Body weight variation is not an independent factor in the determination of functional hypothalamic amenorrhea in anorexia nervosa

OBJECTIVE

Functional hypothalamic amenorrhea (FHA) is one of the foremost manifestations in anorexia nervosa (AN), but a subset of patients have menses despite marked weight loss and underweight. The aim of our study was to investigate parameters potentially influencing FHA in AN.

DESIGN AND METHODS

In this observational retrospective study, we selected 114 female patients with AN who completed a 12 months semi-residential rehabilitation program and a subsequent 12 months outpatient follow-up. We divided our sample into three groups: "Group 0" patients who experienced FHA and recovered their menses, "Group 1" persistent FHA, "Group 2" never experienced FHA, and looked for clinical and hormonal correlations.

RESULTS

At the enrollment, the BMI was higher in Group 2 than in Group 1 (p = 0.0202), but the last follow-up weight was higher in Group 1 (p < 0.0001) despite persistent amenorrhea. At logistic regression, the higher BMI at which patients experienced amenorrhea was the main prediction factor for persistent FHA. Notwithstanding comparable leptin levels at admission, they improved significantly at discharge only in Groups 0 and 2 (p = 0.0054 and p = 0.0104, respectively). FT3 at admission was significantly higher in Group 2 than in Group 0 (p = 0.0249).

CONCLUSIONS

FHA does not correlate strictly with body weight variations in AN patients, indicating a multifactorial origin, likely including an individual predisposition. Higher FT3 levels identify patients who continue having menses at extremely low BMI. AN patients with persistent FHA constitute a subgroup in whom estroprogestins should be considered after significant weight recovery to prevent prolonged tissue hypoestrogenism.

Ultrastructural Alterations of Megakaryocytes in Some Hematologic Disorders

Bone marrow and peripheral blood samples of patients affected by hematologic disorders involving the megakaryocytic line were examined at the electron microscope. While in idiopathic thrombocytopenic purpura the megakaryocytes appeared almost normal, in primary thrombocythemia there were various ultrastructural alterations interpreted as a counterpart of ineffective thrombocytopoiesis. In one patient with blastic chronic myeloid leukemia and in another with acute megakaryoblastic leukemia, the electron microscope study was very useful in the identification of immature megakaryocytes. In fact, analysis of various ultrastructural parameters allowed some blast cells to be attributed to the megakaryocytic series. Furthermore, platelet demarcation system abnormalities and alterations of the circulating thrombocytes confirm the hypothesis that there is a block in megakaryocytic maturation.

Morphologic, Immunologic, and Cytogenetic Characteristics of Secondary Acute Unclassifiable Leukemia in Hodgkin's Disease

Blast cells from five cases of secondary unclassifiable leukemia following therapy for Hodgkin's disease were studied by cytochemical, immunological and cytogenetic analyses. Cytochemical and immunological reactivity were in accordance with poorly differentiated, myeloid blasts. The four cases in which karyotype analysis was performed showed specific chromosomal abnormalities. No evidence of multiple lineage involvement was found. Problems in classifying these cases of secondary ANLL were due to the high grade of undifferentiation of the blast cells. Their low cytochemical reactivity with markers of myeloid differentiation was similar to what may be observed in patients with acute undifferentiated leukemia or with chronic myeloid leukemia in blast crisis.

Distinct morphophenotypic features of chronic B-cell leukaemias identified with CD1c and CD23 antibodies

Morphological criteria usually applied to diagnose various subtypes of B-cell chronic lymphoid leukaemia are largely subjective. Immunophenotyping of 61 relevant cases using a selected panel of monoclonal antibodies (mAb), showed that CD1c and CD23 mAb were able to separate B-cell chronic lymphocytic leukaemia (B-CLL) from other chronic B-cell lymphoproliferative diseases. Lymphocytes of B-CLL were CD1c-, CD23+, whereas those of other types of chronic B-cell leukaemia were CD1c+/-, CD23-, and CD38/-. Non-B-CLL cases had a significantly higher amount of large peroxidase-negative (unstained) cells analyzed with an automated blood cell counter (Technicon H6000). This type of volumetric assessment allowed a separation between typical and "atypical" B-CLL, which otherwise were both CD1c-, and CD23+. These combinations of phenotypic markers corresponded to well-defined haematopathologic entities, conventionally diagnosed on peripheral blood (PB) and bone marrow smears, and on histologic sections of lymph nodes and spleen.

Selective purging by human interleukin-2 activated lymphocytes of bone marrows contaminated with a lymphoma line or autologous leukaemic cells

The ability of recombinant interleukin 2 (rIL2) activated lymphocytes (LAK) to purge BM samples contaminated by tumour cells was evaluated. Human BM mononuclear cells were contaminated with 10% of the lymphoma line CA46 and then cultured in liquid medium containing 1000 U/ml of rIL2 and/or LAK autologous to the used BM. At the end of coculture the growth of residual tumour cells and of CFU-GM were evaluated by clonogenic assay. No tumour cell growth was observed in 5/5 independent experiments after 18 h of coculture with LAK. No significant inhibition of CFU-GM growth was also noted. Subsequently, the effect of LAK on BM obtained from four leukaemic patients and contaminated with 20-50% of their own AML and ALL cells was studied using MAb as a tool for identifying leukaemic cells. LAK eliminated 24-78% of contaminating cryopreserved uncultured autologous leukaemic cells. In five cases the BM was contaminated by a low (2%) amount of ALL cells. In these patients the monoclonal heavy chain rearrangement typical of ALL was no longer visible after coculture with LAK. Evidence for selective tumour cytotoxicity by LAK was confirmed by using autologous BM cells as hot and cold targets in a 51Cr release assay. Finally, successful haematologic reconstitution of lethally irradiated BALB/c mice was obtained using syngeneic BM cocultured with LAK. These results support the investigational use of rIL2 and LAK in the treatment of human leukaemia.

Ciprofloxacin for infection prophylaxis in granulocytopenic patients with acute leukemia

Forty consecutive neutropenic patients with acute leukemia receiving oral ciprofloxacin (500 mg twice daily) and ketoconazole (200 mg daily) for selective intestinal decontamination were compared retrospectively with 33 comparable patients treated with polymyxin E (1,500,000 U x 3/day) and nystatin (1,000,000 U x 3/day). The incidence of febrile episodes was slightly lower in ciprofloxacin treated patients (87.5% vs 100%). No gram-negative sepsis was observed in this group compared with seven cases in patients receiving polymyxin E (p less than 0.01). Furthermore, eight patients in ciprofloxacin group (20%) had gram-positive sepsis, compared with five (15.5%) in the polymyxin E group. The incidence of documented fungal infections was similar in the two groups. Ciprofloxacin appears to be an effective agent for the prevention of gram-negative infections in granulocytopenic patients with acute leukemia, but may contribute to a shift in the type of infections in these patients towards those caused by gram-positive microorganisms, intrinsically fairly sensitive or with acquired drug resistance.

Clinical and laboratory findings in a new case of leukocyte adhesion deficiency

We describe a child suffering from recurrent bacterial infections whose cells exhibited laboratory findings compatible with the leukocyte adhesion deficiency (LAD) syndrome. Surface marker analysis with monoclonal antibodies (MAbs) to the individual alpha and beta chains of LFA-1/Mac-1/p150,95 antigens revealed that the patient's neutrophils did not express the common beta chain and LFA-1/p150,95 alpha subunits, but reacted weakly with four different MAbs specific for the Mac-1 alpha chain; however, no glycoprotein was immunoprecipitated from the patient's cells using the same anti-Mac-1 alpha MAbs. Functional analysis of the patient's phagocytes revealed many of the defects in adherence-dependent functions (adherence, chemotaxis and phagocytosis) described in patients with LAD. The studies performed on the phagocytes of the patient's relatives showed normal phenotypes and function, suggesting the possibility of a non heritable form of disease in this family.

Biological and clinical features of acute lymphoblastic leukaemia with cytoplasmic granules or inclusions: description of eight cases

We describe eight patients (four children and four adults) with an acute lymphoblastic leukaemia (ALL) with cytoplasmic granules or inclusions. The incidence of this variant of acute leukaemia in our whole series of patients with ALL is 1.8%. The granules or inclusions were usually positive for aspecific esterases (ANAE) and/or acid phosphatase, and the immunophenotype was in all cases typical of a CALLA positive B-lineage ALL (CD10+, CD19+ and/or CD24+, DR+, TdT+, anti-T-, anti-My-, SIg-). In one paediatric case, CD33 was unusually coexpressed. Ultrastructural investigations were performed in one case and demonstrated large granules containing vesicles, usually membrane bound, in the majority of blast cells. In the two cases analysed, Ig heavy chain gene rearrangement was detected. In this series of patients prognosis was poor since three never achieved a complete remission, four relapsed and only one is still in first continuous remission.

A case of Waldenström macroglobulinemia terminating in acute lymphoblastic leukemia

A case of acute lymphoblastic leukemia occurring in a patient with Waldenström macroglobulinemia more than 6 years after the onset of the disease is reported. At the time of acute transformation, bone marrow and peripheral blood lymphoid populations were almost entirely represented by lymphoblasts; the serum monoclonal peak had disappeared and no cells bearing surface or intracytoplasmic immunoglobulins were found. This observation suggests that the blast crisis might be derived from a dedifferentiative process within the lymphatic clone of the chronic phase.

Relevance of ultrastructural immunocytochemistry in the characterization of unclassifiable leukemias: correlation with phenotypic and genic studies

Nine cases of acute leukemia presenting unusual phenotype were studied by light microscopy (LM) cytochemistry and transmission electron microscopy (TEM) immunocytochemistry with the immunogold staining (IGS) method; in addition, cytogenetic and molecular analyses were performed. The presence of myeloperoxidase (MPO) was studied at TEM in combination with immunophenotype to identify minor populations not characterizable at LM. Four of nine cases had no TEM/MPO reactivity, whereas the remaining five showed variable percentages of positive cells. Of the MPO negative cases, one was a megakaryoblastic leukemia with a positive platelet peroxidase (PPO) reaction, and three were lymphoid. Among the peroxidase positive cases, the percentage of MPO reactive cells was higher at TEM than at LM examination. In case 5 TEM analysis indicated that cells with some MPO reactivity at LM were non neoplastic myeloid cells. With this combined technique in cases 1 and 2 we excluded the presence of the MPO enzyme in CD15 positive lymphoid cells and, in another case, we documented the existence of CD19/MPO positive cells. The value of cytochemistry and immunology at the ultrastructural level for the characterization of blast cells and for the precise diagnosis of leukemia with "unusual" phenotype is illustrated.

Bone marrow and tissue expression of gpIIb/IIIa, LFA-1, Mac-1 and gp150,95 glycoproteins

Monoclonal antibodies (MAbs) against platelet glycoprotein gpIIb/IIIa and the leucocyte adhesion molecules LFA-1, Mac-1, and gp 150,95 alpha chain (CD11a,b,c) and beta chain (CD18) have been tested in normal and leukaemic bone marrows, in different human tissues, and in a patient with leucocyte adhesion deficiency (LAD). The effect of these MAbs on platelet aggregation was also tested. GpIIb/IIIa showed widespread distribution, while reactivity of CD11/18 antibodies was limited to haematopoietic cells. Platelets and megakaryocytes were reactive with one CD11a (25.5.2), and with no CD11b/c or CD18 MAbs. GpIIb/IIIa was present on the platelets of the patient with LAD, whereas 25.5.2, (CD11a) bound to his platelets but not to his leucocytes. These data indicate that LFA-1, Mac-1, and gp150,95 are not present on human platelets, but they suggest the existence of crossreacting epitopes on gpIIb/IIIa, which is consistent with the hypothesis that these molecules belong to a supergene family of adhesion molecules.

Mixed-lineage leukemias and phenotypic shifts occurring in relapsed cases of acute T lymphoblastic lymphomas

Specimens from 19 patients with NHL were also phenotyped at the onset of the disease; among them, 9 were studied in the relapse phase. The analysis was carried out with monoclonal antibodies directed against T and myeloid cells; at diagnosis, all cases presented an immature thymic phenotype. When analyzed at relapse, phenotypic changes were observed: intra-lineage dedifferentiations (6 cases); mixed-lineage lymphoid and myeloid (2 cases), and pure myeloid relapses (1 case). The molecular analysis of the TCR-genes configuration showed a germ-line pattern at onset and relapse in Case 9 and a modification of the rearrangement patterns during the evolution of the disease in Case 6. These data point out that the relapse is often accompanied by intra-lineage modifications resembling dedifferentiation and, more rarely by a myeloid switch. The phenotypic follow-up of these patients may be important to the implementation of chemotherapeutic protocols that are more adequate for the biological evolution of the disease.

Early lymphocyte activation molecule defined by the monoclonal antibody MLR-3: biochemical and functional studies

The MLR-3 monoclonal antibody reacts with activated but not with resting lymphocytes. We report that MLR-3 identifies an early activation molecule since its binding is detectable on T cells 1.5-2 hr after in vitro activation. Its expression, therefore, does not require DNA synthesis and precedes, by many hours, that of the receptors for interleukin-2 (IL-2R) and transferrin (TF-R). The MLR-3 antigen is also found on activated thymocytes (including the large early thymic CD3- subset) and B cells. The majority of T- and B-lymphoblastoid cell lines, as well as the myeloid and erythroid cell lines HL60, GM1 and K562, are MLR-3+; conversely, non-haemopoietic cell lines are MLR-3 negative. Seventy percent of B-cell chronic lymphocytic leukaemia and 15% of B non-Hodgkin's lymphomas (B-NHL) are MLR-3+. On tissue sections MLR-3 is reactive with epithelia, sweat glands, hair follicles and Henle's loop but not with vessels, connective, endothelium and many other tissues. In vitro studies show that MLR-3 (1-100 micrograms/ml) significantly alters the thymidine uptake of mitogen-treated lymphocytes:augmentation is found when T and B cells are induced with TPA-Ionomycin and reduction when induced with phytohaemoagglutinin (PHA) or Staphylococcus aureus Cowan strain 1 (SAC), respectively. On SDS-PAGE, MLR-3 immunoprecipitates a disulphide-linked heterodimer of MW 29,000-35,000: both subunits are glycosylated, phosphorylated and exhibit a pI of 4.1 and 5.0, respectively. Our data, particularly the in vitro results, suggest that the MRL-3 molecule could have an important role in the early hours of activation for the progression of resting lymphocytes into mitosis.

CD1c but neither CD1a nor CD1b molecules are expressed on normal, activated, and malignant human B cells: identification of a new B-cell subset

The CD1 cluster of monoclonal antibodies (MoAbs) CD1a, CD1b, and CD1c, identifies molecules that are differentially expressed on hematopoietic and nonhematopoietic tissues. Our earlier finding that the mantle zone (MZ) but not the germinal center (GC) of normal lymph nodes (LN) is CD1c+, CD1a-, and CD1b- prompted us to further investigate the expression of these molecules on normal, activated, and malignant B cells. We report that blood and spleen contain CD1c+ B cells that account for 49% +/- 20.4% (mean +/- SD) and 50.9% +/- 4.4% of the total B cell population, respectively. CD1a- and CD1b-specific MoAbs are unreactive with both B and T cells; these latter are CD1c- as well. When CD1c+ and CD1c- B cells are activated in vitro, the CD1c molecule is upregulated in the former subset and induced de novo in the latter. Conversely, activated blood T cells remain CD1c-. Neither CD1a nor CD1b molecules are detected on activated T and B lymphocytes. At ultrastructural level, the CD1c+ B cells exhibit distinctive features, namely, condensed chromatin with or without a nucleolus and a unique cluster of cytoplasmic vesicles and organelles; the number of nucleolated cells is higher in the spleen (95%) than in the tonsil (40%) or blood (5%). These findings further confirm the similarity between blood and MZ B cells. The CD1c expression assessed on 27 B-cell chronic lymphocytic leukemias (B-CLL) and 46 B non-Hodgkin's lymphomas (B-NHL) was detected on 41% and 32% of cases, respectively; the latter comprised four follicular and 11 diffuse histotypes. The Burkitt's lymphomas were CD1c-negative. The B-cell neoplasms were all CD1a- and, except for four with a weak cytoplasmic staining, all CD1b- as well. The clear-cut CD1c distribution in normal LN (MZ+, GC-) contrasted with the evidence that some B-NHL cells of GC origin (eg, follicular with predominantly small cleaved cells) were CD1c+. Overall, the finding that CD1c expression is restricted to a fraction of B cells present in lymphoid organs and in peripheral blood indicates that CD1c is a powerful marker for the identification and dissection of B-cell subsets whose functional properties can now be evaluated.

Leukaemoid reaction with megakaryocytic features in newborns with Down's syndrome

A leukaemoid reaction was observed in 3 newborns with Down's syndrome. Thrombocytopenia was present in 2, requiring platelets transfusions in 1, and red cell transfusions were necessary in 2 patients. Blast cells characterization by specific monoclonal antibodies showed a prevalence of megakaryoblasts in all 3 cases. This feature was confirmed in 2 of them by the demonstration of platelet peroxidase (PPO) activity under transmission electron microscopy (TEM). A spontaneous remission of the leukaemoid picture was observed after 2-3 months. However, in 1 case a relapse of the myeloproliferative disorder with the same features of the blast cell population was diagnosed after 16 months. Chemotherapy with low-dose Ara-C, started because of a relevant clinical involvement, induced a complete remission.

A retrovirus carrying the polyomavirus middle T gene induces acute thrombocythemic myeloproliferative disease in mice

Mice inoculated with an artificially constructed retrovirus carrying the middle T gene of polyomavirus develop acute myeloproliferative disease with severe thrombotic and hemorrhagic disorder and impaired platelet function. The megakaryocytic lineage appears to be a target for polyoma-murine leukemia virus infection and middle T gene expression. This newly described disease represents a unique model system for studying disorders of the megakaryocytic lineage.

Peripheral neuropathy in macroglobulinemia: incidence and antigen-specificity of M proteins

Peripheral neuropathy was found in 12 (46%) of 26 patients with macroglobulinemia. The neuropathy was subclinical in two. Anti-myelin-associated glycoprotein (MAG) activity was found in six (50%) patients with neuropathy. Sural nerve biopsies showed demyelination and IgM deposits on the myelin sheath. In one patient who had no anti-MAG activity, the serum IgM bound to peripheral myelin by indirect immunofluorescence and to several protein bands in peripheral nerve and other tissues by immunoblot. In the other five patients with neuropathy, we found no binding of M proteins to nerve components, but in three patients there were endoneurial IgM deposits in nerve biopsy. Peripheral neuropathy may be related to the antigen-specificity of M proteins.

Immunohistochemical evaluation of bone marrow involvement in hairy cell leukemia during interferon therapy

Bone marrow biopsies from 7 patients afflicted with hairy cell leukemia were studied with a panel of monoclonal antibodies at different intervals during alpha recombinant interferon therapy. Monoclonal antibodies Dako-LC and F 8.11.13 were used because they are highly reactive with hairy cells, and 82H3 and LeuM 1 were also utilized to identify respectively the residual hemopoietic and myeloid tissue. All antibodies are reactive on sections of formalin-fixed, paraffin-embedded biopsy material. Before therapy a uniform hairy cell infiltrate was present and very little tissue was visible even after immunohistochemical staining. During therapy, identification of hairy cells in routine biopsies was difficult, since they were mixed with normal cells and the bone marrow was generally hypoplastic. Immunohistochemical stains seem to allow better identification of hairy cells and a more precise estimate of the degree of repopulation by normal bone marrow cells. It was evident, especially after immunocytochemical analysis, that interferon drastically reduced the extent of the infiltrate and allowed recovery of normal hemopoiesis, but did not produce complete remissions.

Morphological heterogeneity of Leu7, Leu11 and OKM1 positive lymphocyte subsets: an ultrastructural study with the immunogold method

The morphological features of normal peripheral blood lymphocytes reactive with three monoclonal antibodies (MoAb) against natural killer (NK) cells, Leu7, OKM1 (CD11b) and Leu11 (CD16) and with two anti-T cell MoAb, CD4 and CD8, have been analysed at ultrastructural level by an indirect immunogold method. Cells having the features of large granular lymphocytes (LGL) but also lymphocytes displaying different morphological characteristics (non LGL; e.g. high nucleo-cytoplasmic ratio and few cytoplasmic organelles) were seen reactive with each of the MoAb investigated. Leu7 identified a higher proportion of LGL (60-80%) than OKM1 (10-95%) and Leu11 (20-48%), and with a stronger binding. A distinct granular structure, recognized as parallel tubular arrays, was more characteristic of the Leu7+, CD8+ LGL and was less frequently seen in the OKM1 and Leu11 positive LGL subpopulation in four out of the five donors investigated. It is of interest that the Leu11 and OKM1 positive subsets, which correspond functionally to cells with greater NK function, had relatively less LGL than the Leu7 positive subsets, raising the issue of the true morphology of NK cells in man. The existence of a minority of CD4 positive LGL was confirmed. Our findings demonstrate that there is a degree of morphological heterogeneity within the normal NK lymphoid population as defined by the membrane phenotype and that certain variability among normal individuals regarding the proportion and structural features of the NK subpopulations may be present.

Immunocytochemistry of acute myeloid leukemias: an ultrastructural study by the immunogold method

Light microscopy morphology and cytochemistry, immunology, and ultrastructural morphology, cytochemistry and immunocytochemistry studies were performed in 18 cases of acute myeloid leukemia (8 M1, 1 M2, 7 M3 and 2 M4, according to the FAB classification). The aim of the investigation was to assess the value of electron microscopy, particularly the immunogold method, in the different FAB subclasses. Transmission electron microscopy with its more recent techniques of investigation was shown to have an important role in diagnosis of early myeloid (M0-M1) and mixed (M4) cases, where it was determinant in correlating ultrastructural morphology with cytochemistry and immunology and thus identifying the different cell populations. On the contrary, in cases in which the leukemic cells showed homogeneous features, light microscopy was adequate and sufficient for correct diagnosis.

Light and electron microscopic study of cyclosporin A-induced gingival hyperplasia

Four transplant (3 kidney, 1 bone marrow) patients with cyclosporin A (CyA)-induced gingival hyperplasia are described. Light and electron microscopic findings of gingival biopsies showed in all patients that, in addition to an increase of collagen, CyA induced in the subepithelial space an enormous infiltration of morphologically normal plasma cells in different stages of maturation. These data, together with the reversibility of the lesion upon discontinuation of the drug, suggest that individual hypersensitivity is probably the most acceptable explanation of CyA-induced gingival hyperplasia. This hypothesis is also discussed in relation to the CyA-suppression of the functions of some T-lymphocyte subsets.

Biphenotypic Philadelphia positive, monosomy seven acute leukaemia: ultrastructural immunocytochemical study

A case of Ph1 positive acute leukaemia is presented in which an additional chromosome change, monosomy 7 was found. There was no clinical evidence of a pre-existing chronic myeloid leukaemia. Cytochemistry and immunology showed a predominant HLA-DR+, TdT+, cALL- phenotype, with a small percentage of HLA-DR+, Leu-Ml+ and cALL- cells. The true biphenotypic nature of this case was clearly shown by transmission electron microscopy using the immunogold method combined with myeloperoxidase (MPO). Two distinct phenotypes, lymphoid (cALL+, MPO-) and myeloid (LeuMl+, MPO+) were identified with this technique. An immuno-scanning electron microscope technique was also used to study this case, which demonstrated the presence of two different surface morphologies.

Human recombinant interferon alpha-2C enhances the expression of class II HLA antigens on hairy cells

Isolated splenic hairy cells from three untreated patients were cultured in presence of recombinant human interferon alpha-2C (IFN alpha). Ultrastructural cytochemistry and immunophenotype analysis with a large panel of monoclonal antibodies were performed to study cellular modification induced by IFN alpha. Hairy cells showed a typical pheno-type: Smlg+, B1+, BA1+/-, anti-Tac+, OKDR+, Leu-M5+, HC2+, TRAP+, myeloperoxidase-. Under our experimental conditions, we found no direct cytotoxic effects or significant variations in morphology, cytochemistry, and percentage of reactivity with the tested monoclonal antibodies. After culturing in the presence of different doses of IFN alpha, we observed a significant enhancement of the expression of class II HLA antigens as demonstrated by increased fluorescence for OKDR, OKla, Leu-10 at fluorescence-activated cell sorting analysis. In agreement with this finding IFN alpha-treated hairy cells showed an increased stimulatory capacity v allogeneic T cells in one-way mixed lymphocyte reaction. To our knowledge this is the first report describing the induction of class II HLA antigens on hairy cells by IFN alpha.

Characterization of myeloid leukemias with monoclonal antibodies 3C5 and MY9

The expression of two membrane antigens identified by the monoclonal antibodies (McAb) My9 and 3C5 has been investigated in cells from 80 acute leukemias. My9 was positive in the blasts of 33 out of the 38 (87 per cent) cases of acute myeloid leukemia (AML) tested, regardless of FAB subtype, and in 13 of 18 (72 per cent) cases of chronic granulocytic leukemia (CGL) in myeloid blast crisis. The reactivity of 3C5 was confined to myeloblastic (M1) AML, 85 per cent of cases, and to lymphoblastic leukemia (ALL) of B-lineage, 70 per cent of cases, including CGL in lymphoid transformation. My9 was negative in ALL except for an unusual case. The phenotype My9+, 3C5+ was seen exclusively in M1 (69 per cent) and M2 (14 per cent) AML. Ultrastructural analysis with the immunogold method in combination with the myeloperoxidase (MPO) reaction showed that expression of My9 increased in parallel with MPO activity whereas 3C5 was expressed mainly in myeloblasts with little MPO content. We conclude that the use of these two McAb will contribute to the diagnosis and classification of AML and may throw some light to the pathogenesis of biphenotypic acute leukemias, including TdT + AML.

Biphenotypic leukaemia: a case of mixed T lymphoblastic and myeloblastic leukaemia

A case of mixed acute leukaemia with T lymphoblastic, myeloblastic, and monocytic components is described. The use of immunological markers, ultrastructural morphology, cytochemistry, immunochemistry, and combined techniques, simultaneously detecting two markers in individual cells, made it possible to define the different blast cell populations.

Characterization of blast cells in chronic granulocytic leukaemia in transformation, acute myelofibrosis and undifferentiated leukaemia. II. Studies with monoclonal antibodies and terminal transferase

A panel of 19 monoclonal antibodies (McAb) and the enzyme terminal transferase (TdT) have been applied to the characterization of poorly differentiated blasts from 50 patients with chronic granulocytic leukaemia (CGL) and myelofibrosis in blast crisis (BC), acute myelofibrosis and undifferentiated leukaemia. These cells were also extensively studied by transmission electron microscopy (TEM) (see Polli et al, 1985a). McAb against platelet glycoproteins (GP) showed a high specificity for megakaryoblasts, in particular those reactive with the GPIIb/IIIa complex (J15) and GPIIIa (C15 and C17), which were positive in a higher proportion of blasts than the McAb to GPIb (AN51 and FMC25). Findings with these anti-platelet McAb paralleled those of the platelet-peroxidase (PPO) reaction in 76% of cases studied simultaneously. The PPO reaction was always positive in cases in which two or more of the McAb were reactive with the blast cells. The differences observed suggest, nevertheless, that PPO is more sensitive for megakaryoblasts than the McAb and that this TEM technique should be reserved for cases which are negative with the platelet specific McAb. Of the McAb against myeloid antigens used in this series OKM1 was positive in 50% of cases but the others failed to demonstrate early features of differentiation in myeloblasts and monoblasts. In only three cases were erythroid precursors demonstrated by TEM and these were the only ones reactive with a McAb to glycophorin-A (LICR LON/R10). TdT and the McAb J5 helped in the identification of lymphoblasts which were seen as a 'pure' proliferation in 23% of CGL-BC and as part of blast cell mixtures in another 17% of cases. The McAb reactive to haemopoietic precursor cells (RFB1, FMC8 and OKIa), on the other hand, were of no practical value for the classification of blast cell types. The lineage specificity of several of the McAb used in this study, confirmed by TEM, suggest that these reagents are valuable tools for the characterization of immature blast cells.

Characterization of blast cells in chronic granulocytic leukaemia in transformation, acute myelofibrosis and undifferentiated leukaemia. I. Ultrastructural morphology and cytochemistry

A systematic analysis of the blast cell population was carried out on samples from 50 patients suffering from blast transformation of chronic granulocytic leukaemia (CGL) (31) and of myelofibrosis (4), acute myelofibrosis (AM) (11) and undifferentiated acute leukaemia (4). Transmission electron microscopy (TEM), used in 41 samples, included: morphology and techniques for myeloperoxidase (MPO), platelet-peroxidase (PPO) and acid phosphatase (AP). The majority of cases were also studied by light microscopy cytochemistry and with a battery of cell markers which are reported in the accompanying paper (San Miguel et al, 1985). The characterization of the type(s) of proliferating blasts was made from the integration of ultrastructural and immunological data. TEM morphology allowed the precise recognition of specific granules in basophil and mast-cell precursors and of ferritin particles in blasts of erythroid lineage; these rare cell types were not adequately characterized by other methods. The PPO reaction made possible the identification of pure megakaryoblastic proliferations in 38% of cases, including eight of the 11 with AM; megakaryoblasts were also present in nine of 12 cases with mixed blast cell types. The MPO and AP reactions were useful for the characterization of myeloblasts and monoblasts, respectively. Lymphoblasts could be distinguished from other cell types by TEM morphology and negative MPO and PPO reactions. TEM techniques were valuable for diagnosing correctly the type of blast cell in this study in which only four cases (8%) remained unclassifiable.

Scanning immunoelectron microscopy of hairy cell leukemia

Scanning electron microscopy has shown a typical cell surface morphology in hairy cell leukemia. Scanning immunoelectron microscope techniques, utilizing monoclonal antibodies and colloidal gold particles, have recently become available. Eight patients with hairy cell leukemia have been studied with a panel of monoclonal antibodies of which B1, BA1, OKM1, anti-TAC and LeuM5 were shown to be suitable for scanning immunoelectron microscopy and reactive with hairy cells. The combination of typical cell surface features with reactivity for the B1 and LeuM5 monoclonal antibodies permits accurate diagnosis of hairy cell leukemia, particularly when low percentages of hairy cells are present as in hypocellular or in interferon-treated patients.

Monocytic differentiation induced by 1,25 dihydroxyvitamin D3 in myeloid cells: an ultrastructural immunocytochemical study

We have studied, by ultrastructural morphology and immunocytochemistry, the alterations that occur in cells from the HL60 leukaemia cell line and from patients with CGL following incubation in vitro with 1,25(OH)2D3 for 2-5 days. The main morphological changes observed were in the nuclear shape, the development of autophagic vacuoles and the appearance of a population of small granules in the cytoplasm. These changes were associated with a significant reduction in MPO activity and increased expression of membrane antigens detected by the monocyte-specific McAb FMC17 and FMC32, as shown by the IGM at EM level, and a decrease in granulocyte-specific antigens demonstrated by the McAb FMC10. These observations suggest that promyelocytes and myelocytes could transform into monocyte-like cells and that this remodelling of cells was associated with autophagic digestion of cellular structures.

Characterization by ultrastructural cytochemistry of normal and leukemic myeloid cells reacting with monoclonal antibodies

Six monoclonal antibodies (McAb) of the FMC series with specificity for granulocytic or monocytic cells were investigated by means of the immunogold method in combination with the myeloperoxidase reaction at ultrastructural level. This method allowed a precise characterization of the level of myeloid maturation at which the antigens detected by the McAb were expressed and confirmed their specificity for the two myeloid lineages. In addition, it facilitated the identification of granulocytic and monocytic cell components in cases of acute myeloid and chronic myelomonocytic leukemia. Blast cells did not react with any of the McAb used, and the reactivity in more mature cells was parallel to the development of cytoplasmic granules. The pattern of reactivity was similar in normal and leukemic cells, thus suggesting that these McAb could be applied to studies of normal myelopoiesis and to the classification of leukemia.

Simultaneous demonstration of membrane antigens and cytochemistry at ultrastructural level: a study with the immunogold method, acid phosphatase and myeloperoxidase

We describe a method for electron microscopy that combines myeloperoxidase or acid phosphatase cytochemistry with the labelling of cell surface antigens with monoclonal antibodies and colloidal gold. This technique was tested in samples of normal mononuclear cells, leukaemic T cells with a mature or immature phenotype and an acute myeloid leukaemia. This method allows the demonstration at a single cell level of ultrastructural morphology, cytochemical reaction and the presence of a membrane antigen. It will improve further the analytic power of electron microscopy in the characterization of leukaemic cells particularly in cases of mixed leukaemias and in the study of normal haemopoietic differentiation with monoclonal antibodies.

Alkaline phosphatase activity in phagocytizing granulocytes: a backscattered electron imaging study

The scanning electron microscope (SEM) in the backscattered electron imaging (BEI) mode has been used to detect alkaline phosphatase activity in normal human PMNs using a lead method. Unfortunately commercial scanning electron microscopes do not allow resolution of the small and dispersed lead depositions in the secondary granules. However, polymorphonuclear leukocytes (PMNs) previously incubated with latex particles, show well evident lead precipitates allowing identification of different phases of the phagocytic sequence. In fact the finding of irregular depositions arranged around a central not-emitting zone might be due to the secondary granules gathering near the phagocytic vacuole. Moreover, homogeneous, round, well defined precipitates, having a diameter slightly larger than latex particles, probably corresponding to vacuoles filled with the enzyme after granules coaslescence and fusion.