Clinical Efficacy of Programmed Cell Death Ligand 1 Antibody in Treatment of Extranodal Natural Killer/T-Cell Lymphoma With Hemophagocytic Lymphohistiocytosis.

Extranodal natural killer/T-cell lymphoma-associated hemophagocytic lymphohistiocytosis (ENKTCL-LAHS) is a rare disease with poor prognosis. Currently, there are no well-established treatments for LAHS. Almost 50% of patients experience relapsed or refractory disease to anti-hemophagocytic lymphohistiocytosis (HLH) treatment, and the regimen for salvage therapy is limited. We report a case of ENKTCL-LAHS that was successfully treated with a programmed cell death ligand 1 (PD-L1) antibody (sugemalimab) alone and provide a literature review on existing ENKTCL-LAHS treatment options. A 31-year-old man with relapsed ENKTCL complicated by HLH was admitted to our hospital. Following the administration of the PD-L1 antibody sugemalimab, fever was resolved, Epstein-Barr virus (EBV) DNA copy number was negative, and HLH-related blood biochemical markers were decreased in the patient. Consequently, the patient achieved complete remission with a progression-free time (PFS) of 44 months. The prognosis of ENKTCL-LAHS is extremely poor, and the clinical treatment of ENKTCL-HLH is challenging. No previous reports exist regarding the use of PD-L1 antibodies in ENKTCL-LAHS treatment. This study is the first to report a patient with ENKTCL-LAHS treated with the PD-L1 antibody alone, who achieved a long PFS of 44 months. Our results suggest the effectiveness and safety of sugemalimab in the treatment of ENKTCL-LAHS; however, more clinical cases are required for validation. The PD-L1 antibody presents a novel treatment option for patients with ENKTCL-LAHS and warrants further clinical promotion.

Diagnosis and Management of Adult Malignancy-Associated Hemophagocytic Lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of severe, dysregulated inflammation driven by the inability of T cells to clear an antigenic target. When associated with malignancy (mHLH), the HLH syndrome is typically associated with extremely poor survival. Here, we review the diagnosis of secondary HLH (sHLH) syndromes in adults, with emphasis on the appropriate workup and treatment of mHLH. At present, the management of HLH in adults, including most forms of mHLH, is based on the use of corticosteroids and etoposide following the HLH-94 regimen. In some cases, this therapeutic approach may be cohesively incorporated into malignancy-directed therapy, while in other cases, the decision about whether to treat HLH prior to initiating other therapies may be more complicated. Recent studies exploring the efficacy of other agents in HLH, in particular ruxolitinib, offer hope for better outcomes in the management of mHLH. Considerations for the management of lymphoma-associated mHLH, as well as other forms of mHLH and immunotherapy treatment-related HLH, are discussed.

Hemophagocytic syndrome associated with large granular lymphoma in an adult dog.

Hemophagocytic syndrome (HPS) is a rare disorder characterized by dysregulation of the immune response resulting in uncontrolled activation of macrophages with exacerbated phagocytosis of host cells. In dogs, the criteria for diagnosis include the presence of pancytopenia or bicytopenia in the peripheral blood and >2% hemophagocytic macrophages in bone marrow aspirates. When HPS is associated with lymphoma, it is called lymphoma-associated hemophagocytic syndrome (LAHS). Here, we present a case of a 4 ½-year-old female spayed Old English Mastiff that presented with severe thrombocytopenia, mild anemia, mild to moderate leukopenia, and large granular lymphocytes (LGLs) in the peripheral blood. The patient had enlarged lymph nodes with many LGLs seen cytologically, leading to the interpretation of LGL lymphoma. Bone marrow displayed numerous LGLs that stained strongly for CD3 but did not show immunoreactivity to CD4 or CD8, and PCR for antigen receptor rearrangement analysis confirmed a clonal T-cell receptor gamma gene rearrangement. The presence of ~3.5% hemophagocytes present on the bone marrow evaluation raised concern for HPS and, more specifically, LAHS. HPS and LAHS are challenging to diagnose and require many criteria to be fulfilled before a definitive diagnosis can be made; the low number of cases in the literature makes this even more challenging in dogs. This case represents secondary LAHS due to LGL lymphoma in a dog.

HLH Masquerading Lymphoma: Diagnostic Dilemma and Treatment Outcomes.

A case series to illustrate difficulties faced in diagnosis, management and subsequent therapeutic approach patients presenting with HLH secondary to lymphoma. A retrospective review of patients treated for HLH and lymphoma in Clinical Hematology department of a tertiary care hospital in North India, was performed from Jan 2017 to April 2019. Follow up was included till September 2019. Diagnosis of HLH was made using HLH 2004 criteria along with H score. Only patients who fulfilled HLH 2004 criteria were included. Nine patients were treated during above period, three patients with Hodgkins lymphoma, two patients had DLBCL and four patients had T-cell lymphoma. All patients presented with features of HLH and underlying lymphoma was detected on further evaluation. All patients had H score above the cut off value for diagnosis of HLH. Out of 9 patients, 6 received lymphoma directed chemotherapy and 1 was given only steroids, 1 received IVIG with steroids. 1 died early, before institution of therapy. Out of the 6 patients who received chemotherapy, all attained remission status but two patients had early relapse. In the remaining 3 patients who could not be started on chemotherapy, all died within 3 weeks of presentation. Underlying lymphoreticular malignancy should be actively searched in adult patients presenting with HLH. Early diagnosis and initiation of disease specific therapy with or without specific HLH directed treatment can improve the historical poor prognosis.

Profiling and bioinformatics analyses reveal differential circular RNA expression in NK/T-cell lymphoma-associated hemophagocytic syndrome.

Circular RNAs (circRNAs) may be potential biomarkers or therapeutic targets of hemophagocytic syndrome (HPS) due to their high stability, covalently closed structure and implicated roles in gene regulation. The aim of the present study was to determine and characterize the circRNAs from natural killer (NK)/T-cell lymphoma-associated hemophagocytic syndrome (NK/T-LAHS). CircRNA in NK/T-LAHS and healthy control patient serum were assessed using next-generation sequencing (NGS). One hundred and forty-three differentially expressed circRNAs of which 114 were up-regulated and 29 were down-regulated in NK/T-LAHS patients were identified. Next, Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses to explore the roles of these circRNAs were utilized, and a microRNA (miRNA) target gene prediction software to predict the interaction of circRNAs and miRNAs was used. Moreover, five circRNAs were then selected as NK/T-LAHS candidate circRNAs which were related to tumors and contained NK/T-LAHS-related miRNA-binding sites. Using real-time PCR, the significant up-regulation of these five circRNAs in NK/T-LAHS patient serum were verified. Together these results show that circRNAs may serve as valuable diagnostic biomarkers of early NK/T-LAHS, with potential therapeutic targets in disease progression.

Platelet-derived alpha-granules are associated with inflammation in patients with NK/T-cell lymphoma-associated hemophagocytic syndrome.

Due to the variable overlap of multiple symptoms, accurate early diagnosis of NK/T-cell lymphoma-associated hemophagocytic syndrome (NK/T-LAHS) is difficult, making the prognosis extremely poor. Hemophagocytic syndrome (HPS) is now diagnosed primarily based on the hemophagocytic lymphohistiocytosis (HLH)-2004 diagnostic criteria, and platelet count is one of the baseline evaluations. However, in our study, the data showed that decreased platelets were not only a clinical feature of HPS but also the key cells that regulate inflammation by releasing α-granules containing upregulated platelet factor 4 (PF4) and downregulated platelet-derived growth factors (PDGFs). Furthermore, we found that angiopoietin-4 (ANG-4), which has significant differential expression, has been less reported, that may affect hematopoiesis and proinflammatory responses and can be used as diagnostic biomarkers together with PF4 and PDGFs.

Evaluation of lymphocyte function by IFN-γ secretion capability assay in the diagnosis of lymphoma-associated hemophagocytic syndrome.

Lymphoma-associated hemophagocytic syndrome (LAHS) is a highly life-threatening disease characterized by an uncontrolled immune disorder. Both under-recognition and delayed diagnosis may contribute to aggressive diseases, and a poorer prognosis. Identification of laboratory features specific for LAHS patients may allow for early detection and intervention with improved outcomes. In the present study, 120 lymphoma patients at first diagnosis were recruited and the function of lymphocytes was evaluated by IFN-γ secretion assay at first diagnosis and follow up. During the surveillance period, 20 patients who complicated with hemophagocytic lymphohistiocytosis (HLH) were classified as LAHS group, and 30 patients without infectious diseases during the course of treatment were classified as lymphoma control group. In addition, 20 non-malignant associated HLH patients recruited as HLH control group and 50 healthy control (HC) subjects were also included. The IFN-γ secretion capability of lymphocytes was compared between first diagnosis of lymphoma patients who was complicate with HLH or not in the disease progression. Our results showed that only NK cell activity was decreased in lymphoma control group, but the activities of NK, CD4+ and CD8+ T cells were all significantly decreased at the time of lymphoma diagnosis in those who would progress with HLH. During the course of treatment, lymphocyte function was relatively stable in lymphoma patients but became further decreased when suffering from complication of LAHS. The IFN-γ secretion capability of lymphocytes in LAHS and non-malignant associated HLH patients were all significantly decreased compared with HCs. So the occurrence of HLH was the key factor leading to the impaired activity of lymphocytes. These data suggest that decreased lymphocyte function might be used as a predictor of LAHS, which has critical clinical significance in diagnosis and further understanding the pathogenesis of the disease.

Discovery of lahS as a Global Regulator of Environmental Adaptation and Virulence in Aeromonas hydrophila.

Aeromonas hydrophila is an important aquatic microorganism that can cause fish hemorrhagic septicemia. In this study, we identified a novel LysR family transcriptional regulator (LahS) in the A. hydrophila Chinese epidemic strain NJ-35 from a library of 947 mutant strains. The deletion of lahS caused bacteria to exhibit significantly decreased hemolytic activity, motility, biofilm formation, protease production, and anti-bacterial competition ability when compared to the wild-type strain. In addition, the determination of the fifty percent lethal dose (LD50) in zebrafish demonstrated that the lahS deletion mutant (ΔlahS) was highly attenuated in virulence, with an approximately 200-fold increase in LD50 observed as compared with that of the wild-type strain. However, the ΔlahS strain exhibited significantly increased antioxidant activity (six-fold). Label-free quantitative proteome analysis resulted in the identification of 34 differentially expressed proteins in the ΔlahS strain. The differentially expressed proteins were involved in flagellum assembly, metabolism, redox reactions, and cell density induction. The data indicated that LahS might act as a global regulator to directly or indirectly regulate various biological processes in A. hydrophila NJ-35, contributing to a greater understanding the pathogenic mechanisms of A. hydrophila.