Chronic Lymphocytic Leukemia Infiltration Research Articles

Chronic lymphocytic leukemia infiltration of a transplanted kidney successfully treated with venetoclax and obinutuzumab: a case report

Chronic lymphocytic leukemia infiltration of a transplanted kidney successfully treated with venetoclax and obinutuzumab: a case report

S2007 Chronic Lymphocytic Leukemia Presenting as Colonic Ulcers

Introduction: Chronic Lymphocytic Leukemia (CLL) accounts for 25% of leukemias. One can present with hepatomegaly, splenomegaly, and lymphadenopathy. CLL infiltration in the gastrointestinal (GI) mucosa is rare. Colonic CLL can develop late in the disease course with mild to no GI symptoms. Awareness of CLL and its various extra-nodal presentations allow for prompt diagnosis and treatment. Case Description/Methods: An 80-year-old female with untreated CLL presented with 2 months of rectal bleeding. She denied weight loss, anorexia, night sweats, blood thinners, and NSAID use. She had WBC 34.3, platelets 139, and a normal Hgb of 13.2. Colonoscopy showed ulcerations at the ileocecal valve and transverse colon, a 30 mm ascending colon polyp, and multiple 10-20 mm transverse and descending colon polyps. Pathology showed only chronic inflammation of the ulcerated regions, and a sessile serrated adenoma at the ascending colon. The remaining polyps were not removed due to concern for cancer and potential colectomy. A CT chest, abdomen, and pelvis was unremarkable. Tumor markers showed CEA 8 and normal Ca19-9 and Ca-125. Due to an unclear diagnosis, a second colonoscopy was performed with repeat biopsies and removal of all polyps in the descending and sigmoid colon. Pathology results were negative for inflammatory bowel disease and infection. The polyps were tubular adenomas and hyperplastic. However, immunohistochemical analysis was positive for CD5/CD43 and CD23, indicative of CLL in the ulcerated mucosa. Treatment options were discussed with surgery and oncology. The patient was offered right colon resection or endoscopic removal of the remaining polyps prior to chemotherapy (Figure). Discussion: Colorectal lymphomas are rare and account for 1% of all GI malignancies with CLL usually found proximal to the hepatic flexure. In this case, the presence of ulcerations and large polyps were concerning for colorectal cancer. However, the initial work-up was negative. After a repeat colonoscopy, testing for specific CLL markers was requested. In a review of literature, chemotherapy alone for colonic CLL had a perforation risk of 15%. While it is unclear if surgical treatment is beneficial, it is a potential option. Due to the high risk of perforation on chemotherapy, recommendations included right hemicolectomy or endoscopic removal of the remaining polyps prior to starting treatment. This demonstrates the importance of knowing the varying presentations of colonic CLL as its treatment may require multidisciplinary discussion.Figure 1.: Colonic ulcers located at the transverse colon (top left) and IC valve (top right). H&E stain of the colonic mucosa (bottom) that showed positive markers for CLL on IHC analysis.

CENTRAL NERVOUS SYSTEM INFILTRATION IN CHRONIC LYMPHOCYTIC LEUKEMIA: A STUDY ON BEHALF OF THE REGISTRO BRASILEIRO DE LEUCEMIA LINFOCITICA CRONICA

Central nervous system (CNS) infiltration in chronic lymphocytic leukemia (CLL) is a rare presentation of CLL that can potentially have disastrous complications. Reported prognosis is poor. The objective of this study is to report a series of cases of CLL with CNS infiltration. This is a case-series of a Brazilian CLL registry (Registro Brasileiro de Leucemia Linfocitica Cronica). We included patients with CLL and CNS infiltration. This is a descriptive study. A total of 10 (0.28%) in 3610 patients were identified with confirmed (80%) or suspected (20%) CNS infiltration. Median age at CLL diagnosis was 57.5 y/o (range: 50 – 76). Three (30%) patients were diagnosed with CNS infiltration concomitantly with the CLL diagnosis, while others (70%) were diagnosed at a median of 41 months of CLL diagnosis (range: 11 to 119 months). Only three (30%) patients had been previously treated for CLL. Most common symptoms of CNS infiltration were convulsion (30%), altered mental status (30%), headaches (30%), ophthalmologic (30%), and urinary incontinence (20%). Amnesia, asthenia, vomiting, hemiparesis, cervicalgia, and dizziness were also present (one patient each). Of the patients with confirmed CNS infiltration, diagnoses were performed through liquor exam (all patients) and biopsy (one patient). Of the two patients with suspected CNS infiltration, one achieved complete response and the other, partial clinical response, following instituted CLL-directed therapy with (1 patient) or without (1 patient) intrathecal chemotherapy. Of the other 8 patients, 3 achieved complete response, 2 failed treatments, 1 was not evaluated and 2 had missing information. Of all patients, 5 are alive, 3 died of sepsis, multiorgan failure following CNS methotrexate-related toxicity, and COVID, and 2 had missing information. Our results show that the prognosis of CNS infiltration in CLL can be relatively good, with at least 50% of patients alive at 1 year. However, a series of 18 patients published by Strati et al has shown a poorer outcome, with half of the patients dead at 1 year. Although all patients were diagnosed by liquor exam, that same study reported a low specificity for liquor exam in CLL (42%) due to the frequent presence of leukemic cells in the cerebrospinal fluid in other conditions. Establishing CNS CLL as the cause of the symptoms can be difficult, since up to 70% of patients with CLL have CNS infiltration in autopsy studies, and our results may be superestimated. In summary, CNS infiltration in CLL is a rare event, and further studies are needed to address prognosis and management.

Chronic lymphocytic leukemia and light chain proximal tubulopathy: A rare presentation of a common disease

Chronic lymphocytic leukemia (CLL) is the most common leukemia in developed countries. Kidney injuries related to CLL can occur via several mechanisms. Approximately 30%–40% of CLL patients with a kidney biopsy have monoclonal-protein related lesions. However, such lesions mostly involve glomeruli with only rare instances of tubule-interstitial disorders. There is only a single case report of a CLL patient who presented with crystalline light chain proximal tubulopathy (LCPT). Fanconi syndrome (FS) may provide clinical clues in these patients. We report a case of a CLL patient who presented with hypokalemia in the setting of advanced kidney failure in which serum monoclonal IgG kappa was detected. The patient demonstrated typical signs and symptoms of FS. The urinary retinol binding protein was also extremely elevated (638 times upper normal limit). A kidney biopsy revealed non-crystalline LCPT with CLL infiltration. FS in CLL is an extremely rare presentation, as only four cases had been previously reported. Of these, only a single case had crystalline LCPT. Our case is the first report of non-crystalline LCPT in a CLL patient. Obinutuzumab and Venetoclax were started to address the CLL, and an improvement in kidney function was noted thereafter.

Pharmacological modulation of Kv1.3 potassium channel selectively triggers pathological B lymphocyte apoptosis in vivo in a genetic CLL model

BackgroundIon channels are emerging as promising oncological targets. The potassium channels Kv1.3 and IKCa are highly expressed in the plasma membrane and mitochondria of human chronic lymphocytic leukemia (CLL) cells, compared to healthy lymphocytes. In vitro, inhibition of mitoKv1.3 by PAPTP was shown to kill ex vivo primary human CLL cells, while targeting IKCa with TRAM-34 decreased CLL cell proliferation.MethodsHere we evaluated the effect of the above drugs in CLL cells from ibrutinib-resistant patients and in combination with Venetoclax, two drugs used in the clinical practice. The effects of the drugs were tested also in the Eμ-TCL1 genetic CLL murine model, characterized by a lympho-proliferative disease reminiscent of aggressive human CLL. Eμ-TCL1 mice showing overt disease state were treated with intraperitoneal injections of non-toxic 5 nmol/g PAPTP or 10 nmol/g TRAM-34 once a day and the number and percentage of pathological B cells (CD19+CD5+) in different, pathologically relevant body districts were determined.ResultsWe show that Kv1.3 expression correlates with sensitivity of the human and mouse neoplastic cells to PAPTP. Primary CLL cells from ibrutinib-resistant patients could be killed with PAPTP and this drug enhanced the effect of Venetoclax, by acting on mitoKv1.3 of the inner mitochondrial membrane and triggering rapid mitochondrial changes and cytochrome c release. In vivo, after 2 week- therapy of Eμ-TCL1 mice harboring distinct CLL clones, leukemia burden was reduced by more than 85%: the number and percentage of CLL B cells fall in the spleen and peritoneal cavity and in the peripheral blood, without signs of toxicity. Notably, CLL infiltration into liver and spleen and splenomegaly were also drastically reduced upon PAPTP treatment. In contrast, TRAM-34 did not exert any beneficial effect when administered in vivo to Eμ-TCL1 mice at non-toxic concentration.ConclusionAltogether, by comparing vehicle versus compound effect in different Eμ-TCL1 animals bearing unique clones similarly to CLL patients, we conclude that PAPTP significantly reduced leukemia burden in CLL-relevant districts, even in animals with advanced stage of the disease. Our results thus identify PAPTP as a very promising drug for CLL treatment, even for the chemoresistant forms of the disease.

Colonic infiltration of chronic lymphocytic leukemia with Hodgkin Reed Sternberg-like cells

A 72-year-old man was diagnosed with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and signet ring cell carcinoma in a gastric biopsy. He underwent a subtotal gastrectomy + lymphadenectomy + chemotherapy + radiotherapy. He did not receive treatment for the lymphoma. Eight years after the diagnosis, he presented with alternating diarrhea and constipation. Physical examination revealed bilateral laterocervical, axillary, and inguinal lymphadenopathies. The laboratory results showed LDH: 286 UI/l and Beta-2-microglobulin: 6.4 mg/L. CT scan showed a mass that seems to involve the cecum and terminal ileum with multiple locoregional, retroperitoneal, and mesenteric lymphadenopathies. He underwent a right hemicolectomy. Macroscopically, we identified an ulcerated mass of approximately 7 x 6 x 5 cm. in the cecum. The microscopic findings were consistent with chronic lymphocytic leukemia (CD20+ and CD5+) with scattered Hodgkin reed Sternberg-like cells CD30 and EBER+ (Epstein-Barr virus-encoded RNA) by in situ hybridization (ISH) positive (Fig. 1). The patient received treatment with mini-CHOP chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisolone) plus rituximab with partial response after the third cycle.

Characterisation of a New Clinical Presentation of Chronic Lymphocytic Leukemia with Symptomatic Nasopharyngeal Mucosa Involvement

Patients with chronic lymphocytic leukemia (CLL) are prone to infectious complications, including Ears, Nose and Throat (ENT) infections due to the humoral immunodepression and/or to the immunosuppression related to the therapy. However, specific CLL infiltration in non-lymphoid regions of the head and neck causing ENT symptoms but unrelated to an infection is not well described. Extra-nodal localizations of CLL cells, including involvement of the mucosa of the rhinopharynx is uncommon and poorly reported. Here, we retrospectively analyzed the clinical, histopathologic and molecular features of 25 CLL patients with specific head and neck involvement. To date, this is the largest cohort reporting this new entity of CLL also named Nasal Associated Lymphoid Tissue (NALT) CLL.All patients had proven CLL prior to symptoms. Median time between ENT manifestation and CLL was 3 years [1-11 years]. Symptoms included chronic coughing (44%), antero-posterior nasal discharge (44%), nasal congestion (33%) and pharyngitidis (33%). ENT examination evidenced cervical lymphadenopathies in 68 % of cases, a granular aspect of the mucosa of the pharynx in 56%, enlarged tonsil (37%) or adenoids (37%). All patients underwent a biopsy of the mucosa of the nose or the throat. Histology and immunochemistry analysis demonstrated an infiltration of small lymphocytes CD20+, CD5+ and CD23+, consistent with a phenotype of CLL. The infiltration was diffuse in 50% of biopsies and perivascular in 38%.Patients with NALT-CLL had a poor prognosis: the majority was IGHV unmutated (n=18/25, 72%). Furthermore, they all required a treatment according to IWCLL criteria few time after the first ENT symptoms (median time 2 years), indicating that NALT-CLL is associated with a more progressive disease.To characterize the genetic background of NALT-CLL, we analyzed the cytogenetic data and NGS sequencing of 13 CLL-associated mutations from peripheral CLL cells. The karyotype was normal in only 2/24 cases (8%) and complex (>3 abnormalities) in 5/24 cases (20%). Half of the patients had a trisomy 12(12/24; 50%), while 13q, 17p and 11q deletions were found in 29%, 8% and 4% respectively. Eleven patients harbored one mutation (44%) while 9 patients had 2 to 5. Mutation of the NOTCH1 pathway was found in half of the cases (11/25 NOTCH1 and 2/25 FBXW7 mutated cases). TP53 and SF3B1 mutations occurred respectively in 20% (5/25 cases) and in 12% (3/25 cases).To gain insight into the molecular mechanism associated with involvement of the rhinopahrynx, we studied the expression of 70 genes related to cell migration and cell adhesion pathways using a qPCR array in the peripheral CLL cells of patients with NALT (n=4) compare to no NALT-CLL (n=4). Genes significantly up regulated with a fold change >2 included the chemokine receptors CCR7 (p=0.05) and CCR5 (p=0.04), the receptor involved in leukocyte trafficking CXCR3 (p=0.01) or the chemoattractant chemokine-like factor CKLF. By targeted qPCR, we confirmed the up regulation of CCR7 (p=0.002), CXCR3 (p=0.04) and CCR5 (p=0.03) in the cohort NALT-CLL patient (n=25) as compared to 20 age-matched CLL patients without head and neck symptoms (77% with unmutated IGHV, 30% with NOTCH1 mutation and 30% with trisomy 12). Up regulation of those targets was independent of the presence of NOTCH1/trisomy12 aberration or of the IGHV mutation status. These results suggest an increased migratory capacity of the leukemic CLL cells into the rhynopharynx mucosa related to a higher expression of these receptors involved in cell trafficking and migration. In line with these results, immunohistochemistry analysis of 5 patients with nasal involvement showed a strong staining of the CCR7 marker on the membrane of CLL cells infiltrating the mucosa. Interestingly, the staining of CCL21, the cognate ligand of CCR7, was positive in the vessels of the mucosa, suggesting that the recruitment and the transendothelial migration of CLL cells into the mucosa occur through a local secretion of CCL21 by the vessels.In summary, we report here a new presentation of CLL associated with symptomatic and specific ENT localization. CLL cells are predominantly IGHV unmutated, harbor NOTCH1 mutation and/or trisomy12 and show a higher expression of the chemokine receptors CCR7, CCR5 and CXCR3. We are currently studying the expression of those receptors by flow cytometry and the enhanced migratory capacity toward CCL21 through an in vitro chemotaxis assay. DisclosuresLetestu: AbbVie: Research Funding, Speakers Bureau; Roche: Speakers Bureau; Janssen: Research Funding, Speakers Bureau. Cymbalista: Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; ASTRA ZENECA: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Lilly-LOXO: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Chronic lymphocytic leukemia and concurrent seminoma in the same testis.

A 59-year-old man presented with a painless testicular mass and underwent a radical orchiectomy. The resected specimen showed a 5-cm-sized, white-yellow and homogenous solid mass in the testicular parenchyma. Histologically, the central part of the tumor exhibited typical features of seminoma. The peripheral part of the tumor exhibited diffuse infiltration of small, monotonous lymphoid cells involving the tunica albuginea. The monotonous lymphoid cells were immunoreactive for CD20, CD79a, CD5, and CD23, and negative for CD3, CD10, and cyclin D1. Kappa light chain restriction was detected on flow cytometry using the resected specimen. Considering the circulating lymphoid cell count of > 5.0 × 103/μL, we diagnosed the peripheral component of the tumor as an infiltration of chronic lymphocytic leukemia. This extremely rare combination of seminoma and lymphoid neoplasm should be considered in the differential diagnosis of classic seminoma with extensive lymphoid reaction in tumors arising in elderly patients.

MAPK-Erk1/2 Pathway Activation and Survival Of Chronic Lymphocytic Leukemia (CLL) Cells Is Induced By In Vitro Modeling Of The Tumor Microenvironment and Can Be Effectively Inhibited Using The MEK1 Inhibitor MEK162

Infiltration of chronic lymphocytic leukemia (CLL) cells into the lymph node and bone marrow microenvironments promotes leukemic cell survival, proliferation and ultimately drives disease progression. Successful treatment of CLL relies on targeting the cells within these niches.Activity of the MAPK-Erk1/2 pathway is considered to be crucial for the survival of a diverse range of cancer cell types, including CLL cells. However, to date pre-clinical studies of inhibitors of MEK1/2, a key component in this pathway, have demonstrated little efficacy against CLL cells.We have recently shown that MAPK-Erk1/2 pathway activity is attenuated during ex vivo cell processing and subsequent culture of primary CLL cells; an observation which suggests that factors exist in vivo that maintain Erk1/2 activity and promote cell survival.Here we present data that show that in vitro modeling of the effects of the microenvironment on primary CLL cells, using recombinant stroma-derived factor CXCL12 or media conditioned by the HS5 stromal cell line (HS5-CM), results in a significant increase in MAPK-Erk1/2 pathway activity. Treatment with the MEK1/2 inhibitor MEK162 (Novartis) blocked the effects of CXCL12 and HS5-CM on Erk1/2 activation in CLL cells. In the presence of CXCL12 or HS5-CM, MEK162 induced apoptosis in a significantly (P< 0.05) greater proportion of cells compared to treatment of cells cultured in media alone (media: 30.14 ± 5.74%, CXCL12: 78.34 ± 9.06%, HS5 CM: 65.79 ± 12.88%). Furthermore, MEK162 completely abrogated the survival advantage conferred by the presence of HS5-CM and reduced cell migration through a permeable support towards HS5-CM by an average of 35.64 +/- 8.48%.In conclusion, our work suggests that MAPK-Erk1/2 signaling is abrogated in CLL cells during ex vivo processing and subsequent culture. This observation provides a rational explanation for the current lack of in vitro data concerning any efficacy of MEK inhibitors against CLL cells. Our data show that by introducing purified stroma-derived factor (SDF-1a/CXCL12) or media conditioned by the HS5 stromal cell line it is possible to recapitulate the activity of Erk1/2 and increase CLL-cell sensitivity to the MEK1/2 inhibitor MEK162. These observations highlight the importance of modeling the influence of the microenvironment in all pre-clinical drug-efficacy studies in CLL and suggest that inhibition of MEK1/2 may represent a novel treatment strategy for CLL. Disclosures:No relevant conflicts of interest to declare.

Tumor Microenvironment (TME) Regulation of Programmed Death-1 (PD1) Receptor and Its Ligands PDL1 and PDL2 in Chronic Lymphocytic Leukemia (CLL)

The PD1 pathway is involved in the inactivation of immune effectors and is potentially reactive against neoplastic cells in the TME. T cells from CLL patients exhibit defective immunity, decreased proliferative capacity, and impaired effector function leading to T cell exhaustion. These functional defects coincide with higher CD244, CD160 and PD1 expression on T cells. In the Eμ-TCL1 transgenic CLL model, PDL1 checkpoint blockade restores immune dysfunction and impairs leukemia growth. PD1/PDL1 ligation also affects BCR signaling, and because PD1 is also expressed on CLL cells, PD1 interference might directly influence tumor growth and proliferation directly.We studied the 1) expression the PD1 receptor and its ligands and their correlation with TFTT; 2) role of the TME in controlling PD1 axis and miRNA expression; 3) role of the BCRi ibrutinib (IB) in the expression of the receptor and ligands.Early-stage CLL patients were prospectively enrolled at diagnosis (n=211, O-CLL1: clinicaltrial.govID:NCT00917540). Gene expression (GE) profiling was performed using the GeneChipVR Gene1.0 STArray (Affymetrix) and validated by qPCR (Thermofisher) and flow-cytometry (FC, BD Biosciences) in an independent subset of patients. CLL lymph node samples underwent in situ immunolocalization analyses. Autologous T-cells (AAT) were obtained by in vitro exposure of patient T-cells with anti CD3/CD28 Dynabeads (Thermofisher) and IL2 in co-culture with CLL cells. Cultures were monitored until substantial clumping was observed and tested for PD1 axis expression. HS5 stromal cells were used in co-culture experiments with B-CLL (ratio 1:100). MiR-424 expression was evaluated by qPCR using validated TaqMan® MicroRNA Assays (Thermofisher). In selected experiments IB was added to cell culture. PD1 GEP of circulating B-CLL cells was significantly higher than of ligands. No differences in GEP of PD1 or its ligands were observed stratifying cases based on CD38, ZAP-70, or FISH markers. Significantly higher PDL1 GE was detected in IGHV-M cases. GEP results were validated by qPCR on 27 independent CLL samples. The impact of GE of the PD1 axis on clinical outcomes in CLL cases (median follow-up 39 months, range 6−82 months) indicated TTFT was significantly shorter in cases with higher levels of PDL2, while no significant differences were detected based on higher or lower PD1 or PDL1 levels. Multivariate analysis indicated higher PDL2 gene expression retained an independent prognostic power (HR=1.9, 95%CI 1.1-3.4, P=.022) in predicting TTFT together with IGHV-UM status, B-lymphocytosis≥5000/mm3 (P=.020), and CD38 expression (P=.021). In situ immunolocalization of CLL tissue infiltrates showed variable expression of PD1 that characterized small lymphoid elements, while PDL1 and PDL2 (PDL2>PDL1) characterized larger medium-sized elements within proliferation centers. Co-localization studies revealed PD1 co-expression of CD20+CLL cells and in scattered CD3+ cells. Both PDL1 and PDL2 were variably expressed in CD20+CLL cells; few T-cells and macrophages showed expression of both ligands within CLL infiltrates. FC analysis of CLL cells after AAT co-culture showed a higher percentage expression of circulating PD1 axis members (n=27, PDL1>>PDL2>PD1) compared to baseline indicating that the changes in PD1 axis expression may be due to events triggered by activation of the TME. In contrast, T cell populations had higher expression of CD3+, CD4+ and CD8+ cells bearing both PD1 and PDL1, while no substantial increment for either CD3+, CD4+ or CD8+/PDL2+ cells following AAT co-culture. GE analysis also showed a similar increase in PDLs (n=15, PDL2>>PDL1>PD1) expression with respect to non-activated B-CLL cells. Interestingly, a 48h co-culture of B-CLL with HS5 stromal cells (n=6) showed a similar increase in PD1 axis GE pattern as AAT cultures. Expression of miR-424 also decreased significantly (<80%) after AAT co-cultures (n=6), indicating its potential involvement in PDL1 regulation. IB reduced PD1/PDL1 gene and protein expression on CLL B-cells; the IB inhibitory effect was also observed only on CD8+ cells.We indicate that PDL2 expression characterizes a subset of high-risk early stage CLL patients. PD1 axis expression is characteristic of the CLL TME whereby modulatory co-stimulatory signals may be counteracted by IB. Further studies will examine the role of miR-424 regulation with this cellular context. DisclosuresNo relevant conflicts of interest to declare.

Par-4 Overexpression Impedes Leukemogenesis in the Eµ-TCL1 Leukemia Model

Introduction: Prostate apoptosis response 4 (Par-4) is a tumor suppressor protein that is commonly downregulated by promoter methylation, inactivated by Akt1, or mutated in diverse solid tumors. It exhibits a unique cancer-specific activation quality, sensitizing tumor cells to apoptosis and inhibiting proliferation, but not affecting the untransformed cell type of origin. This is thought to be due to hyperactivation of kinases that activate Par-4 in transformed cells, which results from dysregulation of signaling pathways during transformation. In chronic lymphocytic leukemia (CLL) Par-4 is not downregulated, but is in fact more abundant than in healthy B cells. We explored the therapeutic potential of targeting the Par-4 pathway in CLL to exploit an endogenous anti-tumor mechanism.Methods: The Eµ-TCL1 mouse is a leukemia model commonly used to study CLL biology and test experimental therapeutics. We have developed the first B cell specific human Par-4 (Eµ-Par-4) overexpression mouse to explore the effect of Par-4 overexpression in the TCL1 model. Double transgenic Par-4/TCL1 mice were bred from single transgenic mice to produce a B cell specific Par-4 overexpression leukemia model. TCL1 CLL-like B cells express CD5 and CD19, and are abundant in the peripheral blood, bone marrow and spleen. Monthly bleeding for peripheral blood counts and spleen palpation were used to track disease progression in these mice, with the tumor burden in the peripheral blood being roughly equivalent to the severity of disease in this model. Mice with advanced disease show vastly increased white blood cell (WBC) counts, with high proportions of WBCs being the characteristic CD5 positive leukemic B cell, splenomegaly, and various cytopenias.Results: Disease burden in single transgenic TCL1 mice, estimated by abundance of CD45+/CD5+/CD19+ B cells in the peripheral blood, was found to be significantly higher than in the Par-4/TCL1 mice bred from the same founder at 10 months of age (p=.0099). The percentage of CD5+/CD19+ WBCs in the peripheral blood of TCL1 mice averaged 74% while the Par-4/TCL1 mice averaged 37%. TCL1 white blood cell counts were also found to be significantly higher than syngeneic Par-4/TCL1 mice (p=.0028) at 10 months, averaging 65000/µL compared to just 15000/µL in the double transgenic. Animals that met euthanasia criteria were analyzed histologically for infiltration of the spleen and bone marrow by malignant B cells. The degree of CLL infiltration was similar in both the TCL1 single transgenics and the Par-4/TCL1 double transgenics, indicating that while the disease progression is stifled, the cancer does adapt and resume course with similar pathology. EdU incorporation assays were performed to estimate relative rates of clonal expansion in the splenic B cell population. Expansion of CD5+/CD19+ splenocytes was found to be higher in the TCL1 single transgenic mice than the Par-4/TCL1 transgenics (p=.01). We believe this suggests a cell intrinsic defect, imposed by overexpression of Par-4 protein, which creates a hurdle that must be overcome for the malignancy to progress. Mechanistic studies indicate that Par-4 mediated inhibition of NF-κB signaling in leukemic B cells may be responsible for the lag in disease progression in Par-4/TCL1 mice. Immunoblotting revealed that IκBα levels are higher and the proportion of phosphorylated protein is lower in Par-4/TLC1 splenic B cells, relative to single transgenic TCL1 B cells.Conclusions: We have shown that human Par-4 overexpression in a murine leukemia model is capable of influencing disease progression by slowing expansion of malignant cells. Inhibition of the NF-κB pathway by stabilization of IkBα appears to be the mechanism of action, which would place Par-4 in the canonical NF-κB pathway. We know this pathway is integral to CLL cell survival and is downregulated by effective therapeutic agents. These findings indicate that the Par-4 is capable of suppressing development of TCL1 driven leukemia by downregulating survival signals that are essential to apoptosis evasion and proliferation in CLL. These studies warrant further characterization of Par-4 pathway in human CLL cells. DisclosuresByrd:Janssen: Research Funding; Pharmacyclics: Research Funding; Genentech: Research Funding; The Ohio State University: Patents & Royalties: OSU-2S; Acerta Pharma: Research Funding.

Pulmonary and central nervous system infiltration of chronic lymphocytic leukemia with concomitant diffuse large B-cell lymphoma: Case report and review of literature

Introduction: Diffuse large B-cell lymphoma (DLBCL) andchronic lymphoid leukemia (CLL) are lymphoproliferativediseases of B lymphocytes. Objective: To describe the concomitanceof diseases with pulmonary and CNS involvement.Clinical case: A 67-year-old patient with DLBCL and CLLobtained partial remission of the diseases after six cycles ofstandard combined chemotherapy. Relapse of CLL (del17p;TP53+) occurred after 22 months, becoming refractory to anew treatment. Monoclonal B lymphocyte infiltration wasfound in the cerebrospinal fluid and bronchoalveolar lavage,leading to death due to respiratory failure. Conclusion: Theunfavorable outcome shows a rare and serious complicationin the concomitance of these diseases.

Tissue factor pathway inhibitor upregulates CXCR7 expression and enhances CXCL12-mediated migration in chronic lymphocytic leukemia

The infiltration of chronic lymphocytic leukemia (CLL) cells into lymphoid organs correlates with disease severity. CXCL12 is a key chemotactic factor for the trafficking of CLL. Tissue factor pathway inhibitor (TFPI) is a serine protease inhibitor and plays a role in CXCL12-mediated hematopoietic stem cell homing. We aim to explore the role of TFPI in CXCL12-mediated migration of CLL cells. In this study, plasma TFPI concentrations were measured by ELISA. CLL cells were isolated from patients and used for trans-endothelial migration (TEM) assays. Quantitative RT-PCR and Western blotting were used to detect the expression of CXCR7, CXCR4 and β-catenin. Immunofluorescence and co-immunoprecipitation was used to detect the binding of TFPI and glypican-3 (GPC3). We found that plasma TFPI levels in CLL patients were higher than in healthy controls, particularly in the patients with advanced disease. TFPI enhanced CXCL12-mediated TEM of CLL cells by increasing the expression of the CXCL12 receptor CXCR7, but not of the CXCL12 receptor CXCR4. The effect of TFPI on TEM was abolished by the CXCR7 inhibitor, CCX771, while the CXCR4 inhibitor AMD3100 strongly increased TEM. TFPI co-localized with GPC3 on the cell surface. An antibody to GPC3, HS20, decreased CXCR7 expression and abolished the effect of TFPI on TEM. TFPI activated β-catenin and the Wnt/β-catenin inhibitor IWP4 repressed the effect of TFPI on CXCR7 expression and TEM. We conclude that TFPI may contribute to organ infiltration in CLL patients.

The Clinical Relevance of Residual, Persistent and Elongated Abnormal Sized Nodes By Longest Diameter (LDi) in Patients (pts) with Chronic Lymphocytic Leukemia (CLL), Otherwise in a Complete Remission (CR)

Background: IWCLL 2008 and 2018 criteria require that all lymph nodes/nodal masses be ≤ 15mm in longest diameter (LDi) to be consistent with a CR. Lymph nodes or nodal masses &amp;gt;15mm in the LDi are considered abnormal. However, it has been observed that some bulky nodes may become thin and streak-like on follow-up timepoints (Figure 1) and may be normal by clinical and imaging standards (&amp;lt;10mm in short axis diameter) (Cheson et al Journal of Clinical Oncology, 17:1244, 1999) however, they continue to be &amp;gt;15mm in LDi (LDi Positive nodes- LDi+) and, hence, categorized as abnormal per iwCLL criteria. In lymphoma studies, FDG-PET negativity is the driver of CR, and residual disease on CT scan is allowed for CR. However, in the iwCLL response assessment, LDi+ nodes may prevent a true CR. Methods: 1168 patients across multiple phase III CLL clinical trials with targeted agents were analyzed, which were independently reviewed using iwCLL 2008 and 2018 criteria. To assess the impact of LDi+ nodes, we filtered our response to finding pts who had at least one lymph node with LDi &amp;gt;15mm (range 15.1 to 30mm) and, thus, a PR by imaging, but all other identified nodes either resolved or &amp;lt;10mm in short axis and the rest of the disease burden normalized. We also evaluated clinical information on all pts (e.g., bone marrow biopsy, complete blood count (CBC), Absolute Lymphocyte Count (ALC), and other confounding factors, when available). Figure 1: A large right axillary node at baseline (image on left), is reduced in size and is thin, streak like (image on right) but is abnormal as per iwCLL criteria by LDi definition. Results: Of 1168 pts, 161 (13.8%) had an overall response of PR because of these abnormal LDi+ nodes on imaging per iwCLL criteria, even though the rest of the disease burden had normalized and showed CR. Laboratory data (CBC and ALC) were available in all of these 161 patients and were normalized/CR. Bone marrow was available for 31 patients and was negative/CR in all of those patients in at least one follow-up assessment by both cellularity and CLL infiltration assessments (by either morphology, flow cytometry or immuno-histochemistry (IHC)). These pts continued to have a sustained response of CR for all other parameters for multiple follow up visits with a median follow up of about 6 months. Conclusion: Based on these data, approximately 13.8 % of pts with LDi+ nodes normal by clinical/imaging standards, clinical/laboratory parameters normalized and some with a normal bone marrow evaluation, but were labeled PR in overall assessment and denied a CR. These pts likely had achieved a CR as bone marrow is considered a gold standard for normalization of disease burden. These LDi+ lymph nodes by iwCLL criteria which are normal by clinical/imaging standards, likely represent scar tissue and not active disease based on normalization of the rest of the disease. These assessments made by stringent application of iwCLL criteria in assessing lymph nodes may result in underestimating the CR rate in a clinical trial. We propose an adaptation of the iwCLL criteria to allow hematologists/oncologists to update/override the radiology overall assessment from PR to CR if all other components for the oncology review (e.g., blood counts, bone marrow, target lesions, organ assessments) meet CR criteria, based on clinical judgment. This approach is being used universally in daily clinical practice (as well as by the site investigators) when assessing CLL patients and these abnormal LDi+ nodes by iwCLL criteria, do not prevent a CR. This proposed approach may help to reduce site-central discordance in a clinical trial setting. Further studies to correlate these findings with minimal residual disease in bone marrow/blood will help validate our findings. Figure 1 Disclosures Cheson: Trillium: Research Funding; Abbvie: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Jannsen: Consultancy; TG Therapeutics: Speakers Bureau; GSK: Membership on an entity's Board of Directors or advisory committees; Parexel: Consultancy; Kite: Consultancy; Symbio: Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees.

S2405 Post-Infantile Giant Cell Hepatitis

INTRODUCTION: Post-infantile giant cell hepatitis (PIGCH) is a rare disorder among adults. Diagnosis is dependent on liver biopsy and its histologic hallmark is the presence of hepatocyte-derived multinucleated giant cells. This is thought to be due to increased hepatocyte regenerative activity that occurs as a response to noxious stimuli including viral infections, autoimmune disorders, leukemia and drug reactions. We report two cases of PIGCH including its management and outcome. CASE DESCRIPTION/METHODS: Case 1 is a 62-year-old African American male who presented with jaundice, dark urine and generalized malaise. Past medical history notable for alcohol use disorder in remission and chronic hepatitis C treated with antiviral therapy. Physical examination revealed jaundice. Bloodwork included ALT 2,300 U/L, AST 1,900 U/L, ALP 186 U/L, GGT 177 U/L, serum total bilirubin 29 mg/dL, direct bilirubin 20 mg/dL, AFP level 25 μg/L and INR 1.5. Infectious work up was negative and abdominal ultrasound was normal. Autoimmune markers ANA, SMA and AMA were positive. Liver biopsy showed severe syncytial giant cell hepatitis with 75% loss of hepatocytes. Patient was started on steroids with complete normalization of his transaminases on four month follow up. Case 2 is a 69-year-old Caucasian male with history of dyslipidemia, hypertension and chronic lymphocytic leukemia (CLL) on Ibrutinib, who presented with generalized malaise. He denied any alcohol, tobacco, or substance use. Physical examination revealed jaundice. Bloodwork included AST 2,385 U/L, ALT 5,609 U/L, ALP 286 U/L, total bilirubin 31.3 mg/dL, direct bilirubin 23.6 mg/dL and INR was 1.1. Infectious and autoimmune work up was negative. Abdominal ultrasound was normal. Liver biopsy showed syncytial giant cell hepatitis with CLL infiltrates on most portal tracks. Patient was started on steroids with temporary normalization of transaminases. Unfortunately, one week later, the patient died due to cancer-related complications. DISCUSSION: PIGCH has been commonly associated with autoimmune hepatitis but only a few case reports of CLL-associated PIGCH exist. Given its heterogeneous etiologies, PIGCH is difficult to prognosticate and manage. However, it should be considered in all patients with acute liver injury or chronic liver disease of unknown disease. Despite having a good response to immunosuppressive therapy, patients may still develop severe progressive disease requiring liver transplantation. Hence, prompt recognition and treatment is crucial.Figure 1.: The multinucleated giant cell hepatocytes (see arrows) are seen in H&E stained sections of biopsy. These are reactively altered hepatocytes (rather than multinucleated giant cell histiocytes). Immunoperoxidase stains show (see inset images) that within multinucleated hepatocytes, nuclei are strongly positive for Cyclin-D1 and cytoplasm is strongly positive for cytokeratin CK8/CK18 (Cam5.2).Figure 2.: In Case 2, the same stains were used as in Case 1 however the portal tract contains an infiltrate of neoplastic lymphoid cells (CLL).

Intravascular Colonization of Kaposi Sarcoma: Expanding the Spectrum of Specific Infiltrates of B-Cell Chronic Lymphocytic Leukemia

B-cell chronic lymphocytic leukemia (CLL), a low-grade malignancy consisting of CD5(+), CD23(+), and CD43(+) small B lymphocytes, is the most frequent leukemia in the western world. Patients with CLL may exhibit skin changes characterized by histopathologic evidence of infiltration by atypical B lymphocytes, also known as "specific cutaneous infiltrates of CLL"; in addition, CLL is known to be associated with an increased risk of second cancers, including Kaposi sarcoma (KS). The combination of KS and CLL within the same cutaneous biopsy specimen has only rarely been described. We report a peculiar case of KS occurring in a patient with CLL, in which histopathological evaluation of KS lesions revealed prominent accumulation of CLL lymphocytes within neoplastic vascular spaces. We believe that our findings represent a novel example of intravascular colonization of vascular neoplasms by neoplastic lymphoid cells, further expanding the evergrowing spectrum of specific cutaneous infiltrates of CLL.

Extended lymphadenectomy for high-risk prostate cancer in patients with chronic lymphocytic leukemia may not be necessary: a report of two cases

BackgroundChronic lymphocytic leukemia is a malignancy with good prognosis. However, the incidence of secondary tumors increases every year after the diagnosis of chronic lymphotcytic leukemia. One of the induced secondary tumors is prostate cancer. For high-risk prostate cancer in particular, the standard therapy is radical prostatectomy and extended lymphadenectomy, which carries high risks of lymphatic leakage and reduced quality of life. Currently, there has been no study reporting the necessity of extended lymphadenectomy for high-risk prostate cancer in patients with chronic lymphocytic leukemia.Case presentationWe reported two cases with concomitant high-risk prostate cancer and chronic lymphocytic leukemia. The first patient was a 60-year-old male diagnosed with synchronous prostate cancer and chronic lymphocytic leukemia. The second patient was a 70-year-old male initially presented with chronic lymphocytic leukemia alone but was then diagnosed with high-risk prostate cancer nine years later. Both patients received neoadjuvant androgen deprivation therapy and robot-assisted radical prostatectomy. The first patient underwent extended lymphadenectomy and developed prolonged postoperative lymphatic cyst. Histology showed chronic lymphocytic leukemia infiltration in resected lymph nodes. Serum prostate-specific antigen levels at one and 13 months post-operation were both 0.01 ng/ml. The second patient received positron emission tomography/computed tomography before androgen deprivation therapy, which showed mild fluorodeoxyglucose-avidity in lymph nodes across the entire body. Lymph node biopsy showed only chronic lymphocytic leukemia. The patient experienced no postoperative complication. Serum prostate-specific antigen levels at one and nine months post-operation were both 0.02 ng/ml.ConclusionsExtended lymphadenectomy may not be necessary for patients with concomitant high-risk prostate cancer and chronic lymphocytic leukemia, but such patients must undergo thorough preoperative assessment and mindful postoperative follow-up. Positron emission tomography/computed tomography may be valuable in detecting nodal metastases. A lymph node biopsy is necessary for patients with an ambiguous positron emission tomography/computed tomography in the metastatic involvement of lymph node.

Electrochemotherapy for Head and Neck Cancers-A Comprehensive Review

Electrochemotherapy is a therapeutic modality that combines the effect of electroporation with chemotherapy. It is currently being used for the clinical management of cutaneous and subcutaneous tumors, skin metastasis of head and neck neoplasms, basal and merkal cell carcinoma, kaposi's sarcoma, chronic lymphocytic leukemia infiltration, and melanoma metastasis. Although, many different anti-neoplastic agents had been tested for electrochemotherapy, only bleomycin and cisplatin had been found be suitable for clinical practice. In head and neck region, it is suitable for curative therapy of small nodules and palliative treatment of advanced stage tumours. This article is a comprehensive review of electrochemotherapy with special emphasis on it's usefulness in head and neck malignancies.

Granulomatous interstitial nephritis due to chronic lymphocytic leukemia: a case report

BackgroundRenal failure due to the infiltration of chronic lymphocytic leukemia (CLL) cells into the tubulointerstitial area of the kidney is uncommon. Furthermore, granulomatous interstitial nephritis (GIN) is a rare histological diagnosis in patients undergoing a renal biopsy. We herein report a case of GIN due to the diffuse infiltration of CLL cells in a patient who developed progressive renal failure.Case presentationThe patient was a 55-year-old man who had been diagnosed with CLL 4 years earlier and who had been followed up without treatment. Although his serum creatinine level had remained normal for three and a half years, it started to increase in the six months prior to his presentation. A urinalysis showed mild proteinuria without any hematuria at the time of presentation. A renal biopsy revealed the diffuse infiltration of CLL cells into the tubulointerstitial area with non-caseating epithelioid cell granulomas. Despite cyclophosphamide treatment, his renal function did not improve, and he ultimately required maintenance hemodialysis.ConclusionWhen progressive renal failure is combined with CLL, GIN due to the direct infiltration of CLL cells should be considered as a differential diagnosis.

CD11c expression in chronic lymphocytic leukemia revisited, related with complications and survival.

Chronic lymphocytic leukemia (CLL) is a disorder of mature but dysfunctional monoclonal B cells. Microenvironment, antigenic stimulation and genetical mutations are demonstrated in etiopathogenesis. We aimed to evaluate the expression of CD11c in patients with CLL and its possible clinical significance. Data of 259 patients with CLL between 2010 and 2016 in Trakya University Faculty of Medicine, including age at diagnosis, sex, whole blood count, stage, percentage of CLL cells in bone marrow, line of treatments, development of Richter's transformation and secondary tumors, autoimmune complications, IgG level, prognostic cytogenetic analysis, and length of survival were recorded from files. 151 patients were male (58.3%) and 108 were male (41.7%). Mean age was 70 (21-92)years. CD11c was observed to be positive (>%20) in 103 patients (39.8%). Development of Richter's transformation, secondary tumors and ITP was significantly frequent in patients with CD11c positivity (P values .000, .003, .000 respectively). Also, IgG levels were significantly lower in this group (P=.000). Hemoglobin level, RAI stage and bone marrow CLL infiltration percentage were statistically related with CD11c (P values .036, .037, .000 respectively). Finally, CD11c was statistically related (in positive group 70months, negative group 79months, P=.001). CD11c, expressed not only in Hairy cell leukemia but also in dendritic cells, macrophages and monocytes is a differentiation marker for inflammation. Prolonged inflammation in the microenvironment of CLL cells may cause a susceptibility to autoimmune disorders and secondary tumors in CLL, in this way, an increase in mortality.