Association of immune evasion in myeloid sarcomas with disease manifestation and patients' survival.

Introduction: Myeloid sarcomas (MS) comprise rare extramedullary manifestations of myeloid neoplasms with poor patients' outcome. While the clinical relevance of the tumor microenvironment (TME) is well established in many malignancies, there exists limited information in MS. Methods: The expression of the human leukocyte antigen class I (HLA-I) antigens, HLA-I antigen processing and presenting machinery (APM) components and the composition of the TME of 45 MS and paired bone marrow (BM) samples from two independent cohorts were assessed by immunohistochemistry, multispectral imaging, and RNA sequencing (RNAseq). Results: A significant downregulation of the HLA-I heavy chain (HC; 67.5%) and ß2-microglobulin (ß2M; 64.8%), but an upregulation of HLA-G was found in MS compared to BM samples, which was confirmed in a publicly available dataset. Moreover, MS tumors showed a predominantly immune cell excluded TME with decreased numbers of tissue infiltrating lymphocytes (TILs) (9.5%) compared to paired BM (22.9%). RNAseq analysis of a subset of 10 MS patients with preserved and reduced HLA-I HC expression revealed 150 differentially expressed genes and a significantly reduced expression of inflammatory response genes was found in samples with preserved HLA-I expression. Furthermore, low HLA-I expression and low TIL numbers in the TME of MS cases were linked to an inferior patients' outcome. Discussion: This study demonstrated a high prevalence of immune escape strategies in the pathogenesis and extramedullary spread of MS, which was also found in patients without evidence of any BM pathology, which yields the rational for the development of novel individually tailored therapies for MS patients.

Late-stage tumors induce anemia and immunosuppressive extramedullary erythroid progenitor cells.

Impaired immunity in patients with late-stage cancer is not limited to antitumor responses, as demonstrated by poor vaccination protection and high susceptibility to infection1-3. This has been largely attributed to chemotherapy-induced impairment of innate immunity, such as neutropenia2, whereas systemic effects of tumors on hematopoiesis and adoptive immunity remain incompletely understood. Here we observed anemia associated with severe deficiency of CD8+ T cell responses against pathogens in treatment-naive mice bearing large tumors. Specifically, we identify CD45+ erythroid progenitor cells (CD71+TER119+; EPCs) as robust immunosuppressors. CD45+ EPCs, induced by tumor growth-associated extramedullary hematopoiesis, accumulate in the spleen to become a major population, outnumbering regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). The CD45+ EPC transcriptome closely resembles that of MDSCs, and, like MDSCs, reactive oxygen species production is a major mechanism underlying CD45+ EPC-mediated immunosuppression. Similarly, an immunosuppressive CD45+ EPC population was detected in patients with cancer who have anemia. These findings identify a major population of immunosuppressive cells that likely contributes to the impaired T cell responses commonly observed in patients with advanced cancer.

Expression of programmed death ligand 1 is associated with poor prognosis in myeloid sarcoma patients.

Myeloid sarcoma (MS) is a rare condition and is an extramedullary tumour of immature myeloid cells. It is now known that the programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway suppresses the host antitumor responses and that these products are expressed on both tumour cells and tumour-infiltrating cells in various malignancies. However, little is known about the significance of PD-1/PD-L1 expression on tumour cells and tumour microenvironmental cells in MS. To investigate the clinicopathological significance of PD-1/PD-L1 expression in MS, we analyzed 98 patients by immunohistochemistry. Of these, 10.2% of cases had neoplastic tumour cells positive for PD-L1 (nPD-L1+ ). However, the rate of nPD-L1+ was <5% (range: 0.27 to 2.97%). On the other hand, PD-L1 expression on 1 or more of stromal cells in the tumour microenvironment (miPD-L1+ ) was observed in 37.8% of cases. Because all nPD-L1+ cases expressed PD-1 on less than 5% of tumour cells, we compared the miPD-L1+ and miPD-L1- groups. There was a correlation between miPD-L1+ status and the number of PD-1-expressing tumour -infiltrating lymphocytes (PD-1+ TILs; P = .0229). miPD-L1+ was found to be associated with poorer overall survival and progression-free survival (P = .00392, P = .00261, respectively). Multivariate analysis also confirmed miPD-L1+ to be an independent poor prognostic factor. In conclusion, our study indicated that the immunotherapy blocking the PD-1/PD-L1 pathway may improve the clinical outcome of MS.

Effectiveness of a Double-Carbapenem Regimen in a KPC-Producing Klebsiella pneumoniae Infection in an Immunocompromised Patient.

The progressive increase of infections produced by extensively drug-resistant carbapenemase-producing Klebsiella pneumoniae (XDR-CPKP) represents an important threat to public health. Unfortunately, optimal therapeutic options are scarce. Retrospective studies have recommended combined therapy with more than one antibiotic and, more recently, a double-carbapenem regimen has been reported to be an effective alternative therapy. Here, we describe an episode of sepsis in an immunocompromised patient after allogeneic hematopoietic stem cell transplantation, caused by an XDR-CPKP. Several in vitro synergy tests revealed a synergistic effect combining ertapenem and meropenem, which were used as combination therapy achieving clinical and microbiological success.

First case report of acute myeloid sarcoma post renal transplant.

BACKGROUND: Although lymphoproliferative disorders are well-described and known entities post renal transplantation, acute myeloid sarcoma is a rare if ever reported occurrence in this setting. Immunosuppressive therapy is thought to be the main culprit in these cases. CASE REPORT: A 51-year-old man underwent renal transplantation 3.5 years earlier from a living unrelated donor. His posttransplant history was relevant for a road traffic accident after which a rise in the serum creatinine warranted 4 renal biopsies over a period of 7 months. The biopsies showed mainly acute tubular injury with sharp increase of the interstitial fibrosis and tubular atrophy between the first and the last biopsies. The patient was put on hemodialysis for 7 months, after which the allograft started functioning. The patient was followed a routinely, until he re-presented with increased creatinine and was found to have intra- and perirenal masses. Biopsies revealed acute myeloid sarcoma. The patient was started on fludarabine and cytosine arabinoside followed by All-trans retinoic acid and arsenic trioxide. CONCLUSIONS: The patient was disease free on his last positron emission tomography 1 year after the initial diagnosis.

Myeloid sarcoma of the head and neck region.

CONTEXT: Myeloid sarcoma of the head and neck region can pose diagnostic challenges because of the low frequency of myeloid sarcoma and the potential for tumors of almost any lineage to occur in the head and neck. OBJECTIVE: To study the clinicopathologic and immunohistochemical characteristics of myeloid sarcoma in the head and neck region and to review the differential diagnosis. DESIGN: We searched for cases of myeloid sarcoma involving the head and neck region for a 24-year period at our institution. The medical records and pathology slides were reviewed. Additional immunohistochemical stains were performed. RESULTS: We identified 17 patients, age 17 to 85 years. Most tumors involved the oral cavity. Myeloid sarcoma was the initial diagnosis in 9 patients (53%); the remaining 8 patients (47%) had a history of bone marrow disease. Immunohistochemical analysis using antibodies specific for lysozyme, CD43, and CD68 were highly sensitive for diagnosis but were not specific. By contrast, assessment for myeloperoxidase in this study was less sensitive but more specific. We also used antibodies specific for CD11c and CD33 in a subset of cases, and these reagents seem helpful as well. CONCLUSIONS: The clinical presentation of myeloid sarcoma involving the head and neck, particularly the mouth, is often nonspecific, and a high degree of suspicion for the possibility of myeloid sarcoma is needed. Immunohistochemistry is very helpful for establishing the diagnosis.

Identification of a new allele HLA-B*40:213 by polymerase chain reaction sequence based typing in a Chinese patient suffering from chloroma.

This new HLA-B allele differs from the closest allele B*40:01:01 by two nucleotide changes at codons 102 and 267.

Clinical significance of granulocytic sarcoma in adult patients with acute myeloid leukemia.

To investigate the clinical significance of granulocytic sarcoma (GS) in adults with acute myeloid leukemia (AML), 434 consecutive patients with AML were analyzed retrospectively. Forty-five patients (10.4%) with GS at diagnosis were younger (P < 0.001), presented with higher white blood cell counts (P = 0.03) and were more likely to conform to French-American-British M4 (P = 0.001) and M5 (P = 0.045) classifications than those without GS. In contrast, no significant difference in frequency of cytogenetic abnormalities was found between the GS and non-GS groups. Treatment outcomes in 260 patients (40 with GS) who underwent intensive chemotherapy, excluding patients with acute promyelocytic leukemia, were investigated. Complete remission rates did not differ significantly between the GS and non-GS groups (75.0% vs 79.1%; P = 0.192, respectively) or the 5-year overall survival (OS) rates (39.9% vs 38.7%; P = 0.749, respectively). However, the GS group had a significantly higher relapse rate than the non-GS group (74.2% vs 55.3%; P = 0.048) and a significantly lower 5-year disease-free survival rate (8.2% vs 25.7%, respectively; P = 0.005). When considered together with the results of multivariate analysis, which identified the presence of GS as an independent predictor for disease-free survival time, these findings indicate that GS might identify a high-risk subset of patients with AML.

Clonal evolution including partial loss of human leukocyte antigen genes favoring extramedullary acute myeloid leukemia relapse after matched related allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Relapse of acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (HSCT) leaves few therapeutic options, and mechanisms of immune escape of recurring leukemic cells remain poorly understood. Recently, acquired loss of mismatched human leukocyte antigen (HLA) was demonstrated in patients with AML undergoing haploidentical allogeneic HSCT and was suggested not to occur in HLA-matched HSCT. We hypothesized that this mechanism applies to extramedullary AML relapse which occurs frequently after allogeneic HSCT and might also not be restricted to haploidentical HSCT. METHODS: DNA from extramedullary AML relapse after HSCT was compared with bone marrow at diagnosis with array comparative genomic hybridization to investigate relapse-specific genomic aberrations in relapsing AML after allogeneic HSCT. Formalin-fixed, paraffin-embedded tissues from the same points of time were assessed for HLA, major histocompatibility complex class I chain-related gene A, and TAP2 immunohistochemistry staining to assess cell surface expression of deleted loci encoded on chromosome 6p. RESULTS: Array comparative genomic hybridization revealed a partial loss of chromosome 6p in extramedullary myeloid sarcoma relapse of AML after sustained complete remission was achieved through matched related allogeneic HSCT. Among others, a deleted region 6p21.32-p21.33, which included several HLA class I genes, was detected. CONCLUSIONS: These results suggest that the loss of HLA class I haplotype also occurs in AML relapse after HLA-matched related HSCT. Partial loss of several HLA class I genes and subsequent reduced presentation of minor histocompatibility antigens and reduced ligation of activating natural killer-cell receptors may explain the loss of graft-versus-leukemia response and extramedullary AML relapse in tissue with reduced immunologic surveillance.

Multiple extramedullary relapses without bone marrow involvement after second allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia.

EMR without BM involvement after allogeneic HSCT is extremely rare, especially in children; only a few cases have been reported. A two-yr-old boy was diagnosed with AML (M4) and underwent allogeneic HSCT in first complete remission with BM from HLA-matched unrelated donor without GVHD. Four yr later, he had a BM relapse and after induction and consolidation chemotherapy, he received a second HSCT from an unrelated donor using peripheral blood stem cells. His second post-transplant course was complicated by extensive chronic GVHD involving the skin, oral cavity, and lungs, which was treated with tacrolimus and corticosteroid. Two yr later, he noticed a mild swelling in the right cheek area. The BM showed a complete remission marrow and a soft tissue biopsy was compatible with granulocytic sarcoma. PET-CT showed multifocal bone involvements. He received chemotherapy, and the chloromas decreased in size. We report a case of diffuse EMR of AML without BM involvement after a second allogeneic HSCT.

Unusual presentation of myeloid sarcoma in a case of acute promyelocytic leukemia with a cryptic PML-RARA rearrangement involving multiple sites including the atrium.

Myeloid sarcoma is an extramedullary tumor mass composed of immature myeloid cells. Myeloid sarcoma may develop de novo, concurrently with acute myeloid leukemia (AML), or at relapse. Although myeloid sarcoma can occur at any site, myeloid sarcoma involving the heart is extremely rare. Reported here is the case of a 30-year-old man, initially diagnosed with acute promyelocytic leukemia (APL) in bone marrow, who presented later with myeloid sarcoma at multiple anatomical sites (left scapula, thoracic vertebra, right atrium, and supraclavicular mass) in multiple relapses. Conventional cytogenetic studies performed on the atrial sample revealed a karyotype with additional material on the short arm of chromosome 7, at 7p22. Fluorescence in situ hybridization studies confirmed a cryptic PML-RARA fusion on the short arm of chromosome 7, as well as a second fusion on one copy of chromosome 15. With the fourth and latest relapse, molecular cytogenetic studies performed on interphase nuclei of the myeloid sarcoma specimen (a supraclavicular mass) showed evidence of six related abnormal clones with a PML-RARA fusion, suggesting clonal evolution. This represents a rare case of APL with a cryptic PML-RARA rearrangement presenting as myeloid sarcoma at multiple relapses and involving multiple anatomical sites, including cardiac atrium.

[Extramedullary infiltration of acute monocytic leukemia/monoblastic sarcoma: a clinicopathologic and immunophenotype analysis of 5 cases].

OBJECTIVE: To study the clinicopathologic features, diagnosis and differential diagnosis of extramedullary infiltration of acute monocytic leukemia/monoblastic sarcoma. METHODS: Five cases of extramedullary infiltration of acute monocytic leukemia/monoblastic sarcoma were selected from 102 cases of myeloid sarcoma diagnosed during the period from 1990 to 2006. The clinicopathologic findings and followup data were retrospectively analyzed. Immunohistochemical study was also carried out with SP method. RESULTS: Among the 5 cases studied, 3 were males and 2 were females, including 2 children and 3 adults. Generalized lymphadenopathy was found in 4 patients and skin lesions were observed in 2 patients. The tumor cells in all cases were positive for CD68 (KP1), CD68 (PGM1), lysozyme and CD45. They were negative for MPO, CD15, CD163, TdT, CD117, T and B cell markers. The Ki-67 index ranged from 40% to 80%. Follow-up data were available in all the 5 patients. Four of the 5 patients died of the disease, with the average survival time being 6.25 months. CONCLUSIONS: Monoblastic sarcoma is a rare disease with poor prognosis. It is almost impossible to distinguish monoblastic sarcoma from granulocytic sarcoma and other types of small round cell tumors on the basis of morphologic examination alone. Immunohistochemistry is mandatory for a correct diagnosis.

CD33 detection by immunohistochemistry in paraffin-embedded tissues: a new antibody shows excellent specificity and sensitivity for cells of myelomonocytic lineage.

A new monoclonal antibody to CD33 that reacts in paraffin-embedded tissue samples was evaluated. The expected reactivity in granulocytic and monocytic cells was found in a tissue microarray composed of multiple tissue sites. There was no unexpected reactivity found in a wide variety of hematolymphoid and nonhematolymphoid disorders. In cases of acute leukemia, the CD33 antibody showed equivalent results by immunohistochemical analysis compared with flow cytometric analysis. The CD33 antibody was also found to be a useful marker in the workup of myeloid sarcomas. This anti-CD33 antibody will be a useful marker in the workup of acute leukemias and myeloid sarcomas on paraffin-embedded tissue samples.

Precursor B lymphoblastic leukemia 32 months after local therapy for a primary extramedullary myeloid cell tumor.

A primary extramedullary myeloid cell tumor (pEMT) of an inguinal lymph node was completely excised without subsequent anti-tumor therapy in a 6-year-old child. Clinical observation and monitoring of blood and bone marrow (BM) did not reveal any pathologic results before 32 months, when a precursor B lymphoblastic leukemia was diagnosed. Identical T-cell receptor gamma rearrangement in nodal pEMT and in precursor B lymphoblastic leukemia in BM indicates a clonal relationship of these two tumors.