Patients were sub-classified into limited cutaneous (lSSc, N = 5 or 46 patients for polySia quantification in the dermis or serum; respectively), diffuse cutaneous (dSSc, N = 11 or 18 patients for polySia quantification in the dermis or serum; respectively), or patients with dSSc treated with an autologous stem cell transplantation (post-ASCT, N = 4 patients for quantification in the dermis). Dermal polySia levels were measured via immunofluorescence microscopy in 10 µm dermal sections, quantified in each group (healthy volunteers (HC), lSSc, dSSc, and post-ASCT) and correlated with skin fibrosis (via the modified Rodnan skin score (mRSS)). Similarly, serum polySia was quantified in each group, and correlated with the mRSS. RESULTS: Dermal polySia levels were highest in patients with dSSc (compared to HC < 0.001), and correlated with the degree of fibrosis in all of the groups (P = 0.008). Serum polySia was higher in all SSc groups (p < 0.001) and correlated with the severity of mRSS (p < 0.0001). CONCLUSION: Polysia is more abundant in the skin and sera from patients with SSc and correlates with the degree of skin fibrosis. The aberrant expression of polySia highlights its potential use as a biomarker in patients with progressive forms of SSc. Dysregulated polySia levels in SSc further emphasizes the cancer-like phenotype present in SSc, which may promote fibrosis and immune dysregulation.

Hematopoietic Cell Transplantation for Systemic Sclerosis-A Review.

Systemic sclerosis (SSc) is an autoimmune, multi-organ, connective tissue disease associated with significant morbidity and mortality. Conventional immunosuppressive therapies demonstrate limited efficacy. Autologous hematopoietic stem cell transplantation (HCT) is more efficacious but carries associated risks, including treatment-related mortality. Here, we review HCT as a treatment for SSc, its efficacy and toxicity in comparison to conventional therapies, and the proposed mechanisms of action. Furthermore, we discuss the importance of and recent developments in patient selection. Finally, we highlight the knowledge gaps and future work required to further improve patient outcomes.

Genomic instability in early systemic sclerosis.

OBJECTIVES: Systemic sclerosis (SSc) is associated with secondary malignancies. Previous studies have suggested that mutated cancer proteins, such as RNA polymerase III, are autoantigens promoting an inflammatory response in SSc. However, it has never been previously investigated whether non-neoplastic tissue in SSc harbors mutations which may play a role in SSc pathogenesis. METHODS: Skin biopsies were obtained from 8 sequential patients with a progressive form of early stage SSc (with severe skin and/or lung involvement). Areas of dermal fibrosis were microdissected and analyzed with deep, whole exome sequencing. Gene mutation patterns were compared to autologous buccal mucosal cells as a control. RESULTS: SSc skin biopsies were hypermutated with an average of 58 mutations/106 base pairs. The mutational pattern in all samples exhibited a clock-like signature, which is ubiquitous in cancers and in senescent cells. Of the 1997 genes we identified which were mutated in at least two SSc patients, 39 genes represented cancer drivers (i.e. tumor suppressor genes or oncogenes) which are commonly found in gynecological, squamous and gastrointestinal cancer signatures. Of all the mutations, the most common mutated genes were important in regulating pathways related to epigenetic histone modifications, DNA repair and genome integrity. CONCLUSIONS: Somatic hypermutation occurs in fibrotic skin in patients with early progressive SSc. Cancer driver gene mutations may potentially play a fundamental role in the pathogenesis of SSc.

Efficacy of Allogeneic Hematopoietic Cell Transplantation for Autoimmune Diseases.

Allogeneic hematopoietic cell transplantation (HCT) may be efficacious for autoimmune diseases (AIDs), but its efficacy for individual AIDs is unknown. Factors influencing the likelihood of relapse for each AID are also unknown. This study aimed to determine the likelihood of relapse for each common AID and to generate hypotheses about factors influencing the likelihood of relapse. We reviewed charts of adult patients with nonhematologic AIDs who had undergone HCT in Alberta (n = 21) and patients described in the literature (n = 67). We used stringent inclusion criteria to minimize the inclusion of patients whose AID may have been cured before transplantation. We also used stringent definitions of AID relapse and remission. AID relapsed in 2 of 9 patients (22%) with lupus, in 4 of 12 (33%) with rheumatoid arthritis (RA), in 0 of 4 (0%) with systemic sclerosis (SSc), in 3 of 16 (19%) with psoriasis, in 1 of 12 (8%) with Behçet's disease (BD), in 1 of 15 (7%) with Crohn's disease (CD), in 0 of 5 (0%) with ulcerative colitis (UC), in 4 of 8 (50%) with multiple sclerosis (MS), and in 3 of 3 (100%) with type 1 diabetes mellitus (T1DM). Among highly informative patients (followed for >1 year after discontinuation of immunosuppressive therapy if no relapse, or donor AID status known if relapse), relapse occurred in 0 of 3 patients with lupus, in 2 of 7 with RA, in 0 of 2 with SSc, in 3 of 6 with psoriasis, in 0 of 3 with BD, in 0 of 10 with CD, in 0 of 3 with UC, in 2 of 3 with MS, and in 2 of 2 with T1DM. There appeared to be no associations between AID relapse and low intensity of pretransplantation chemoradiotherapy, multiple lines of AID therapy (surrogate for AID refractoriness) except perhaps for lupus, absence of serotherapy for graft-versus-host disease (GVHD) prophylaxis, lack of GVHD except perhaps for lupus, or incomplete donor chimerism. Even though remission commonly occurs after HCT in lupus, RA, SSc, psoriasis, BD, CD, and UC, HCT is efficacious for only a subset of patients. The efficacy appears to be unrelated to pretransplantation therapy, GVHD, or chimerism. Large studies are needed to determine the characteristics of patients likely to benefit from HCT for each AID.

Patient Preferences for Disease-modifying Antirheumatic Drug Treatment in Rheumatoid Arthritis: A Systematic Review.

OBJECTIVE: To summarize patients' preferences for disease-modifying antirheumatic drug (DMARD) therapy in rheumatoid arthritis (RA). METHODS: We conducted a systematic review to identify English-language studies of adult patients with RA that measured patients' preferences for DMARD or health states and treatment outcomes relevant to DMARD decisions. Study quality was assessed using a published quality assessment tool. Data on the importance of treatment attributes and associations with patient characteristics were summarized across studies. RESULTS: From 7951 abstracts, we included 36 studies from a variety of countries. Most studies were in patients with established RA and were rated as medium- (n = 19) or high-quality (n = 12). The methods to elicit preferences varied, with the most common being discrete choice experiment (DCE; n = 13). Despite the heterogeneity of attributes in DCE studies, treatment benefits (disease improvement) were usually more important than both non-serious (6 of 8 studies) and serious adverse events (5 of 8), and route of administration (7 of 9). Among the non-DCE studies, some found that patients placed high importance on treatment benefits, while others (in patients with established RA) found that patients were quite risk averse. Subcutaneous therapy was often but not always preferred over intravenous therapy. Patient preferences were variable and commonly associated with the sociodemographic characteristics. CONCLUSION: Overall, the results showed that many patients place a high value on treatment benefits over other treatment attributes, including serious or minor side effects, cost, or route of administration. The variability in patient preferences highlights the need to individualize treatment choices in RA.

Antirelapse effect of pretransplant exposure to rabbit antithymocyte globulin.

It remains unknown why rabbit antithymocyte globulin (ATG; Thymoglobulin) has not affected relapse after hematopoietic cell transplantation (HCT) in randomized studies. We hypothesized that high pre-HCT ATG area under the curve (AUC) would be associated with a low incidence of relapse, whereas high post-HCT AUC would be associated with a high incidence of relapse. We measured serum levels of ATG capable of binding to mononuclear cells (MNCs), lymphocytes, T cells, CD4 T cells, or CD33 cells. We estimated pre- and post-HCT AUCs in 152 adult recipients of myeloablative conditioning and blood stem cells. High pre-HCT AUCs of MNC- and CD33 cell-binding ATG were associated with a low incidence of relapse and high relapse-free survival (RFS). There was a trend toward an association of high post-HCT AUC of lymphocyte-binding ATG with a high incidence of relapse and low RFS. High pre-HCT AUCs were also associated with faster engraftment and had no impact on graft-versus-host disease (GVHD) or fatal infections. High post-HCT AUCs were associated with a low risk of GVHD, seemed associated with an increased risk of fatal infections, and had no impact on engraftment. In conclusion, pre-HCT AUC seems to have a positive, whereas post-HCT AUC seems to have a negative, impact on relapse.

Antithymocyte Globulin at Clinically Relevant Concentrations Kills Leukemic Blasts.

In contrast to cyclosporine or methotrexate, rabbit antithymocyte globulin (ATG) used for graft-versus-host disease (GVHD) prophylaxis with myeloablative conditioning does not increase the risk of relapse after hematopoietic cell transplantation. The reason for this is unknown. We hypothesized that ATG at concentrations achieved with our standard ATG dose of 4.5 mg/kg exerts antileukemic activity. We measured ATG-induced killing of leukemic blasts via complement-dependent cytotoxicity (CDC) and via complement-independent cytotoxicity (CIC) in marrow or blood from 36 patients with newly diagnosed acute leukemia. The median percentage of blasts killed by CDC was 0.3% at 1 mg/L ATG, 2.8% at 10 mg/L ATG, 12.6% at 25 mg/L ATG, and 42.2% at 50 mg/L ATG. The median percentage of blasts killed by CIC after a 4-hour incubation with ATG was 1.9% at 1 mg/L ATG, 7.15% at 10 mg/L ATG, 12.1% at 25 mg/L ATG, and 13.9% at 50 mg/L ATG. CIC appeared to represent a direct induction of apoptosis by ATG. There was a high variability in the sensitivity of the blasts to ATG; at 50 mg/L, the percentage of blasts killed ranged from 2.6% to 97.2% via CDC and from 1.4% to 69.9% via CIC. In conclusion, ATG at clinically relevant concentrations kills leukemic blasts in vitro. Some acute leukemias are highly sensitive to ATG, whereas others are relatively resistant. This finding could lead to personalized administration of ATG.

Selective pharmacological inhibition of phosphoinositide 3-kinase p110delta opposes the progression of autoimmune diabetes in non-obese diabetic (NOD) mice.

During the progression of autoimmune (type 1) diabetes, T cells and macrophages infiltrate the pancreas, disrupt islet function, and destroy insulin-producing beta cells. B-lymphocytes, particularly innate like B-cell populations such as marginal zone B cells and B-1 cells, have been implicated in many autoimmune diseases, and non-obese diabetic (NOD) mice that lack B cells do not develop spontaneous autoimmune diabetes. Hence, inhibitors of B cell signaling pathways could be useful for limiting the autoimmune processes that contribute to type 1 diabetes. Signaling via phosphoinositide 3-kinase (PI3K) regulates many cellular processes. The p110δ isoform of PI3K is expressed primarily in cells of hematopoietic origin and the catalytic activity of p110δ is important for B cell migration, activation, proliferation, and antigen presentation. Because innate-like B cells are particularly sensitive to inhibition of p110δ activity, and p110δ inhibitors also suppress pro-inflammatory functions of other cell types that contribute to autoimmunity, we tested whether a p110δ inhibitor could delay the onset or reduce the incidence of autoimmune diabetes in NOD mice. We found that long-term preventative treatment of pre-diabetic NOD mice with IC87114, a highly selective small molecule inhibitor of p110δ, reduced the infiltration of inflammatory cells into the pancreatic islets and, accordingly, delayed and reduced the loss of glucose homeostasis. Moreover in a therapeutic treatment mode, IC87114 treatment conferred prolonged protection from progression to overt diabetes in a number of animals. These findings suggest that PI3Kδ inhibitors could be useful for managing type 1 diabetes.

Phosphoinositide 3-kinase p110 delta regulates natural antibody production, marginal zone and B-1 B cell function, and autoantibody responses.

B-1 and marginal zone (MZ) B cells produce natural Abs, make Ab responses to microbial pathogens, and contribute to autoimmunity. Although the delta isoform of the PI3K p110 catalytic subunit is essential for development of these innate-like B cells, its role in the localization, activation, and function of normal B-1 and MZ B cells is not known. Using IC87114, a highly selective inhibitor of p110delta enzymatic activity, we show that p110delta is important for murine B-1 and MZ B cells to respond to BCR clustering, the TLR ligands LPS and CpG DNA, and the chemoattractants CXCL13 and sphingosine 1-phosphate. In these innate-like B cells, p110delta activity mediates BCR-, TLR- and chemoattractant-induced activation of the Akt prosurvival kinase, chemoattractant-induced migration, and TLR-induced proliferation. Moreover, we found that TLR-stimulated Ab responses by B-1 and MZ B cells, as well as the localization of MZ B cells in the spleen, depend on p110delta activity. Finally, we show that the in vivo production of natural Abs requires p110delta and that p110delta inhibitors can reduce in vivo autoantibody responses. Thus, targeting p110delta may be a novel approach for regulating innate-like B cells and for treating Ab-mediated autoimmune diseases.

The Rap GTPases mediate CXCL13- and sphingosine1-phosphate-induced chemotaxis, adhesion, and Pyk2 tyrosine phosphorylation in B lymphocytes.

The localization of B cells to lymphoid organs where they can become activated and differentiate into antibody-secreting plasma cells is controlled by multiple chemoattractants that promote cell migration and integrin-mediated adhesion. CXCL13 and sphingosine 1-phosphate (S1P) are two important chemoattractants that control the trafficking of B cells. CXCL13 directs B lymphocytes to lymphoid follicles where they receive survival signals and, if activated, undergo a germinal center response. In contrast, S1P allows B cells and plasma cells to exit lymphoid organs and re-enter the circulation. The Rap1 GTPase is a key regulator of cell adhesion and cell migration in a number of systems. We now show that Rap activation is required for CXCL13 and S1P to induce B cell migration as well as adhesion to ICAM-1 and VCAM-1. We also show that Pyk2, a tyrosine kinase involved in cytoskeleton rearrangements and B cell migration, is a downstream target of both CXCL13 and S1P signaling and that Rap activation is important for CXCL13 and S1P to stimulate tyrosine phosphorylation of Pyk2, a modification that increases Pyk2 kinase activity. This suggests that the ability of CXCL13 and S1P to direct the trafficking and localization of B cells in vivo may be dependent on Rap activation.