Improvement of microangiopathy after haematopoietic stem cell transplantation in systemic sclerosis.

OBJECTIVES: Haematopoietic stem cell transplantation (HSCT) is a treatment option for patients with severe systemic sclerosis (SSc), but the efficacy of the procedure in remodelling the nailfold microvascular array is largely unknown. Therefore, this study aimed to evaluate the effect of HSCT on microangiopathy assessed through nailfold capillaroscopy (NC) and to compare the results with findings in patients receiving conventional immunosuppression. METHODS: We included SSc patients with severe SSc and whose pre- and post-treatment NC images were available. Findings in patients treated with HSCT were compared with patients not treated with HSCT. Images were scored by two independent observers blinded for clinical data and treatment history. Capillary pattern was determined and semiquantitative scores from 0 (no changes) to 3 (>66% alterations per millimetre) were used to quantify the degree of specific microvascular characteristics. Changes in severity of microangiopathy between baseline and post-treatment were compared between groups. RESULTS: Images of 18 HSCT patients and 21 controls were scored. From baseline to follow-up, 33% of HSCT patients showed improvement from scleroderma pattern to normal NC, compared to 6% of controls (p=0.15). Pre- to post-treatment differences in semiquantitative scores showed significant improvement in HSCT patients compared to controls regarding capillary loss (-0.5 vs. 0.0, p<0.05) and disorganisation (-0.8 vs. 0.0, p<0.05). CONCLUSIONS: The degree of microangiopathy improved significantly in severe SSc patients treated with HSCT compared with patients receiving conventional immunosuppressive therapy.

Identification of Risk Factors for COVID-19 Hospitalization in Patients With Anti-Rheumatic Drugs: Results From a Multicenter Nested Case Control Study.

Patients with inflammatory rheumatic diseases (IRDs) do not have an increased risk for coronavirus disease 2019 (COVID-19) compared with the general population. However, it remains uncertain whether subgroups of patients with IRD using different immunosuppressive antirheumatic drugs carry a higher risk for severe COVID-19 compared with other patients with IRD. The aim of this study is to identify risk factors for severe COVID-19, requiring hospitalization in patients with IRD. This is a multicenter nested case control study conducted in the Netherlands. Cases are hospital known patients with IRD requiring hospitalization for COVID-19 between March 1, 2020, and May 31, 2020. Controls are hospital known patients with IRD not requiring hospitalization for COVID-19 in this period, included at a 4:1 ratio. Patient, disease, and treatment characteristics were extracted from electronic medical records and a questionnaire. Potential risk factors were analyzed using unconditional logistic regression, corrected for confounders and multiple testing. Eighty-one cases and 396 controls were included. General risk factors of older age and obesity apply to patients with IRD as well (odds ratio (OR) for age ≥ 75 3.5, 95% confidence interval (CI) 1.9-6.3, OR for body mass index ≥ 40 4.5, 95% CI 1.5-14). No significantly increased ORs for COVID-19 hospitalization were found for any antirheumatic agent or IRD. A protective effect was found for use of methotrexate (OR 0.53, 95% CI 0.31-0.92). In conclusion, similar to the general population, elderly and obese patients with IRD have a higher risk for hospitalization for COVID-19. We did not identify a specific antirheumatic agent or IRD to increase the risk of COVID-19 hospitalization in patients with IRD, except for a possible protective effect of methotrexate.

A phase I clinical trial to study the safety of treatment with tipifarnib combined with bortezomib in patients with advanced stages of myelodysplastic syndrome and oligoblastic acute myeloid leukemia.

PURPOSE: To determine the safety of tipifarnib in combination with escalating doses of bortezomib and to determine the maximum tolerated dose in patients with untreated high-risk MDS and oligoblastic acute myeloid leukemia, who were not eligible for intensive therapy. EXPERIMENTAL DESIGN: In a "3 + 3″ design, patients received fixed doses of tipifarnib 200 mg bid (days 1-21) and escalating doses of bortezomib (days 8, 15, 22) every 4 weeks in 4-6 cycles. RESULTS: The combination was tolerated well by the 11 patients in this study without reaching the maximum tolerated dose. Myelosuppression was the most frequent side effect, but usually of short duration. Interestingly a complete response with or without complete count recovery was observed in three patients and three additional patients had stable disease. The median duration of overall survival was 449 days. Two patients were still alive at 4.0 and 4.3 years, including one patient in continuing CR. CONCLUSIONS: The combination of tipifarnib and bortezomib was tolerated well and appeared to have clinical activity in patients with high-risk MDS and AML with low counts of marrow blasts. Our results warrant further evaluation in a phase II study.

Predictive factors for treatment-related mortality and major adverse events after autologous haematopoietic stem cell transplantation for systemic sclerosis: results of a long-term follow-up multicentre study.

BACKGROUND: Autologous haematopoietic stem cell transplantation (HSCT) improves survival in systemic sclerosis (SSc) with poor prognosis, but is hampered by treatment-related mortality (TRM). OBJECTIVE: To evaluate event-free survival (EFS), TRM, response to treatment, disease progression and patient characteristics associated with events. METHODS: All patients treated with HSCT for SSc in The Netherlands until 2017 (n=92) were included. Data on skin involvement (modified Rodnan skin score (mRSS), pulmonary function (forced vital capacity (FVC) and diffusion capacity of the lungs for carbon monoxide (DLCO)), extent of interstitial lung disease on high-resolution CT using Goh scores and left ventricular ejection fraction (LVEF) were collected at baseline, 1, 2 and 5 years. Occurrence of events, defined as death or major organ failure, were collected until 2019. As control, a comparison between patients treated with cyclophosphamide (CYC) and patients with HSCT who participated in the Autologous Stem Cell Transplantation International Scleroderma (ASTIS) trial was performed. RESULTS: Median follow-up was 4.6 years. EFS estimates at 5, 10 and 15 years were 78%, 76% and 66%, respectively. Twenty deaths occurred. Mean FVC, DLCO, mRSS and Goh scores all improved significantly. Disease progression occurred in 22 patients. Frequency of TRM decreased over time and occurred more often in males. Events were independently associated with male sex, LVEF <50% and older age. In ASTIS, patients treated with HSCT (n=23) 7 events occurred versus 13 in the CYC group (n=22). CONCLUSION: Our data confirm long-term efficacy of HSCT in improving survival, skin and lung involvement in SSc. Male sex, lower LVEF and older age at baseline were identified as risk factors for events.

Induction of myelodysplasia by myeloid-derived suppressor cells.

Myelodysplastic syndromes (MDS) are age-dependent stem cell malignancies that share biological features of activated adaptive immune response and ineffective hematopoiesis. Here we report that myeloid-derived suppressor cells (MDSC), which are classically linked to immunosuppression, inflammation, and cancer, were markedly expanded in the bone marrow of MDS patients and played a pathogenetic role in the development of ineffective hematopoiesis. These clonally distinct MDSC overproduce hematopoietic suppressive cytokines and function as potent apoptotic effectors targeting autologous hematopoietic progenitors. Using multiple transfected cell models, we found that MDSC expansion is driven by the interaction of the proinflammatory molecule S100A9 with CD33. These 2 proteins formed a functional ligand/receptor pair that recruited components to CD33's immunoreceptor tyrosine-based inhibition motif (ITIM), inducing secretion of the suppressive cytokines IL-10 and TGF-ß by immature myeloid cells. S100A9 transgenic mice displayed bone marrow accumulation of MDSC accompanied by development of progressive multilineage cytopenias and cytological dysplasia. Importantly, early forced maturation of MDSC by either all-trans-retinoic acid treatment or active immunoreceptor tyrosine-based activation motif­bearing (ITAM-bearing) adapter protein (DAP12) interruption of CD33 signaling rescued the hematologic phenotype. These findings indicate that primary bone marrow expansion of MDSC driven by the S100A9/CD33 pathway perturbs hematopoiesis and contributes to the development of MDS.

T cells expressing the activating NK-cell receptors KIR2DS4, NKG2C and NKG2D are elevated in paroxysmal nocturnal hemoglobinuria and cytotoxic toward hematopoietic progenitor cell lines.

OBJECTIVE: To investigate the presence of T cells with natural killer cell receptors (NKR) in paroxysmal nocturnal hemoglobinuria (PNH), and their potential involvement in clonal expansion of glycosylphosphatidylinositol (GPI)-deficient hematopoietic stem cells by selective immune attack to normal and not GPI-deficient hematopoietic stem cells. MATERIALS AND METHODS: By flow cytometry, the frequency and number of T cells expressing NKR was evaluated in 39 PNH patients and compared to healthy controls. Elevated T cell subsets in PNH were assessed for differential cytotoxic lysis of GPI(+) and GPI(-) CD34(+) hematopoietic progenitor cell lines. RESULTS: In PNH patients, the frequency (p < 0.001) and absolute number of T cells expressing the NKR CD56 (p = 0.01) were significantly increased. Furthermore, a higher percentage of T cells expressed the activating NKR NKG2D (p < 0.01), NKG2C (p < 0.01), and KIR2DS4 (p = 0.01). Further characterization showed that these populations predominantly consist of CD8(+) effector memory CD45RA(+) T cells (T(EMRA)). NKR(+) cytotoxic T-lymphocyte lines isolated from PNH patient peripheral blood and bone marrow displayed high cytotoxicity towards CD34(+) hematopoietic progenitor cell lines and K562 cells, suggesting major histocompatibility complex class I-independent cytotoxicity. These cytotoxic T lymphocyte (CTL) lines are capable of differential lysis of GPI(+) and GPI(-) hematopoietic cell lines, however, not in all cases. This suggests that multiple factors, such as the highly activated status of in vitro cultured CTLs, influence whether GPI-dependent lysis occurs. CONCLUSIONS: The increased frequency of CD8(+) effector-memory T cells with activating NKR and cytotoxicity toward hematopoietic cell lines suggests involvement in bone marrow failure and clonal expansion in PNH.