Tailored anticoagulant treatment after a first venous thromboembolism: protocol of the Leiden Thrombosis Recurrence Risk Prevention (L-TRRiP) study - cohort-based randomised controlled trial

INTRODUCTION

Patients with a first venous thromboembolism (VTE) are at risk of recurrence. Recurrent VTE (rVTE) can be prevented by extended anticoagulant therapy, but this comes at the cost of an increased risk of bleeding. It is still uncertain whether patients with an intermediate recurrence risk or with a high recurrence and high bleeding risk will benefit from extended anticoagulant treatment, and whether a strategy where anticoagulant duration is tailored on the predicted risks of rVTE and bleeding can improve outcomes. The aim of the Leiden Thrombosis Recurrence Risk Prevention (L-TRRiP) study is to evaluate the outcomes of tailored duration of long-term anticoagulant treatment based on individualised assessment of rVTE and major bleeding risks.

METHODS AND ANALYSIS

The L-TRRiP study is a multicentre, open-label, cohort-based, randomised controlled trial, including patients with a first VTE. We classify the risk of rVTE and major bleeding using the L-TRRiP and VTE-BLEED scores, respectively. After 3 months of anticoagulant therapy, patients with a low rVTE risk will discontinue anticoagulant treatment, patients with a high rVTE and low bleeding risk will continue anticoagulant treatment, whereas all other patients will be randomised to continue or discontinue anticoagulant treatment. All patients will be followed up for at least 2 years. Inclusion will continue until the randomised group consists of 608 patients; we estimate to include 1600 patients in total. The primary outcome is the combined incidence of rVTE and major bleeding in the randomised group after 2 years of follow-up. Secondary outcomes include the incidence of rVTE and major bleeding, functional outcomes, quality of life and cost-effectiveness in all patients.

ETHICS AND DISSEMINATION

The protocol was approved by the Medical Research Ethics Committee Leiden-Den Haag-Delft. Results are expected in 2028 and will be disseminated through peer-reviewed journals and during (inter)national conferences.

TRIAL REGISTRATION NUMBER

NCT06087952.

Invasive fungal infections in patients treated with Bruton's tyrosine kinase inhibitors

Bruton's tyrosine kinase (BTK) inhibitors are increasingly used in untreated and previously treated chronic lymphocytic leukaemia (CLL) patients. Invasive fungal infections (IFI) were rarely observed in patients treated for CLL in the pre-BTK era. In this article, we describe two patients with CLL who developed an IFI during treatment with the BTK inhibitor ibrutinib. The atypical presentation and the serious course of this complication are described.

Predictors of short-term and long-term mortality in critically ill patients admitted to the intensive care unit following allogeneic stem cell transplantation

Historically, the mortality of patients admitted to the ICU after allogeneic stem cell transplantation (alloSCT) is high. Advancements in transplantation procedures, infectious monitoring and supportive care may have improved the outcome. This study aimed to determine short-term and long-term mortality after ICU admission of patients after alloSCT and to identify prognostic clinical and transplantation-related determinants present at ICU admission for long-term outcome. A multicenter cohort study was performed to determine 30-day and 1-year mortality within 2 years following alloSCT. A total of 251 patients were included. The 30-day and 1-year mortality was 55% and 80%, respectively. Platelet count <25 × 10⁹/L (OR: 2.26, CI: 1.02-5.01) and serum bilirubin >19 μmol/L (OR: 2.47 CI: 1.08-5.65) at admission, other donor than a HLA-matched-related or HLA-matched-unrelated donor (OR: 4.59, CI: 1.49-14.1) and vasoactive medication within 24 h (OR: 2.35, CI: 1.28-4.31) were associated with increased 30-day mortality. Other donor than a HLA-matched-related or HLA-matched-unrelated donor (OR: 1.9, CI: 1.13-3.19), serum bilirubin >77 (OR: 2.05, CI: 1.28-3.30) and vasoactive medication within 24 h (OR: 1.65, CI: 1.12-2.43) were associated with increased 1-year mortality. Neutropenia was associated with decreased 30-day and 1-year mortality (OR: 0.29, CI: 0.14-0.59 and OR: 0.70, CI: 0.48-0.98). Myeloablative conditioning and T cell-depleted transplantation were not associated with increased mortality.

CMV seronegative donors: Effect on clinical severity of CMV infection and reconstitution of CMV-specific immunity

BACKGROUND

Cytomegalovirus (CMV)-specific T-cells are crucial to prevent CMV disease. CMV seropositive recipients transplanted with stem cells from a CMV seronegative allogeneic donor (R⁺D^-) may be at risk for CMV disease due to absence of donor CMV-specific memory T-cells in the graft.

METHODS

We analyzed the duration of CMV reactivations and the incidence of CMV disease in R⁺D^- and R⁺D⁺ patients after alemtuzumab-based T-cell depleted allogeneic stem cell transplantation (TCD alloSCT). To determine the presence of donor-derived primary CMV-specific T-cell responses we analyzed the origin of CMV-specific T-cells in R⁺D^- patients.

RESULTS

The duration of CMV reactivations (54 versus 38 days, respectively, p = 0.048) and the incidence of CMV disease (0.14 versus 0.02, p = 0.003 at 1 year after alloSCT) were higher in R⁺D^- patients compared to R⁺D⁺ patients. In R⁺D^- patients, CMV-specific CD4⁺ and CD8⁺ T-cells were mainly of recipient origin. However, in 53% of R⁺D^- patients donor-derived CMV-specific T-cells were detected within the first year.

CONCLUSIONS

In R⁺D^- patients, immunity against CMV was predominantly mediated by recipient T-cells. Nevertheless, donor CMV serostatus significantly influenced the clinical severity of CMV reactivations indicating the role of CMV-specific memory T-cells transferred with the graft, despite the ultimate formation of primary donor-derived CMV-specific T-cell responses in R⁺D^- patients.

Tissue Damage Caused by Myeloablative, but Not Non-Myeloablative, Conditioning before Allogeneic Stem Cell Transplantation Results in Dermal Macrophage Recruitment without Active T-Cell Interaction

Introduction

Conditioning regimens preceding allogeneic stem cell transplantation (alloSCT) can cause tissue damage and acceleration of the development of graft-versus-host disease (GVHD). T-cell-depleted alloSCT with postponed donor lymphocyte infusion (DLI) may reduce GVHD, because tissue injury can be restored at the time of DLI. In this study, we investigated the presence of tissue injury and inflammation in skin during the period of hematologic recovery and immune reconstitution after alloSCT.

Methods

Skin biopsies were immunohistochemically stained for HLA class II, CD1a, CD11c, CD40, CD54, CD68, CD86, CD206, CD3, and CD8. HLA class II-expressing cells were characterized as activated T-cells, antigen-presenting cells (APCs), or tissue repairing macrophages. In sex-mismatched patient and donor couples, origin of cells was determined by multiplex analysis combining XY-FISH and fluorescent immunohistochemistry.

Results

No inflammatory environment due to pretransplant conditioning was detected at the time of alloSCT, irrespective of the conditioning regimen. An increase in HLA class II-positive macrophages and CD3 T-cells was observed 12–24 weeks after myeloablative alloSCT, but these macrophages did not show signs of interaction with the co-localized T-cells. In contrast, during GVHD, an increase in HLA class II-expressing cells coinciding with T-cell interaction was observed, resulting in an overt inflammatory reaction with the presence of activated APC, activated donor T-cells, and localized upregulation of HLA class II expression on epidermal cells. In the absence of GVHD, patient derived macrophages were gradually replaced by donor-derived macrophages although patient-derived macrophages were detectable even 24 weeks after alloSCT.

Conclusion

Conditioning regimens cause tissue damage in the skin, but this does not result in a local increase of activated APC. In contrast to the inflamed situation in GVHD, when interaction takes place between activated APC and donor T-cells, the tissue damage caused by myeloablative alloSCT results in dermal recruitment of HLA class II-positive tissue repairing macrophages co-existing with increased numbers of patient- and donor-derived T-cells, but without signs of specific interaction and initiation of an immune response. Thus, the local skin damage caused by the conditioning regimen appears to be insufficient as single factor to provoke GVHD induction.

Selective graft-versus-leukemia depends on magnitude and diversity of the alloreactive T cell response

Patients with leukemia who receive a T cell-depleted allogeneic stem cell graft followed by postponed donor lymphocyte infusion (DLI) can experience graft-versus-leukemia (GVL) reactivity, with a lower risk of graft-versus-host disease (GVHD). Here, we have investigated the magnitude, diversity, and specificity of alloreactive CD8 T cells in patients who developed GVL reactivity after DLI in the absence or presence of GVHD. We observed a lower magnitude and diversity of CD8 T cells for minor histocompatibility antigens (MiHAs) in patients with selective GVL reactivity without GVHD. Furthermore, we demonstrated that MiHA-specific T cell clones from patients with selective GVL reactivity showed lower reactivity against nonhematopoietic cells, even when pretreated with inflammatory cytokines. Expression analysis of MiHA-encoding genes showed that similar types of antigens were recognized in both patient groups, but in patients who developed GVHD, T cell reactivity was skewed to target broadly expressed MiHAs. As an inflammatory environment can render nonhematopoietic cells susceptible to T cell recognition, prevention of such circumstances favors induction of selective GVL reactivity without development of GVHD.

Overwhelming primary Epstein-Barr virus infection requiring corticosteroid treatment

A 20-year-old woman presented with a 2-week history of fever and malaise. Physical examination was unremarkable. Viral infection was suspected and Epstein-Barr virus serology confirmed acute infectious mononucleosis. During admission, she gradually developed pancytopenia and liver enzyme abnormalities. The patient clinically deteriorated with persisting fever, orthostatic hypotension and hepatosplenomegaly. Bone marrow examination showed haemophagocytic lymphohistiocytosis (HLH). Treatment with high-dose corticosteroids was started and patient recovered quickly. Ferritin decreased immediately, fever resolved within 3 days, viral clearance was reached within 3 weeks. Steroid therapy was gradually tapered off in three months. The Histiocyte Society recommends immunochemotherapy with steroids, etoposide and cyclosporine. Potential side effects of etoposide are severe bone marrow depression and leukaemia. Our patient survived on corticosteroids alone. Early recognition of HLH and prompt treatment are of utmost importance for survival. Treatment with steroids alone can be life-saving.