Large granular lymphocytes (LGL) following non-myeloablative allogeneic bone marrow transplantation: a case report

Large Granular Lymphocytosis With Cytopenias After Allogeneic Blood or Marrow Transplantation: Clinical Characteristics and Response to Immunosuppressive Therapy

Large granular lymphocytosis (LGL)-or LGL leukemia-is a T- or NK-cell lymphoproliferative disorder that often results in cytopenias and autoimmune phenomena. Several studies have described LGL in a subset of patients after allogeneic blood or marrow transplantation (alloBMT), almost exclusively in the setting of asymptomatic lymphocytosis. Some have suggested an association with improved transplant-related outcomes. In contrast, clinically significant LGL after alloBMT is only described in small case reports. This study sought to assess the characteristics, significance, and response to treatment of LGL associated with unexplained anemia, thrombocytopenia, or neutropenia after alloBMT. We performed a retrospective analysis of 150 patients who were evaluated for LGL by peripheral blood flow cytometry (LGL flow) for unexplained cytopenias following initial engraftment after alloBMT from January 1 2012 to July 1, 2019. We identified patients with abnormally increased populations of LGL cells (LGL+) as assessed by Johns Hopkins Hematopathology. We collected demographic, transplantation, and LGL treatment information from electronic medical records. We compared LGL+ patients to patients with unexplained cytopenias with negative flow cytometry for LGL (LGL-) in this cohort. We also assessed change in blood counts after 4 weeks of immunosuppressive therapy in LGL+ patients. Cytopenias occurred at a median of 5.7 months (range 1-81) after alloBMT. The majority of the transplants were nonmyeloablative from haploidentical donors, and all patients received post-transplantation cyclophosphamide for graft-versus-host disease prophylaxis, consistent with the overall alloBMT characteristics at our center. We identified 70 patients with LGL and cytopenias, representing 47% of those evaluated by flow cytometry. There were no significant demographic or transplant-related differences between LGL+ patients and LGL- patients. The median age was 59, and 63% were male. LGL+ patients were more likely to have had cytomegalovirus (CMV) viremia (73% versus 28%, P < .0001), but not acute or chronic graft-versus-host disease. LGL+ patients had higher absolute lymphocyte counts (1500 versus 485/ mm³, P < .0001), a trend toward lower absolute neutrophil count (660 versus 965/mm³, P = .17), and lower neutrophil to lymphocyte ratio (0.39 versus 1.71, P < .001). There were no differences in overall survival or relapse-free survival. Of those with T-cell LGL, 45 were assessed for T-cell receptor clonality. In all, 22% were clonal, 53% oligoclonal, 4% polyclonal, and 20% indeterminate. Thirty (43%) LGL+ patients received immunosuppressive therapy (IST) for cytopenias. First-line treatment was corticosteroids for 25 (83%). Among those treated, there was an increase in median absolute neutrophil count from 720 before treatment to 1990/mm³ after 4 weeks (P = .0017). Thrombocytopenia and anemia showed at most a mild improvement with IST. LGL was a common association with otherwise unexplained cytopenias after alloBMT, almost always after prior CMV infection. LGL in the setting of cytopenias did not predict improved transplantation outcomes compared to those with cytopenias without presence of LGL. IST was effective at improving neutropenia associated with LGL after alloBMT.

[Clinical features and risk factors analyses of patients with T cell large granular lymphocytosis following allo-HSCT]

目的

探讨异基因造血干细胞移植（allo-HSCT）后发生T大颗粒淋巴细胞增多（T-LGL）患者的临床特征、相关因素以及对预后的影响。

方法

回顾性分析2013年6月至2020年2月接受allo-HSCT的359例患者连续性资料，男216例，女143例，中位年龄为38（7~65）岁。分析T-LGL的临床特征、累积发生率，比较发生与未发生T-LGL患者的总生存（OS）率、无病生存（DFS）率、累积复发率（CIR）及非复发死亡率（NRM）的差异，并研究影响移植后发生T-LGL的相关因素。

结果

共入组359例患者，T-LGL组17例，非LGL组342例，中位随访38（3~92）个月，移植后1、2、3年T-LGL累积发生率分别为3.64%（95%CI 1.09%~6.19%）、4.50%（95%CI 1.36%~7.64%）和4.84%（95%CI 1.10%~8.76%）；移植受者CMV再激活（P=0.013）、EBV血症（P=0.034）以及急性移植物抗宿主病（P=0.027）均与T-LGL发生有关，且多因素分析显示，良性血液病[P=0.027，OR=3.36（95%CI 1.15~9.89）]、单倍型移植[P=0.030，OR=4.67（95%CI 1.16~18.75）]、无关供者移植[P=0.041，OR=5.49（95%CI 1.10~28.16）]为移植后发生T-LGL的独立预测因素。两组患者移植后3年OS、DFS率、CIR以及NRM差异均有统计学意义[OS：100.0%对78.6%（95%CI 74.1%~83.1%），P=0.04；DFS：100.0%对70.0%（95%CI 64.9%~75.1%），P=0.01；CIR：0对16.1%（95%CI 11.8%~22.4%），P<0.01；NRM：0对12.6%（95%CI 12.5%~12.6%），P=0.02]。亚组分析结果显示，恶性疾病患者移植后发生T-LGL者预后良好，NRM、DFS率以及CIR差异均有统计学意义（P值均<0.05），而良性疾病患者移植后发生T-LGL对预后无明显影响。

结论

恶性疾病患者移植后T-LGL可能是一个较为持久的良性临床过程，与免疫重建和T细胞调节机制相关的因素可作为移植后T-LGL发生的主要预测因素。

Large granular lymphocytosis after transplantation

Post-transplant lymphoproliferative disorders (PTLD) represent a heterogeneous group of diseases that occur following transplantation. Large granular lymphocytic (LGL) lymphocytosis is one type of PTLD, ranging from reactive polyclonal self-limited expansion to oligo/monoclonal lymphocytosis or even to overt leukaemia. LGL lymphocytosis in transplant recipients may present as a relatively indolent version of the condition and may be more common than reported, but its natural history and clinical course have not been well described, and the lack of a reliable classification system has limited studies on this disease. Patients with unexplained cytopenias, autoimmune manifestations, or unexpected remissions may be mislabelled. The purpose of this review was to evaluate the clinical features, immunophenotypes, etiopathogenesis, diagnosis, outcomes and treatment of post-transplantation LGL lymphocytosis. In conclusion, LGL lymphocytosis is a frequent occurrence after transplantation that correlates with certain procedural variables and post-transplant events. LGL lymphocytosis should be considered in patients with unexplained lymphocytosis or when pancytopenia develops after transplantation. The diagnosis of LGL lymphocytosis requires a demonstration of monoclonality, but clonality does not indicate malignancy. Additional studies are necessary to further delineate the potential effects of large granular lymphocytes in the long-term prognosis of post-transplant patients.

T-large granular lymphocyte leukemia: current molecular concepts

T-large granular lymphocyte (T-LGL) leukemia is a chronic and often indolent T cell lymphoproliferation characterized by extreme expansion of a semi-autonomous cytotoxic T lymphocyte (CTL) clone. Clinically, T-LGL can be associated with various cytopenias; neutropenia constitutes the most frequent manifestation. LGL clone represents a pathologic counterpart of the cytotoxic effector T cell but an abnormal memory CD8 cell seems to provide the supply of the matured LGL population. Analysis of clonal T cell receptor (TCR) rearrangement and complementarity determining region 3 (CDR3) of the TCR beta-chain is a useful tool to investigate clonal expansions, track the frequency of expanded clones and also clinically useful to monitor the response to therapy. The lessons learned from molecular analysis of clonal repertoire support a clinically-derived conclusion that the LGL clone arises in the context of an initially polyclonal immune response or an autoimmune process. Consequently, specific manifestations of T-LGL may be a result of the recognition spectrum of the transformed clone and the cytokines it produces. Due to the often monoclonal manifestation, T-LGL constitutes a suitable model to investigate polyclonal CTL-mediated processes. Application of new technologies, including TCR repertoire analysis by sequencing, clonotypic quantitative PCR and VB flow cytometry facilitate clinical diagnosis and may allow insights into the regulation of TCR repertoire and consequences resulting from the contraction of clonal diversity.

Expansion of a clonal CD8+CD57+ large granular lymphocyte population after autologous stem cell transplant in multiple myeloma

Clonal expansions of large granular lymphocytes (LGLs) have been identified in patients following stem cell transplants and may represent posttransplant LGL leukemias or reactive immune responses. To differentiate between these 2 possibilities, we assessed peripheral blood and bone marrow of patients with myeloma after autologous stem cell transplant. All patients examined shortly after autologous stem cell transplant had significant increases in the LGLs in the peripheral blood and bone marrow (71% of lymphocytes) as compared with controls (39%). This increase was detectable years after transplant. The LGLs had a reproducible immunophenotype of CD8+CD57+ T cells without phenotypic abnormalities in 19 of 20 patients. Sixty-five percent of the post-autologous stem cell transplant patients had clonal T-cell receptor gene rearrangements in the bone marrow, yet no patients had neutropenia or splenomegaly. Although the LGL expansions were clonal and persistent, the lack of clinical sequelae suggests the clonal LGL expansion is a reactive, potentially beneficial, immune response to autologous stem cell transplant.

Natural killer or natural killer/T cell lineage large granular lymphocytosis associated with dasatinib therapy for Philadelphia chromosome positive leukemia

Dasatinib, a dual tyrosine kinase inhibitor, is known to modulate or suppress T-cell activation and proliferation. We report a series of 8 patients who developed chronic peripheral lymphocytosis, identified as natural killer cells or natural killer/T-cells based on their large granular lymphocyte morphologies and CD16(+), CD56(+), CD3(-) or CD3(+) immunophenotypic profiles, out of 18 patients receiving dasatinib therapy. All cases that developed large granular lymphocyte lymphocytosis achieved optimal molecular response (8/8 in large granular lymphocyte(+) patients vs. 3/10 in large granular lymphocyte(-) patients, p=0.002). A (51)Cr release assay demonstrated that natural killer cell cytotoxicity has been enhanced in a case of large granular lymphocyte lymphocytosis compared to normal healthy donors, and that natural killer cell cytotoxicity in dasatinib-responders was superior to that in non-responders. In summary, the present study suggests that natural killer or natural killer/T cell lineage large granular lymphocyte lymphocytosis develops in association with dasatinib therapy and that large granular lymphocyte might have a therapeutic effect on Ph(+) leukemic cells.

Molecular TCR diagnostics can be used to identify shared clonotypes after allogeneic hematopoietic stem cell transplantation

OBJECTIVE

In allogeneic hematopoietic stem cell (HSCT) transplantation, recovery of the T cell receptor (TCR) repertoire depends upon the composition of the graft and is modulated by peri-transplant immunosuppression, viral infections, and graft-vs-host disease (GVHD). We hypothesized that after allogeneic HSCT, molecular analysis of the TCR repertoire can be used to identify and quantitate immunodominant T cell clones that may play a role in GVHD or other clinical events.

METHODS

We utilized a rational strategy for the analysis of the expanded CTL clones. First, we studied the VB spectrum in a cohort of patients who had received either matched sibling or unrelated donor grafts. The CDR3 sequences of immunodominant clones were identified and clonotypic PCR and sequencing was applied to determine the level of clonotype sharing.

RESULTS

Significant expansions of VB families were observed following transplantations; 61% were oligo/monoclonal. Immunodeficiency was reflected by depletion of multiple VB families from both the CD8 and CD4 repertoires. The level of sharing varied between clonotypes, suggesting that some antigens have a more "public" spectrum while others are restricted to specific patients. Immunodominant CDR3 sequences common to allogeneic HSCT, healthy controls, and other conditions were identified.

CONCLUSION

The clonotypes of expanded CTL clones may reflect responses to alloantigens (e.g., in correlation with clinical GVHD) or pathogens. In the future, molecular T cell diagnostics may become a powerful clinical tool in transplantation to monitor disease and to direct treatment.

Granular lymphocyte proliferative disorder after autologous peripheral blood stem cell transplantation for multiple myeloma

A 57-yr-old woman with multiple myeloma underwent tandem autologous peripheral blood stem cell transplantation (APBSCT). Fever, anemia, and thrombocytopenia, followed by the proliferation of granular lymphocytes in the peripheral blood occurred, after a second APBSCT. Clonal rearrangement of the T-cell receptor was detected using Southern blot analysis of peripheral blood samples. Granular lymphocyte proliferative disorders (GLPD) were diagnosed. After steroid therapy, the symptoms resolved. Lymphocytosis did not recur after the discontinuation of steroids. There have been a few reports of GLPD after solid organ and allogeneic hematopoietic stem cell transplantations. We report a first case of GLPD after APBSCT.

Features of large granular lymphocytes (LGL) expansion following allogeneic stem cell transplantation: a long-term analysis

Large granular lymphocyte (LGL) proliferation typically follows a chronic course during which major features are cytopenia and immune abnormalities. Elevated numbers of LGL were reported in a few cases following allogeneic stem cell transplantation (allo-SCT). In this report, we present a retrospective analysis of LGL cases that occurred following allo-SCT in a cohort of 201 consecutive patients transplanted over a period of 7 years. Six cases were identified and LGL expansion occurred more frequently following a reduced fludarabine and anti-T lymphocyte globulin-based preparative regimen (4 cases/49), than after a conventional myeloablative regimen (2 cases/152). Expansion of LGL was seen between 3 and 15 months following allo-SCT. Hematopoiesis, with mild to severe cytopenia, was a favored target for LGL. Autoimmune manifestations including polyarthritis and hypergammaglobulinemia were also observed. LGL proliferation was observed in the context of chronic antigenic stimulation associated with recurrent viral infections especially CMV. Moreover, five out of these six high risk patients achieved a long-term complete remission concomitant or following LGL expansion. These data suggest that LGL might be a subset of effector lymphocytes which may participate to the graft-versus-tumor effect.