Recipient Immune Modulation with Atorvastatin for Acute Graft-versus-Host Disease Prophylaxis after Allogeneic Transplantation

New target-HMGCR inhibitors for the treatment of primary sclerosing cholangitis: A drug Mendelian randomization study

Background

No intervention definitively extends transplant-free survival in primary sclerosing cholangitis (PSC). Statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), may enhance PSC prognosis, but their efficacy is debated.

Methods

We analyzed HMGCR single-nucleotide polymorphisms from published genome-wide association studies using Mendelian randomization to assess the causal relationship between HMGCR and PSC risk. Effects of HMGCR were compared with proprotein convertase subtilisin kexin 9 (PCSK9) inhibitors, common lipid-lowering drugs, using coronary heart disease risk as a positive control. The inverse-variance weighted (IVW) method was the primary analysis, complemented by the weighted median method. Heterogeneity analysis, examination of horizontal pleiotropy, and leave-one-out sensitivity analysis were conducted for result robustness.

Results

Genetically predicted HMGCR exhibited a pronounced detrimental effect on PSC in both the IVW method (odds ratio [OR] [95%] = 2.43 [1.23-4.78], P = 0.010) and the weighted median method (OR [95%] = 2.36 [1.02-5.45], P = 0.044). However, PCSK9 did not reach statistical significance. Moreover, all analyses passed through heterogeneity analysis, horizontal pleiotropy analysis, and leave-one-out sensitivity analysis.

Conclusion

This study has confirmed a causal relationship between HMGCR and PSC risk, suggesting statins targeting HMGCR could enhance PSC patient outcomes.

Impact of Donor Statin Treatment on Graft-versus-Host Disease after Allogeneic Hematopoietic Cell Transplantation

Some retrospective studies have suggested that long-term donor statin use may protect against graft-versus-host disease (GVHD) in patients receiving cyclosporine (CSP)-based immunosuppression after allogeneic hematopoietic cell transplantation (HCT), but prospective studies of short-term treatment of donors with statin have shown conflicting results. We conducted 2 consecutive prospective clinical trials to assess whether donor statin treatment was associated with protection against severe acute GVHD (aGVHD). In a single-arm phase II trial (study 1), we evaluated whether short-term statin treatment of HLA-matched related donors for 14 days before HCT prevented grade III-IV aGVHD. In a prospective observational cohort study (study 2), we evaluated whether longer-term (>14 days) donor statin use was required for GVHD-protective effects. Study 1 was terminated after 6 of the 35 recipients (17%) developed grade III-IV GVHD. For study 2, we identified 135 patients whose unrelated donors had received long-term treatment with statins up to the time of HCT and 4942 patients whose donors had not received long-term statin treatment. The adjusted odds ratio for grade III-IV aGVHD (statin versus no statin) was .83 (95% confidence interval [CI], .46 to 1.50; P = .54). Multivariable analysis showed no statistically significant differences between the 2 groups in the risk of grade II-IV aGVHD, chronic GVHD, nonrelapse mortality, recurrent malignancy, or overall mortality. Among patients receiving CSP-based immunosuppression, including 35 with donors receiving long-term statin treatment and 973 with donors who did not receive statins, the adjusted odds ratio of grade III-IV aGVHD was .30 (95% CI, .07 to 1.35; P = .12). In study 1, short-term statin treatment of donors was ineffective in preventing grade III-IV GVHD. In study 2, in the prespecified subgroup of recipients given CSP-based immunosuppression, nondefinitive evidence suggested that donor statin use was associated with a reduced risk of severe aGVHD.

Endothelial cell dysfunction: a key determinant for the outcome of allogeneic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (alloSCT) carries the promise of cure for many malignant and non-malignant diseases of the lympho-hematopoietic system. Although outcome has improved considerably since the pioneering Seattle achievements more than 5 decades ago, non-relapse mortality (NRM) remains a major burden of alloSCT. There is increasing evidence that endothelial dysfunction is involved in many of the life-threatening complications of alloSCT, such as sinusoidal obstruction syndrome/venoocclusive disease, transplant-associated thrombotic microangiopathy, and refractory acute graft-versus host disease. This review delineates the role of the endothelium in severe complications after alloSCT and describes the current status of search for biomarkers predicting endothelial complications, including markers of endothelial vulnerability and markers of endothelial injury. Finally, implications of our current understanding of transplant-associated endothelial pathology for prevention and management of complications after alloSCT are discussed.

Putting function back in dysfunction: Endothelial diseases and current therapies in hematopoietic stem cell transplantation and cellular therapies

Endothelial dysfunction is characterized by altered vascular permeability and prothrombotic, pro-inflammatory phenotypes. Endothelial dysfunction results in end-organ damage and has been associated with diverse disease pathologies. Complications observed after hematopoietic stem cell transplantation (HCT) and chimeric antigen receptor-T cell (CAR-T) therapy for hematologic and neoplastic disorders share overlapping clinical manifestations and there is increasing evidence linking these complications to endothelial dysfunction. Despite advances in supportive care and treatments, end-organ toxicity remains the leading cause of mortality. A new strategy to mitigate endothelial dysfunction could lead to improvement of clinical outcomes for patients. Statins have demonstrated pleiotropic effects of immunomodulatory and endothelial protection by various molecular mechanisms. Recent applications in immune-mediated diseases such as autoimmune disorders, chronic inflammatory conditions, and graft-versus-host disease (GVHD) have shown promising results. In this review, we cover the mechanisms underlying endothelial dysfunction in GVHD and CAR-T cell-related toxicities. We summarize the current knowledge about statins and other agents used as endothelial protectants. We propose further studies using statins for prophylaxis and prevention of end-organ damage related to extensive endothelial dysfunction in HCT and CAR-T.

Fluvastatin-Pretreated Donor Cells Attenuated Murine aGVHD by Balancing Effector T Cell Distribution and Function under the Regulation of KLF2

Prevention of acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is still to be explored. Statins are potent immunomodulatory agents that hold promise as novel and safe agents for aGVHD prophylaxis, yet the controversial effect and regulatory mechanism are incompletely understood. Here, in an MHC mismatched murine model, we found that Fluvastatin-pretreated donor cells could attenuate aGVHD severity by remission tissue pathological injury. Fluvastatin served to restrain effector T cells entry into aGVHD target organs from secondary lymphoid organs (SLOs). The potential mechanism of correcting the effector T cell biased distribution was that Fluvastatin elevated CD62L and CCR7 expression while decreased CXCR3 and CD44 levels, which were correlated with Kruppel-like factor 2 (KLF2) sustention in donor-derived cells. In addition, Fluvastatin was contributed to reducing cytokines IFN-γ, TNF-α, and granzyme-B production in allogeneic effector CD4⁺ and CD8⁺ T cells. Furthermore, evidence confirmed that Fluvastatin had a long-lasting effect to sustain KLF2 expression both in vitro and in vivo even under the stimulated circumstance. In conclusion, administration of Fluvastatin to donor mice showed protective effects against recipient aGVHD when compared to untreated mice due to the retention of effector T cells in lymphoid organs accompanying with reduction of nonlymphatic infiltration and related inflammatory cytokines.

Steroid-refractory acute graft-versus-host disease graded III-IV in pediatric patients. A mono-institutional experience with a long-term follow-up

aGvHD remains a major obstacle to successful HSCT. We report our experience on steroid-refractory aGvHD III and IV from 1989 to 2017. Ninety patients with aGvHD III or IV were stratified according to the HSCT year: 1989-1998, 1999-2007, and 2008-2017 and to aGvHD extension (GvHD III vs IV) and finally the probability of OS, RI, and TRM was calculated accordingly. aGvHD III patients had a substantial improvement over time: day 100 OS raised from 64% (95% CI 39-89) in the first cohort to 100% in the latest (P = .022), and it was mainly due to a reduction of TRM (it was 28% [95% CI 12-65] in the first cohort to 0% in the latest (P = .01). The aGvHD IV patients did not present a significant improvement. Day 100 OS was 42% (95% CI 16-68) in the first group and 54% (95% CI 25-83) in the year 2008-2017 (P = NS), and the day-100 TRM was very similar (it was 57% [95% CI 36-90] in the first cohort and 45% [95% CI 23-89] in the latest (P = NS). We report significant improvements in OS and TRM in patients diagnosed with grade III aGvHD. Patients with the most severe aGvHD appear to have no or fewer benefits on long-term outcomes.

Current approaches to prevent and treat GVHD after allogeneic stem cell transplantation

Allogeneic hematopoietic cell transplantation is a potentially curative therapy for many malignant and nonmalignant hematologic diseases. Graft-versus-host disease (GVHD) is a common complication after transplantation and remains a major cause of morbidity and mortality, limiting the success of a potentially curative transplant. This paper reviews the current and emerging strategies in GVHD prevention and treatment. New insights are leading the way to the development of novel targeted approaches to minimize the risk of disease relapse and infection. Continued collaborative efforts to conduct high-quality, multicenter clinical trials with standard end points and risk stratification are needed to determine the optimal approach to minimize GVHD and limit toxicities.

Mortality and risk factors among Israeli bullous pemphigoid patients

There are differences concerning reported mortality rates and prognostic factors of bullous pemphigoid (BP) patients in different studies. Our objectives were to evaluate the mortality rates and prognostic factors among Israeli BP patients compared to matched control subjects. Three age- and sex-matched patients without BP (n = 261) who were treated in our clinic were selected and compared to BP patients (n = 87). Mean survival period of the BP group was 4.1 years (95% CI: 3.3-4.8 years) and 5.9 years among the non-BP group (95% CI: 5.6-6.3 years). The 1-year mortality rate was 24.1% for the BP group and 6.5% for the control group. In multivariate analysis, age above 80 was a significant risk factor for mortality [HR 3.22 (95% CI, 1.15-8.96), p = 0.03], while statins intake had a protective role [HR 0.36 (95% CI, 0.15-0.88), p = 0.03]. In univariant analysis, dementia [HR 2.44 (95% CI, 1.02-5.99), p = 0.04] was a risk factor. In conclusion, BP patients' mortality is correlated to increasing age at diagnosis, dementia, and statins use. Statins' protective role is newly discussed in the literature.

Immune modulatory effects of statins

Despite major advances in recent years, immunosuppressive regimens for multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus and graft-versus-host disease still have major adverse effects and immunomodulation rather than immune paralysis would be desirable. Statins inhibit the rate-limiting enzyme of the l-mevalonate pathway, the 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase. It was shown that blocking the l-mevalonate pathway reduces inflammation through effects on downstream metabolites of the pathway including farnesylpyrophosphates and geranylgeranylpyrophosphates, which are essential for the attachment of GTPases like RhoA, Rac and Ras to the cell membrane. Therefore, l-mevalonate pathway downstream products play critical roles in the different steps of an immune response including immune cell activation, migration, cytokine production, immune metabolism and survival. This review discusses the relevance of the different metabolites for the immunomodulatory effect of statins and connects preclinical results with data from clinical studies that tested statins for the treatment of different inflammatory diseases.