Absence of chlamydial infection in Japanese patients with orbital adnexal MALT lymphoma

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Background: The extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is a distinct B-cell lymphoma that develops in extranodal sites and usually has an indolent clinical course as a localized disease. Recent clinicopathological studies suggest a strong relation between MALT lymphoma and inflammatory diseases of the epithelium such as autoimmune diseases and infections (Sjogren’s syndrome, Hashimoto’s thyroiditis, Helicobacter pylori infection, and etc.), because chronic antigen stimulation has been causally linked to the development of B-cells lymphoproliferative diseases. MALT lymphoma grows in extranodal lymphoid tissue and exists in epithelium tissues, and it is often difficult to distinguish malignant lymphoid tissue from benign inflammation. This is one cause since recent positive or negative correlations between ocular adnexal MALT lymphomas and chlamydial infections have been reported from different researchers, indicate several possible explanations. Methods: Twenty-three cases of ocular adnexal MALT lymphoma in southern regions of Japan, whose monoclonality was confirmed by immunoglobulin heavy chain gene rearrangement and/or cell surface antigens, were analyzed for evidence of several causative factors using ELISA analysis to detect antibodies and Southern blot analysis followed by specific PCR gene amplification. Results: Our series of patients did not show any serological relations to Epstein-Barr virus, Hepatitis C virus, and Chlamydophila psittaci. Two cases had positive serum antibodies for autoimmunity, and another two cases had positive antibodies against Chlamydia trachomatis. None of our cases showed the presence of chlamydial 16S rRNA and 16S-23S spacer rRNA genes (C. psittac, C trachomatis, C. pneumoniae, and C. felis) after Southern blot analysis followed by PCR amplification. Conclusions: Inflammatory agents are still unknown in our series of orbital adnexal MALT lymphomas, and some types of chlamydial infections are not associated with orbital adnexal MALT lymphoma in southern regions of Japan.

No significant financial relationships to disclose.

Rapidly progressive glomerulonephritis in a patient with Chlamydia pneumoniae infection: a possibility of superantigenic mechanism of its pathogenesis

Herein we describe a case of a patient with rapidly progressive glomerulonephritis after Chlamydia pneumoniae infection. An 88-year-old woman who had had C. pneumoniae infection two months previously was admitted to our hospital with complaints of dyspnea and generalized edema. Laboratory tests revealed acute renal failure, polyclonal hypergammaglobulinemia, highly increased level of C-reactive protein, and hematoproteinuria. A renal biopsy revealed mesangial and endocapillary proliferative glomerulonephritis with crescents. She responded to high-dose steroids, cyclophosphamide, minocycline, and plasma exchange treatment with the remission of oliguric renal failure. The percentage of the subset of CD3+ TCR+ Vbeta11+ cells markedly increased to 9.6% (normal range: < 1.04%) at the onset of the disease and decreased to 0.1% after the treatment. These clinicopathological features were similar to those of superantigen-associated glomerulonephritis after methicillin-resistant Staphylococcus aureus infection. We suggest that the superantigenic mechanism is one of the possible pathomechanisms of this glomerulonephritis.

A case of elderly-onset systemic lupus erythematosus presenting as acute renal failure due to disseminated intravascular coagulation

Herein we describe a case of a patient with elderly-onset systemic lupus erythematosus presenting as acute renal failure due to disseminated intravascular coagulation. A 78-year-old man was admitted to our hospital with fever and generalized lymphadenopathy. He was diagnosed as having systemic lupus erythematosus on the basis of renal involvement, hematological abnormality and positivity for antinuclear and anti-double-stranded DNA antibodies. Renal biopsy revealed lupus nephritis (class III and V (A/C)) with focal glomerular thrombosis. He responded to hemodialysis and corticosteroid therapy with remission of serological values and renal function. Possible mechanisms underlying the coexistence of these conditions are discussed.

HLA class II-restricted antigen presentation of endogenous bcr-abl fusion protein by chronic myelogenous leukemia-derived dendritic cells to CD4(+) T lymphocytes

Bcr-abl fusion peptide-specific CD4+ T-lymphocyte clones have recently been shown to augment colony formation by chronic myelogenous leukemia (CML) cells in a bcr-abl type-specific and HLA class II-restricted manner without addition of exogenous antigen. These findings suggest that CML cells can naturally process and present endogenous bcr-abl fusion protein to CD4+ T lymphocytes in the context of HLA class II molecules. To verify this possibility, the ability of CML-derived dendritic cells (DCs) to present endogenous bcr-abl fusion protein to bcr-abl fusion peptide-specific CD4+ T-lymphocyte clones was investigated. The bcr-abl b3a2 peptide-specific and HLA-DRB1*0901-restricted CD4+ T-lymphocyte clones produced interferon-gamma in response to stimulation with monocyte-derived DCs from HLA-DRB1*0901+ patients with b3a2 type CML. In contrast, DCs from patients with HLA-DRB1*0901- or b2a2 type CML and those from healthy individuals did not exert stimulatory activity on bcr-abl-specific CD4+ T-lymphocyte clones. The response of CD4+ T-lymphocyte clones to CML-derived mature DCs was higher than that to immature DCs and was inhibited by anti-HLA-DR monoclonal antibody. These data suggest that CML-derived DCs can process and present endogenous bcr-abl fusion protein to CD4+ T lymphocytes.

An alloantibody recognizing the FVIII A1 domain in a patient with CRM reduced haemophilia A due to deletion of a large portion of the A1 domain DNA sequence

We report the development of a FVIII inhibitor in a patient with severe, cross reacting material reduced (CRM(R)) haemophilia A. The level of Factor VIII antigen (FVIII:Ag) measured by ELISA using anti-C2 monoclonal and alloantibodies was 1.9 U/dl. This baseline FVIII:Ag level was increased to 8.3 U/dl after administration of DDAVP. The anti-FVIII inhibitor titer was 2.9 Bethesda U/ml. DNA analysis showed a large deletion of the FVIII gene from exon 4 to 7, corresponding to amino acid residues 111-317 included within the A1 domain. The size of the gene deletion was approximately 28 kb. 5' and 3' breakpoints were identified by sequencing in intron 3 and intron 7, respectively. FVIII mRNA was detected in the patient's peripheral lymphocytes and the deletion spanning exon 4 to 7 was confirmed at the RNA level. Immunoprecipitation experiments using 125I labeled A1, A2 and light chain demonstrated that the inhibitor reacted only with the 54 kDa A1 domain. The inhibitor activity was more than 95% neutralized by A1 domain polypeptide. Our findings suggest a close relationship between the inhibitor epitope and the specific gene deletion with regard to the pathogenesis of the inhibitor in this patient.

FcgammaRII tyrosine phosphorylation differs between FcgammaRII cross-linking and platelet-activating anti-platelet monoclonal antibodies

Using glutathione S-transferase Syk fusion proteins, we evaluated the mode of platelet FcgammaRII tyrosine phosphorylation induced by FcgammaRII cross-linking or anti-CD9 monoclonal antibodies (mAb). The N-terminal SH2 domain of Syk (Syk-N-SH2), the C-terminal SH2 domain of Syk (Syk-C-SH2), and the domain having both the N- and C-terminal SH2 of Syk (Syk-NC-SH2) all bound to tyrosine-phosphorylated FcgammaRII with FcgammaRII cross-linking. In the case of anti-CD9 mAb-induced platelet activation, only Syk-C-SH2 and Syk-NC-SH2 bound to tyrosine-phosphorylated FcgammaRII. Since the SH2 domain is specific for a particular structure containing phosphotyrosine, these findings suggest that only one tyrosine residue in the immunoreceptor tyrosine-based activation motif (ITAM) is phosphorylated with anti-CD9 mAb, and that both are phosphorylated with FcgammaRII cross-linking. Synthetic peptides corresponding to the ITAM of human platelet FcgammaRII with the N-terminal tyrosine residue phosphorylated (N-P) or the C-terminal tyrosine residue phosphorylated (C-P), were used. N-P more potently dissociated Syk-C-SH2 from tyrosine-phosphorylated FcgammaRII than C-P, suggesting that the N-terminal tyrosine residue is phosphorylated upon anti-CD9 mAb-induced activation. Furthermore, these findings imply that Syk-N-SH2 binds to the phosphorylated C-terminal tyrosine residue of ITAM, and Syk-C-SH2 to the N-terminal tyrosine. Taken together, our findings suggest that FcgammaRII-dependent platelet activation without FcgammaRII dimerization, such as with anti-CD9 mAb, is distinct from that induced by FcgammaRII cross-linking.

Mechanisms and consequences of affinity modulation of integrin alpha(V)beta(3) detected with a novel patch-engineered monovalent ligand

Integrin alpha(V)beta(3) mediates diverse responses in vascular cells, ranging from cell adhesion, migration, and proliferation to uptake of adenoviruses. However, the extent to which alpha(V)beta(3) is regulated by changes in receptor conformation (affinity), receptor diffusion/clustering (avidity), or post-receptor events is unknown. Affinity regulation of the related integrin, alpha(IIb)beta(3), has been established using a monovalent ligand-mimetic antibody, PAC1 Fab. To determine the role of affinity modulation of alpha(V)beta(3), a novel monovalent ligand-mimetic antibody (WOW-1) was created by replacing the heavy chain hypervariable region 3 of PAC1 Fab with a single alpha(V) integrin-binding domain from multivalent adenovirus penton base. Both WOW-1 Fab and penton base bound selectively to activated alpha(V)beta(3), but not to alpha(IIb)beta(3), in receptor and cell binding assays. alpha(V)beta(3) affinity varied with the cell type. Unstimulated B-lymphoblastoid cells bound WOW-1 Fab poorly (apparent K(d) = 2.4 microM), but acute stimulation with phorbol 12-myristate 13-acetate increased receptor affinity >30-fold (K(d) = 80 nM), with no change in receptor number. In contrast, alpha(V)beta(3) in melanoma cells was constitutively active, but ligand binding could be suppressed by overexpression of beta(3) cytoplasmic tails. Up-regulation of alpha(V)beta(3) affinity had functional consequences in that it increased cell adhesion and spreading and promoted adenovirus-mediated gene transfer. These studies establish that alpha(V)beta(3) is subject to rapid regulated changes in affinity that influence the biological functions of this integrin.

Complementary roles for receptor clustering and conformational change in the adhesive and signaling functions of integrin alphaIIb beta3

Integrin alphaIIb beta3 mediates platelet aggregation and "outside-in" signaling. It is regulated by changes in receptor conformation and affinity and/or by lateral diffusion and receptor clustering. To document the relative contributions of conformation and clustering to alphaIIb beta3 function, alphaIIb was fused at its cytoplasmic tail to one or two FKBP12 repeats (FKBP). These modified alphaIIb subunits were expressed with beta3 in CHO cells, and the heterodimers could be clustered into morphologically detectable oligomers upon addition of AP1510, a membrane-permeable, bivalent FKBP ligand. Integrin clustering by AP1510 caused binding of fibrinogen and a multivalent (but not monovalent) fibrinogen-mimetic antibody. However, ligand binding due to clustering was only 25-50% of that observed when alphaIIb beta3 affinity was increased by an activating antibody or an activating mutation. The effects of integrin clustering and affinity modulation were additive, and clustering promoted irreversible ligand binding. Clustering of alphaIIb beta3 also promoted cell adhesion to fibrinogen or von Willebrand factor, but not as effectively as affinity modulation. However, clustering was sufficient to trigger fibrinogen-independent tyrosine phosphorylation of pp72(Syk) and fibrinogen-dependent phosphorylation of pp125(FAK), even in non-adherent cells. Thus, receptor clustering and affinity modulation play complementary roles in alphaIIb beta3 function. Affinity modulation is the predominant regulator of ligand binding and cell adhesion, but clustering increases these responses further and triggers protein tyrosine phosphorylation, even in the absence of affinity modulation. Both affinity modulation and clustering may be needed for optimal function of alphaIIb beta3 in platelets.

[A case of renal pelvic cancer with recurrence of liver metastasis showing partial response by injection of methotrexate and intraarterial infusion of cisplatin and pirarubicin]

The patient was a 71-year-old man who had been diagnosed as having a left renal pelvic cancer with liver metastasis. We performed total left nephroureterectomy with lymphnode cleaning and partial resection of the liver. Because abdominal CT 5 months after the operation revealed multiple metastasis of the liver, we performed chemotherapy with a regimen consisting of methotrexate 50 mg (intravenous injection), cisplatin 30 mg and pirarubicin 20 mg (intraarterial infusion), and leucovorin 3 mg (intramuscular injection), three times at intervals of 6 hours. Ten days after chemotherapy, CT revealed the disappearance of most of the liver metastatic lesions, and a partial response was obtained. We are now performing the regimen at an interval of a month to a month and one-half to control the metastatic lesions.

Multiple diffuse fibrosarcoma of bone associated with extramedullary hematopoiesis

We report a case of multiple diffuse fibrosarcoma of bone. The patient, a 38-year-old man, was referred to our hospital with knee pain, anemia and thrombocytopenia. No solid mass was seen on radiographic examination of the kneejoint, but magnetic resonance imaging showed hypointensity of the distal femur. Femoral biopsy revealed proliferation of long spindle-shaped fibrosarcoma cells, while a bone marrow biopsy of iliac bone (which appeared normal on radiographic examinations) showed replacement of hematopoietic cells by fibroblast-like spindle cells. A diagnosis of multiple diffuse fibrosarcoma of bone was therefore made. Autopsy revealed tumor invasion into multiple bones and several visceral organs and extramedullary hematopoiesis in the liver, spleen and lymph nodes. As this patient had leukoerythroblastic anemia with poikilocytosis, splenomegaly exhibiting extramedullary hematopoiesis, and apparent fibrotic change in his bone marrow, we suggest that this extremely rare disease should be considered in the differential diagnosis of myelofibrosis.

Polymorphisms of HPA-1 through 6 on platelet membrane glycoprotein receptors are not a genetic risk factor for myocardial infarction in the Japanese population

We examined HPA genotypes derived from polymorphisms of platelet membrane receptors in 88 Japanese patients with early-onset myocardial infarction and in 100 control subjects. The results indicated that HPA genotypes 1 through 6 are not associated with early-onset myocardial infarction.

Outside-in signaling from integrin alpha IIb beta 3 into platelets in the absence of agonist-induced signaling

Platelet agonists generate intracellular signals which lead to activation of the platelet membrane glycoprotein IIb-IIIa (integrin alpha IIb beta 3). The resulting occupancy of alpha IIb beta 3 by ligands also generates signals into the cell (outside-in signaling). We reported previously that unlike platelet agonists, the F(ab')2 fragments of an anti-alpha IIb beta 3 monoclonal antibody, PMA4, induced fibrinogen binding to alpha IIb beta 3 without causing intracellular activation. In this study, in order to determine whether outside-in signaling occurs in the absence of agonist-induced intracellular signals, we used PMA4 F(ab')2 as an inducer of fibrinogen binding to alpha IIb beta 3. PMA4 F(ab')2-induced fibrinogen binding and subsequent platelet aggregation triggered tyrosine phosphorylation of several proteins including pp72syk but not pp125FAK. No Ca2+ influx or mobilization, thromboxane B2 synthesis, phosphorylation of pleckstrin or the myosin light chain, cytoplasmic alkalinization, or platelet shape changes, were detected. These findings suggest that, in the absence of agonist-induced signaling, alpha IIb beta 3 occupied by soluble fibrinogen generates only a limited outside-in signal.

Detection of platelet adhesion/aggregation to immobilized ligands on microbeads by an aggregometer

Platelet aggregation is believed to follow platelet adhesion to vascular injury sites. We have developed a turbidimetric assay for platelet aggregation following platelet adhesion to immobilized ligands using an aggregometer. The addition of polystyrene beads coated with von Willebrand factor (vWF) or fibrinogen (Fg) to platelet suspensions caused prompt aggregation of beads and platelets, which was detected as an increase in light transmission. Electron microscopic analysis revealed that platelets adhered to the bead surfaces and that additional platelets adhered to already adhering platelets, leading to the formation of platelet aggregates. vWF-coated beads induced larger aggregates than Fg-coated beads. The interaction of vWF-coated beads with platelets was abolished by both GPIb and GPIIb-IIIa blockers, while that of Fg-coated beads was abolished by GPIIb-IIIa blockers. vWF-coated beads induced modest secretion of granules from platelets but no thromboxane B2 synthesis. Fg-coated beads induced neither reaction. However, pleckstrin phosphorylation and protein tyrosine phosphorylation was induced by both types of bead. Platelet aggregation following platelet adhesion to both types of bead was inhibited by ADP scavengers, a protein kinase C inhibitor and a tyrosine kinase inhibitor, but not by aspirin. These findings suggest that vWF- and Fg-coated beads can induce platelet aggregation following platelet adhesion through specific ligand-receptor interactions and intracellular signaling. Our simple assay using these beads may represent a useful test for immobilized ligand-induced platelet adhesion and aggregation.

Differential inhibition of fibrinogen binding to agonist- and RGDS peptide-activated states of GPIIb-IIIa by an anti-GPIIIa monoclonal antibody, PMA5

Platelet agonists and RGD-containing peptides can convert platelet membrane glycoprotein (GP) IIb-IIIa from its resting state to an activated state competent to bind soluble fibrinogen. We examined the effects of two anti-GPIIb-IIIa monoclonal antibodies, PMA1 and PMA5, on fibrinogen binding to agonist- and RGD-activated GPIIb-IIIa. PMA1 abolished aggregation of both agonist- and RGDS peptide-activated fixed platelets, and inhibited the binding of 125I-fibrinogen to these platelets almost completely. PMA5 had the same effects on agonist-activated platelets, but had little effect on the aggregation of RGDS-activated fixed platelets, and inhibited fibrinogen binding to RGDS-activated fixed platelets by only 44%. PMA5 bound to agonist- and RGDS-activated platelets equally. Immunoblot analysis showed that PMA5 bound to intact GPIIIa, but not to a 66 kDa fragment of GPIIIa digested by chymotrypsin. Although PMA5 inhibited platelet adhesion to immobilized fibrinogen by 94%, 44% of the remaining adherent platelets were spread. In contrast, no platelet spreading was observed in the presence of PMA1. These findings indicate that PMA5 is a novel anti-GPIIIa monoclonal antibody with the ability to inhibit fibrinogen binding to agonist- and RGD-activated states of GPIIb-IIIa differentially, and suggest that binding of immobilized fibrinogen to RGD-activated GPIIb-IIIa is necessary for platelet spreading.

[Successful treatment of combined interferon-alpha and hydroxycarbamide for chronic myelogenous leukemia following therapy for malignant lymphoma]

A 57-year-old woman was diagnosed as having non-Hodgkin lymphoma (follicular mixed cell, B-cell type, Stage III) in February 1988. Since then, she had been treated with radiation and chemotherapy contained with alkylating agents and etoposide for 6 years. In April 1994, peripheral blood study disclosed leukocytosis with basophilia and thrombocytosis. Bone marrow was hypercellular. The karyotype of bone marrow cells was 46, XX, t(9:22) (q34:q11). Rearrangement of bcr was detected in bone marrow, but not in lymph node cells. On the basis of these findings, she was diagnosed as having the chronic phase of chronic myelogenous leukemia (CML) following the therapy for malignant lymphoma and treated with interferon-alpha (IFN-alpha) and hydroxycarbamide. Following this therapy, the lymphoadenopathy promptly disappeared and chromosome analysis showed disappearance of Ph chromosome positive cells. Although CML is rare in secondary leukemia, the present case seemed therapy-related CML and the treatment with IFN-alpha and hydroxycarbamide was effective for both CML and malignant lymphoma.

[CD5-negative B-cell chronic lymphocytic leukemia (B-CLL) associated with massive splenomegaly and without lymphadenopathy]

A 39-year-old male was referred to our hospital in June, 1993, because of leukocytosis. Physical examinations showed massive splenomegaly without any lymphadenopathy. The white blood cell count was 13,800/microliters with 87% morphologically mature lymphocytes. Bone marrow aspirate revealed hypercellularity with 67% lymphocytes morphologically similar to peripheral lymphocytes. The lymphocytes displayed monoclonal rearrangements of immunoglobulin genes and the phenotype of CD5-CD19+CD20+ CD21+ and Smlg+. Splenectomy was effective against neutropenia and thromboytopenia. The clinical and laboratory findings of this case were unusual compared to those of typical B-CLL in massive splenomegaly, no lymphadenopathy and CD5-phenotype, suggesting the heterogeneity of B-CLL.

A novel mechanism for exposure of fibrinogen binding sites on GPIIb-IIIa by a monoclonal antibody

Conformational changes in platelet membrane glycoprotein (GP) IIb-IIIa, whose nature is not defined, lead to exposure of fibrinogen binding sites. We have reported previously that F(ab')2 fragments of a monoclonal antibody, PMA4, directed against the GPIIb-IIIa complex-specific domain, induced binding of fibrinogen to platelets without causing intracellular activation, whereas Fab did not. In this study, we examined the mechanism responsible for the difference in the ability of PMA4 F(ab')2 and Fab to expose fibrinogen binding sites. PMA4 Fab had affinity for GPIIb-IIIa similar to that of PMA4 F(ab')2. Addition of F(ab')2 goat anti-mouse Fab antibody to cross-link PMA4 Fab-bound GPIIb-IIIa molecules induced fibrinogen binding. There was a direct correlation between the number of molecules of PMA4 F(ab')2 and the amount of fibrinogen bound. PMA4 did not recognize ligand-induced binding sites (LIBS). These results suggest that the cross-linking of special sites on the GPIIb-IIIa complex-specific domain by bivalent antibody alters the conformation of GPIIb-IIIa to a state competent to bind soluble fibrinogen and that conformational changes in non-LIBS are involved in the mechanism for exposing fibrinogen binding sites on GPIIb-IIIa.

Monoclonal proliferation of double-negative (CD4-CD8-) T-cells bearing T-cell receptor-alpha beta followed by subsequent development of Hodgkin's disease

Expression of CD4 or CD8 on the cell surface is an important guide for discriminating the immunologic functions of T-cells. However, a minor T-cell subset lacking both CD4 and CD8 molecules but bearing the usual form of T-cell receptor (TCR)-alpha beta (CD4-CD8-TCR-alpha beta+ T-cells) has recently been found not only in mice but also in humans, and the clinical relevance of this newly defined subpopulation to human diseases is now of considerable interest. The authors present a patient in whom CD4-CD8-TCR-alpha beta+ T-cells showed monoclonal proliferation in the peripheral blood for more than 3 years, then disappeared spontaneously, followed by subsequent development of Hodgkin's disease. The pathologic roles of double-negative T-cell proliferation in this case are discussed from the viewpoint of premalignancy in lymphoproliferative diseases.

Successful treatment of transfusion-associated graft-versus-host disease

We present an immunocompetent patient with transfusion-associated graft-versus-host disease (GVHD), in which chimaerism of peripheral blood lymphocytes was demonstrated by analysis of a highly polymorphic genome. The patient was treated successfully with anti-CD3 monoclonal antibody, OKT3 and cyclosporin A. Although it is undoubtedly important to prevent transfusion-associated GVHD by irradiation of cellular blood components, intensive therapy with OKT3 and cyclosporin A in the early phase of onset may be effective for treatment of this potentially fatal condition. The mechanism of the effectiveness of this treatment for transfusion-associated GVHD is discussed.

Acute transformation of chronic large granular lymphocyte leukemia into an aggressive form associated with preferential organ involvement

In most patients with large granular lymphocyte (LGL) leukemia, the disease appears to progress slowly if at all, and no therapy is generally required. We present a patient with CD3+ CD8+ CD16+ LGL leukemia, who showed a benign clinical course for more than 7 months without therapy, but subsequently developed aggressive disease. A feature of considerable interest was the transformation into an acute or aggressive form in this patient affected preferentially the liver and spleen, and was not associated with the hematologic features of the circulating leukemic cells, as assessed by morphologic, phenotypic and molecular analyses. The patient was treated with combination chemotherapy; this resulted in clinical remission with persistence of the abnormal clone in the peripheral blood. The mechanism responsible for the preferential organ involvement and the process of progression from the chronic to the acute form in this case are discussed from the viewpoint of a lymphoproliferative disorder.

Malignant lymphoma originating from the earliest T-lineage precursor cell

The earliest T-lineage precursor cells with a CD3-CD4+CD8- phenotype and germline-state T-cell receptor (TCR) genes have recently been identified in the murine thymus. We report a case of malignant lymphoma that was considered to originate from the human counterpart of this newly defined murine T-cell population. The surface phenotype of the lymphoma cells was CD2+CD3-CD4+CD8-CD25-CD34-CD44+HLA-DR+. TCR-beta, -gamma, -delta chain genes and immunoglobulin heavy and light chain genes were all in a germline state. These characteristics were markedly similar to those of the murine earliest T-lineage precursor cells. The present case thus strongly suggests the presence of the human counterpart of this novel murine T-cell population.

Immunological analysis of T cells bearing T cell receptor alpha/beta or gamma/delta in patients with granular lymphocyte proliferative disorder

Immunological analysis of 2 cases of granular lymphocyte proliferative disorder with clonal expansion of CD3+4-8+ T cells bearing either T cell receptor alpha/beta (patient 1) or T cell receptor gamma/delta (patient 2) is reported. Significant cytotoxic activity against K562 was observed in peripheral blood mononuclear cells (PBMC) isolated from patient 2, but not in PBMC from patient 1, although the cytotoxic activity of patient 1 could be augmented following incubation with anti-CD3 monoclonal antibody (MoAb). Northern blot analysis revealed that perforin mRNA was expressed in both patients. Proliferative response to phytohemagglutinin, anti-CD3 MoAb and 12-O-tetradecanoylphorbol-13-acetate was low in PBMC from both patients compared to that from healthy controls. Cytoplasmic free calcium of PBMC from the 2 patients increased similarly to that of healthy controls after treatment with anti-CD3 MoAb.

[Inversion of chromosome 16 observed in acute myeloblastic leukemia (M2) with biphenotypic surface markers lacking monocytosis and eosinophilia]

Inversion of chromosome 16 was found in a 73-year-old female with acute myeloblastic leukemia (FAB:M2). Complete remission was achieved by combined chemotherapy (DNR, Ara-C, 6-MP, Prednisolone), but she relapsed 6 months later without CNS involvement and died of respiratory failure presumably due to cerebrovascular accident during remission reinduction chemotherapy. Biphenotypic surface markers (CD2+ and CD13+) were observed on relapse. Eosinophilia was not observed throughout. Our patient and the other reported case suggest that biphenotypism and the lack of eosinophilia and monocytosis in inv (16) leukemia may be correlated with a poor prognosis.

Exposure of platelet fibrinogen receptors by a monoclonal antibody to the GPIIb-IIIa complex, PMA4

We found that a monoclonal antibody to the glycoprotein (GP) IIb-IIIa complex, PMA4, induces fibrinogen binding to platelets, and we examined the mechanism involved. Affinity chromatography and crossed immunoelectrophoresis showed that PMA4 recognized an epitope on the GPIIb-IIIa complex-specific domain. The binding of 125I-fibrinogen to platelets was induced by PMA4 in a concentration-dependent manner and was blocked by EDTA, RGDS peptides and an anti-GPIIb-IIIa monoclonal antibody, PMA1. Binding of the divalent antibody to the GPIIb-IIIa complex was necessary to induce fibrinogen binding and subsequent platelet aggregation, since Fab fragments, unlike PMA4 IgG and F(ab')2 fragments, did not induce fibrinogen binding or aggregation. The PMA4 IgG induced fibrinogen binding, serotonin secretion, and Ca2+ mobilization, whereas F(ab')2 induced fibrinogen binding only. In addition, F(ab')2-induced fibrinogen binding was not abolished in the presence of aspirin, H-7, a protein kinase C inhibitor, PGE1 or dibutyryl cyclic AMP. These results demonstrate that the binding of PMA4 divalent molecules to the GPIIb-IIIa complex can expose platelet fibrinogen receptors in the absence of the stimulatory effects of intracellular mediators on platelets. Thus, we conclude that the fibrinogen receptors on the GPIIb-IIIa complex can be exposed by direct action of the antibody on the complex molecules.

Adult T cell leukemia associated with eosinophilia: analysis of eosinophil-stimulating factors produced by leukemic cells

The mechanism of eosinophilia in a patient with adult T cell leukemia (ATL) was investigated. A 61-year-old woman with ATL presented marked eosinophilia. No parasite infections or allergic diseases were found in this patient. The number of eosinophils fluctuated in parallel with that of ATL cells during her clinical course. The patient's serum and the culture supernatant of ATL cells showed eosinophil colony-stimulating activity. Northern blot analysis of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and interleukin-5 (IL-5), which are known eosinophil CSFs, showed that only GM-CSF but not IL-3 or IL-5 was expressed in freshly separated and cultured ATL cells. Since neutrophil and monocyte numbers did not increase, it is suggested that GM-CSF and unknown cytokines other than IL-3 and IL-5 produced by ATL cells synergistically stimulated eosinophil precursors in the present case.

Proliferation of double-negative (CD4-CD8-) T cells bearing T-cell receptor-alpha beta in a haemophiliac with human immunodeficiency virus type 1 infection and factor VIII inhibitor: functional properties of double-negative T-cell receptor-alpha beta+ T cells

We present a patient with haemophilia A showing human immunodeficiency virus type 1 (HIV-1) infection and factor VIII inhibitor in whom a novel T-cell subpopulation, double-negative (CD4-CD8-) T cells bearing T-cell receptor (TCR)-alpha beta, proliferated polyclonally in the peripheral blood. An interleukin-2-dependent T-cell line with a CD4-CD8-TCR-alpha beta+ phenotype was established from the peripheral blood lymphocytes of the patient, and its biological functions were studied. It was found that the CD4-CD8-TCR-alpha beta+ T cells possessed both HLA-unrestricted cytotoxicity and helper function for immunoglobulin production by B cells. In addition, these T cells were found to produce interferon-gamma and interleukin-2 following activation via CD3-TCR complexes. These data demonstrating the multifunction of these newly defined CD4-CD8-TCR-alpha beta+ T cells thus suggest that these cells play an important role in protection against HIV infection. The mechanism of production of factor VIII inhibitor in the present case is also discussed focusing on the CD4-CD8-TCR-alpha beta+ T cells.

Discrepancy between antiplatelet antibody activities detected by immunoblot procedure and platelet counts in idiopathic thrombocytopenic purpura

By immunoblot procedure it is possible to identify the pathogenic autoantibody responsible for platelet destruction in idiopathic thrombocytopenic purpura (ITP). We assessed the relationship between antiplatelet antibody activities detected by this technique and clinical thrombocytopenia in a patient with ITP whose antiplatelet autoantibody was directed toward an 85-kDa antigen. In this patient, over a 2-year-period, the platelet counts were not correlated with the levels of antiplatelet autoantibody detected by immunoblotting. The present observations suggest that IgG autoantibody directed toward a specific antigen is not necessarily a critical determinant of the degree of thrombocytopenia, and that factors other than IgG-Fc-receptor-mediated platelet destruction are also important in the determination of the disease activity in ITP.

Induction of platelet Ca2+ influx and mobilization by a monoclonal antibody to CD9 antigen

We found that a monoclonal antibody (MoAb) to CD9 antigen, PMA2, induced a rise in cytosolic free calcium concentration ([Ca2+]i) in fura-2-loaded platelets, and we examined whether this response was due to direct action of PMA2 on CD9 antigen. The rise in [Ca2+]i was dependent on the PMA2 concentration, irrespective of the presence or absence of extracellular Ca2+. The role of secreted adenosine diphosphate (ADP) and thromboxane in the [Ca2+]i response to PMA2 was studied using creatine phosphate/creatine phosphokinase (CP/CPK) and aspirin. Combined treatment with CP/CPK and aspirin abolished the rise in [Ca2+]i, although either CP/CPK or aspirin alone produced only partial inhibition. Inhibition of adenosine triphosphate (ATP) secretion and thromboxane B2 synthesis by an MoAb to the glycoprotein IIb-IIIa complex, PMA1, resulted in little [Ca2+]i response to PMA2. In contrast, thrombasthenic platelets, in which ATP secretion and thromboxane B2 synthesis were normal, showed a normal [Ca2+]i response. When PMA2 was added to CD9+ mononuclear cells, no rise in [Ca2+]i was observed. Thus, we conclude that binding of monoclonal immunoglobulin G molecules to the CD9 antigen raises [Ca2+]i through the effect of secreted ADP and thromboxane on platelets, and that CD9 antigen is not directly involved in induction of Ca2+ influx and mobilization.

Exposure of platelet fibrinogen receptors by a monoclonal antibody to CD9 antigen

We found that a monoclonal antibody to CD9 antigen, PMA2, induces fibrinogen binding to platelets and examined the mechanism for this. That PMA2 recognized the CD9 antigen was confirmed by its immunoblot-reactivity with a 24,000-dalton protein, reactivity with platelets and common acute lymphoblastic leukemia (ALL) cells, and competitive binding with the ALB6 antibody known as the CD9 antibody. At saturation, PMA2 bound to approximately 46,000 sites per platelet. The binding of 125I-fibrinogen to platelets occurred in a PMA2 concentration-dependent manner and was blocked by EDTA or an anti-glycoprotein (GP)IIb-IIIa monoclonal antibody. PMA2-stimulated platelets caused ATP secretion and thromboxane B2 synthesis under non-stirred conditions. The role of secreted ADP and thromboxane in fibrinogen-binding and subsequent platelet aggregation was studied using creatine phosphate/creatine phosphokinase (CP/CPK) and aspirin. CP/CPK or aspirin alone reduced fibrinogen binding to 20% to 30%; however, this binding was sufficient to support full platelet aggregation. Combined treatment with CP/CPK and aspirin abolished fibrinogen binding and aggregation. These results demonstrate that the binding of IgG molecules to the CD9 antigen exposes fibrinogen receptors through both secreted ADP and thromboxane and that either one of both can expose the receptors to an extent sufficient to aggregate platelets.

Expression of CD9 (p24) antigen on hematopoietic cells following treatment with phorbol ester

Expression of the leukemia-associated cell surface antigen p24 (CD9) on human hematopoietic cell lines and B-cell chronic lymphocytic leukemia (B-CLL) cells was analyzed before and after treatment with the phorbol ester 12-o-tetradecanoyl-phorbol 13-acetate (TPA). Little or no expression of CD9 was detected in any of the cell lines used or in B-CLLs before treatment with TPA. After exposure to TPA, HL-60, Epstein-Barr virus-immortalized B-cell lines, Molt-3, MT-2 and B-CLLs showed markedly augmented CD9 expression. U937 and K562 showed slight increases of CD9 expression. However, no expression of CD9 was induced in CCRF-CEM or HUT-102. Although CD9 is known to be one of the most useful markers of pre-B-cell common acute lymphoblastic leukemia, the expression of CD9 does not seem to be restricted to any specific cell lineage and can be induced in various hematopoietic cell lineages by treatment with TPA.

Phenotypic and genotypic analysis of chronic myelogenous leukaemia with T lymphoblastic and megakaryoblastic mixed crisis

A case of blast crisis in chronic myelogeneous leukaemia (CML) in which two distinct cell lineages were involved is presented. The phenotype of blasts in lymph nodes was T11 (CD2)+, Ia+, TdT+, suggesting T cell lineage. On the other hand, blasts in bone marrow and peripheral blood expressed platelet glycoprotein IIb/IIIa complex on their surface, suggesting megakaryocyte lineage. Cytogenetic analysis of lymph node and bone marrow cells revealed the abnormalities, inv(7) (p15q34) and t(1;3) (q23;q21), respectively, as well as the presence of the Ph1 chromosome in both cell types. Rearrangement of the T cell receptor beta-chain gene was detected in lymph node blasts, although blast cells in peripheral blood showed a germ line configuration. The involvement of T cell and megakaryocyte lineages in the blast crisis phase of CML was confirmed in our phenotypic and genotypic analysis, and the pathogenic association between blast crisis lineages and the additional chromosome abnormalities present is discussed.

Platelet cyclo-oxygenase deficiency in a Japanese

A case of platelet cyclo-oxygenase deficiency in a Japanese was investigated. There was a marked decrease of aggregation with collagen and absence of aggregation with epinephrine and arachidonic acid. The platelet response to a labile aggregation stimulating substance (LASS) was normal. There was no biosynthesis of prostaglandin endoperoxides from arachidonate. The platelets, including granular volume, showed no ultrastructural abnormalities. The responses to various inducers of platelet aggregation, except for arachidonate, were different from the cases described by others. It is concluded that the defective platelet function, due to a deficiency of platelet cyclo-oxygenase, is heterogeneous.