The acute monocytic leukemias: multidisciplinary studies in 45 patients

LILRB4 ITIMs mediate the T cell suppression and infiltration of acute myeloid leukemia cells

We recently demonstrated that leukocyte Ig-like receptor 4 (LILRB4) expressed by monocytic acute myeloid leukemia (AML) cells mediates T-cell inhibition and leukemia cell infiltration via its intracellular domain. The cytoplasmic domain of LILRB4 contains three immunoreceptor tyrosine-based inhibitory motifs (ITIMs); the tyrosines at positions 360, 412, and 442 are phosphorylation sites. Here, we analyzed how the ITIMs of LILRB4 in AML cells mediate its function. Our in vitro and in vivo data show that Y₄₁₂ and Y₄₄₂, but not Y₃₆₀, of LILRB4 are required for T-cell inhibition, and all three ITIMs are needed for leukemia cell infiltration. We constructed chimeric proteins containing the extracellular domain of LILRB4 and the intracellular domain of LILRB1 and vice versa. The intracellular domain of LILRB4, but not that of LILRB1, mediates T-cell suppression and AML cell migration. Our studies thus defined the unique signaling roles of LILRB4 ITIMs in AML cells.

Disrupting LILRB4/APOE Interaction by an Efficacious Humanized Antibody Reverses T-cell Suppression and Blocks AML Development

Therapeutic strategies are urgently needed for patients with acute myeloid leukemia (AML). Leukocyte immunoglobulin-like receptor B4 (LILRB4), which suppresses T-cell activation and supports tissue infiltration of AML cells, represents an attractive drug target for anti-AML therapeutics. Here, we report the identification and development of an LILRB4-specific humanized mAb that blocks LILRB4 activation. This mAb, h128-3, showed potent activity in blocking the development of monocytic AML in various models including patient-derived xenograft mice and syngeneic immunocompetent AML mice. MAb h128-3 enhanced the anti-AML efficacy of chemotherapy treatment by stimulating mobilization of leukemia cells. Mechanistic studies revealed four concordant modes of action for the anti-AML activity of h128-3: (i) reversal of T-cell suppression, (ii) inhibition of monocytic AML cell tissue infiltration, (iii) antibody-dependent cellular cytotoxicity, and (iv) antibody-dependent cellular phagocytosis. Therefore, targeting LILRB4 with antibody represents an effective therapeutic strategy for treating monocytic AML.

LILRB4 signalling in leukaemia cells mediates T cell suppression and tumour infiltration

Immune checkpoint blockade therapy has been successful in treating some types of cancer but has not shown clinical benefits for treating leukaemia¹. This result suggests that leukaemia uses unique mechanisms to evade this therapy. Certain immune inhibitory receptors that are expressed by normal immune cells are also present on leukaemia cells. Whether these receptors can initiate immune-related primary signalling in tumour cells remains unknown. Here we use mouse models and human cells to show that LILRB4, an immunoreceptor tyrosine-based inhibition motif-containing receptor and a marker of monocytic leukaemia, supports tumour cell infiltration into tissues and suppresses T cell activity via a signalling pathway that involves APOE, LILRB4, SHP-2, uPAR and ARG1 in acute myeloid leukaemia (AML) cells. Deletion of LILRB4 or the use of antibodies to block LILRB4 signalling impeded AML development. Thus, LILRB4 orchestrates tumour invasion pathways in monocytic leukaemia cells by creating an immunosuppressive microenvironment. LILRB4 represents a compelling target for the treatment of monocytic AML.

Cutaneous herald: leukaemia cutis as presenting manifestation of relapse in acute promyelocytic leukaemia

Leukaemia cutis or cutaneous infiltration of neoplastic myeloid or lymphoid cells is usually seen in the acute myelomonocytic and acute monocytic variants of acute myeloid leukaemia. Here, we report a case of acute promyelocytic leukaemia who achieved remission, presenting with skin lesions, the biopsy of which revealed leukaemia cutis, heralding the relapse of the disease. After establishing the diagnosis with bone marrow analysis, the patient was started on daunorubicin chemotherapy along with arsenic trioxide and all-trans retinoic acid. Afterwards, the skin lesions resolved, and the patient is planned for consolidation with bone marrow transplantation.

Clinical activity of sequential flavopiridol, cytosine arabinoside, and mitoxantrone for adults with newly diagnosed, poor-risk acute myelogenous leukemia

Flavopiridol, a cyclin-dependent kinase inhibitor, is cytotoxic to leukemic blasts. In a Phase II study, flavopiridol 50 mg/m(2) was given by 1-h infusion daily x 3 beginning day 1 followed by 2 g/m(2)/72 h ara-C beginning day 6 and 40 mg/m(2) mitoxantrone on day 9 (FLAM) to 45 adults with newly diagnosed acute myelogenous leukemia (AML) with multiple poor-risk features. Thirty patients (67%) achieved complete remission (CR) and 4 (9%) died. Twelve (40%) received myeloablative allogeneic bone marrow transplant (BMT) in first CR. Median OS and DFS are not reached (67% alive 12.5-31 months, 58% in CR 11.4-30 months), with median follow-up 22 months. Sixteen received FLAM in CR, with median OS and DFS 9 and 13.1 months, and 36% alive at 21-31 months. Short OS and DFS correlated with adverse cytogenetics, regardless of age or treatment in CR. The addition of allogeneic BMT in CR translates into long OS and DFS in the majority of eligible patients.

Spectrum of clinical presentation, treatment and prognosis in a series of eight patients with leukaemia cutis

All types of leukaemia can disseminate to the skin, producing cutaneous deposits known as leukaemia cutis (LC). We undertook a retrospective study to review the clinical presentations, treatment and outcome of eight patients with LC managed in our department over a period of 12 years. The clinical phenotype varied, with erythematous papules and nodules occurring with greatest frequency. Infiltrated haemorrhagic plaques and perifollicular acneiform papules were also seen. Although patients were treated aggressively for their underlying leukaemia, and received therapy directed towards LC, they tended to be refractory to treatment and the diagnosis was generally associated with a poor prognosis. The exception was a patient with chronic lymphocytic leukaemia, who survived 3 years after developing LC.

Isolated myelosarcoma in children--update and review

Primary myelosarcomas, also called leukemia cutis, granulocytic sarcomas or chloromas, are rare extramedullary manifestations of acute myeloid leukemia (AML) which precede bone marrow involvement. Skin infiltration was the most frequent localization associated with a myelomonocytic differentiation. Although first remission was achieved by most children, risk of relapse seemed to be increased. This might be caused by the specific biology of myelosarcomas, but also may be the result of delayed or reduced treatment. During the AML-BFM-studies 87/93/98 (11/1987-7/2000) 37 children with isolated myelosarcomas were diagnosed. Eighteen of the 37 patients survived with a 5-year overall survival estimation of 0.54+/-0.09 compared to 0.59+/-0.02; p(log rank) = 0.94. However, reduced or delayed treatment in 17 children led to an increased relapse rate of 71% compared to 35% in children treated soon after diagnosis. The 5-year overall survival in these patients was 0.41+/-0.11. According to our experience and review of the literature, an early diagnostic workup is needed in children with unusual skin lesions or tumors, considering myelosarcoma as primary manifestation of AML. Intensive AML-specific chemotherapy is generally recommended soon after diagnosis.

Leukemia cutis in a patient with chronic neutrophilic leukemia

Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative disorder. Less than 50 cases have been reported. We report the first case of CNL with an associated leukemia cutis. CNL was diagnosed in a 74-year-old white woman in 1998, based on neutrophilic infiltration of the bone marrow and absence of the Philadelphia chromosome. The patient presented to the dermatology service in August 1998 with a 2-week history of a pruritic eruption on the arms, hands, and legs. Physical examination revealed red to violaceous plaques on both thighs and knees, in addition to purpuric patches and plaques on the dorsal hands, arms, and legs. Leukemia cutis was demonstrated on biopsy specimens of several lesional sites. The eruption progressed, despite treatment with topical and systemic corticosteroids. Treatment with systemic chemotherapy did affect partial resolution of the eruption, with parallel decreases in bone pain and white blood cell count, but the disease progressed and the patient ultimately died 5 months after her initial skin findings. Only one other case of CNL with dermatologic manifestations has been reported, CNL associated with a reactional neutrophilic dermatosis. Comparison to and differentiation from this case is discussed. The importance of distinguishing the specific infiltrates of leukemia from the nonspecific infiltrates of reactional dermatoses, such as Sweet's syndrome, is illustrated.

Plasminogen activation in human acute leukaemias

Plasminogen activation is implicated in solid tumour growth, invasion and metatastic spread. However, little is known about its role in leukaemia. We investigated the production by leukaemic cells of plasminogen activators [urokinase (uPA) and tissue-type PA (tPA)], cell surface receptor for uPA (uPAR) and PA inhibitors (PAI-1 and PAI-2). Leukaemic cells from 37 patients [26 with acute myeloid leukaemia (AML) and 11 with acute lymphoid leukaemia (ALL)] were analysed for mRNA content and enzymatic activities. High levels of uPA mRNA were found in M1, M2, M3 and M4-M5 AMLs, whereas tPA mRNA was not detected in any of the analysed cases. uPAR mRNA was confined to subtypes M4-M5. PAI-1 mRNA was detected in M3 and M4-M5. PAI-2 mRNA was found predominantly in M2 and M4-M5. SDS-PAGE/zymography analyses of cell extracts and supernatants after 24 and 48 h of culture confirmed the production of active uPA by AML cells (mainly M4-M5). but not by ALL. The finding of uPA, uPAR, PAI-1 and PAI-2 synthesized by leukaemic cells suggests that plasminogen activation may contribute to the invasive behaviour of these cells, the fibrinolytic imbalance observed in leukaemic patients and the differentiation and proliferation of M4-M5 by interaction of uPA with uPAR.

Infantile acute monocytic leukemia with tumor formation in the skin expressing adhesion molecules as seen by electronmicroscopy

We report a case of infantile acute monocytic leukemia associated with solid tumors in the skin. Light microscopy showed that the tumor cells were mainly spindle-shaped and arranged in tandem. Immunohistochemical staining showed that fibronectin was detected in the extracellular matrix (and partially on the surface of tumor cells), integrin alpha 5 beta 1 on the cell surface, and vinculin and actin were detected in the cytoplasm of the tumor cells. Electron microscopy showed that the tumor cells had perpendicular transmembranous fibrils and closely situated collections of cytoplasmic microfilaments beneath the cell membrane suggesting fibronexus-like structures. We conclude that the expression of fibronectin, integrin alpha 5 beta 1, vinculin, cytoplasmic actin and fibronexus-like structure in leukemic cells indicate these cells possess an adhesive function. The mechanism of formation of the extramedullary solid tumors in this patients involved these adhesion molecules of the tumor cells.

Leukemia cutis in acute promyelocytic leukemia: report of three cases after treatment with all-trans retinoic acid

Acute promyelocytic leukemia (APL) is a distinct form of acute myelogenous leukemia characterized by an abundant number of abnormal progranulocytes, a severe coagulopathy and a distinct chromosomal abnormality t(15;17). Recently all-trans retinoic acid (ATRA) has been shown to induce complete remissions in APL. We report three patients with APL treated with ATRA, who at the time of relapse had leukemic infiltration of the skin (leukemia cutis), a manifestation which we had not seen previously in over 60 patients with APL treated with chemotherapy alone and has only rarely been reported in the literature. We hypothesize that ATRA treatment for APL may be associated with an increased incidence of extramedullary disease at the time of relapse, which may be mediated through an increase in expression of adhesion molecules. Careful observation for extramedullary relapses in patients treated with ATRA for APL will be needed to confirm our observation.

Testicular relapse in adult acute myelogenous leukemia

Testicular relapse (TR) in adult acute myelogenous leukemia (AML) is uncommon, occurring in only 1-2% of patients with bone marrow relapse. TR in the absence of systemic relapse has been reported previously in 2 adults and 12 children, of which 67% were monocytic variants of AML. This article presents the case of a 29-year-old man with AML that relapsed in his testicle without evidence of bone marrow relapse. This patient and the two previously mentioned adults experienced bone marrow relapse within 2 months and died within 7 months of their TR. TR in adult myelogenous leukemia should be considered a harbinger of systemic relapse and suggests a need for aggressive local and systemic therapy.

Leukemic dermal infiltrates at permanent indwelling central venous catheter insertion sites

Three cases of leukemic dermal infiltrates at permanent indwelling central venous catheter insertion sites in patients with acute myelogenous leukemia are reported. Two patients had a localized soft tissue mass at the previous permanent indwelling catheter insertion site as the sole initial manifestation of relapse after achieving complete remission and undergoing bone marrow transplantation. The third patient had catheter tunnel sepsis preceding leukemic dermal infiltration. A review of the English language literature showed that this condition is rare with no specific pathogenetic mechanisms identified. Patients with unresolved catheter tunnel infections in acute leukemia and persistent chest wall masses that appear after a previous permanent indwelling catheter should have a biopsy done and be treated promptly.

Leukemia cutis in acute myelomonocytic leukemia: infiltration to minor traumas and scars

We describe a patient with acute myelomonocytic leukemia who demonstrated leukemic cell infiltration to scratched wounds and scars from trauma. A 65-year-old Japanese woman developed low grade fever, headache and exanthema. Hematology testing disclosed leukocytosis of 95,600/mm3 with 65% monocytes and 9% blast cells. Infiltrated erythema and nodules were disseminated over most of her body. Moreover, linear scratched wounds and traumatic scars were indurated. Skin biopsy showed dense atypical mononuclear cell infiltration with monocytic characteristics. We discuss the possible reasons for the infiltration of leukemia cells into the wounds and scars from trauma.

Cutaneous involvement as a presenting feature of monocytic leukemia: morphological and immunohistochemical studies

The clinical and pathological findings in a patient with monocytic aleukemic leukemia presenting initially as multiple monoblastic tumors of the skin is described. The patient was a 35-year-old Japanese woman, who had first noticed multiple, asymptomatic, reddish-brown papules on her trunk. Asymptomatic enlargements of several lymph nodes were present in the bilateral cervical and axillary areas. There was no hepatosplenomegaly, sternal tenderness, bruising, or bleeding. The skin and lymph node biopsies were originally interpreted as malignant lymphoma. The diagnosis of acute monocytic leukemia was established when bone marrow involvement was detected. Immunohistochemical observation of the skin eruptions revealed the following: Positive staining with lysozyme was noted in almost half of the infiltrating atypical cells. Most of the infiltrating cells reacted positively with antisera to Leu-M5 and some of them reacted to Leu-M1. The helper T cell antibody, Leu-3a+3b, showed weak positive staining of most infiltrating cells. However, there were no reactions with antisera to Leu-6, Leu-7, Leu-14, CALLA, OKT 6, OKT 8, OKT 16, OKB 19, OKM 14, beta F1, or delta TCS1. OKM 5-positive keratinocytes were observed in some parts of the upper epidermis, although no OKM 5 expression could be detected on any tumor cells. Cytochemistry, immunohistochemistry, and electron microscopy can aid in the diagnosis of monocytic leukemia. This case illustrates the importance of using an expanded panel of monoclonal antisera in certain hematopoietic tumors.

Acute monocytic leukaemia in adults: treatment and prognosis in 99 cases

Acute monocytic leukaemia (AMoL) was diagnosed in 99 adults, aged 18-85 years (median 56) over a period of 10 years. Sixty-five patients had extramedullary leukaemia, 13 had clinical signs of leucostasis, and 19 had disseminated intravascular coagulation. Four patients died before receiving any treatment, 12 received supportive care only and seven received low dose AraC, but only one of them responded. Seventy-six patients received intensive chemotherapy, 72 of them with an anthracycline-AraC based regimen, with or without an epipodophyllotoxin. Fifteen patients died within 7 d of diagnosis, due to leucostasis in nine cases. Predictive factors for early death were advanced age, leucostasis, fever, leucocytes above 100 x 10(9)/l, and renal failure. Fifty (66%) of the patients treated intensively reached complete remission (CR). Advanced age, fever and complex cytogenetic abnormalities were significantly associated with a lower CR rate. Median actuarial disease-free survival was 20.5 months, and was not significantly influenced by any pretreatment parameter. Five patients relapsed in the central nervous system (CNS), in spite of systematic CNS prophylaxis. No differences in CR rates were seen with the three anthracycline-AraC based regimens used in our patients. Significant differences in disease-free survival were seen between them, however, suggesting that early consolidation chemotherapy and, more hypothetically, epipodophyllotoxin agents could prolong remission duration in AMoL.

Uncommon leukemias: implications for clinical practice

The nursing management of patients with rare leukemias involves physiologic, psychologic, and ethical activities. Specific nursing interventions aimed at supporting bone marrow suppressed patients have been addressed in the literature and other reports in this issue. The potential for oncologic emergencies in these rare leukemias is great. These include disseminated intravascular coagulation (DIC), cerebral and pulmonary leukostasis, sepsis, and acute renal failure. Recognition that patients are at risk for these acute events prepares nurses for their assessment, diagnosis, and plans of care. Eleven high-incidence problems for cancer patients have been described, and all can be applied to these patients. Emotionally, patients and their families rely on nurses to assist them in coping with a new diagnosis of cancer, and/or dealing with the chronic nature of their disease. Open communication, firmly based on a thorough knowledge of the particular disease and treatment, will promote trust and a sense of comfort as the patient begins treatment. Finally, it is important for all nurses caring for cancer patients to identify their personal feelings and biases. In the current environment where clinical investigation is a part of everyday care, the nurse must be comfortable with the research process and the participation of human subjects in clinical trials. Nurses play a role in the development of clinical trials and the process of informed consent, and in the management of patients involved in clinical trials. Over the last 5 years, we have witnessed a dramatic increase in the number of therapies available for one particular rare leukemia (hairy cell leukemia). This has resulted in significant improvements in patient outcomes.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic and prognostic factors in acute monocytic leukaemia: an analysis of 51 cases

Diagnostic features (cytochemistry, immunophenotyping and serum biochemistry) were examined in 51 cases of acute monocytic leukaemia (AMoL). Peroxidase, Sudan black B and alpha naphthyl acetate esterase (ANAE) cytochemical reactions were unrelated to morphological (FAB groups M5a and M5b) or immunological subtype. ANAE cytochemistry, however, indicated that AMoL cases could be subdivided into those with typical (M-type) reactions and those with insignificant staining or monocytic ANAE isoenzymes (defined by IEF). All cases were phenotypically CD13/CD33 positive and, with one exception, had greater than 30% HLA-DR positive cells. Membrane CD14 expression was insignificant or variable in 33% of M5a cases in contrast to 23/24 M5b cases which showed high proportions of CD14-staining cells with at least two monoclonal antibodies. Serum lysozyme, LDH and beta-2 microglobulin (beta 2m) were increased in 88%, 68% and 81% of cases respectively but, with the exception of statistically higher lysozyme levels in CD14+ cases, were unrelated to the morphological, cytochemical or immunological diagnostic subgroups. Clinical and diagnostic features were also examined as possible prognostic indicators. The morphological, cytochemical and immunological subgroups of AMoL were not found to be of prognostic relevance but age (P = 0.004), renal failure (P = 0.005) and serum beta 2m levels (P = 0.002) were related to patient survival. Moreover, renal failure and serum beta 2m remained significant (P = 0.012 respectively) when age was taken into account and were shown to be independent prognostic variables.

The production of myeloid blood cells and their regulation during health and disease

The regulation of myelopoiesis in vivo most likely entails a complex set of interactions between cell-derived biomolecules and their target cells: hematopoietic stem and progenitor cells and accessory cells. Stimulating and suppressing factors have been characterized through in vitro studies, and their mechanisms of action in vitro and in vivo have begun to be elucidated. Among those factors being studied are the hematopoietic colony-stimulating factors (CSF): interleukin-3 (multi-CSF), granulocyte-macrophage-CSF, granulocyte-CSF, and macrophage-CSF; other molecules include erythropoietin, B-cell-stimulating factor-1, interleukin-1, interleukin-2, prostaglandin E, leukotrienes, acidic ferritins, lactoferrin, transferrin, the interferons-gamma, -alpha, and -beta, and the tumor necrosis factors-alpha and -beta (lymphotoxin). These factors interact to modulate blood cell production in vitro and in vivo. The proposed review characterizes these biomolecules biochemically and functionally, including receptor-ligand interactions and the secondary messengers within the cell which mediate their functional activity. The production and action of the molecules are described under conditions of hematopoietic disorders, as well as under normal conditions. Studies in vitro are correlated with studies in vivo using animal models to give an overall view of what is known about these molecules and their relevance physiologically and pathologically.

Central nervous system involvement in acute nonlymphocytic leukemia. A prospective study of adults in remission

To identify adults with acute nonlymphocytic leukemia at risk for the development of central nervous system involvement, we performed periodic cerebrospinal fluid examinations on patients in remission. Among 58 consecutive patients monitored during first remission, central nervous system leukemia developed in nine (16 percent). Four patients, including one who was symptomatic, had central nervous system leukemia detected simultaneously with marrow relapse. Five additional patients were asymptomatic and continue to have bone marrow remission. Following central nervous system and systemic treatment, two of these five patients have never had relapse, and three had relapse in the bone marrow five, 10, and 21 months later. Factors at diagnosis associated with the subsequent development of central nervous system leukemia were elevated leukocyte count, serum lysozyme and lactate dehydrogenase, extramedullary infiltration including splenomegaly, and monocytic (FAB M4 or M5a) morphology. In six of 17 patients (35 percent) with monocytic morphology, central nervous system leukemia developed compared with only three of 41 patients (7 percent) with other subtypes (p = 0.02). Discriminant analysis identified leukocyte count, splenomegaly, and M4 or M5a morphology as the most important risk factors and led to a mathematical formula that correctly identified 90 percent of the patients. Although the risk of central nervous system leukemia in adults with acute nonlymphocytic leukemia is too low to justify routine prophylaxis, those patients recognized to be at a greater risk should receive prophylaxis or be monitored closely with periodic lumbar punctures.

Isolated leukemia cutis--a case report

A 67-year-old woman with acute myelomonocytic leukemia had a clinical course characterized by the initial appearance of leukemia cutis without bone marrow involvement. When marrow involvement subsequently occurred, induction chemotherapy cleared all manifestations of the illness. Shortly thereafter, while blood and bone marrow remained in remission, the skin lesions reappeared. The introduction of 6-thioguanine, as part of the maintenance treatment protocol, resulted in the rapid and permanent disappearance of the leukemic skin infiltrates.

Interleukin-1 producing ability of leukaemia cells and its relationship to morphological diagnosis

Interleukin-1 (IL-1) is a low molecular weight polypeptide produced by monocyte-macrophage lineage cells. IL-1 production by primary-cultured leukaemic cells of several FAB subtypes was estimated and compared with in vitro and in vivo lysozyme production. The results indicate that IL-1 production by monocytic leukaemia cells (M4 and M5) is significantly higher than that of myelocytic leukaemia cells (M1, M2 and M3). On the other hand, the serum lysozyme level was not correlated with the FAB subtypes and in vitro lysozyme production by monocytic leukaemia cells was higher than that of myelocytic leukaemia cells, but the M2 subtype was indistinguishable from monocytic leukaemia cells solely on the basis of lysozyme production. We concluded that measurement of IL-1 production by leukaemic cells, as a marker of monocytic leukaemias, was convenient and reliable, and might be useful for the diagnosis of morphologically or cytochemically atypical cases.

Acute leukemia with mediastinal mass, lymphadenopathy, and monocytic precursor cells

Cell marker analysis with monoclonal antibodies (MoAb) as well as differentiation studies with the chemical inducer TPA were used to identify a population of apparently lymphoid cells as monocytic precursor cells in a patient with acute leukemia. The initial manifestation of the disease with mediastinal mass and lymphadenopathy was followed by the appearance of small lymphocyte-like blast cells in bone marrow (BM) and peripheral blood (PB). Although a lymph node biopsy revealed an infiltration with monoblasts, the leukemic cells in BM and PB were not classifiable. However, when the patient relapsed after chemotherapy with large monoblasts and again with morphologically lymphoid blast cells, the latter could be classified by treatment with TPA. After incubation with the inducer (12-48 hr) the cells became positive with the MoAB VIM-D5, showed a strong reaction with alpha-naphthyl-acetate-esterase and developed macrophage like morphology, as well as phagocytic properties. During the terminal phase of the disease, small, lymphocyte-like blast cells predominated. These cells could be classified by a panel of MoABs. They expressed myeloid determinants (VIM-D5, VIM-2, MY 9, VIM-12, VIM-13) but showed no reactivity with MoABs specific for lymphocytic cells.

Serum enzyme concentrations in untreated acute myeloid leukaemia

Serum concentrations of lactate dehydrogenase (LDH), alpha-hydroxybutyrate dehydrogenase (HBD), phosphohexose isomerase (PHI), leucine aminopeptidase (LAP), beta-glucuronidase (beta-gluc) and angiotensin-converting enzyme (ACE), were measured in 107 cases of untreated acute myeloid leukaemia which were classified by morphological, immunological and cytochemical criteria. The results show that serum LDH was increased in most cases, irrespective of leukaemic subtype, serum PHI and LAP were significantly higher in monocytic variants and serum beta-gluc and ACE levels were generally within normal limits. In addition, significant (p less than 0.05) relationships were found between serum LDH, PHI, LAP and beta-gluc concentrations and the numbers of circulating leucocytes.

Dermal monocytic sarcoma/monoblastic tumour: report of two cases of acute monocytic leukemia with initial dermal manifestations only

The clinical and pathological findings in 2 patients with acute monocytic leukemia (AMOL) presenting initially as multiple monoblastic tumours of the skin (monocytic sarcoma) were reviewed. The skin biopsies were originally interpreted as malignant lymphoma and the diagnosis of AMOL was established when overt bone marrow and/or peripheral blood involvement was detected. The time interval from initial skin biopsy to either blood or bone marrow involvement by AMOL was 2 and 18 mth. After diagnosis of extracutaneous dissemination, survival was less than 1 mth. Cytochemistry, immunohistochemistry and electron microscopy can aid in the diagnosis of a monocytic sarcoma. Generally, the most practical way to confirm the diagnosis, in everyday practice, on fixed paraffin-embedded tissues is the demonstration of alpha-1-antitrypsin (A1AT) and/or lysozyme by the immunoperoxidase technique.

Cytogenetic findings in acute monocytic leukemia in a renal allograft recipient

Chromosome analysis of bone marrow cells from a patient with acute monocytic leukemia, who had had a renal transplant followed by immunosuppressive treatment 45 months prior to the onset of leukemia, showed an unusual karyotype: 48,XX,+8,+8, t(1q12----pter::11q12----qter), t(4p12----qter::6p11----pter),t(7p22----qter::12q23 ----qter?), t(1q11----qter::17p11----11qter).

Cytochemical and immunological characteristics of acute monocytic leukaemia

Immunological and cytochemical findings are presented from 12 cases of morphologically unequivocal acute monocytic leukaemia (AMoL). The results indicate considerable heterogeneity and three main non-morphological subgroups were identified. The blast cells from half the patients were positive for the presence of both cytoplasmic alpha naphthyl acetate esterase (ANAE) and monocyte-associated membrane determinants whereas the cells from three cases lacked detectable monocytic antigens despite the presence of strong cytochemical ANAE activity. A further three cases expressed monocytic antigens but were cytochemically unreactive for ANAE. These cytochemical results, which were extended by electrophoretic studies of ANAE isoenzymes, suggest that the absence of significant cytoplasmic ANAE activity does not preclude the diagnosis of AMoL and that serum lysozyme estimations may be of value in the recognition of immunocytochemically-atypical cases.

Adult acute nonlymphocytic leukemia

Chemotherapy of adults with acute nonlymphocytic leukemia has improved in recent years, yielding complete remissions in 65 per cent and cure in 10 to 15 per cent of all treated patients. Allogeneic bone marrow transplantation cures approximately one half of eligible young patients who gain an initial remission with chemotherapy. Autologous bone marrow transplantation may ultimately prove to be of value for the large numbers of patients who are over 40 years of age or who lack histocompatible siblings. Current investigative approaches in all these areas, based on insights into the pathophysiology of disease discussed in this article, should enhance the outcome for affected patients in the next decade.

Acute monoblastic leukaemia. Clinical, biological data and survival in 45 cases

Between 1978 and 1980, 45 cases of acute monoblastic leukaemia have been diagnosed, treated and followed in our institute. Morphological diagnosis was performed according to the French-American-British classification. Tumoral syndrome (particularly extra-medullary) and hyperleucocytosis were the most striking findings at the time of diagnosis. Cytogenetic analysis performed in 31 cases before treatment has showed that abnormality of the long arm of chromosome 11 seemed to be more frequently associated with the poorly differentiated cytological subtype M5 (a). Intensive chemotherapy with zorubicin and cytosine arabinoside led to complete remission in 75% of the cases. Central nervous system prophylaxis appeared definitively useful in preventing meningeal relapse. Despite a prolongation of the median duration of complete remission which now reaches 12 months, the prognostic is still poor.

Colony assays of hematopoietic progenitor cells and correlations to clinical situations

The production of blood cells is a dynamic process that is noticeably aberrant during disease. The availability of colony assays in vitro that allow detection of hematopoietic stem and progenitor cells for the neutrophil, monocyte-macrophage, erythroid and/or megakaryocyte lineages has been of importance for the present understanding of the mechanisms controlling the proliferation, self-renewal capacity, and differentiation of morphologically nonrecognizable immature cells which give rise to the mature progeny circulating in the blood. It is through the use of these assays that the existence of potentially relevant stimulatory and inhibitory feedback interactions has been demonstrated. Abnormalities in these interactions, which may be of significance during leukemia and related disorders, have been uncovered. This communication will discuss regulatory interactions detected via the colony assays, their potential relevance physiologically and pathologically, and the use of these assays for diagnosis, prognosis, and for monitoring the clinical status of patients.

Lymphoma-like presentation of acute monocytic leukaemia

Four patients in whom a diagnosis of acute monocytic leukaemia (M5) was subsequently made presented with extramedullary disease clinically resembling lymphoma. In all patients histological sections were initially misinterpreted as showing malignant lymphoma or anaplastic carcinoma. The diagnosis of M5 leukaemia was subsequently made on the basis of morphological and cytochemical studies of peripheral blood and bone marrow. The histological diagnosis of the soft tissue lesions of M5 leukaemia (monocytic sarcoma) is difficult, although features such as abundant cytoplasm and the presence of some reniform nuclei are helpful. If there is no peripheral blood or bone marrow involvement and only fixed paraffin-embedded tissues are available, demonstration of lysozyme by an immunoperoxidase technique may confirm the diagnosis but results are not invariably positive. An early diagnosis of M5 leukaemia has therapeutic implications since the disease evolves through a progressive leukaemia phase and systemic therapy is essential.

Acute non-lymphoid leukemia

Acute non-lymphoid leukemia is a group of hematologic neoplasms which have been the subject of intensive basic and clinical research. These studies have led to a better understanding of the genetic basis of leukemia and may ultimately help establish the molecular mechanisms of malignant transformation. They also have increased our understanding of myeloid differentiation. As a result of clinical trials, we can now induce a clinical remission in a large majority of patients with acute non-lymphoid leukemia. Future studies will attempt to lessen toxicity and to maximize the response rate. Many of these advances will come from improvements in supportive care given during the periods of therapy-related marrow aplasia. The role of intensive chemotherapy to prolong remission duration and to increase the usefulness of allogenic bone marrow transplantation will be clarified during the next several years.

Acute myelomonocytic leukaemia presenting as xanthomatous skin eruption

A case of acute myelomonocytic leukaemia (AMMOL) is reported in which skin infiltration with xanthomatous nodules was the presenting feature. The histological, including ultrastructural, appearances are described.

Bone biopsy in haematological disorders

Bone marrow biopsies are now widely used in the investigation and follow-up of many diseases. Semi-thin sections of 8216 undecalcified biopsies of patients with haematological disorders were studied. Observations were made on the cytopenias and the myelodysplastic syndromes, the acute leukaemias the myeloproliferative disorders, Hodgkin's disease and the malignant lymphomas including multiple myeloma, hairy cell leukaemia and angioimmunoblastic lymphadenopathy. Bone marrow biopsies are essential for the differential diagnosis of most cytopenias and for the early recognition of fibrosis which most frequently occurred as a consequence of megakaryocytic proliferation in the myeloproliferative disorders. Different patterns of bone marrow involvement were found in the lymphoproliferative disorders and both their type and extent constituted factors of prognostic significance. A survey of the literature is given and the conclusion is drawn that bone marrow biopsies provide indispensible information for the diagnostic evaluation and the follow-up of patients with haematological disorders.