Serum levels of the soluble form of CD30 molecule as a tumor marker in CD30+ anaplastic large-cell lymphoma.

PURPOSE: To determine serum levels of the soluble form of CD30 molecule (sCD30) in patients with Ki-1/CD30+ anaplastic large-cell lymphoma (ALCL), and to evaluate its correlation with clinical features at presentation and its possible role as a tumor marker to monitor response to treatment and subsequent follow-up. PATIENTS AND METHODS: sCD30 serum levels were measured with an improved commercial sandwich enzyme-linked immunosorbent assay (ELISA) test kit in 24 patients with CD30+ ALCL at diagnosis and in 13 after treatment. RESULTS: Increased values (> 20 U/mL) at diagnosis were observed in 23 of 24 cases (median, 842.5 U/mL; range, 16 to 37,250) as compared with controls (P < .0001). These values were greater than those of 60 stage-matched cases of Hodgkin's disease (HD) (P < .0001). The highest median value was observed in patients with T-cell-type ALCL (1,690 U/mL), with a significant overall difference as compared with B- and null-cell types (P = .004). Phenotype maintained its significance when results were corrected for other parameters, such as age, sex, and stage (P = .03). sCD30 values returned to the normal range in complete remission (CR), but remained increased in one patient who only partially responded to treatment. Subsequent increases of sCD30 levels were recorded in four of four patients after relapse. CONCLUSION: sCD30 appears to be a new biologic serum tumor marker of possible use in the clinical setting of CD30+ ALCL.

Leukemic cells in hairy cell leukemia and B cell chronic lymphocytic leukemia release soluble TNF receptors.

The two tumor necrosis factor receptors (TNF-Rs) exist in their soluble form in different biological fluids. In this study we investigated the concentrations of soluble tumor necrosis factor receptors (sTNF-Rs) in the culture supernatants of leukemic cells and in the serum obtained from 33 patients: 12 with hairy cell leukemia (HCL) and 21 with B cell chronic lymphocytic leukemia (B-CLL). In seven patients with HCL, sTNF-Rs were also evaluated following in vivo treatment with interferon-alpha (IFN-alpha). Purified leukemic cells from patients with HCL and B-CLL spontaneously released sTNF-R75 but not sTNF-R55. The levels of sTNF-R75 were higher in supernatants obtained from cultured hairy cells than from cultures of B-CLL cells. The shedding of sTNF-R75 was further increased both in HCL and B-CLL subjects by some B cell-related stimuli, including BCGF, PMA, SAC and was partially inhibited by IFN-alpha in patients with HCL. Sera from HCL patients presented increased levels of both sTNF-Rs with respect to normal controls. Treatment of HCL patients with IFN-alpha resulted in a decrease in serum levels of sTNF-Rs, particularly sTNF-R75. These findings suggest that leukemic cells account for the increased serum levels of sTNF-R75 observed in patients with HCL and B-CLL, but not for sTNF-R55.

High serum level of the soluble form of CD30 molecule in the early phase of HIV-1 infection as an independent predictor of progression to AIDS.

OBJECTIVE: To determine the serum levels of the soluble form of the CD30 (sCD30) activation molecule in the early phase of HIV-1 infection, and to investigate the possible correlation with evolution to AIDS. METHODS: sCD30 values were determined by an enzyme-linked immunosorbent assay (ELISA) on serum samples collected at the time of the first evidence of HIV-1 infection in 110 individuals with a median follow-up of 56 months (range, 12-88 months), at the A1 (74 cases) or A2 (36 cases) stages of the 1993 revised Centers for Disease Control and Prevention classification. The data were evaluated using established clinical and immunological parameters, including circulating CD4+ T-cell count. The controls were 110 blood donors and 51 HIV-1-negative subjects belonging to groups at risk for HIV-1 infection. RESULTS: Elevated sCD30 levels (> 20 U/ml) were found in 83.6% of HIV-1-infected cases and in 47% of at-risk seronegatives. Data analysis revealed that HIV-1-infected patients with higher sCD30 levels (> 35 U/ml) experienced faster disease progression (P = 0.0002). This was also the case in patients at the earliest stage (A1) of HIV infection (P = 0.0027). In these latter cases the predictive value of sCD30 was independent of the initial absolute number of circulating CD4+ lymphocytes. CONCLUSIONS: Serum levels of sCD30 are increased in the large majority of patients in the early phase of HIV-1 infection and represent an indicator of progression to AIDS independent of other prognostic parameters.

Shedding of the soluble form of the CD8 complex by CD8+/HLA-DR+ cells in HIV-1-infected patients.

High levels of the soluble form of the CD8 molecule (sCD8) are detectable in the serum of HIV-1-infected patients. To investigate the mechanisms accountable for the release of this molecule we evaluated the presence of sCD8 in the supernatants obtained from in vitro cultures of highly purified CD8 cells isolated from 20 HIV-1-infected patients. At resting conditions cultured CD8 cells from HIV-1-infected patients released low amounts of sCD8; no statistically significant differences were observed between unstimulated cultures from HIV-1-seropositive patients and from HIV-1-seronegative subjects at risk for HIV-1 infection or normal healthy controls. Following in vitro activation of highly purified CD8 cells with a series of stimulatory agents, including phorbol myristate acetate, phytohemagglutinin (PHA) and recombinant interleukin-2, CD8 cells of HIV-1-infected patients significantly increased the shedding of sCD8. By expressing the results of activation-related release index (ARRI = sCD8 levels detected in the cultures with stimulatory agent/sCD8 levels detected in the unstimulated cultures), significantly higher values were observed upon PHA stimulation in HIV-1-infected patients than in control subjects. In order to identify the cell subset responsible for the enhanced release of sCD8 by PHA-stimulated cultures, we correlated the amounts of sCD8 detected in the supernatants with the phenotypic profile of CD8+ cells recovered from the cultures. A significant relationship was demonstrated between the percentage of CD8+/HLA-DR+ lymphocytes and sCD8 levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Lymphocyte membrane antigen expression and intracellular cytokine patterns in an asymptomatic patient with persistently high serum levels of IgE.

BACKGROUND: Patients completely asymptomatic with extremely high levels of IgE have rarely been reported. One such case, in which the immunophenotype pattern of lymphocyte subsets and their cytokine profile were investigated, is described here. OBJECTIVE: To assess whether the cytokine production was consistent with a T helper 2-type immune response, as suggested by theories regarding the functional polarization of helper and cytotoxic T cells in hyper-IgE conditions. METHODS: An asymptomatic 79-year-old man presented with persistent high levels of serum IgE and sporadic hypereosinophilia without any evidence of an underlying pathologic condition. We investigated the immunophenotype of circulating lymphocytes, the expression/release of CD30 (a member of the tumor necrosis factor receptor family preferentially associated with T helper 2-type immune responses) and the intracellular patterns of interferon-gamma (IFN-gamma), Interleukin-2 (IL-2), IL-4, IL-5, and IL-10 production by T cell subsets, as evaluated by single-cell flow-cytometric analysis. RESULTS: The majority of lymphocytes displayed the membrane immunophenotype of NK cells. Both CD4+ and CD8+ T cells were reduced and expressed the "memory" (CD4+/CD45RO+) and the "naive" (CD8+/CD45RA+) phenotypes, respectively. Among CD4+ T cells, CD30 expression was increased in the resting condition and was further inducible following stimulation with mitogenic anti-CD3. Interleukin-4, IL-2, and IL-10 production by CD4+ T cells was increased, whereas IFN-gamma was reduced as compared with normals. CONCLUSIONS: The data suggest that a polarization of CD4+ T cells towards a T helper 0/2-type cytokine pattern occurred in this patient in spite of CD4+ cell reduction and NK cell expansion.

Peripheral T lymphocyte cytokine profile (IFNgamma, IL-2, IL-4) and CD30 expression/release during measles infection.

BACKGROUND AND OBJECTIVE: Measles virus infection (MVI) has been reported to be characterized by an imbalanced Th(1/2)-type cytokine profile. CD30 has been proposed as a receptor preferentially associated with the Th(0/2)-type cytokine pattern. The aim of this study was therefore to define the peripheral T lymphocyte cytokine profile and to test which CD30 expression pattern it was associated with in MVI. DESIGN AND METHODS: The design of the study was a prospective evaluation with comparative analysis. The serum levels of the soluble form of CD30 (sCD30) were determined at diagnosis and at weekly intervals up to 4 weeks, using an ELISA, in 23 males (median age 19), who developed MVI while serving in the Italian army and who were admitted to the Infectious Disease Unit of the Military Hospital in Padua. In 10 of the patients at diagnosis we studied the lymphoid immunophenotype and, after non-specific ex vivo stimulation, the expression of IFNgamma, IL-2 and IL-4 by peripheral T cells using flow cytometry single cell analysis. In 3 patients such evaluations were also performed 7 weeks later. RESULTS: At diagnosis, we found (i) reduction of IFNgamma+/CD4+ T cells (p=0.048 vs controls) in the absence of substantial variation of IL-2+ and IL-4+ T cells (p=ns vs controls); (ii) expansion of CD30+/ CD4+ and CD30+/CD8+ T cell subsets (p<0.01 vs controls); (iii) high sCD30 values (median 61 U/mL; p<0.001 vs controls); (iiii) a context of lymphopenia (0. 728+/-0.292 lymph x10(9)/L). sCD30 remained elevated up to 4 weeks from MVI onset [median values 53, 49, 50, 34 U/mL after 1, 2, 3 and 4 weeks, respectively (p=ns between different time points)]. In 3 patients tested 7 weeks after diagnosis, we still observed decreased IFNgamma production by CD4+ and CD8+ T cells (p=0.05 and <0.01, respectively vs controls) and reduction of CD4+ and CD8+/IL-2+ T cells (p<0.01). INTERPRETATION AND CONCLUSIONS: MVI was characterized by featuresof inadequate Th/Tc(1) activation associated with increased circulating CD30+ T cells and elevated sCD30 levels, supporting a correlation between Th/Tc status and CD30 expression/release pattern in vivo.

Serum levels of soluble CD30 in chronic hepatitis B virus infection.

There is evidence that both cellular and humoral components of the immune response are required for viral clearance to occur in chronic hepatitis B. Recent studies demonstrated that CD30 molecule, a member of the tumour necrosis factor superfamily of membrane cytokine receptors, is expressed on, and released as a soluble molecule (sCD30) by activated T cells producing T helper 2 (Th2) cytokines, which modulate antibody responses. To better characterize the immunoregulatory mechanisms in chronic hepatitis B virus (HBV) infection, sCD30 values were evaluated by an ELISA in 90 hepatitis B surface (HBsAg)-positive patients with chronic hepatitis, selected on the basis of active viral replication and biochemical activity. At presentation abnormal levels (> 20 U/ml) of sCD30 were detected in 57 (63%) out of 90 patients with chronic hepatitis B, and median value was significantly higher in this group of patients compared with that of healthy HBsAg carriers (26.7 versus 10.5 U/ml, P < 0.000 05) and with normal controls (26.7 versus 3 U/ml P < 0.000 01). Sequential studies of chronic hepatitis B did confirm the association of raised sCD30 levels with the active phase of the illness. On the other hand, a significant decrease was noted when sCD30 levels at diagnosis and after termination of HBV replication and biochemical remission of hepatitis were compared in 10 untreated patients (median, 28 U/ml at entry versus 8 U/ml at remission, P < 0.01) and in six patients responding to interferon-alpha therapy (median, 29.5 U/ml at entry versus 6 U/ml at remission, P < 0.05). The high serum sCD30 levels reported during the active phase of HBsAg-positive chronic hepatitis suggest a certain degree of immune competence of these patients, at least with respect to a Th2-type response. These data are in agreement with recent serologic surveys showing that most chronic hepatitis B patients do demonstrate ongoing humoral immune response to HBV antigens, using novel immunoassays designed to detect antibody in the presence of excess serum viral antigen. Th2 functions that mainly promote humoral immunity to HBV antigens may be critical, in association with a competent virus-specific cytotoxicity, for efficient termination of HBV replication in chronic hepatitis B.

Correlation between clinical features and circulating levels of soluble intercellular adhesion molecule-1 in Hodgkin's disease.

Previous reports have suggested soluble intercellular adhesion molecule-1 as a marker of disease activity in Hodgkin's disease. In the present study we investigated serum levels of intercellular adhesion molecule-1 at diagnosis in 104 patients with Hodgkin's disease and in 77 of these patients following the achievement of complete remission (within 12 months of diagnosis). Mean serum levels at diagnosis were significantly higher in patients than in controls (P < 0.0001) and were related to advanced stages of disease (P = < 0.0001), presence of "B" symptoms (P < 0.0001), abnormality of laboratory indexes (P < 0.0001), erythrocyte sedimentation rate values (r = 0.41, P < 0.0001) and serum levels of soluble interleukin-2 receptor alpha chain (r = 0.51, P < 0.0001). Mean values in complete remission were significantly lower than at diagnosis (P = 0.003). Lower mean values at diagnosis were detected in 30 patients with advanced disease who attained complete remission, compared with 6 patients who failed to attain complete remission with standard treatment. We conclude that in Hodgkin's disease, high serum levels of soluble intercellular adhesion molecule-1 are detectable at presentation and strictly correlate with some clinical features. Response to treatment is paralleled by reduced serum levels. Larger prospective studies are needed to evaluate the possible prognostic significance of serum levels of soluble intercellular adhesion molecule-1 at diagnosis.

High serum level of soluble CD30 in acute primary HIV-1 infection.

CD30 has been suggested to play a role in HIV infection. In this study the serum concentration of soluble CD30 (sCD30) was determined by an ELISA essay on samples collected from patients with acute primary HIV-1 infection during the acute phase (n = 17) and after seroconversion (n = 13). sCD30 during acute infection was consistently elevated (137.58 +/- 120.33 versus 6.4 +/- 5.4 U/ml (mean +/- s.d.) in normal controls, P<0.0001) and decreased after seroconversion (49.1 +/- 66.17 U/ml; P = 0.0018 compared with acute infection). This trend mirrored the disappearance of detectable levels of HIV antigen in the blood, resulting in a direct correlation between sCD30 and HIVAg values (P = 0.002). These data suggest that the high levels of sCD30 observed during the peak concentration of HIVAg in acute primary HIV infection might reflect the high rate of viral replication.

Circulating levels of soluble CD23 reflect clinical and biological features of leukemic B-cell chronic lymphoproliferative disorders.

One hundred and twenty-four sera from patients with various leukemic B-cell chronic lymphoproliferative diseases were investigated at diagnosis by ELISA for their soluble CD23 content. Immunophenotyping was carried out in all patients, and in a selected subset the mean number of membrane-bound CD23 molecules per cell was also investigated. Seventy-three patients had typical B chronic lymphocytic leukemia, 41 leukemic B-cell disorders with atypical morphological and/or immunophenotypic features, 5 had low-grade follicular cell lymphoma in the leukemic phase, and 5 had splenic lymphoma with villous lymphocytes. Soluble CD23 levels were significantly higher than in normal sera (mean +/- SD: typical B chronic lymphocytic leukemia 3,650 +/- 4,654 U/ml, atypical B chronic lymphocytic leukemia 3,440 +/- 4,671 U/ml, follicular cell lymphoma 3,200 +/- 1,511 U/ml, splenic lymphoma with villous lymphocytes 8,236 +/- 7,294 U/ml, controls 137 +/- 128 U/ml; P < 0.001). More advanced Rai's stages were related to higher soluble CD23 levels (P < 0.01), both in typical and atypical B chronic lymphocytic leukemias, the highest levels and the best correlation with the absolute number of circulating CD19+ cells (r = 0.50) being observed in the typical form. The number of membrane-bound CD23 molecules per cell was significantly higher in typical than in atypical B chronic lymphocytic leukemias (mean number 156,727 +/- 94,668 vs. 12,010 +/- 10,643, P < 0.001). Our data suggest that soluble CD23 levels correlate with the clinical and biological features of leukemic B-cell lymphoproliferative disorders.

Progressive polarization towards a T helper/cytotoxic type-1 cytokine pattern during age-dependent maturation of the immune response inversely correlates with CD30 cell expression and serum concentration.

In order to investigate the T cell cytokine profile during age-dependent maturation of the immune response, we evaluated the cytokine expression of CD4+ and CD8+ circulating cells by flow cytometric single-cell analysis after non-specific stimulation in vitro in different age groups of normal individuals, from cord blood to adulthood. Moreover, we correlated these lymphocyte cytokine patterns with the expression/release of CD30, a member of the tumour necrosis factor (TNF) receptor superfamily, which has been suggested to be related to the T helper/cytotoxic (Th(c))2-type immune responses, in order to verify this association in vivo, in non-pathological conditions. The results showed a progressive increase of circulating Th(c)1-type, interferon-gamma (IFN-gamma)- and/or IL-2-producing T cells along with ageing and, conversely, a stable number, although higher than in cord blood samples, of CD4+/IL-4+ T cells in the post-natal groups. In addition, serum levels of soluble CD30 (sCD30) and numbers of circulating CD4+/CD30+ and CD8+/CD30+ T cells were significantly higher in children aged < 5 years in comparison with those found either in cord blood or in blood from both older children and adults. These data support the concept of a progressive polarization of the Th(c) cell cytokine profile towards the Th(c)1 pattern during age-dependent maturation of the immune response. Moreover, the peak of CD30 expression/release in early infancy before the Th(c)1 shifting occurs, although not associated with a significant increase of circulating IL-4+ T cells, raises the question of the possible relationship in vivo between CD30 and Th(c)2-type immune responses.

Soluble forms of p55-IL-2R alpha, CD8, and CD30 molecules as markers of lymphoid cell activation in infectious mononucleosis.

BACKGROUND: Epstein-Barr virus (EBV) infection in infectious mononucleosis (IM) is associated with lymphocyte activation leading to the expansion of cells expressing activation-associated antigens. Most of these antigens are released as soluble molecules in vitro and in vivo. METHODS: We investigated the serum levels of the soluble forms of the CD8 (sCD8), p55-IL-2R alpha (sIL-2R alpha), and CD30 (sCD30) molecules in 55 patients following primary EBV infection. These data were compared with the phenotypic pattern of circulating lymphoid subsets. RESULTS: In all cases at presentation, lymphocytosis, mainly characterized by the expansion of a CD8+, HLA-DR+, p75-IL-2R beta+, p55-IL-2R alpha- population, was associated with high levels of the investigated soluble molecules. Their mean values (+/- SD) were: 17,172 +/- 12,885 U/mL for sCD8 (vs 334 +/- 95 in controls), 2,922 +/- 2,813 U/mL for sIL-2R alpha (vs 331 +/- 115 in controls), and 477 +/- 451 U/mL for sCD30 (vs 4.9 +/- 6.4 in controls). Follow-up study (15 cases, up to 60 days) showed a progressive decline of all soluble molecules, associated with a reduction of activated CD8+/HLA-DR+/p75-IL-2R beta+ T-cells. By the 30th day, values of sIL-2R alpha and sCD30 (729 +/- 333 U/mL and 20 +/- 21 U/mL, respectively) were only slightly higher than in normal controls, whereas sCD8 levels remained consistently higher (1,777 +/- 1,385 U/mL, p < .001). CONCLUSIONS: sCD8, sIL-2Ra and sCD30 serum levels in IM reflect the total bulk and/or the activation-related events of infected and reactive cells. The variations in these soluble molecules during the follow-up provide useful information on the in vivo biological modifications occurring after EBV infection.

Serum levels of soluble interleukin-2 receptor in Hodgkin disease. Relationship with clinical stage, tumor burden, and treatment outcome.

BACKGROUND: Previous studies suggested a possible role for the detection of soluble interleukin-2 receptor (sIL-2R) in Hodgkin disease (HD). In this study, the authors investigated, in a large series of patients, sIL-2R serum levels in relation to disease features at presentation and prognosis. Their usefulness as markers in the management of individual cases was evaluated. METHODS: The sIL-2R serum levels were measured in 195 patients at diagnosis. In 72 of these patients, sIL-2R serum levels were also monitored after diagnosis. An additional 87 cases were tested only in complete remission (CR), and 25 were tested only at relapse. RESULTS: The sIL-2R levels at diagnosis were increased (mean +/- 1222 +/- 1012 versus 331 +/- 145 U/ml in controls, P < 0.0001) and correlated with the stage and tumor burden (Stages I and II = 1058 +/- 1007, Stages III and IV = 1502 +/- 942 U/ml, P = 0.003; Stage A = 954 +/- 705, Stage B = 1880 +/- 1238 U/ml, P < 0.0001; bulky presentation = 1958 +/- 1430, nonbulky presentation = 1043 +/- 791 U/ml, P < 0.0001). Response to treatment was associated with progressive reduction of sIL-2R levels, which were normal in virtually all cases 1 year after CR. Significantly greater levels at diagnosis were found in 11 patients who experienced a poor response or progression after treatment (P = 0.004). Overall, abnormal data in CR were found in 59 of 159 patients and 9 of them subsequently experienced a relapse. CONCLUSIONS: The sIL-2R serum levels in HD correlate with features at presentation and subsequent clinical courses. Higher levels at diagnosis entail a significantly higher risk of treatment failure.

ICAM-1 tissue overexpression associated with increased serum levels of its soluble form in Hodgkin's disease.

We investigated ICAM-1/CD54 tissue immunoreactivity and serum levels of its soluble form (sICAM-1) in patients with Hodgkin's disease (HD) at diagnosis. ICAM-1 was strongly expressed in involved tissues, and sICAM-1 serum levels were higher in HD (79 patients) than in controls (P < 0.01), and in patients with more advanced or more active disease (stages III + IV vI + II: P = 0.002; stage 'B' v 'A': P < 0.0001; 'bulky' disease v non-'bulky': P = 0.042). We suggest that tissue ICAM-1 overexpression leading to increase of circulating sICAM-1 may interfere with the lymphocyte adhesion machinery thus contributing to the well-known immune derangement of HD.

Soluble interleukin-2 receptor in hairy-cell leukemia: a reliable marker of disease.

The CD25 molecule, which corresponds to the p55 alpha chain of the interleukin-2 receptor, is strongly expressed by neoplastic cells in hairy-cell leukemia and is released in large amounts in the soluble form which is detectable in serum. In order to assess the reliability of the soluble interleukin-2 receptor as a disease marker in the management of patients with hairy-cell leukemia, we investigated serum levels in 35 untreated patients and in 2 patients with the hairy-cell leukemia variant. In 21 of 35 patients soluble receptor levels were also monitored during and after recombinant interferon-alpha therapy. Clinical and hematological parameters were also assessed. Soluble interleukin-2 receptor levels were extremely high at the time of diagnosis in patients with typical hairy-cell leukemia [32,722 +/- 27,001 vs. 331 +/- 145 units/ml in controls (mean +/- SD)], but not in patients with the leukemia variant. A progressive decrease in soluble interleukin-2 receptor levels paralleled the clinical response to treatment, although normal values were never detected, even in patients who achieved an apparent complete remission. After recombinant interferon-alpha discontinuation, disease recurrence was accompanied by a progressive increase to pre-treatment soluble receptor levels. Overall, a close correlation was found between soluble interleukin-2 receptor values and total tumor burden (r = 0.84, P < 0.001). On the basis of these data, soluble interleukin-2 receptor should be regarded as a key marker in the management of patients with hairy-cell leukemia.

Preferential release of high amounts of interleukin-8 by myeloid blasts showing monocytic differentiation.

BACKGROUND: In myeloid blasts, the expression and release of the multifunctional chemokine IL-8 could be expected to be differentiation-associated. METHODS: We investigated the profile of interleukin-8 (IL-8) expression and release by leukemic cells obtained at diagnosis from 42 untreated adult patients with acute myeloid leukemia of various FAB subtypes (2 M0, 7 M1, 6 M2, 6 M3, 10 M4 and 11 M5). IL-8 transcripts were evaluated by Northern blot and densitometric analysis. IL-8 release by myeloid blasts was evaluated by a specific ELISA either in sera at diagnosis or in supernatants (SN) obtained from cultured leukemic cells. RESULTS: In basal conditions, Northern blot analysis revealed detectable IL-8 transcripts in 15/29 cases, eleven of which were classified as M4-M5 and 4 as FAB M0-M3. Densitometric analysis of IL-8 transcript bands showed higher expression in M4-M5 than in M0-M3 cases (mean values +/- SD: 16.5 +/- 21 and 0.77 +/- 1.36 densitometric units, respectively; p = 0.012). Higher IL-8 serum levels were observed in leukemic patients as opposed to normal controls (mean values +/- SD: 0.53 +/- 0.75 vs 0.003 +/- 0.014 ng/mL, respectively; p = 0.006). Furthermore, a trend (though not of statistical significance) towards higher IL-8 serum values was observed in M4-M5 as opposed to M0-M3 subtypes. After 24 hours of culture, the majority of myeloid blasts (95%) spontaneously released detectable amounts of IL-8 into SN. However, M4-M5 released substantially higher amounts of IL-8 than M0-M3 blasts (mean +/- SD: 68 +/- 46 and 8.5 +/- 12 ng/mL, respectively; p < 0.001). This difference between M0-M3 and M4-M5 blasts was already observed after 6 hours of culture and increased over 72 hours. CONCLUSIONS: Our findings confirm and further support the preferential release of high levels of IL-8 by myeloid blasts showing monocytic differentiation.

Serum levels of p55 and p75 soluble TNF receptors in adult acute leukaemia at diagnosis: correlation with clinical and biological features and outcome.

The tumour necrosis factor (TNF)/TNF-receptor (TNFR) complex plays a role in the growth of leukaemic cells. We retrospectively investigated the relationship between pretreatment serum concentration of soluble TNFR (p55- and p75-sTNFRs) and outcome in adult acute myeloid (AML 82 cases) and lymphoid (ALL 44 cases) leukaemia. Both sTNFRs were significantly higher in AML (p55-sTNFR 4.53 +/- 3.7, median 3.75; p75-sTNFR 6.51 +/- 5.25 ng/ml, median 4.72) and ALL sera (3.31 +/- 1.5, median 2.95; 5.30 +/- 2.3 ng/ml, median 4.56, respectively) than in controls (1.89 +/- 0.5, median 1.98; 2.22 +/- 0.8 ng/ml, median 2.37) (P < 0.01 for both sTNFRs). Fresh leukaemic cells expressed p55- and p75-sTNFRs, which were modulated and released into the supernatant (SN) following short-term in vitro culture, suggesting that in vivo sTNFRs were also leukaemia-derived. Whereas no correlation was observed between sTNFRs and outcome in ALL, in AML higher p55-sTNFR levels (> 3.75 ng/ml) were associated with shorter disease-free survival (DFS) (P = 0.006) and overall survival (OS) (P = 0.0004). At multivariate analysis p55-sTNFR was the most significant predictor of DFS (P = 0.006) and OS (P < 0.001). Our data suggest that the prognostic significance of p55-sTNFR in AML could be related to relevant biological features of AML blasts.