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Background: Circulating tumor DNA (ctDNA) are short DNA sequences shed by tumor cells into the systemic circulation. Studies have shown potential utility of the test to predict relapse or recurrence following treatment in solid tumors, but sensitivity and specificity have varied widely, ranging from 19-100% and 80-100% respectively, in breast cancer specifically. Moreover, literature describing the utility of monitoring dynamic changes in ctDNA trends is limited. We aim to evaluate the correlation between ctDNA test, both single test as well as dynamic trends in value over time, with imaging findings. Methods: We retrospectively analyzed the medical records of all adult patients diagnosed with breast cancer who underwent ctDNA testing at the hematology-oncology clinic at William Beaumont - Royal Oak and Troy Hospitals, Michigan, from August 2017 to June 2022. Patients who had ctDNA testing done but did not have imaging to correlate it with were excluded from the study. We calculated the sensitivity and specificity of a single positive ctDNA test to detect disease progression or residual disease on imaging. In patients with multiple ctDNA tests, we calculated the sensitivity and specificity of dynamic trends in ctDNA values to detect progression, regression, or absence of disease on imaging. Moreover, we calculated the lead time for positive ctDNA results to detect disease progression compared to imaging. Results: Nineteen patients were included in the study, with 34 total ctDNA test results, each utilized as a separate data point to compare with corresponding imaging findings (Table 1). Ten out of the 19 patients had multiple(>=2) ctDNA test results reported, with a total of 15 pairs of ctDNA values and each pair was analyzed separately as up trending (N=7), down trending (N=4), or persistent negative (N=4) to compare with a corresponding pair of imaging findings (Table 2). The median age at diagnosis was 55 years, and 94.7% were female. At diagnosis, majority of patients (68.4%) had either stage III or IV disease. Our primary endpoint, the correlation of single positive ctDNA result with imaging showing either progression or residual disease, showed a sensitivity and specificity of 100% and 93.3%, respectively. Secondarily, serial ctDNA trend analysis in ten patients revealed both sensitivity and specificity of 100% for up-trending ctDNA values to detect progression, down-trending to detect regression, and persistent negative results to detect absence of disease on imaging, respectively. The positive ctDNA results detected disease progression with a median lead time of 44.5 days compared to imaging. Conclusion: Given the high sensitivity and specificity to detect disease progression and regression in breast cancer patients by single ctDNA results and dynamic ctDNA trends in our study, we conclude that this may be a valid way to reliably monitor for changes in disease status before they become evident in imaging studies. Further clinical studies are required to prove the utility of ctDNA to detect changes in disease status and to guide therapeutic interventions in breast cancer. Table 1. Correlation of single ctDNA result with imaging findings. Table 2. Correlation of dynamic trends in ctDNA values with imaging findings. Citation Format: Ujjwal Karki, Bipin Ghimire, Emma Herrman, Siddhartha Yadav, Mohammad Muhsin Chisti. Detection of progression or regression of breast cancer by circulating tumor DNA (ctDNA) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-05-07.

Catastrophic antiphospholipid syndrome (CAPS) is a rare but severe form of antiphospholipid syndrome (APS). The syndrome manifests itself as a rapidly progressive multiorgan failure that is believed to be caused by widespread micro-thrombosis. Seldom does bleeding comanifest with thrombosis. We present a patient with APS who presented with nausea, vomiting and fatigue, and rapidly progressed into multiorgan failure before being diagnosed with CAPS. The clinical course was complicated by an atraumatic intracranial haemorrhage which demanded discontinuation of anticoagulation. The patient was treated with high dose steroid, intravenous immunoglobulin, followed by weekly rituximab infusion. Although the trigger for CAPS was not obvious during her hospital stay, she was diagnosed with acute cytomegalovirus (CMV) infection soon after discharge. In this case report, we explore the differential diagnoses of CAPS, investigate the possibility of CMV infection as a potential trigger, present the therapeutic challenges of anticoagulation and discuss the emerging use of rituximab.

Poster: "RANZCR-AOCR 2012 / R-0001 / The Correlation between Lymphoma Cell Size and PET-CT Metabolic Activity in Follicular Lymphomas" by: "C. Y. O. Wong, G. Brahmanday, M. M. Chisti, A. Muslimani, I. Jaiyesimi, P. Rigo, B.-T. Hung, P.-L. Khong, J. Huang"

Xp11.2 translocation renal cell carcinoma (TRCC) is a rare and aggressive variant of renal cell carcinoma (RCC) when presenting in adults. We report a case of a man in his early 40s who was diagnosed with stage III Xp11.2 TRCC and underwent radical nephrectomy. Seven months following the surgery, an adrenal nodule and bilateral pulmonary nodules were discovered. He underwent cryoablation of the adrenal nodule and systemic treatment with daily pazopanib. He displayed stable disease for approximately 6 years. Following this period, multiple hospitalisations interrupted daily pazopanib therapy resulting in progression of disease. His regimen was then changed to ipilimumab and nivolumab, followed by current daily therapy with axitinib. The patient now shows stable disease in his 10th year after diagnosis. This case study demonstrates the efficacy of pazopanib for metastatic Xp11.2 TRCC and warrants further investigation to supplement the guidelines regarding the use of targeted therapy for TRCC.

Rationale: Treatment of acute myelogenous leukemia (AML) remains a challenge in elderly populations, those with comorbid conditions, and patients with poor performance status indices. The optimal choice for induction therapy as well as further agent selection is unclear, and current guidelines recommend enrollment in a controlled clinical trial. Methods: Institutional cases of AML via an electronic medical record query performed in November 2017 containing cases of AML in patients 65 years of age or greater from 01/01/2000 to 06/21/2017 were extracted. Instances of acute myelogenous leukemia were identified by ICD codes. Age, gender, induction therapy, cytogenetics, molecular analyses, and overall survival were collected. Results: A total of 61 cases of AML in patients aged 65 or greater were identified, with those having incomplete data being excluded from analysis. The mean age of included patients was 78.9 years of age, 35 were male and 26 were female. 60 confirmed deaths were recorded. 26 patients received conventional 7+3 (42.6%), 22 received a hypomethylating agent (HMA) (31.1%), 16 (26.2%) did not receive treatment. Conclusion: Our institutional data showed overall survival was significantly longer when treated with 7+3, 354 days (95% CI [93, 614]), vs. 61 days (95% CI [15, 107]). Similarly, OS was significantly longer when treated with HMA, 303 days (95% CI [23, 583]). Risk of death, accordingly, was as follows: 7+3 HR .347 (.179-.672), HMA HR .348 (.173-.703). Our institutional mortality data reasonably reflected SEER data analysis reported by Medeiros et al concerning untreated patients, but trended toward a greater OS for those treated with 7+3 or HMA. Registry data, as well as our institutional data, demonstrate a survival benefit to intensive chemotherapy and palliative chemotherapy, while controlled trials have not shown this benefit consistently in elderly populations. Practices regarding induction therapy vary greatly between institutions. Determination of which elderly patients to treat with intensive therapy remains difficult. References: Almeida AM, Ramos F. Acute myeloid leukemia in the older adults. Leuk Res Rep. 2016;6:1-7. Eleni LD, Nicholas ZC, Alexandros S. Challenges in treating older patients with acute myeloid leukemia. J Oncol. 2010;2010:943823. Medeiros BC, Satram-hoang S, Hurst D, Hoang KQ, Momin F, Reyes C. Big data analysis of treatment patterns and outcomes among elderly acute myeloid leukemia patients in the United States. Ann Hematol. 2015;94(7):1127-38. Disclosures Chisti: Eli Lilly: Speakers Bureau; Medscape: Honoraria; UpToDate: Honoraria.

A patient with a diagnosis of myelodysplastic syndrome (MDS) with isolated 5q deletion underwent repeat bone marrow biopsy to assess haematological response after 6 months of initial lenalidomide therapy. Subsequent bone marrow biopsies revealed persistent MDS with del(5q) in addition to a small atypical mast cell population with >25% of mast cells with spindle-shaped morphology and immunohistochemistry characteristics consistent with mastocytosis. Molecular testing on the bone marrow was positive for cKIT D816V and the patient was diagnosed with systemic mastocytosis (SM) with an associated haematological neoplasm. MDS with SM is well known to be associated; however, to the best of our knowledge, only one prior case report identifies MDS with del(5q) and associated cKIT D816V positive mastocytosis. While the exact clonal origin of both chromosomal aberrations is unclear, this case illustrates the therapeutic efficacy of lenalidomide in a patient with MDS with del(5q) and rarely associated cKIT positive SM.

Extrapulmonary small cell carcinomas (SCCs) are rare and often have an aggressive natural course. A 42-year-old female presented to the hospital with vaginal bleeding and lower abdominal pain. She was eventually diagnosed with SCC of cervix by biopsy. She was treated with chemoradiation. However, on follow-up positron emission tomography (PET) scan, fluorodeoxyglucose (FDG) uptake was noted in bilateral breasts. Biopsy of these lesions was consistent with metastatic SCC. Breast is a very unusual site for metastasis of cervical SCC and only four cases have been reported in the medical literature to date. Our case highlights the importance of considering metastatic disease when evaluating breast mass in patients with history of SCC of cervix. World J Oncol. 2015;6(1):301-303 doi: http://dx.doi.org/10.14740/wjon858w

Acute promyelocytic leukemia (APL) with the unique t(15;17) translocation has a high complete remission and disease-free survival rates following chemotherapy with all-trans-retinoic acid. Chemotherapy complications including secondary malignancies are rare. In this report we present therapy-related T-lymphoblastic lymphoma following APL treatment. The bone marrow analysis showed MLL and MAML2 genes rearrangement that can explain the molecular basis for the lymphoma development.

Cancer-associated retinopathy (CAR) is an uncommon paraneoplastic retinopathy usually associated with small cell lung carcinoma. To our knowledge, there is no previous report in the English literature of CAR syndrome occurring in lymphoma patients. We describe a rare case of CAR syndrome in a 62-year-old male with non-Hodgkin’s lymphoma (NHL) treated with four doses of intravenous immunoglobulin.

Dear Editor, A 66-year-old female was diagnosed in 2000 with hairy cell leukemia (HCL). Flow cytometry from her bone marrow biopsy (BMB) demonstrated a monotypic B cell population expressing CD11c, CD22, CD25, and CD103. She was successfully treated with cladribine [1]; however, in 2003, she relapsed, and BMB showed a monotypic B cell population. Cytogenetic analysis revealed an abnormal hyperdiploid karyotype in 2 of 20 metaphase cells: 48,XX,+4,del(6)(q23), del(8)(p21)x2,+12,del(14)(q24), add(17)(p13) (Fig. 1). She was again treated with cladribine and rituximab [2]. In 2008, imaging revealed splenomegaly. Splenectomywas performed, and pathology showed HCL. BMB revealed extensive involvement by a monotypic B cell population negative for CD5, CD10, CD103, and CD25. This phenotype was the same as reported on previous BMB, but differed in that it was CD25 and CD103 negative. Five months later, the patient presented with a left pyriform sinus mass (SUV of 32.8 on PET scan) which was biopsied (Fig. 2). BMB revealed involvement by the previously diagnosed HCL with a monoclonal B cell population demonstrating a phenotype similar to that observed in previous studies. Based on histologic and immunophenotypic findings, this tumor was classified as Langerhans/dendritic cell sarcoma (L/DCS) (expression S100, CD1a; negative for B and T cell markers and CD30). Cytogenetic evaluation identified the hyperdiploid complex karyotype: 47,XX,+4,del(6)(q23),del(8)(p21)x2,+12, -13,del(14)(q24),add(17)(p13). This karyotype and the one obtained in 2003 BMB positive for HCL were essentially identical, although L/DCS presented with monosomy 13. In addition, clonal immunoglobulin gene rearrangements identified by polymerase chain reaction from both specimens were also identical. Combined, cytogenetic, and immunoglobulin gene rearrangement studies suggest that both the HCL and L/DCS developed from the same precursor cells. The patient was treated with three cycles of gemcitabine and docetaxel [3]. However, due to significant progression, the patient opted for hospice. Clinical data have shown that two hematopoietic populations in the same patient may share identical genetic changes or abnormalities, raising the possibility that tumors expressing the phenotype of one hematopoietic lineage might “transdifferentiate” into a genetically similar but phenotypically distinct tumor of a different lineage [4]. Histiocytic/dendritic cell sarcomas (H/DCS) arising from follicular lymphoma (FL) have been reported earlier (eight patients) [5]. In six of these patients, both lesions possessed the same genetic aberration, namely the FL-associated IGH/BCL2 gene rearrangement associated with the t(14;18)(q32;q21). The remaining two demonstrated identical BCL2/JH or clonal IGH gene rearrangements or both. Based on these observations, the authors suggested a clonal relationship between FL and H/DCS. Feldman et al. also demonstrated a common clonal origin in a patient with acute lymphoblastic leukemia and subsequent histiocytic sarcoma, based on identical IGH and TCRγ gene rearrangements in both lesions [6]. Zhang et al. described a Electronic supplementary material The online version of this article (doi:10.1007/s00277-011-1399-5) contains supplementary material, which is available to authorized users. A. Muslimani :M. M. Chisti (*) : I. Boxwala : I. Jaiyesimi Department of Hematology and Oncology, Oakland University William Beaumont School of Medicine, William Beaumont Hospital, 3577 W 13 Mile Rd, Suite 202, Royal Oak, MI 48073, USA e-mail: mohsinchisti@yahoo.com

A man in his early 40s with a history of ulcerative colitis, treated with infliximab, was diagnosed with plasmablastic multiple myeloma. He was treated with chemotherapy and stem cell transplant but developed recurrence and ultimately died from metastatic disease. Could inflammatory bowel disease or infliximab therapy have any role in development of myeloma in this young patient? The role of inflammatory bowel disease and infliximab therapy in the development of multiple myeloma is controversial but interesting and worth considering.

A 46-year-old man with a long-standing history of Crohn’s disease who was treated with multiple therapies over a period of 9 years presented with oral lesions which on biopsy demonstrated peripheral T-cell lymphoma. Initially, the development of T-cell lymphoma was presumed to be secondary to prolonged immunosuppression but it did not respond to withholding immunosuppressive therapy. On treatment with CHOP (cyclophosphamide, hydroxydaunorubicin, oncovin and prednisone) chemotherapy, complete remission was achieved. Although development of malignancies in the immune-suppressed patient with Crohn9s disease has been previously described but we present a rare case of T-cell lymphoma in a similar patient, which has not been reported before.

CD20, expressed on greater than 90% of B-lymphocytic lymphomas, is an attractive target for antibody therapy. Rituximab is a chimeric murine/human-engineered monoclonal antibody which can selectively deplete CD20-expressing cells in peripheral blood and lymphoid tissues. The immobilization of B-lymphoblast-like Burkitt's lymphoma Raji cells on the quartz crystal microbalance (QCM) gold electrode surface using arginine-glycine-aspartic acid (RGD) tripeptide was electrochemically confirmed. The real-time processes of attachment of Raji cells on the gold electrode and the subsequent binding of Rituximab to the cells were studied using a QCM biosensor. The interaction between Rituximab and Raji cells led to the increased resonant frequency shifts (Δf0) in the studied antibody concentration range from 5 to 250 μg mL(-1) following the Langmuir adsorption model. From these observations, the apparent binding constant between a single-layer of Rituximab and Raji cells was calculated to be 1.6 × 10(6) M(-1). Control experiments using other therapeutic antibodies (i.e., Trastuzumab and Bevacizumab) and different cells (i.e., T cells and endothelial cells) proved the specific interaction between Rituximab and B cells. The effects of Ca(2+) and Mn(2+) ions on the Rituximab-Raji cell interaction were also studied providing the enhanced QCM signals, in particular with Ca(2+), further indicating that CD20 is a calcium ion channel that can transport these metal ions into the cells and accelerate the cell lysis induced by Rituximab. Thus, the real time capability of QCM and its simplicity of operation are shown to be highly suitable for multipurpose studies on living cells including cell-immobilization, cytotoxicity of drugs, and the cell action mechanisms.

Background: Antigens like CD20 antigen, are established targets for antibody therapy with monoclonal antibodies (mAb) like Rituximab. Mixed clinico-pathological responses to mAb have been reported either due to presence of antibodies, rapid clearance or low density of target receptor/antigens. This demands need for an assay to monitor serum mAb therapeutic levels to ensure appropriate dosage. Enzyme-linked immunosorbent assay (ELISA) is still the most widely used technique to detect mAb level in human serum which is expensive and time consuming. Understanding properties and interactions of antigens is quintessential for developing better targeted agents and overcoming resistance. Flow cytometry is still the most widely used technique to detect CD20 level in human serum which is expensive, time consuming and does not reveal any details of interaction between the molecules. We have developed a new innovative biosensor based novel technique to not only monitor levels but also study real time interaction of antigens with antibodies using QCM Piezo-immunosensor. This quantitative label free peptide based assay can be used to characterize cell surface antigen, to study antigen- antibody interactions and obtain understanding of mechanisms of resistance to therapy. Method:Mimotope was used as a substitute for the antigen like CD20 and HER2 receptor protein in QCM assays to detect mAb level. The validation samples were prepared from the standard T solution in 10% human serum at three concentrations (10, 20 and 40 ug/ml). The changes in frequencies (ΔF) of sera from 3 female patients were obtained by calculating the differences between frequency shifts in pre and post mAb infusion. mAb level was calculated by equation, (ΔF +1.0022) ÷ 0.9997 μg / ml. The real-time processes of attachment of Cells like Raji cells on the gold electrode and the subsequent binding of antibody like Rituximab to the cells were studied using QCM biosensor. The interaction between Antigen and Antibody led to the increased resonant frequency shifts (df0) in the studied antibody concentration range from 5 to 250 μg mL-1 . Control experiments using other therapeutic antibodies (i.e., Trastuzumab and Bevacizumab) and different cells (i.e., T cells and endothelial cells) proved very specific interaction between Rituximab and CD20 antigens on B cells Results: Antigen and Antibody binding was very specific. This binding decreased the electrochemical activity and stability of the cells, supporting the cell lysis mechanisms of action of Rituximab. We showed that assay sensitivity was dependent upon the amino acids used to tether and link the peptide to the sensor surface and the buffers used. QCM assay was capable of detecting mAb like Trastuzumab serum level as low as 0.038 nM (linear operating range of 0.038-0.859 nM). The time frame of assay was 20-30 minutes. These results were in concordance with previously published results using ELISA. We have shown a systematic approach for using QCM technique to quantify the apparent binding constant between antigen and antibody can reveal antigen density. Conclusion: We have established a low cost, highly sensitive, fast, synthetic peptide based QCM assay which could be used as a basis for developing a new generation of affinity-based Immunosensor assays to monitor mAb serum levels like Rituximab, Trastuzumab and other monoclonal antibodies, helping physicians to determine the clinical efficacy of these drugs and ensuring appropriate dosages. Moreover antigen density and interactions of antigens with respective monoclonal antibodies like CD20 with Rituximab will help physicians to determine the clinical efficacy and resistance mechanisms to targeted antibodies like Rituximab and Ofatumumab. This could be used as a basis for developing a new generation of affinity-based Immunosensor assays. Our study shows that peptide mimotopes have potential benefit in sensor applications as the peptide-peptide interactions in the peptide mimotopes could be manipulated by the addition of functional groups to the peptide to influence binding of the target protein as well as for surface immobilization. Disclosures No relevant conflicts of interest to declare.

Patients with diffuse large B cell lymphoma can occasionally develop hypercalcemia but it is rare at the onset of disease. We present a case of an elderly female who presented with refractory hypercalcemia, workup of which led to the diagnosis of B cell lymphoma. We discuss about various etiologies for development of hypercalcemia in a patient with lymphoma or leukemia.

Therapeutic antibodies are antigenically similar to human antibodies and are difficult to detect in assays of human serum samples without the use of the therapeutic antibody's complementary antigen. Herein for the first time, we established a platform to detect Herceptin in solutions by using a small (2.2 kDa), inexpensive, highly stable human epidermal growth factor receptor (HER2) mimotope-derived synthetic peptide immobilized on the surface of a Au quartz electrode. We used the HER2 mimotope as a substitute for the HER2 receptor protein in piezoimmunosensor or quartz crystal microbalance (QCM) assays to detect Herceptin in human serum. We demonstrated that assay sensitivity was dependent upon the amino acids used to tether and link the peptide to the sensor surface and the buffers used to carry out the assays. The detection limit of the piezoimmunosensor assay was 0.038 nM with a linear operating range of 0.038-0.859 nM. Little nonspecific binding to other therapeutic antibodies (Avastin and Rituxan) was observed. Levels of Herceptin in serum samples obtained from treated patients, as ascertained using the synthetic peptide-based QCM assay, were typical for those treated with Herceptin. The findings of this study are significant in that low-cost synthetic peptides could be used in a QCM assay, in lieu of native or recombinant antigens or capture antibodies, to rapidly detect a therapeutic antibody in human serum. The results suggested that a synthetic peptide bearing a particular functional sequence could be applied for developing a new generation of affinity-based immunosensors to detect a broad range of clinical biomarkers.

Background: CD20 antigen, expressed on greater than 90% of B-cell lymphomas, is an established target for antibody therapy with monoclonal antibodies like Rituximab, which can selectively deplete CD20-expressing cells in peripheral blood and lymphoid tissues. Understanding properties and interactions of CD20 antigens is quintessential for developing better targeted agents and overcoming resistance. It has not been clearly established yet whether CD20 antigen density corresponds with response to Rituximab. Flow cytometry is still the most widely used technique to detect CD20 level in human serum which is expensive, time consuming and does not reveal any details of interaction between the molecules. We have developed a new innovative biosensor based novel technique to study real time interaction of CD20 antigens with Rituximab using QCM Piezo-immunosensor. This quantitative label free peptide based assay can be used to characterize cell surface antigen, to study antigen- antibody interactions and obtain understanding of mechanisms of resistance to therapy. Method: The immobilization of Raji cells on the QCM gold electrode surface using RGD tripeptide was electrochemically confirmed (Figure 1). The real-time processes of attachment of Raji cells on the gold electrode and the subsequent binding of Rituximab to the cells were studied using QCM biosensor. The interaction between Rituximab and Raji cells led to the increased resonant frequency shifts (df0) in the studied antibody concentration range from 5 to 250 μg mL-1 following the Langmuir adsorption model (Figure 2). From these observations, the apparent binding constant between a single-layer of Rituximab and Raji cells was calculated to be 1.6×106 M-1 (Figure 3). Control experiments using other therapeutic antibodies (i.e., Trastuzumab and Bevacizumab) and different cells (i.e., T cells and endothelial cells) proved very specific interaction between Rituximab and CD20 antigens on B cells. Calcium and Manganese ions were added to the cell culture and corresponding responses by QCM were monitored. Results: CD20 binding with Rituximab was very specific. This binding decreased the electrochemical activity and stability of the cells, supporting the cell lysis mechanisms of action of Rituximab. We have shown a systematic approach for using QCM technique to quantify the apparent binding constant between Raji cells and Rituximab which can reveal CD20 antigen density. Moreover, increased QCM responses were found in the presence of Ca2+ ions and high concentration Mn2+ ions, supporting the function of CD20 as a calcium ion channel. Microscopic inspection proved that increased Ca2+ ions could promote the Rituximab binding and cell lysis induced by Rituximab, which was not seen with Manganese. Conclusion: CD20 antigen density and interactions of CD20 antigens with respective monoclonal antibodies will help physicians to determine the clinical efficacy and resistance mechanisms to targeted antibodies like Rituximab and Ofatumumab. For the first time, we have established a low cost, highly sensitive, fast, synthetic, QCM assay which could be used as a basis for developing a new generation of affinity-based Immunosensor assays. This real time capability of QCM and its simplicity of operation are highly suitable for multipurpose studies on living cells including cell immobilization, cytotoxicity of drugs, and the cell action mechanisms. Figure 1 Figure 1. Figure 2 Figure 2. Figure 3 Figure 3. Disclosures No relevant conflicts of interest to declare.

We report a rare case of haemorrhagic colitis attributed to dasatinib therapy in a 47-year-old African-American woman who was diagnosed with extramedullary T-lymphoblastic transformation of chronic myeloid leukaemia. The patient received intensive chemotherapy and dasatinib 100 mg/day. After achieving complete cytogenetic and major molecular response after 9 months of therapy, she developed bloody diarrhoea and pancytopenia. Colonoscopy showed inflammation of the descending colon and histopathology revealed patchy increase in intraepithelial lymphocytes. Dasatinib was stopped with prompt resolution of diarrhoea. The current literature suggests that there is an association in a subset of patients on dasatinib between clonal T-cell lymphocytosis in the peripheral blood and developing colitis and pleural effusions. These patients had a good response to dasatinib as did our patient. Our patient illustrates a unique disease presentation along with a rare drug adverse event.

Abstract 4319 Background: CBs are highly variable at diagnosis and during the course of IT in AML patients. Assessing response to IT carries a huge implication on the prognosis of individual patient with AML. Our study investigates whether late clearance of CBs during IT using standard cytarabine + anthracycline regimen is associated with refractory phenotype. Methods: We retrospectively reviewed the chart of 83 AML patients (43 males, 40 females, mean age 61.7) who received standard cytarabine and anthracycline regimen during induction between January, 2000-January, 2011 at William Beaumont Health System. Data collected include complete blood count with blast count during course of induction, and bone marrow response. AML is considered refractory if morphological evaluation, flow cytometry or cytogenetic study was positive in the first bone marrow post induction. Response to IT was assessed according to Cancer and Leukemia Group B (CALGB) criteria as complete remission versus residual leukemia or treatment failure (failing to achieve complete remission). Results: We noted that 57 of 83 patients (68.7%) showed CBs at the time of diagnosis. During the IT, CBs clearance occurred within 7 days (early clearance) in 38 of these 57 patients. The remaining 19 patients had CBs persistent more than 7 days (delayed clearance). The frequency of bone marrow residual disease at count recovery post IT was significant higher in patients with late clearance and those with early clearance (84% vs 42%, p=0.0015). Further analysis of data showed the frequency of bone marrow residual disease was not significantly different between patients with no CBs at the diagnosis and those with early clearance of CBs (38% vs 42%, p=0.8). Conclusion: Adult AML patients with persistent CBs >7 days during IT with standard induction cytarabine and anthracycline regimen are more likely to have induction failure. CBs clearance can be used as an early assessment of response to the IT. Disclosures: No relevant conflicts of interest to declare.

Abstract 3148 Background: VTEs are common complications in association with IT which may cause additional morbidity and mortality in AML patients. However, treating patients with AML is challenging because of the cytopenias due to chemotherapy and the high risk for bleeding during IT. This study investigates frequency, risk factors, and safety of using anticoagulation (AC) therapy for VTEs during IT. Method: We retrospectively reviewed the charts of AML patients who received IT between January, 2000-January, 2011 at William Beaumont Health Systems. Exclusion criteria included a documented personal history of inherited thrombophilia. Data retrieved included the following: patient characteristics, leukemia subtype, cytogenetic risk, location of the VTEs, FLT3 mutations, IT regimen used (cytarabine and anthracycline regimens or hypomethylating agents), AC therapy, bleeding complications, mortality related to AC therapy. All patients who received AC were initially treated with regular intravenous unfractionated heparin or subcutaneous low molecular weight heparin. Patients were subsequently started on oral warfarin during the first 10 days of the initial treatment with a targeted INR of 2.0–3.0. Results: We found 48 of 363 (13.2%) AML patients developed VTEs during IT. Of those patients, 56.3 % were female. The VTEs occurred most frequently in upper extremities (58%) and were catheter-related. Other locations for VTEs included lower extremities (21%), pulmonary embolism (15%), and mesenteric or portal veins (6%). We note that 41 patients (87%) received AC therapy. Of these, three patients (7.3%) had bleeding complications and no AC therapy-related deaths were observed. When the three cytogenetic risk groups were compared, there was no difference in the incidence of VTEs (good vs intermediate vs poor). Patients with FLT 3 mutations, however, had a significant higher incidence of VTEs when compared to patients without FLT3 mutations (55.3% vs 12% p Conclusions: We found that 13% of AML patients developed VTEs during IT, most commonly in upper extremities and were catheter-related. The risk for VTEs was markedly increased in patients with FLT3 mutations. Furthermore, using a cytarabine + anthracycline regimens carried a higher risk for VTEs when compared to regimens using a hypomethylating agents. Finally, using AC therapy during IT is relatively safe and is associated with low risk of bleeding complications. Disclosures: No relevant conflicts of interest to declare.

Abstract 2087 Background: During IT, AML patients may develop PI due to infection, leukostasis, pneumonitis, drug reaction or even acute respiratory distress syndrome. The risk association and the clinical outcome of such PI are poorly characterized in the literature. This study investigates the frequency, radiologic patterns, and outcome of PI during the IT of AML patients. Methods: We retrospectively reviewed 363 cases of AML patients who received IT either cytarabine and anthracycline regimens, or hypomethylating agents between January, 2000-January, 2011 at William Beaumont Health System. Of 363 patients, 120 developed PI during IT, those patients were divided into 2 groups based on distribution of the infiltrate presenting whether localized or diffuse infiltrate. Distribution of the infiltrate was evaluated by dividing the thorax vertically in the midline, then horizontally by two lines originating above and below the hilus resulting in six areas. Localized infiltrate was defined as involvement of 1–3 areas, and diffuse infiltrate was defined as >3 areas were involved. Detected by either Bronchioalveolar lavage culture or sputum culture revealing a pathogen other than coagulase-negative staphylococci or corynebacteria was considered as pathogenic microorganisms. Treatment end points were defined as resolve or persistence of the infiltrate or death. Data on pts characteristics, leukemia subtype, cytogenetic risk, microorganism type, white blood cell count (WBC) at diagnosis, neutrophils count at the time of the infiltrate reported, response to antibiotic and/or antifungal therapy, using respiratory support, mortality rate, were retrieved from the records. Results: Our study involved 120 patients. Of these, 33% developed PI during their IT. This population was 53.3 % female, median age 66 years (range 23–93). We noted that 63 patients (52.5%) had localized infiltrate and 57 patients (47.5%) had diffuse infiltrate. Of the 120 patients, 46 (39.3%) had pathogenic microorganisms. These microorganisms were found to be 50% gram positive, 32% gram negative, 10.8% fungal, and 4.3% anaerobic. All 120 patients received two broad-spectrum antibiotics and/or an antifungal. Of the total number of patients, 58 (48.7%) required intubation and ventilatory support. The repeat computed tomography at the end of the hospital stay (after the treatment) showed resolution of the infiltrate in 67 patients (55.8%). During our study, 46 patients died from PI (38.3 %). Further analysis of the data showed patients with localized PI (when compared to patients with diffuse infiltrate) were more likely to have positive pathogenic microorganisms (68.3% vs 8.8%, p Patients with diffuse infiltrate (when compared to patients with localized infiltrate) were more like to require intubation (78.9% vs 21%, p 100 Bil/L) at diagnosis (54.4% vs 0%, p Conclusions: During IT about one third of the AML patients developed PI. The radiological patterns of PI showed specific etiological and prognostic associations, may guide the clinical decision making processes. Diffuse PI is an unfavorable characteristic with overall dismal outcome. Disclosures: No relevant conflicts of interest to declare.