Injection of human primary effusion lymphoma cells or associated macrophages into severe combined immunodeficient mice causes murine lymphomas

The pathogenesis of immunodeficiency-associated lymphoma is poorly understood. During the past several years, numerous lines of evidence implicating a multistep process of malignant transformation, also known as sequential pathogenesis, have emerged. Tumor-associated macrophage production of specific lymphostimulatory products has been demonstrated and hypothesized to be central to this process. While attempting to establish primary effusion lymphoma in severe combined immunodeficient (SCID) mice, we discovered a potential model of murine lymphomagenesis consistent with the sequential pathogenesis model. This pathogenesis-based model of lymphoma could significantly impact the current thinking about posttransplantation and other immunodeficiency-related lymphoproliferative disorders. Human primary effusion lymphoma-derived CD14+ cell-injected SCID mice developed aggressive murine large cell lymphomas. Tumor cell preparations containing CD14 cells or isolated CD14 cells induced lymphoma/lymphoproliferative diseases in 74% (20 of 27) of injected SCID mice. No tumors were induced by tumor-associated CD3 cells (0 of 4), normal human macrophages (0 of 13), or a murine macrophage cell line (0 of 10). Human macrophages were detected in tumor-bearing animals up to 6 months postinjection in association with the murine T-cell tumors but were not detected in controls or unaffected animals. These observations are consistent with the macrophage-initiated sequential pathogenesis model of disease (M. S. McGrath et al., Acquir. Immune Defic. Syndr., 8: 379-385, 1995; M. S. McGrath et al., Infectious Causes of Cancer: Targets for Intervention, pp. 231-242, Totowa, NJ: Humana Press, 2000).

Soluble HLA class I molecules in malignant pleural and peritoneal effusions and its possible role on NK and LAK cytotoxicity

PURPOSE

To examine the amount of sHLA-I in malignant pleural and peritoneal effusions and its possible role in natural immune defense.

METHODS

Three groups of patients (75 patients with malignancy, 21 with infection, and 27 with other diseases) were studied for sHLA-I value using an ELISA method. Cytolytic activity of freshly isolated pleural and peritoneal effusion-associated lymphoid (EAL) cells from 14 of cases with malignancy were examined and compared to that of ten non-cancerous patients. EAL cells were co-cultured with the autologous cell-free effusions immediately after collection and 3 days after incubation with IL-2.

RESULTS

The mean value of sHLA-I in effusions was 1.01+/-1.36 micro g/ml, 0.97+/-1.20 micro g/ml, and 0.49+/-0.45 micro g/ml, respectively. Despite higher mean sHLA-I levels in malignant and infected patients, no significant difference between these groups was observed ( P >0.05). Generally, the amount of sHLA-I in peritoneal effusions was higher than that for pleural effusions, but the difference was not significant. There were also no statistical differences in the sHLA-I levels between sub-groups of patients with malignancy. EAL cells' killing activity in malignant and infected effusions was 68.15+/-11.73 and 78.28+/-14.41, respectively ( P=0.08). No correlation between sHLA-I level and NK activity of EAL cells from the patients was found. Almost all malignant cases after exposure to cell-free effusions displayed an increase in NK activity (from 68.66+/-11.13 to 74.2+/-12.39, P=0.042) and a decrease in LAK activity (74.5+/-18.30 vs 67.72+/-16.46, P=0.040). Whereas, the same experiment performed for non-malignant effusions showed a decrease in both NK activity and LAK activity. Changes in NK and LAK activity were not correlated with the amount of sHLA-I in the effusions.

CONCLUSION

The presence of sHLA-I, particularly in malignant effusions, suggests a role for these molecules in tumor immunity in the peritoneal or plural environment; however, at least with these group of patients, sHLA-I appears not to be a unique determining factor on EAL cells' killing activity.

Additive effect of Interleukin-12 and Interleukin-18 on the T-helper cell pathway of malignant pleural effusion

Interleukin-18 (IL-18) is a novel cytokine with interferon-gamma (IFN-gamma)-inducing activity, thus favoring the T-helper type 1 (Th-1) pathway. The present study attempts to define the role of IL-18 on the functions of lymphocytes isolated from malignant pleural effusions (EAL, effusion-associated lymphocytes). EAL from 10 patients with malignant pleural effusion were incubated with IL-2, IL-12, or IL-18 with/without a alpha CD3 antibody. ELISA, proliferation, and cytotoxicity assays were performed. IL-18 alone was found to have no significant effect on EAL in terms of cytokine production, lymphocyte proliferation, or cytotoxicity against tumor targets. IL-18 also had no significant additive or synergistic effect on IL-2, IL-12, or alpha CD3 co-cultured EAL. However, when IL-18 was used with IL-12, the highest IFN-gamma/IL-10 ratio was derived, suggesting that these two cytokines had an additive effect in leading EAL from the Th-2 to the Th-1 pathway. Furthermore, 1 of 5 patients' EAL had its strongest cytolytic activity against an autologous tumor when the EAL was cultured with IL-2 plus IL-18, as compared with the other 4 patients whose EAL cytolytic activity against autologous tumor was highest when using IL-2 plus alpha CD3. These findings suggest that IL-18 alone did not have a significant effect on EAL, and that IL-18 did not enhance alpha CD3's activity on EAL. However, its additive effect with IL-12 in the Th-1 pathway and with IL-2 in its cytolytic activity against an autologous tumor deserve further studies.

Malignant effusions and immunogenic tumour-derived exosomes

BACKGROUND

Exosomes derived from tumours are small vesicles released in vitro by tumour cell lines in culture supernatants. To assess the role of these exosomes in vivo, we examined malignant effusions for their presence. We also investigated whether these exosomes could induce production of tumour-specific T cells when pulsed with dendritic cells.

METHODS

We isolated exosomes by ultracentrifugation on sucrose and D(2)O gradients of 11 malignant effusions. We characterised exosomes with Western blot analyses, immunoelectron microscopy, and in-vitro stimulations of autologous T lymphocytes.

FINDINGS

Malignant effusions accumulate high numbers of membrane vesicles that have a mean diameter of 80 nm (SD 30). These vesicles have antigen-presenting molecules (MHC class-I heat-shock proteins), tetraspanins (CD81), and tumour antigens (Her2/Neu, Mart1, TRP, gp100). These criteria, including their morphological characteristics, indicate the similarities between these vesicles and exosomes. Exosomes from patients with melanoma deliver Mart1 tumour antigens to dendritic cells derived from monocytes (MD-DCs) for cross presentation to clones of cytotoxic T lymphocytes specific to Mart1. In seven of nine patients with cancer, lymphocytes specific to the tumour could be efficiently expanded from peripheral blood cells by pulsing autologous MD-DCs with autologous ascitis exosomes. In one patient tested, we successfully expanded a restricted T-cell repertoire, which could not be recovered carcinomatosis nodules.

INTERPRETATION

Exosomes derived from tumours accumulate in ascites from patients with cancer. Ascitis exosomes are a natural and new source of tumour-rejection antigens, opening up new avenues for immunisation against cancers.

Identification of the primary site of metastatic adenocarcinoma in serous effusions. Value of an immunocytochemical panel added to the clinical arsenal

OBJECTIVE

To use an immunocytochemical panel as ancillary method to identify the origin of adenocarcinomas in serous effusions.

STUDY DESIGN

Serous effusion samples examined cytologically in the Department of Surgical Pathology, A. C. Camargo Hospital, between 1966 and 1990, were investigated. Of 4,297 cases, 2,317 were associated with adenocarcinoma, and 1,099 were positive for adenocarcinoma by cytologic examination. We selected a total of 248 cases of different origins to subject to immunoreactions. A panel composed of CA-125, CA-19.9, HBME-1, lactoferrin and BRST 2 was tested for the efficiency of these antibodies under two conditions: the panel alone and associated with clinical data, such as anatomic localization of the effusion (pleural or ascitic) and patient sex and age.

RESULTS

BRST 2 and lactoferrin were both positive in 29.9% of cases of adenocarcinoma of breast origin; CA-125 and HBME-1 were 28.6% and 25.0% positive in cases of adenocarcinoma of the ovaries, respectively. These immunoreactivities were highly specific when compared to the others. The statistical significance of the results was improved by information on the anatomic location of the effusions and patient sex.

CONCLUSION

Our data strongly indicate that BRST 2 and lactoferrin are important components of an immunocytochemical panel used to identify carcinomas of breast origin. Similarly, CA-125 and HBME-1 may be useful in suggesting the ovaries as possible primary sites.

A large quantity of CD3-/CD19-/CD16- lymphocytes in malignant pleural effusion from a patient with recurrent cholangio cell carcinoma

Tumor infiltrating lymphocytes (TILs) are candidates for adoptive cellular immunotherapy. Here we report on a patient whose TILs presented unusual lymphocyte antigens. Pleural effusions were collected from a 47-year-old man with recurrent cholangio cell carcinoma and malignant effusion. Effusion-associated lymphocytes (EALs) were separated by Ficoll-Hypaque gradient, and the EAL phenotype was determined by flow cytometry. The percentage of positive cells was determined for each lymphocyte-related differentiation antigen. The percentages of CD3+, CD19+, and CD16+ lymphocyte subpopulations among EALs were 20%, 7%, and 3%, respectively. Nearly 70% of EALs were CD3-/CD19-/CD56-/CD16- cells. The phenotypes of peripheral blood lymphocytes (PBLs) collected simultaneously from the patient's peripheral blood were CD3+ (52%), CD19+ (20%), and CD16+ (20%). When EALs were cultured in medium without pleural effusion, T cell-related antigens, but not B cell- or natural killer (NK) cell-related antigens, were newly expressed on EALs, and this expression reached a plateau after 48 h in culture. The proportions of CD3+, CD19+, and CD16+ cells were 69%, 7%, and 3%, respectively. However, when EALs were cultured in medium with pleural effusion, increased expression of T cell-related antigens was not observed; the proportions of CD3+, CD19+, and CD16+ cells were 16%, 6%, and 1%, respectively. Neither total cell numbers nor cellular viability of EALs changed significantly after in-vitro culture, suggesting that significant proliferation or death of EALs did not occur during the culture period. Co-culture of the patient's PBLs with autologous pleural effusion for 96 h did not alter the expression of lymphocyte-related antigens on the PBLs. These results indicate that expression of T cell-related antigens, but not B cell- or NK cell-related antigens, on EALs was blocked temporarily by the malignant pleural effusion. This is the first report concerning the existence of a large quantity of unclassified lymphocytes in which the T cell-related antigens were reversibly masked in the malignant pleural effusion.

Expression of ST2 in helper T lymphocytes of malignant pleural effusions

The objective of this study was to test the hypothesis that accumulated helper T lymphocytes in malignant pleural effusions may shift to T-helper type 2 (Th2) and produce soluble ST2 protein. We took samples of serum and pleural effusions (p-) from patients with carcinomatous pleurisy (CA, n = 17), tuberculous pleurisy (TB, n = 8), and congestive heart failure (HF, n = 5) and compared the concentration of cytokines or ST2. Ex vivo production of interleukin (IL)-4 and IL-10, though not that of interferon (IFN)-gamma or IL-12, from CD4+ T cells isolated from pleural effusions was higher in the CA group than in the TB or HF group. The p-ST2 concentrations were significantly higher in the CA group than in the TB or HF group, positively correlated with the percentage of pleural effusion CD4+ T cells (r = 0.432, p = 0.016) and inversely correlated with p-IFN-gamma concentrations (r = -0.423, p = 0.019). Furthermore, mRNA expression of ST2 in CD4+ T cells isolated from group CA was upregulated, compared with that in those isolated from the TB group. These results suggest that CD4+ T cells in CA shift to Th2, which can produce soluble ST2 protein, resulting in increased concentrations of p-ST2 in malignant pleural effusion.

Elevated soluble CD26 levels in patients with tuberculous pleurisy

SETTING

Several reports have shown that tuberculous infection elicits a Th1-like immune response with increased levels of IFN-gamma. Recently, expression of CD26 on CD4+ lymphocytes has been shown to correlate with the production of Th1-like cytokines. We therefore hypothesized that CD26 expression might increase in tuberculous pleural effusion, and might thus be a possible marker for detecting tuberculous pleurisy.

OBJECTIVE AND DESIGN

To test this hypothesis, we measured soluble CD26 levels in the serum and pleural fluid of patients with tuberculous pleurisy (TB; n = 13), carcinomatous pleurisy (CA, n = 17), empyema (EM, n = 6), and congestive heart failure (HF, n = 10).

RESULTS

The pleural CD26 levels, but not the serum CD26 levels, in patients with tuberculous pleurisy were significantly higher than those in other groups, and were correlated with levels of adenosine deaminase and interferon-gamma in the tuberculous pleural effusion. Furthermore, when the cut-off value for p-CD26 was set at 544.5 ng/ml, the positive rate for the TB group was significantly higher than that for the CA, EM and HF groups (P < 0.05).

CONCLUSION

These results suggest that elevation of soluble CD26 in pleural fluid is implicated in Th1-like immune response, and may be a useful marker for tuberculous pleurisy.

Interleukin-7 and interleukin-12 have different effects in rescue of depressed cellular immunity: comparison of malignant and tuberculous pleural effusions

The present study attempts to determine the role of interleukin-7 (IL-7) and IL-12 in recovering the functions of the lymphocytes of malignant effusion, in terms of cytokine production, proliferation, and cytolytic activity, compared with lymphocytes from tuberculous pleural effusion. Effusion-associated lymphocytes (EAL) were isolated from tuberculous (tEAL) and malignant (mEAL) pleural effusions. The EAL proliferate response was measured after 3 days in culture. Interferon-gamma (IFN-gamma) production and cytotoxicity against K-562 cells or autologous tumor cells were assessed after 6 days in culture. It was found that the mEAL had depressed proliferation, IFN-gamma production, and cytolytic activity, as compared with tEAL. Stimulation with IL-12 plus IL-2, but not with IL-7 plus IL-2, fully restored the IFN-gamma production of mEAL to that of tEAL levels. In contrast, the proliferate response of mEAL was enhanced significantly more with IL-7 plus IL-2 than with IL-12 plus IL-2. Both the IL-7 plus IL-2 and IL-12 plus IL-2 stimulation of mEAL showed a significant increase in cytolytic activity against autologous tumor cells, although the cytolytic activity against K-562 cells did not increase. These results suggest that tEAL had a higher cellular activity than mEAL. This depressed cellular function of mEAL could be reversed with cytokines. However, different cytokines had different effects on mEAL; for example, IL-7 had a better effect in the stimulation of lymphocyte proliferation compared with IL-12, which had a better effect in driving the lymphocytes to the T helper 1 (TH1) pathway and a higher IFN-gamma production. Both IL-7 and IL-12, in the presence of IL-2, can restore the immunosuppressed cytolytic activity of the lymphocytes of malignant pleural effusion against autologous tumor.

Interleukin-6 and its relationships to acute phase proteins in serous effusion differentiation

The aim of the study was to assess the discriminative power of cytokine interleukin 6 (IL-6) between transudative and exudative pleural and peritoneal effusions, and to compare IL-6 with common acute phase proteins in serous effusion differentiation. One hundred and forty-five consecutive patients with pleural or peritoneal effusion underwent diagnostic parecentesis. Patients were categorized in three groups. Malignant effusion (group A) 56 patients, non-malignant effusion (group B) 46 patients and transudate (group C) 43 patients. Serum and effusion levels of IL-6, C-reactive protein (CRP), alpha2-macroglobuline (alpha2-MG), alpha1-antitrypsin (alpha1-AT) and alpha1-acid glycoprotein (alpha1-AG) were determined. Serum IL-6 levels were significantly higher in groups A and B in comparison to group C (p<0.001 and 0.001, respectively). In addition, serum IL-6 levels were higher in group A compared to group B (p<0.001), while the studied acute phase proteins were not significantly different. All the studied parameters were higher in the effusions of groups A and B compared to group C. At a cut-off value of 72.1 fmol/ml IL-6 had a sensitivity of 82.6-89.3%, specificity of 88.4-90.7% and positive predictive value of 90.7-94.6% among the three groups. Our results suggest that IL-6 at levels > or =72.1 fmol/ml, alpha1-AT at > or =170 mg/dl and alpha1-AG at > or =52.3 mg/ml give strong evidences for malignancy in exudates.

Expression of Fas and Fas ligand and apoptosis in tumor-associated lymphocytes and in tumor cells from malignant pleural effusions

The CD95 (APO-1/Fas)-Fas ligand (FasL) system is an important mediator of antitumor T cell cytotoxicity. The aim of the current study was to assess its significance in human cancer. Malignant effusions were selected as an environment allowing direct cell-to-cell contact in a fluid phase. Malignant pleural effusions collected from 23 patients with metastatic carcinoma of the bronchus, ovary, stomach or breast were examined by means of flow cytometry. The expression ofFas and FasL, probed with the appropriate antibodies, apoptosis of tumor cells and the characteristics of tumor-associated lymphocytes (TAL) were determined by TUNEL reaction in malignant and nonmalignant (control) effusions. All malignant cells had partially or completely lost the expression of CD95 and expressed an elevated level of FasL. In contrast, TAL obtained from malignant pleural effusions demonstrated a marked decrease in the expression of surface FasL and an increase in surface-bound Fas. The percentage of apoptotic malignant cells was significantly decreased, as compared to TAL and lymphocytes from nonmalignant pleural effusions. There were also differences in the expression of Fas and FasL among mononuclear cells from malignant and nonmalignant pleural effusions. The ability of TAL from malignant pleural effusions to induce apoptosis of K562 cells was diminished, as compared to peripheral blood lymphocytes. Taken together, these data suggest that tumor cells in the microenvironment of malignant pleural effusions can evade immune attack by downregulation of the CD95 receptor and by killing lymphocytes through the expression of FasL. These results confirm earlier reports which showed that lymphocytes from a tumor microenvironment appear to have a depressed cytotoxic action.

Ovarian carcinoma and serous effusions. Changing views regarding tumor progression and review of current literature

Carcinoma of the ovary is the leading cause of death from gynecological cancer in western countries. Ovarian carcinoma is commonly associated with the accumulation of fluid containing malignant cells in the peritoneal, and not infrequently in the pleural cavity. The differentiation of these cells from reactive mesothelial cells is at times difficult. In addition, tumor progression in ovarian carcinoma and the biological characteristics of carcinoma cells in effusions compared to their counterparts in solid tumors are poorly understood. This review details the current knowledge regarding diagnostic and biologic aspects of effusion cytology, with emphasis on ovarian carcinoma. Results from our first studies of effusions are subsequently presented. These attempt to address several issues. First, to improve the diagnostic ability to detect cancer cells in effusions using antibodies designed for the differentiation of epithelial cells from mesothelial cells. Secondly, to study genotypic and phenotypic differences between ovarian carcinoma cells in effusions, solid primary tumors and metastatic lesions, as well as to compare malignant cells in peritoneal and pleural effusions. These studies of carbohydrate antigens, E-cadherin complex and matrix metalloproteinases (MMP) attempted to evaluate whether ovarian carcinoma cells in effusions possess true metastatic properties, or are similar to the cells in primary tumors, thereby merely representing the result of a shedding process. Finally, the prognostic role of these molecules was studied in solid tumors from a patient cohort consisting of long- and short-term survivors, followed for up to 20 years. Figure 1 on http://www.esacp.org/acp/2001/23-3,4/davidson.htm.

Correlation between DNA content, expression of Ki-67 antigen of tumor cells and immunophenotype of lymphocytes from malignant pleural effusions

Malignant cells isolated from 26 malignant pleural effusions, collected from patients bearing metastatic carcinoma, were examined using flow cytometry. Expression of Ki-67 antigen, DNA ploidy, S phase fraction, DNA index of tumor cells and the percentage of aneuploid cell populations were determined. Lymphoid cells from the same malignant effusions and from 10 nonmalignant ones were examined using a panel of monoclonal antibodies (mAb) versus several CD antigens. While the percentages of T cells (CD3+, CD4+, CD8+) and B cells (CD19+) did not differ significantly in malignant versus nonmalignant effusions, those of CD56+ lymphocytes were found to be significantly depressed in malignant diploid and malignant aneuploid effusions as compared to benign ones. Expression of IL-2 receptors on lymphocytes, demonstrated by anti-CD25 mAb, was significantly higher in malignant diploid and malignant aneuploid effusions as compared with nonmalignant ones. An increase in the percentage of Ki-67-positive malignant cells was significantly correlated with the decrease of NK cells. S phase fraction, DNA index and the percentage of aneuploid populations did not correlate with the picture of lymphoid cells from pleural effusion. On the other hand, the percentage of Ki-67-positive tumor cells in pleural effusions was inversely proportional to the patients' survival time, although it was not statistically significant. Our data suggest that the poor prognosis of cancer characterized by the presence of an aneuploid cell population of malignant cells and the high percentage of proliferating cells in pleural effusions can be linked to the depression of NK cells.

Diagnostic value of a second generation CA 15-3 antibody to detect adenocarcinoma in body cavity effusions

BACKGROUND

Detecting malignant cells in body cavity effusions can be diagnostically challenging. Several monoclonal antibodies have been studied to improve the diagnostic yield of effusion cytology but without widespread acceptance. The CA 15-3 antibody has demonstrated high sensitivity but limited specificity for breast carcinoma in surgical pathology. A second generation CA 15-3 antibody has been developed that has not been studied in serous effusions to the authors' knowledge. The authors examined this second generation CA 15-3 antibody for its diagnostic utility in detecting adenocarcinomas in this cytologic setting.

METHODS

Cell block material from 114 cases of unequivocally benign or malignant body cavity effusions were studied. Slides were stained for CA 15-3 by using the avidin-biotin complex method. The percentage of cells exhibiting strong staining was estimated both for breast carcinoma and for all adenocarcinomas as a group. These results were compared with CA 15-3 staining exhibited by benign mesothelium.

RESULTS

CA 15-3 was expressed in at least 10% of tumor cells in 97% of breast carcinoma cases and in 90% of adenocarcinomas overall. The highest sensitivity was observed in carcinomas of the breast, ovary, and lung. Of 40 cases of benign mesothelium, only 4 (10%) were positive (P < 0.001). The sensitivity of CA 15-3 was 97% for breast carcinoma and 91% for adenocarcinomas overall. Specificity was 95% for breast carcinoma and 91% for adenocarcinomas.

CONCLUSIONS

CA 15-3 is an immunostain with high specificity and sensitivity for adenocarcinomas in cell block material from effusions. The antibody holds particular promise for detecting breast carcinoma. Cancer (Cancer Cytopathol)

Reactivity of six antibodies in effusions of mesothelioma, adenocarcinoma and mesotheliosis: stepwise logistic regression analysis

Anti-CEA, anti-vimentin, CAM5.2, BerEp4, Leu-M1 and anti-EMA were applied to effusions from 36 mesotheliomas, 53 adenocarcinomas and 24 reactive mesothelial proliferations. Stepwise logistic regression analysis selected three criteria of major importance for distinguishing between adenocarcinoma and mesothelioma: BerEp4, CEA and EMA accentuated at the cell membrane (mEMA), these three being of similar diagnostic value. The pattern BerEp4-, CEA- and mEMA+ was fully predictive for mesothelioma (sensitivity 47%), whereas the opposite pattern was fully predictive for adenocarcinoma (sensitivity 80%). Only EMA seemed to distinguish between mesotheliosis and mesothelioma. Comparison of reactivity in cytological and histological material from the same mesotheliomas showed similar staining frequencies for CEA and CAM5.2, with some random variation for Leu-M1 and EMA, whereas vimentin and BerEp4 reactivity was more frequent in cytological specimens.

[Pseudo-Meigs' syndrome]

Cytologic examination of the body cavity effusions in patients with ovarian tumours is performed to differentiate between reactive processes and tumour spread. While detection of malignant cells is a marker of metastatic disease and a sign of bad prognosis, benign effusions affect neither disease stage nor the patient's prognosis. Determination of the presence or absence of tumour spread is based primarily on cellular morphology. As distinction between reactive mesothelial and cancer cells can be difficult, immunocytochemistry may be employed in equivocal cases. The case of a 42-year-old woman who presented with a large pelvic mass accompanied by ascites and hydrothorax is described. Cytomorphology of preoperative pleural fluid specimen was inconclusive. Immunocytochemical examination of cell block sections using: BerEP4, B72.3, CA 125, CD15, CEA, E-cadherin and calretinin was done. No epithelial cells were detected and diagnosis of reactive mesothelial cells was made. Laparotomy was performed and adnexal tumour removed. Borderline mucinous tumour of the ovary was diagnosed. There was no recurrence of the ascites or hydrothorax. The clinicopathologic features and terminology of pseudo-Meigs' syndrome are briefly reviewed. The role of ancillary studies in diagnosis of body cavity effusions is emphasized.

Diagnostic utility of eosinophils in the pleural fluid

This study was conducted to assess the prevalence of eosinophilia in 358 consecutive samples of pleural fluid (all cases corresponded to first thoracentesis), to review the cause of eosinophilic pleural effusions, and to determine whether the presence of eosinophils increases the likelihood of nonmalignant underlying disorders. Eosinophilic pleural effusions were identified in 45 patients (12.6%): malignant underlying conditions were diagnosed in 11 patients (24.4% with eosinophilic effusions) and benign aetiologies were found in 27 patients. Benign aetiologies included uncomplicated paraneumonic effusion in 10 patients, tuberculosis in seven, complicated paraneumonic in five, liver cirrhosis in three, hydronephrosis in one and pulmonary thromboembolism in one. Seven pleural effusions were idiopathic. There was no difference in the prevalence between eosinophilic and noneosinophilic effusions according to the different diagnoses. With parameters of sensitivity, specificity, pretest and post-test probability and positive and negative predictive values for any prevalence figure using the Bayes' theorem and for any value of eosinophils (both in percentage or absolute numbers) in the pleural fluid (receiver operating characteristic curve) an adequate predictor of benign disease was not found. It is concluded that pleural eosinophilia at the initial thoracentesis cannot be considered as a predictor of an underlying benign disorder.

Restoration of cytotoxic T lymphocyte function in malignant pleural effusion: interleukin-15 vs. interleukin-2

The present study attempts to define the role of interleukin-15 (IL-15), as compared with IL-2, in generating cytotoxic T lymphocytes (CTL) from the malignant effusions of cancer patients. Effusion-associated lymphocytes (EAL) from malignant effusion were incubated with IL-15 or IL-2 with or without alphaCD3. Proliferation and cytotoxicity assays were performed. IL-15 was found to have at least an equivalent, if not higher, activity to IL-2 in terms of lymphocyte proliferation and generation of CTL from EAL. The proliferative response of EAL, cocultured with IL-15, with or without alphaCD3, was partly inhibited by pretreatment with an anti-IL2 receptor beta chain monoclonal antibody (mAb). The proliferative response of EAL, cocultured with alphaCD3, IL-2, or both, was partly inhibited by pretreatment with an anti-IL-2 receptor alpha chain mAb. Overnight [5lCr] release assays against K562, Daudi, and the patients' autologous tumor cells were done to evaluate EAL's cytolytic activity. MHC class I Ab blocked the stimulated cytolytic activity of EAL against autologous tumors. An mAb depletion assay showed that the phenotype of the restored EAL was CD16-CD4-CD8+; thus, the restored activity of EAL was CTL activity. The results suggest that both IL-15 and IL-2 can restore CTL activity from EAL in the presence of T cell receptor (TCR)-CD3 engagement, but the effect of IL-15 was superior.

Diagnostic significance of immunoglobulins and adenosine deaminase in pleural effusion

OBJECTIVES

1) To evaluate the diagnostic significance of ELISA for detection of antibodies to antigen A60 of Mycobacterium tuberculosis and adenosine deaminase (ADA) in patients with pleural effusion without prior history of tuberculosis, 2) To study the importance of the above tests in patients with HIV infection and pleural effusion.

METHOD

Eighty one patients with pleural effusion were studied. In addition to diagnostic paracentesis and pleural biopsy, pleural fluid specific IgG, IgM, IgA against antigen A60 and fluid ADA were estimated. HIV testing (ELISA) was done in all patients.

RESULTS

Out of 81 patients, 13 were HIV positive. IgG anti A60 had a sensitivity and specificity of 90.71% and 33.33% respectively. The combination of IgG and IgM had a sensitivity and specificity of 96.3% and 55.55% respectively. IgA alone or in combination did not offer any diagnostic advantage. ADA had a sensitivity and specificity of 76% and 60% respectively. In presence of HIV infection, antibodies against A60 had a sensitivity of 76.92% and ADA had a sensitivity of 61.54%.

CONCLUSIONS

In patients with pleural effusion, immunoglobulins against antigen A60 have a limited diagnostic role with high false positive rates. Co infection with HIV further reduces the value of above diagnostic tests.

The role of tumor necrosis factor (TNF)-alpha in the antitumor effect of intrapleural injection of Lactobacillus casei strain Shirota in mice

The involvement of several cytokines in the antitumor effect induced by intrapleural (i.pl.) injection of heat-killed cells of Lactobacillus casei strain Shirota (LC 9018) in mice was investigated. Injection of LC 9018 i.pl. into Meth A fibrosarcoma (Meth A)-bearing mice not only significantly prolonged the survival of the mice, but also effectively inhibited the accumulation of malignant pleural fluid in the thoracic cavity. In the thoracic cavity of tumor-bearing mice treated with LC 9018, we observed large amounts of several cytokines including interleukin (IL)-1beta, interferon (IFN)-gamma, IL-12 and tumor necrosis factor (TNF)-alpha. Both anti-IFN-gamma and anti-IL-12 monoclonal antibody (mAb) treatments partially diminished the antitumor activity of LC 9018 in vivo, while the treatment of anti-IL-1beta mAb did not influence the survival of the mice. However, anti-TNF-alpha mAb treatment completely abolished the antitumor effect of LC 9018 in vivo, suggesting that in this model LC 9018 has a survival-prolonging effect involving certain cytokines. Moreover, i.pl. injection of mouse recombinant TNF-alpha into Meth A-bearing mice pretreated with anti-TNF-alpha mAb partially restored the survival-enhancing effect of LC 9018. These results led us to conclude that TNF-alpha induced by i.pl. injection of LC 9018 plays an important role in the antitumor effect of LC 9018 in vivo.

MUC1 isoform specific monoclonal antibody 6E6/2 detects preferential expression of the novel MUC1/Y protein in breast and ovarian cancer

The products of the MUC1 gene are known to be highly expressed in human breast cancer cells. The best characterized MUC1 protein is a polymorphic, type 1 transmembrane molecule containing a large extracellular domain composed primarily of a variable number of 20 amino acid tandem repeats. We have recently identified a novel protein product of the MUC1 gene, the MUC1/Y protein, that is also a transmembrane protein but is devoid of the tandem repeat array and its immediate flanking sequences. To analyze its expression in tumor cells we generated monoclonal antibodies directed against the MUC1/Y extracellular domain (anti-MUC1/Yex MAbs). Epitope mapping identified the MAb, 6E6, which recognized the MUC1/Y isoform with exquisite specificity- the repeat-array-containing MUC1 isoform could not compete out this immunoreactivity. A 30mer peptide which is unique for MUC1/Y and corresponds to the "join" region generated by the MUC1/Y specific splice, abrogated all 6E6 MAb immunoreactivity towards MUC1/Y. Immunoprecipitation of the MUC1/Y protein with 6E6 MAbs revealed that, in contrast with the proteolytic cleavage of the tandem-repeat-array-containing MUC1 isoform, MUC1/Y is not cleaved. Flow cytometry analyses using the 6E6 MAbs demonstrated that the MUC1/Y isoform is expressed on the cell surface of both MCF-7 breast cancer cells and malignant epithelial cells present in effusions obtained from breast and ovarian cancer patients. Our results unequivocally establish that the MUC1/Y protein is expressed on the surface of breast cancer cells and cells of other epithelial malignancies. The anti-MUC1/Y MAbs described here can target MUC1/Y expressing tumor cells in vivo and are likely to be important reagents both for epithelial tumor diagnosis and immunotherapy.

Immunohistochemical detection of cytotoxic lymphocytes in malignant serous effusions

The use of ancillary techniques to aid in the diagnosis of metastatic carcinoma in serous effusions has been the subject of numerous studies. In this article, we study 35 cases of malignant effusions (metastatic adenocarcinoma) and 20 benign effusions using a panel of immunohistochemical markers to determine whether changes in the subpopulations of accompanying lymphoid cells can be detected with this technique and whether such changes are associated with the presence of malignancy. We noted a significant increase in cytotoxic lymphocytes, defined as the percentage of all lymphoid cells staining with an antibody to TIA-1 (an antigen localized to the cytotoxic granule membranes of cytotoxic T cells and natural killer cells) in malignant compared with benign effusions (23% vs. 12%; P < 0.05). In addition, nearly all cases in which cytotoxic lymphocytes composed > 20% of the lymphoid cell population contained metastatic tumor. Thus, immunohistochemical staining for TIA-1 can reliably detect cytotoxic lymphocytes in cell blocks of serous effusions; in addition, a relative increase in their number is associated with the presence of malignancy.

Overexpression of sialomucin complex, a rat homologue of MUC4, inhibits tumor killing by lymphokine-activated killer cells

Sialomucin complex (SMC) is a large heterodimeric glycoprotein complex composed of a mucin subunit ascites sialoglycoprotein-1 and a transmembrane subunit ascites sialoglycoprotein-2. It is a rat homologue of human mucin gene MUC4 and is abundantly expressed on the cell surface of highly metastatic ascites 13762 rat mammary adenocarcinoma cells. Because of their extended and rigid structures, mucin-type glycoproteins are suggested to have suppressing effects on cell-cell and cell-matrix interactions. During the metastatic process, these effects presumably cause tumor cell detachment from the primary tumor mass and facilitate escape of the tumor cells from immunosurveillance. Analyses of human breast cancer cells in solid tumors and tumor effusions showed that the more aggressive cells in effusions are stained with polyclonal antibodies against SMC more frequently than cells in solid tumors, suggesting a role for MUC4/SMC in tumor progression and metastasis. Previously, we generated recombinant cDNAs for SMC that vary in the number of mucin repeats to study the putative functions of SMC in tumor metastasis. These cDNAs were transfected into human cancer cell lines and tested for the effect of the expression of this gene. Here, using a tetracycline-responsive inducible expression system, we demonstrate that overexpression of SMC masks the surface antigens on target tumor cells and effectively suppresses tumor cell killing by cytotoxic lymphocytes. This effect results from the ability of SMC to block killer cell binding to the tumor cells and is dependent on both overexpression of the mucin and the number of mucin repeats in the expressed SMC. These results provide an explanation for the proposed role of SMC/MUC4 in tumor progression.