A morphometric study of bone marrow angiogenesis in hairy cell leukaemia with clinicopathological correlations

Bone marrow angiogenesis has recently been implicated in the pathophysiology and course of various haematological malignancies. Little is known, however, about the significance of this phenomenon in hairy cell leukaemia (HCL). We evaluated various morphometric characteristics of microvessels, highlighted by means of anti-CD34 immunohistochemistry, in the bone marrow of 44 patients with typical HCL, before and after treatment with interferon-alpha (IFN-alpha). Overall, bone marrow from 103 HCL patients and 20 controls was examined. Microvessel density (MVD) and several size- and shape-related parameters were quantified in the region of most intense vascularization using image analysis. MVD, size-related parameters and the percentage of branching microvessels were higher in HCL than in controls. Likewise, perimeter counts were higher in partial/non-responders than in complete responders. Achievement of complete response was accompanied by smaller calibre microvessels. IFN-alpha induced a decrease in MVD and branching values in cases with diffuse marrow involvement. In univariate analysis, progression-free survival was adversely affected by MVD, branching and major axis length. Multivariate analysis indicated that MVD/branching independently affected progression-free survival and the likelihood of complete response. Our data suggest that the generation of bone marrow microvessels indicated an increased risk of progression and IFN-alpha treatment failure in HCL. Furthermore, the prognostic significance of angiogenesis requires the concomitant assessment of MVD and the complexity of the microvascular network.     

Hyposialated 185 kDa CD45RA+ molecules attain a high concentration in B lymphoma cells and in activated human B cells

Alternate splicing of exons of the CD45 molecule generates multiple isoforms differing in their molecular weights (MWs). In B-lymphocytes the CD45RA isoform was previously shown to be expressed on glycoproteins with MWs of 220 and 205 kDa, while the CD45RO isoform was expressed on glycoproteins with MW of 180 kDa. The present study demonstrated that B cell lymphomas and activated B-cells contain CD45 molecules with a MW of 185 kDa that express the CD45RA and CD45RC specificities but neither the CD45RB nor the CD45RO specificities. 185 kDa CD45RA+ molecules were detected in B cell lymphoma B lines, in Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines, and in tonsillar B cells, but not in normal, unstimulated peripheral blood B cells. These molecules were not detected in neoplastic and normal T cells. CD45RA+ 185 kDa molecules were present in B cells from three non-Hodgkin's patients in leukemic phase were not detected in B lymphocytes of seven of nine CLL patients tested. Trypsin treatment eliminated only 220 kDa CD45RA+ molecules but not 185 kDa CD45RA+ molecules, indicating that the 185 kDa CD45RA+ molecules are not expressed on the cell surface. Pulse-chase experiments, and studies on the effects of tunicamycin, neuraminidase and O-glycosidase, indicated that the 185 kDa molecules are partially glycosylated CD45RABC molecules that constitute precursors of the 220 kDa molecules. The high concentration of 185 kDa CD45RA+ molecules in B lymphoma cells and in activated B cells seems to reflect a high turnover of CD45RA+ molecules characteristic for these cells.     

Analysis of CD34+ cell subsets in stem cell harvests can more reliably predict rapidity and durability of engraftment than total CD34+ cell dose, but steady state levels do not correlate with bone marrow reserve

In peripheral blood stem cell transplantation (PBSCT), the number of CD34+ cells transplanted has been shown to correlate well with both rapidity and durability of engraftment. However, it is clear that engraftment does not necessarily correlate with total CD34+ cell numbers in some patients. Consequently, there is increasing interest in evaluating the role of CD34+ subsets in haemopoietic recovery as a more accurate marker of harvest quality. We analysed the numbers of CD34+ cell subsets, namely Thy-1+, L-Selectin+ and CD38-, and correlated this with engraftment in 86 patients undergoing PBSCT. Adequate engraftment was defined as being a platelet count greater than 50 x 10(9)/l and a neutrophil count greater than 1.0 x 10(9)/l. CD34+L-Selectin+ provided the best prediction of engraftment rapidity, although the improvement over total CD34+ cell dose was minor. Only the dose of CD34+Thy-1+ cells transplanted correlated with durable engraftment. The probability of adequate 3-month engraftment increased with the dose of CD34+ cells transplanted, but 10% of patients receiving > 5 x 10(6)/kg still showed poor engraftment at 3 months. However, all patients receiving > 2.5 x 10(5)/kg CD34+Thy-1+ showed adequate engraftment at this time point. We also demonstrated that CD34+Thy-1+ progenitors were restricted to the bone marrow under normal conditions and, during stem cell mobilization, their kinetics generally paralleled total CD34+ numbers.     

Poor lymphocyte recovery following CD34-selected autologous peripheral blood stem cell transplantation for non-Hodgkin's lymphoma

Positive selection of CD34+ cells in autologous grafts, designed to deplete tumour cells, also results in T-cell depletion. To assess the reconstitution of the different lymphocyte subsets and of the T-cell repertoire diversity following autologous transplantation of selected CD34+ peripheral blood stem cells (PBSC), we analysed sequential blood samples in eight patients autografted for advanced B-cell non-Hodgkin's lymphoma in a phase I-II pilot study. Although natural killer cell recovery was rapid, T- and B-cell recovery was delayed with a median of 110/microliters CD4+, 175/microliters CD8+ T cells and 45/microliters B cells at 12 months post-transplant. The naive CD45RA+ T-cell compartment was profoundly deficient up to 12 months for both CD4+ and CD8+ subsets. A transient expansion of memory CD8+CD45RO+ T cells consisting of an increased percentage of CD57+CD28- cells occurred within the first 3 months post-transplant, but the memory CD4+CD45RO+ T cells remained far below the normal value. The CD8+CD28+ T-cell subset did not recover. Using multiplex PCR analysis of the T-cell receptor gamma locus, we found that the repertoire diversity improved at 12 months after being poor and oligoclonal during the first 3 months post-transplant. As shown by monoplex PCRgamma analysis of every VJ combination, despite T-cell depletion of the graft, mature T cells were carried over with the selected CD34+ PBSC and contributed to the T-cell recovery after transplantation.     

A longitudinal study of immunological status in Chinese haemophiliacs: importance of the heat viral inactivation of factor concentrates. I. Immunological associations with the consumption of factor concentrates

Summary . Twenty-four of 117 cases of haemophilia A (20.5%) and none of 18 cases of haemophilia B reported in this study had an antibody to the human immuno-deficiency virus (HIV). Both groups of patients showed similar immunological alterations. HIV-seropositive haemophilia A patients had an increased CD8 cell count and a similarly decreased CD4/CD8 ratio as compared to HIV-seronegative haemophilia A patients. Multiple regression analysis for the association of CD4/CD8 ratio with HIV infection status and dosage of plasma products in haemophilia A and B patients, respectively, revealed that there was a significant negative association of ln(CD4/CD8) with dosage of factor VlII concentrates (P = 0.0435) and factor IX concentrates (P = O.O028), respectively. N o association occurred between CD4/CD8 ratio and HIV infection as well as dosage of other plasma products. These data indicate that the immunological abnormalities of our haemophilia A and B patients in their early years were primarily caused by various viral infections and/or a suppressive effect of allogeneic protein through infusion of factor concentrates and not caused simply by HIV infection.     

The levels of memory (CD45RA−, RO+) CD4+ and CD8+ peripheral blood T-lymphocytes correlate with IgM rheumatoid factors in rheumatoid arthritis

We investigated whether, in rheumatoid arthritis (RA), the CD45 isoform expression of peripheral blood T-lymphocytes (T-PBL) is related to auto-immune processes (e.g. IgM rheumatoid factors) and to clinical manifestations. By three-colour flow cytometry, we quantified three subsets of CD4+ or CD8+ T-PBL: naive CD45RA+,RO–, transient CD45RA+,RO+, and memory CD45RA–,RO+ cells, in 102 patients with RA and in 41 age- and sex-matched controls. The serum levels of rheumatoid factors (RF) were determined — besides conventional agglutination tests — by ELISA (IgM-RF). Extensive clinical examination was performed at the time of blood sampling. In RA, age, sex and drug therapy did not constitute major influences on the CD45RA/RO patterns. In healthy men, higher age significantly correlated with fewer naive and more memory CD4+ T-PBL (P<0.01). In RA, distinct correlations between the T-PBL subsets, autoimmune and clinical manifestations became obvious when patients with low and high levels of RF against human IgG Fc fragments, as determined by ELISA, were analysed separately. RA patients with high IgM-RF had elevated proportions of CD45RO+ T-PBL (P<0.05), that correlated with clinical parameters of disease activity (tender joint count, Ritchie index, P<0.05) and outcome (Health Assessment Questionnaire, Larsen radiographic scores, P<0.05). The proportions of memory CD4+ and CD8+ T-PBL correlated strongly (P<0.001) with the IgM-RF levels. Within 1 year, only three of 34 patients (disease duration of 5–9 years) showed seroconversion from low to high levels of IgM-RF (and positive agglutination tests); this was paralleled by reductions in naive and increases in transient T-PBL (P<0.02). Thus, in RA, the proportions of memory CD4+ and CD8+ T-PBL correlate with the level of IgM-RF and, together with transient T-PBL, with clinical parameters of disease activity and outcome.     

Peripheral virus-specific T-cell interleukin-10 responses develop early in acute hepatitis C infection and become dominant in chronic hepatitis

BACKGROUND /AIMS: Interleukin-10 (IL-10) has been ascribed pro-viral but anti-fibrotic properties in chronic hepatitis C virus (HCV) infection. In this study, we examined the role of HCV-specific T-cell IL-10 response in patients with acute and chronic HCV infection. METHODS: Peripheral HCV-specific T-cell IL-10 and IFNgamma responses were measured in cytokine Elispot assay using overlapping HCV-derived peptides in patients with chronic (n=61), resolved (n=15) and acute (n=8) hepatitis C, looking for their onset, quantity, breadth and durability relative to clinical and virological outcomes. The source and effect of HCV-specific IL-10 response were determined in depletion and IL-10 neutralization experiments. RESULTS: Both HCV-specific IL-10 and IFNgamma responses were detected early within 1-2 months of acute clinical hepatitis C. However, only HCV-specific IL-10 response correlated with elevated liver enzymes, increased viremia and suppressed HCV-specific CD4(+) T-cell proliferation in acute infection. While these associations were lost in established chronic infection, HCV-specific IL-10 responses were increased in patients without cirrhosis while IL-10 blockade enhanced antiviral effector IFNgamma responses. CONCLUSIONS: HCV-specific IL-10 Tr1 responses may play a dual role in HCV infection, dampening effector T-cells to promote viral persistence in acute infection but also protecting against progressive fibrosis in chronic infection.     

慢性肾炎患者外周血共刺激分子CD28和CD137水平变化研究

目的　研究慢性肾炎患者外周血共刺激分子CD2 8和CD1 37的表达特点及其在慢性肾炎免疫病理机制中的作用。方法　采用免疫荧光标记和流式细胞仪分析 ,对 5 2例慢性肾炎患者外周血共刺激分子CD2 8、CD1 37和T淋巴细胞亚群的表达进行检测。结果　慢性肾炎患者T细胞亚群明显失衡 ,表现为CD4减少 ,CD8增加 ,CD4 CD8比值显著降低。共刺激分子CD2 8表达显著低于正常对照组 (P <0 0 1) ,且CD+4 CD+2 8T细胞和CD+8CD+2 8T细胞均显著减少 (P <0 0 1)。共刺激分子CD1 37表达显著高于正常对照组 (P <0 0 1)。结论　慢性肾炎患者外周血T细胞亚群失衡和T细胞活化所必需的共刺激分子CD2 8、CD1 37异常表达 ,可能在慢性肾炎发生和病变进展中起着重要作用     

Telomerase activity in acute myelogenous leukaemia: clinical and biological implications

We examined telomerase activity in myeloid leukaemic cell lines, normal haemopoietic cells, and leukaemic blasts from acute myelogenous leukaemia (AML) patients. Normal bone marrow mononuclear (BMNC) cells expressed low telomerase activity. Higher telomerase activity was detected in 10 myeloid leukaemic cell lines compared to normal BMNC cells. Treatment with 1,25(OH)₂D₃, and vitamin D₃ analogues, EB1089 and KH1060, reduced telomerase activity in vitamin D₃-sensitive HL-60 cells, whereas vitamin D₃ insensitive K562 cells did not change its activity. This down-regulation of telomerase activity by EB1089 was associated with induction of p21 protein. The rank order of telomerase activity was leukaemic CD34⁻ cells > leukaemic CD34⁺ cells > normal CD34⁻ cells > normal CD34⁺ cells. Telomerase activity was positive in all of the AML patients tested; however, heterogeneity of telomerase activity was found amongst this group. Therefore we compared telomerase activity with clinical response. Unexpectedly, we found that a higher rate of complete remission was noted in AML patients with higher telomerase activity. No association between telomerase activity and biological parameters including percentage of S-phase, cytotoxicity to cytosine arabinoside and percentage of CD34⁺ cells in AML blasts was found. These results suggest that telomerase activity in AML patients is detected with high frequency, but is heterogenous. Expression level of telomerase activity may have a clinical implication in AML patients regarding clinical response.     

CD13/aminopeptidase N in collagen vascular diseases

To determine the significance of CD13/aminopeptidase N in collagen vascular diseases (CVD), we examined its activity and expression in sera and disease sites of patients with CVD. Significantly higher aminopeptidase activity was detected in bronchoalveolar lavage fluid from patients with interstitial lung diseases due to rheumatoid arthritis (RA), polymyositis/dermatomyositis (PM/DM), systemic sclerosis (SSc), and Sjögren's syndrome than from control subjects. Increased aminopeptidase activity and increased expression of CD13/aminopeptidase N protein were found in alveolar macrophages from CVD patients with interstitial lung diseases. Significantly higher aminopeptidase activity was detected in pleural effusions from patients with systemic lupus erythematosus (SLE) than in transudate effusions. The mean aminopeptidase activity in synovial fluids from RA patients was significantly higher than from patients with osteoarthritis. The mean value of serum aminopeptidase activity was significantly higher in patients with SLE, RA, SSc, and PM/DM than in normal subjects. This study suggests that the activity of CD13/aminopeptidase N, locally produced in the disease site, is a useful marker for CVD and that CD13/aminopeptidase N may have an important role in the pathogenesis of CVD.