Diversity of leukaemic cell morphology in ATL correlates with prognostic factors, aberrant immunophenotype and defective HTLV-1 genotype

To investigate the diversity of morphology in adult T-cell leukaemia/lymphoma (ATL) and its possible association with the pathophysiology of ATL, we selected 36 acute cases and 14 chronic cases phenotypically confirmed to have >90% ATL cells in peripheral blood mononuclear cells. Prototype ATL cells were observed in all cases, although the percentage of all lymphoid cells varied considerably (48.9 +/- 23.8 in acute type, 29.6 +/- 18.9 in chronic type; P = 0.015). Chronic lymphocytic leukaemia (CLL)-like morphology with round nuclei was more frequent in chronic type than in acute type (52.0 +/- 24.9% v 16.6 +/- 13.1%; P < 0.0001). Unusual morphology (UM; lymphoblastic, vacuolated, granular pleomorphic or large cells) was more frequent in acute type than in chronic type (20.1 +/- 18.7% v 2.7 +/- 3.2%; P < 0.0001). Furthermore, there were significant negative and positive correlations of % CLL-like cells and % UM cells respectively, with serum LDH level, hypercalcaemia, performance status, and total number of involved lesions. Cases with aberrant immunophenotype (n = 6) or defective HTLV-1 integration (n = 22) showed lower % CLL-like cells and higher % UM cells than other cases, respectively. Cases with >50% CLL-like cells (n = 7; all chronic type) were younger (53.1 +/- 12.2 v 66.9 +/- 10.6 years; P = 0.038) and showed longer acute-crisis free survival (mean: 16.7 v 3. 0 years; P = 0.012) than chronic cases with <50% CLL-like cells. These results suggest that diversity in genotype, phenotype, morphology and behaviour of ATL are closely associated, and that CLL-like morphology is a good prognostic factor for chronic type.

Low prevalence of Helicobacter pylori in individuals with HTLV-I infection

BACKGROUND

The prevalence of Helicobacter pylori in HIV-positive individuals is significantly lower than in HIV-negative controls. However, its prevalence in individuals infected with human T-cell leukaemia virus type I (HTLV-I), another important member of the human retrovirus family, has not been previously investigated.

OBJECTIVE

To establish the prevalence of H. pylori in HTLV-I-positive individuals in the Nagasaki Prefecture, which is an area endemic for HTLV-I.

METHODS

We examined sera from 146 HTLV-I-positive individuals with a mean age of 56.7 years, consisting of 45 adult T-cell leukaemia (ATL) patients, 13 HTLV-I-associated myelopathy (HAM) patients and 88 healthy carriers. Serum samples of 292 age- and sex-matched HTLV-I-negative controls were also examined. Serum anti-H. pylori immunoglobulin (Ig) G antibody was examined using an enzyme-linked immunosorbent assay kit. Twenty-eight HTLV-I-positive patients were examined endoscopically, assessed for H. pylori by culture, histology and CLO test using gastric biopsy specimens, and gastritis in these patients was also graded histologically.

RESULTS

The seroprevalence of H. pylori was 48% in HTLV-I-positive individuals versus 64% in HTLV-I-negative controls (P < 0.01). In the three HTLV-I-positive groups, ATL patients and carriers had significantly lower seroprevalence of H. pylori than the HTLV-I-negative controls (P < 0.05). Assessment of H. pylori using gastric biopsy specimens also showed a significantly lower prevalence of H. pylori infection in HTLV-I-positive patients than controls (46% versus 70%, P < 0.05). Histological examination showed a significantly higher degree of activity, inflammation and glandular atrophy in the antrum and corpus in H. pylori-positive patients compared to H. pylori-negative patients. H. pylori-positive patients with HTLV-I infection had a more severe degree of glandular atrophy in the corpus than H. pylori-positive controls without HTLV-I infection.

CONCLUSION

We have found a reduced prevalence of H. pylori in HTLV-I-positive individuals. Whatever the explanation, infection with HTLV-I does not predispose to the risk of H. pylori infection.

Genetic analysis of serotype 23F Streptococcus pneumoniae isolates from several countries by penicillin-binding protein gene fingerprinting and pulsed-field gel electrophoresis

We characterized 21 strains of serotype 23F Streptococcus pneumoniae isolated in various countries with various levels of penicillin susceptibility by penicillin-binding protein (PBP) gene fingerprinting and pulsed-field gel electrophoresis (PFGE). Pneumococci isolated in Israel, Hungary, Bulgaria, Slovakia, Rumania, France, the United States, Spain and Japan were included. These strains were classified into 12 and 18 groups by PBP gene fingerprinting and PFGE, respectively. Some of the pneumococci isolated in Spain, the United States and France appeared to be genetically related by PFGE, showed the same PBP gene pattern and had similar antimicrobial susceptibility patterns. One penicillin-susceptible Bulgarian strain, with a similar PFGE pattern but a different fingerprinting pattern, may be an ancestral recipient strain that became transformed into the resistant variants. Rumanian and Israeli strains were also genetically related by PFGE. These results indicate the existence of widely spread but related pneumococci in the world. PBP 2X gene profiles of pneumococci with MICs of 0.25 microg/ml were different from each other and from penicillin-susceptible pneumococci (PSP). PBP 2B gene profiles of these resistant strains were identical. PBP 2B gene profiles of pneumococci (penicillin MICs >/=0.5 microg/ml) were different from PSP. PBP gene profiles may not only be useful for genetic analysis but also for presumed penicillin susceptibility.

Fas gene mutation in the progression of adult T cell leukemia

Fas antigen (Apo-1/CD95) is an apoptosis-signaling cell surface receptor belonging to the tumor necrosis factor receptor superfamily. Adult T cell leukemia (ATL) cells express Fas antigen and show apoptosis after treatment with an anti-Fas monoclonal antibody. We established the ATL cell line KOB, which showed resistance to Fas-mediated apoptosis, and found that KOB expressed two forms of Fas mRNA, the normal form and a truncated form. The truncated transcript lacked 20 base pairs at exon 9, resulting in a frame shift and the generation of a premature stop codon at amino acid 239. The same mutation was detected in primary ascitic cells and peripheral blood cells. The mutation was not detected in lymph node cells, however, although all of the primary ATL cells were of the same clonal origin. A retroviral-mediated gene transfer of the truncated Fas to Jurkat cells rendered the cells resistant to Fas-mediated apoptosis, suggesting a dominant negative interference mechanism. These results indicate that an ATL subclone acquires a Fas mutation in the lymph nodes, enabling the subclone to escape from apoptosis mediated by the Fas/Fas ligand system and proliferate in the body. Mutation of the Fas gene may be one of the mechanisms underlying the progression of ATL.

Multi-clonal expansion of unique human T-lymphotropic virus type-I-infected T cells with high growth potential in response to interleukin-2 in prodromal phase of adult T cell leukemia

We established a simple IL-2-dependent colony-forming assay for T cells infected with human T-lymphotropic virus type-I (HTLV-I). IL-2-dependent cell lines were subsequently established by expanding individual colonies in liquid cultures. Lymphocyte-rich fractions were prepared from 31 HTLV-I carriers, 12 patients with smoldering ATL, 11 chronic ATL, 12 crisis ATL and 10 acute ATL. Primary colonies of CD4+ p19+ T cells were formed in all cases of carriers, smoldering and chronic ATL, and in 10 of 12 crisis cases. In contrast, no colony was formed from cells of patients with acute ATL. The rate of establishment of cell lines in HTLV-I carriers was significantly lower than that in patients of prodromal phase ATL. Cell lines established from cells of three prodromal cases were clonally identical to the parent ATL cells, while others had clonally distinct cell lines. Our results indicated the presence of four components of HTLV-I-infected T cells: (1) normal carrier T cells capable of forming colonies but not cell lines; (2) pre-malignant T cells capable of forming colonies as well as cell lines; (3) malignant T cells capable of forming colonies as well as cell lines; (4) fully malignant T cells unresponsive to IL-2. Our results suggest the presence of a multiclonal expansion of unique T cells in the prodromal phase of ATL, which have a high growth potential in response to IL-2. The coexistence of multiclonality with a dominant ATL clone may be closely related to the underlying pathology in HTLV-I leukemogenesis.

Qualitative and quantitative characterization of Fas (APO-1/CD95) on leukemic cells derived from patients with B-cell neoplasms

Expression density and function of Fas (APO-1/CD95) on malignant B-cells, an antigen thought responsible for abnormal tumor biology, remains to be fully understood. Fifty-five cases with B-cell neoplasms of acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL), hairy cell leukemia (HCL), B-cell malignant lymphoma (ML), and myeloma (MM) were studied for qualitative and quantitative expression and function of Fas using flow cytometry and annexin-V staining methods. Fas expression was flow cytometrically unimodal with heterogeneous density and showed quantitatively characteristic features among different diseases; weak in ALL, faint in CLL, moderate in HCL, and strong in ML, respectively. Not only full-length but also alternatively spliced truncated mRNAs were detected even in leukemic B-cells with qualitatively faint or negative Fas, and then band density of the former transcripts by RT-PCR was correlated to the Fas protein expression level. Short-term culture of freshly isolated cells gave rise to increases of Fas density and susceptibility for apoptosis, suggesting that the mRNA and inducible Fas are functional at least in vitro. These results show that Fas is a biological marker for characterizing B-cell neoplasms reflecting various stages of B-cell ontogeny and may have clinical utility as a therapeutic strategy.

Analysis of genetic relationships and antimicrobial susceptibility of verotoxin-producing Escherichia coli strains isolated in Nagasaki Prefecture, Japan in 1996

A total of 19 Escherichia coli O157 isolates were obtained in Nagasaki Prefecture, in the south-western part of Japan, between 1990 and 1996. Pulsed-field gel electrophoresis (PFGE) and computer-assisted analysis were applied to determine genetic relationships among these strains. Fragment patterns of the isolates in Nagasaki, as determined by PFGE, were compared with those of isolates in other areas where large outbreaks and sporadic cases of E. coli O157 infection occurred. Similarity values of all the strains isolated in Nagasaki Prefecture were over 0.65 except for E. coli O26. Some strains were identical to the strains isolated from the areas where large outbreaks occurred. All strains were susceptible to ampicillin, fosfomycin, minocycline, amikacin, ofloxacin and sulfamethoxazole-trimethoprim.

Immunohistochemical expression of ABH/Lewis-related antigens in primary breast carcinomas and metastatic lymph node lesions

The expression of blood group antigens A, B, and H, as well as sialylated and nonsialylated forms of Lewis(a) and Lewis(x), was studied using immunohistochemical methods in normal and tumor tissues in the following cohort of patients: 51 patients with primary breast carcinoma, 13 with metastatic lymph node lesions, and 16 with benign tumors of the breast. As a control, normal tissue was obtained from a similar group of 22 patients with breast cancer. The noncancerous tissues expressed the same A/B/H antigens as the patients' red blood cells and also usually expressed Lewis-related antigens. Seventy-six percent of primary carcinomas failed to express the appropriate A/B/H antigens, and in one blood group A patient the tumor tissue expressed B antigen. In the metastatic lesions, Lewis(a)/sialyl Lewis(a) expression was reduced when compared with the primary tumors, but Lewis(x)/sialyl Lewis(x) antigens were still expressed. These results suggest a possible relationship between the metastatic behavior of the tumor and expression of the blood group antigens.

Genetic relationship between blood and nonblood isolates from bacteremic patients determined by pulsed-field gel electrophoresis

A total of 148 isolates from 55 bacteremic patients were examined by pulsed-field gel electrophoresis. Genetically different nonblood strains were isolated from 13.9% of patients with bacteremia caused by gram-positive cocci and 42.1% with Pseudomonas aeruginosa bacteremia, indicating that antibiograms of a single nonblood P. aeruginosa isolate are not always informative for treatment of bacteremia.

Escherichia coli O157 interactions with human intestinal Caco-2 cells and the influence of fosfomycin

It is not clear how Escherichia coli O157 invades human enteric epithelium and causes the haemolytic uraemic syndrome (HUS), and nor has the most appropriate treatment of E. coli O157 infection been established. Verotoxins, leucocytes and proinflammatory cytokines, such as tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-6 and IL-8, are considered essential for the development of HUS. We used the Caco-2 cell monolayer system, well-known as an in-vitro model of human intestinal infection, to determine how E. coli O157 interacts with intestinal epithelial cells and also studied the influence of fosfomycin on the virulence of the bacteria. Results showed that the E. coli O157 used in this study did not penetrate the Caco-2 cell monolayer system, unlike Salmonella typhimurium SL1344, and verotoxin 1 (VT 1), but not VT 2, translocated across the system. In an in-vitro conventional assay, fosfomycin increased the amount of verotoxins but it did not influence penetration of bacteria and translocation of verotoxins in the Caco-2 cell monolayer system. The production of both IL-8 (a potent neutrophil activator) and TNF-alpha in the human monocytic THP-1 cell line was reduced by fosfomycin-treated basolateral medium in this system. These results indicate that fosfomycin may be a potent drug for preventing HUS caused by E. coli O157 infection.

Rapid detection and evaluation of clinical characteristics of emerging multiple-drug-resistant gram-negative rods carrying the metallo-beta-lactamase gene blaIMP

Gram-negative rods (GNR) carrying the transferable carbapenem resistance gene blaIMP, including Pseudomonas aeruginosa and Serratia marcescens, have been isolated from more than 20 hospitals in Japan. Although the emergence of such multiple-drug-resistant bacteria is of utmost clinical concern, little information in regard to the distribution of blaIMP-positive GNR in hospitals and the clinical characteristics of infected patients is available. To address this, a system for the rapid detection of the blaIMP gene with a simple DNA preparation and by enzymatic detection of PCR products was developed. A total of 933 ceftazidime-resistant strains of GNR isolated between 1991 and 1996 at Nagasaki University Hospital, Nagasaki, Japan, were screened for the blaIMP gene; 80 isolates were positive, including 53 P. aeruginosa isolates, 13 other glucose-nonfermenting bacteria, 13 S. marcescens isolates, and 1 Citrobacter freundii isolate. Most of the patients from whom blaIMP-positive organisms were isolated had malignant diseases (53. 8%). The organisms caused urinary tract infections, pneumonia, or other infections in 46.3% of the patients, while they were just colonizing the other patients evaluated. It was possible that blaIMP-positive P. aeruginosa strains contributed to the death of four patients, while the other infections caused by GNR carrying blaIMP were not lethal. DNA fingerprinting analysis by pulsed-field gel electrophoresis suggested the cross transmission of strains within the hospital. The isolates were ceftazidime resistant and were frequently resistant to other antibiotics. Although no particular means of pathogenesis of blaIMP-positive GNR is evident at present, the rapid detection of such strains is necessary to help with infection control practices for the prevention of their dissemination and the transmission of the resistance gene to other pathogenic bacteria.

Paroxysmal nocturnal haemoglobinuria clones in patients with myelodysplastic syndromes

Among acquired stem cell disorders, pathological links between myelodysplastic syndromes (MDS) and aplastic anaemia (AA), and paroxysmal nocturnal haemoglobinuria (PNH) and AA, have been often described, whereas the relationship between MDS and PNH is still unclear. We analysed blood cells of patients with MDS to determine the incidence of the PNH clone, and analysed the PIG-A gene to find mutations characteristic of the PNH clone in MDS. In four (10%) of 40 patients with MDS, flow cytometry showed affected erythrocytes and granulocytes negative for decay-accelerating factor (DAF) and CD59. The population of affected erythrocytes was smaller in MDS patients with PNH clone (MDS/PNH) than in patients with de novo PNH, and haemolysis was milder in the MDS/PNH patients. PIG-A mutations were found in granulocytes of all patients with MDS/PNH. In type and site, the PIG-A mutations were heterogeneous, similar to that observed in de novo PNH; i.e. no mutation specific to MDS/PNH was identified. Of note, three of four patients with MDS/PNH each had two PNH clones with different PIG-A mutations, suggesting that PIG-A is mutable in patients with MDS/PNH. In a MDS/PNH patient with trisomy 8, FISH detected a distinct karyotype in a portion of granulocytes with PNH phenotype, indicating that PNH and MDS partly shared affected cells. Thus, MDS predisposes to PNH by creating conditions favourable to the genesis of PNH clone. Considering the increasing prevalence and incidence of MDS, these disorders could be useful for investigating the mechanism by which PIG-A mutation is induced.

Retinoic acids induce growth inhibition and apoptosis in adult T-cell leukemia (ATL) cell lines

Adult T-cell leukemia (ATL) is a peripheral T-cell neoplasm caused by human T-cell leukemia virus type I (HTLV-I). Despite the administration of combined intensive chemotherapy, the reported survival time of patients with acute and lymphoma types of ATL is less than 10 months. We therefore examine the effects of all-trans-retinoic acid (ATRA), 9-cis-RA and 13-cis-RA and tried to elucidate the mechanisms of inducing growth inhibition and apoptosis by these RAs using four ATL cell lines established in our laboratory. All the investigated RAs inhibited cell growth and the cells were arrested at the G1 phase. Apoptosis was induced in three out of four cell lines. Among the growth regulatory proteins examined, the level of p21Waf1/Cip1 protein was found to increase after RA treatment, thus resulting in pRb hypophosphorylation which also induced the arrest of the cells at the G1 phase. In addition, the p53 level decreased at the same time. Fas-FasL system and the downregulation of CD25 (IL-2R/alpha) expression did not seem to be involved. Based on these findings, the ability of RAs to induce a remission of ATL is thus strongly suggested.

Interleukin-15 (IL-15) can replace the IL-2 signal in IL-2-dependent adult T-cell leukemia (ATL) cell lines: expression of IL-15 receptor alpha on ATL cells

Interleukin-15 receptor (IL-15R) and IL-2R have the same beta and gamma chains, but IL-15R has a specific alpha chain distinct from that of IL-2Ralpha, which is indispensable for the high affinity binding of IL-15. In the present study, we examined four IL-2-dependent adult T-cell leukemia (ATL) cell lines for their IL-15R expression. All cell lines bound IL-15, which was not inhibited by a 100-fold excess amount of IL-2, proliferated in response to IL-15 to the same degree as to the stimulation with IL-2, and were maintained without IL-2. The responses to 1L-15 were inhibited by the antibodies against IL-2R beta or gamma chains but was not by the IL-2R alpha chain antibody. [125I]-IL-15 exhibited a single high-affinity binding with an apparent kd of 0.17 nmol/L. Reverse transcription-coupled polymerase chain reaction (RT-PCR) showed that the cell lines had the mRNA of IL-15R alpha. The cell lines also had IL-15 mRNA. Despite the presence of IL-15 mRNA, the cell lines did not secrete IL-15, and the culture supernatants of fresh ATL cells and plasma from the patients did not contain a detectable amount of IL-15 with a few exceptional cases, although fresh ATL cells also responded to IL-15. These results suggest that ATL cells have the complete form of IL-15R and respond to IL-15. Such an IL-15-dependent cell proliferation mechanism might be used in the development of ATL and for the invasion and proliferation of ATL cells in the visceral organs.

Antimicrobial susceptibility testing of Bilophila wadsworthia isolates submitted for routine laboratory examination

MICs of antibiotics against Bilophila wadsworthia isolates were measured by agar and broth microdilution with pyruvic acid and by Etest. The inoculum size influenced greatly agar dilution. Despite discrepancies in MICs depending on the measurement method used, clindamycin consistently showed potent activity. Broth microdilution and Etest appear to be candidates for laboratory susceptibility testing.

Systemic mastocytosis with extensive polypoid lesions in the intestines; successful treatment with interferon-alpha

A 35-year-old female presented in 1989 with hepatosplenomegaly, but no conclusive diagnosis was established. From 1992, she experienced transient episodes of facial flushing and palpitations. Osteosclerotic change was detected radiologically. Colonoscopy revealed massive polypoid lesions. Mast cells were demonstrated in bone marrow smear and imprinted preparations of colon biopsy specimens by toluidine blue staining. Plasma concentrations of histamine and soluble c-kit were elevated. She was successfully treated with interferon-alpha and prednisolone, resulting in the disappearance of histamine-related attacks and a gradual decrease in tumor size. However, the remission was interferon dose dependent. This case was considered as systemic mastocytosis with massive polypoid colon lesions and showed the importance of maintenance therapy with interferon-alpha.

Adherence to and penetration of human intestinal Caco-2 epithelial cell monolayers by Pseudomonas aeruginosa

Clinical isolates of Pseudomonas aeruginosa from blood adhered to and penetrated intestinal Caco-2 cell monolayers to a greater degree than did isolates from sputum, with a concomitant drastic decrease in transepithelial electrical resistance. PAO-PR1, an avirulent exotoxin A mutant of PAO1, did not cause a decrease in the resistance. The Caco-2 monolayer system may be useful for the evaluation of certain P. aeruginosa virulence factor activities.

In vitro activities of quinupristin-dalfopristin and the streptogramin RPR 106972 against Mycoplasma pneumoniae

The in vitro activities of quinupristin-dalfopristin and streptogramin RPR 106972 were determined with 44 strains of Mycoplasma pneumoniae and compared to those of macrolides, minocycline, and quinolones. All isolates tested were highly susceptible to macrolides and to quinupristin-dalfopristin (MIC at which 90% of the isolates are inhibited [MIC90], 0.0625 microg/ml), followed by RPR 106972 (MIC90, 0.5 microg/ml), quinolones, and minocycline.

Possible association between adult T-cell leukemia/lymphoma and acute myeloid leukemia

BACKGROUND

To the authors' knowledge, an association between adult T-cell leukemia/lymphoma (ATL) and acute myeloid leukemia (AML) has been reported only in four patients. The authors identified five additional patients with both neoplasms.

METHODS

A review of the clinical records of patients with AML, ATL, or lymphoid neoplasms other than ATL diagnosed between 1986 and 1995 was performed. Cytokine levels were assayed in selected patients. The authors searched for reports from other institutions using MEDLINE and the proceedings of two Japanese hematology societies.

RESULTS

ATL was diagnosed in 134 patients, whereas 180 had AML. Five patients with both neoplasms were identified (3.7% of ATL patients and 2.8% of AML patients). In seven of the nine patients (including four patients in the literature) with ATL and AML, the ATL was diagnosed prior to the AML, whereas in the remaining two patients both neoplasms were diagnosed simultaneously. Six of the nine cases were therapy-related (t)-AML, which developed after chemotherapy for ATL. Monoclonal integration of proviral human T-lymphotropic virus type 1 was detected in ATL cells but not in AML cells in the six patients examined. The plasma levels of macrophage colony-stimulating factor (M-CSF), granulocyte-colony stimulating factor, and granulocyte-macrophage-colony stimulating factor (GM-CSF) were elevated in 3, 1, and 1, respectively, of the 4 patients examined at AML onset who had active ATL. In one case, the levels of several cytokines, including GM-CSF and M-CSF, in the supernatant fluid of short term cultured ATL cells were elevated. Three patients with de novo ATL and AML received remission induction therapy, and two achieved a complete remission (CR) of both diseases. Among the four patients who received chemotherapy for t-AML, two achieved CR.

CONCLUSIONS

ATL patients also can develop AML, irrespective of treatment with chemotherapy for ATL. This association does not indicate exclusive chemoresistance of both neoplasms. Cytokines produced by ATL cells may support the growth of AML cells.

The methylthioadenosine phosphorylase gene is frequently co-deleted with the p16INK4a gene in acute type adult T-cell leukemia

Adult T-cell leukemia (ATL) is a retrovirus-associated leukemia with poor prognosis and often has deletions of the p16INK4a and p15INK4b genes on chromosome 9p21. The gene for methylthioadenosine phosphorylase (MTAP), a purine and methionine metabolic enzyme, resides approximately 100 Kb telomeric to the p16INK4a gene and is frequently co-deleted with the tumor suppressor gene in a variety of cancers. This enzyme deficiency can be exploited for selective chemotherapy with de novo purine synthesis inhibitors and/or methionine depletion. To determine whether ATL can be a candidate for selective chemotherapy based on genetic alterations on chromosome 9p21, we analyzed the MTAP gene in 41 samples from ATL patients (27 acute type and 14 chronic type ATL) and 3 cell lines established from ATL patients. Five samples from the acute type had deletions of the MTAP gene (4 total deletions and 1 partial deletion of exons 6-8). The MTAP gene was always co-deleted with p16INK4a. No deletion of the MTAP gene was detected in samples from the chronic type. Of 3 cell lines, 2 showed partial deletions of exons 5-8 of the MTAP gene, and 1 lost all exons. The p16INK4a gene was deleted in all cell lines. In conclusion, deletions of the MTAP gene were found in 5 of 27 acute type ATL samples. Acute type ATL with MTAP deficiency can be a good candidate for selective chemotherapy by depleting purines and/or methionine.

Circulating interleukin-6 levels are elevated in adult T-cell leukaemia/lymphoma patients and correlate with adverse clinical features and survival

We measured the circulating levels of interleukin (IL)-6 in adult T-cell leukaemia/lymphoma (ATL) patients using an enzyme-linked immunosorbent assay. The IL-6 levels in 59 ATL patients (median 8.2 pg/ml; range < 1.0 to 185.7 pg/ml) were significantly higher than in 30 healthy controls (median < 1.0 pg/ml; range < 1.0 to 3.5 pg/ml) (P < 0.0001) or 32 human T-lymphotropic virus type-I (HTLV-I) carriers (median 4.2 pg/ml: range < 1.0 to 13.3 pg/ml) (P = 0.002). Among the ATL patients, the IL-6 levels in the acute- or lymphoma-type patients were significantly higher than those in the chronic-type patients (P < 0.0001). The IL-6 levels were also higher in the patients with B symptoms than in those without B symptoms (P = 0.039), and were significantly correlated with increased serum lactate dehydrogenase (LDH) (P = 0.0004) and C-reactive protein (CRP) (P < 0.0001) and decreased serum albumin (P = 0.0003) values. The patients with elevated IL-6 levels had inferior overall survival periods compared to those with normal IL-6 levels (P = 0.025). ATL is a single disease entity, although its clinical features are quite diverse; the increased production of cytokines may cause the diversity of clinical features. The results of our study indicate that IL-6 is one such cytokine.

Proliferation of adult T cell leukemia/lymphoma cells is associated with the constitutive activation of JAK/STAT proteins

Human T cell leukemia/lymphotropic virus type I (HTLV-I) induces adult T cell leukemia/lymphoma (ATLL). The mechanism of HTLV-I oncogenesis in T cells remains partly elusive. In vitro, HTLV-I induces ligand-independent transformation of human CD4+ T cells, an event that correlates with acquisition of constitutive phosphorylation of Janus kinases (JAK) and signal transducers and activators of transcription (STAT) proteins. However, it is unclear whether the in vitro model of HTLV-I transformation has relevance to viral leukemogenesis in vivo. Here we tested the status of JAK/STAT phosphorylation and DNA-binding activity of STAT proteins in cell extracts of uncultured leukemic cells from 12 patients with ATLL by either DNA-binding assays, using DNA oligonucleotides specific for STAT-1 and STAT-3, STAT-5 and STAT-6 or, more directly, by immunoprecipitation and immunoblotting with anti-phosphotyrosine antibody for JAK and STAT proteins. Leukemic cells from 8 of 12 patients studied displayed constitutive DNA-binding activity of one or more STAT proteins, and the constitutive activation of the JAK/STAT pathway was found to persist over time in the 2 patients followed longitudinally. Furthermore, an association between JAK3 and STAT-1, STAT-3, and STAT-5 activation and cell-cycle progression was demonstrated by both propidium iodide staining and bromodeoxyuridine incorporation in cells of four patients tested. These results imply that JAK/STAT activation is associated with replication of leukemic cells and that therapeutic approaches aimed at JAK/STAT inhibition may be considered to halt neoplastic growth.

Quantitative characterization and potential function of membrane Fas/APO-1 (CD95) receptors on leukaemic cells from chronic B and T lymphoid leukaemias

The expression and function of the Fas-receptor (Fas-R) were examined in chronic lymphocytic leukaemia (CLL), hairy cell leukaemia-variant (HCL-v) and adult T-cell leukaemia (ATL). The expression of Fas-R in freshly isolated leukaemic cells was qualitatively and quantitatively different between each disease; faint in B-CLL, moderate in HCL-v and strong in ATL. Both full-length and alternatively spliced truncated forms of Fas mRNA were detected even in CLL B cells with faint to negative Fas-R, and Fas mRNA was also shown to be capable of increasing in vitro expression, i.e. the message was functional. In contrast, Fas-R expression on ATL cells was heterogenous and usually intense with a mean density approximately 3-fold higher than that of normal T cells. Fas-R was confirmed to have the potential function for anti-Fas monoclonal antibody-mediated cell death in vitro in Fas-R+ ATL cells. The expression level of Fas-R on the cells was higher in chronic than acute ATL (10,360 v 6260 antibody-binding capacity per cell, mFasABC; P<0.05) and was inversely correlated with serum LDH activity, suggesting that the strong Fas-R accounts for the slow progression of chronic ATL and the negative Fas-R protects from Fas-mediated cell death. These results show that Fas-R expression on leukaemic cells is valuable in their characterization and perhaps their function, and may contribute to the progression and immune evasion of malignant clones.

[Clinical evaluation of a reagent for detection of DNA of Mycobacterium tuberculosis complex using the ligase chain reaction (LCR) method]

We evaluated the clinical efficacy of LCR MTB, a reagent developed by Abbott in the USA, in the full automatic ligase chain reaction (LCR) for detection of DNA of M. tuberculosis complex using a thermostable ligase. Using 458 samples isolated from patients with tuberculosis, LCR was compared with a smear method and with a culture method, and was also compared with two other methods of gene amplification, MTD and Amplicor, using 340 and 200 of the 458 samples, respectively. The LCR method detected M. tuberculosis in 49.8% (228/458) of the samples, and was superior to the smear method (31.9%, 146/458) and the culture method (39.1%, 179/458) in sensitivity. The LCR method was also superior to the MTD and Amplicor methods; sensitivity were 37.9% (129/340) for MTD vs. 47.6% (162/340) for LCR, and 56.5% (113/200) for Amplicor vs. 59.5% (119/200) for LCR. These favorable results and the convenience of the LCR method, which enables rapid detection of target genes with a high degree of sensitivity, strongly suggest that LCR MTB is useful as a reagent for detection of M. tuberculosis using nucleic acid amplification.

[Support system for diagnosing hematologic malignancies]

We established a Southern blot hybridization using a DIG-labeled probe to detect monoclonal integration of HTLV-1 proviral genome. DIG was labeled by the PCR method and this probe was as sensitive as the 32P-labeled probe and able to detect only 1.6% of ATL cells. The clinical diagnoses of 44 patients with monoclonal band(s) were all ATL. In contrast, the clinical diagnoses of 39 patients without monoclonal band(s) were diseases other than ATL. We also performed a long PCR of HTLV-1 to characterize the integrated provirus. The method allowed us to find a defective provirus, which was frequently observed in aggressive forms of ATL; 14 of the 18 patients with acute type(78%), 6 of the 9 patients with lymphoma type(67%), and 2 of the 12 patients with chronic type(17%) had the defective provirus. We established a simultaneous PCR for each region of HTLV-1 for further examination of the defective provirus. To detect the monoclonality of IgH gene rearrangement of B-cells, we performed PCR according to the method described. None of 13 patients with T-lymphoproliferative disorders showed a monoclonal band. In contrast, 12 of 13 patients with CLL(92%), 22 of 25 patients with common ALL(88%), 18 of 24 patients with B-lymphoma(75%), and 3 of 3 patients with hairy cell leukemia(100%) showed a monoclonal band. We are now expanding this kind support system for the clinical diagnosis at a molecular biology level in the central laboratory.