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The aim of this study was to describe the clinical, manometric, and serological characteristics of 12 patients with paraneoplastic GI motor dysfunction and to assess the contributory role of diagnostic tests.Twelve patients diagnosed with malignant tumors and GI motor dysfunction were identified at the Mayo Clinic from 1985 to 1996.Cancers identified were: nine small cell lung carcinoma (SCLC), one anaplastic lung adenocarcinoma, one retroperitoneal lymphoma, and one ovarian papillary serous adenocarcinoma. GI symptoms preceded the tumor diagnosis in all cases of SCLC (mean, -8.7 months, range, -1 to -24 months, n = 9). The diagnosis of a malignant tumor preceded the onset of GI symptoms in the three patients with other neoplasms (6, 12, and 24 months). Five of the nine patients found to have SCLC had no evidence of tumor on initial chest x-ray. One or more paraneoplastic autoantibodies were found in 10 of the 11 patients tested by autoimmune serology. Type 1 antineuronal nuclear antibody (ANNA-1 or anti-Hu) was detected in eight of the nine patients with SCLC (one patient was not tested). The patient with ovarian carcinoma had type 1 Purkinje cell cytoplasmic antibody (Pca-1 or anti-Yo). N-type calcium channel antibodies were found in one patient with SCLC, one with a retroperitoneal B cell lymphoma, and one with ovarian carcinoma. Gastric emptying was delayed in 89% (eight of nine tested) and 80% (four of five tested) had esophageal dysmotility. Autonomic reflex tests were abnormal in the seven patients tested.The diagnosis of paraneoplastic GI motor dysfunction requires a high index of clinical suspicion. A panel of serological tests for paraneoplastic autoantibodies, scintigraphic gastric emptying, and esophageal manometry are useful as first-line screening tests. Seropositivity for ANNA-1, Pca-1, or N-type calcium channel-binding antibodies should prompt further evaluation for an underlying malignancy even when routine imaging studies are negative.
A new monoclonal antibody which recognizes plasma cells was developed by utilizing two myeloma cell lines, KMS12PE (12PE) and KMS12BM (12BM), established from the pleural effusion and bone marrow, respectively, of the same patient. Since 12BM expresses CD20, CD38, and Pca-1 antigens, while 12PE has lost CD20, 12PE is considered to be phenotypically more mature than 12BM. The 12PE cells were used to immunize a BALB/c mouse and a MoAb was produced which was more reactive to 12PE than to 12BM. Thus, a clone, D2, was obtained. On Western blotting, D2 detected a single band of 54 kD under both reduced and non-reduced conditions. This antigen was not detected by Western blotting in peripheral blood lymphocytes that had been stimulated with pokeweed mitogen (PWM) for 7 days or in those not so stimulated. On flow cytometry, D2 detected a myeloma cell line, RPMI 8226. Another myeloma cell line, U266, was negative for D2 antigen. Staining various cell lines by D2 and other antiplasma cell antibodies, Pca-1 and CD38, showed that D2 is distinct from Pca-1 and CD38. The fresh myeloma cells of 14 myeloma patients were stained by D2 and for other plasma cell antigens. D2 strongly stained three samples obtained from patients with clinically aggressive myeloma, while CD38 stained all cases except one. Pca-1 was positive in nine samples and negative in five. Pca-1 expression was observed in plasma cells obtained from pleural effusion and peripheral blood, while Pca-1-negative cases were not found in such samples, suggesting that Pca-1 expression was related to extramedullary invasion. The morphology of the myeloma cells, classified according to Greipp's criteria, showed that there was no correlation between plasma cell antigen expression and plasma cell morphology. Analysis of D2 antigen expression should provide more information about the heterogeneity of myeloma cells.
Two monoclonal antibodies that define distinct plasma cell-associated antigens, termed Pca-1 and PCA-2, were developed against human plasma cell leukemia cells. These antigens are strongly expressed on human myelomas, plasma cell leukemia, and plasmacytoma tumor cells, but are not detected on other lymphoid malignancies of B, T, null, or myeloid origin. Pca-1 and PCA-2 are not expressed on either normal T or B lymphocytes, but are weakly expressed on granulocytes and monocytes. When pokeweed mitogen is used to induce human B lymphocyte differentiation, Pca-1 is expressed when other B cell determinants are lost and plasmacytoid morphology, intracytoplasmic immunoglobulins, and surface T10 staining characteristic of plasma cells appear. In contrast, PCA-2 cannot be induced and may therefore appear later in the B cell differentiation scheme. These antigens may be of utility for the study and regulation of normal and abnormal plasma cell growth, traffic, and tissue distribution and may aid in understanding heterogeneity within plasma cell dyscrasias.
The efficacy of immunomagnetic beads to purge human myeloma cells from bone marrow ex vivo was evaluated. The optimal conditions for purging were studied first by using three myeloma cell lines: RPMI-8226, SKO-007, and SKMM-2. Myeloma cells labeled with the vital fluorescent dye Hoechst 33342 were admixed with normal bone marrow cells, and two monoclonal antibodies reactive with the myeloma cells (Pca-1 and BL-3) were added alone or in combination with the cells. Magnetic beads coated with goat antimouse immunoglobulin G were then added, and the tumor cells to which beads were attached were separated from the mixture with a magnet. The efficacy of tumor cell removal was dependent on the bead-to-tumor ratio; a ratio of more than 500 was optimal in the presence of excess normal marrow cells. The combination of monoclonal antibodies Pca-1 and BL-3 increased the tumor cell removal as compared with either antibody alone. Two cycles of treatment were more effective than one cycle was. Under optimal conditions, 2.3 to 4 logs of tumor cells could be removed from the mixture containing 10% myeloma cells without a significant loss of normal hematopoietic progenitors as measured by CFU-GM, CFU-GEM, and BFU-E. When the efficacy of this procedure was tested on fresh bone marrow from patients with multiple myeloma (MM) by using the combination of Pca-1, BL-3, and J-5, 1.6 to 2.5 logs of tumor cells could be removed by one cycle of treatment, even from marrows containing less than 10% myeloma cells. These observations support the use of monoclonal antibody combinations and immunobeads as a reliable and nontoxic method to eliminate contaminating myeloma cells ex vivo in preparation for autologous bone marrow transplantation in patients with MM.
Peripheral blood mononuclear cells from 24 patients with prolymphocytic leukemia (PLL) were isolated using a Ficoll-Hypaque gradient and stained by indirect immunofluorescence using a wide panel of monoclonal antibodies against B cell restricted and associated antigens, including HLA DR (Ia), CD19, CD21 (C3dR) surface membrane immunoglobulin (Slg), CD10 (CALLA), C3b, B5, CD25 (TAC), Pca1, T9, and T10. The cells were also tested for the FMC7, defined previously on PLL cells and the RAB1, a newly described hairy cell leukemia antigen. Thirteen out of the 24 samples expressed with variable intensity all the above antigens. While Ia, CD19, CD20, FMC7, and RAB1 were strongly or moderately expressed in all, the complement receptors (CD21 and C3b) were only weakly expressed in 12 cases; and the activation antigens B5, TAC, T9, T10, and Pca1 were found with variable intensity in two-thirds of the cases. In 50% of the cases tested, the CD5 antigen (usually strongly expressed on B CLL cells) was weakly to moderately expressed. These findings (absence or weak expression of complement receptors with variable expression of activation antigens) suggest that the PLL cells are activated B cells. When stimulated in vitro by anti-mu and TPA, (phorbol ester) tumor cells showed a decrease in CD21 and Slg and a stronger expression of CD25, T9, T10, and Pca1, with evidence of Ig secretion in four out of the seven cases studied. This confirms that the PLL cells arrested at an advanced stage of differentiation progressed narrowly to more differentiated cells. In view of our findings, we believe that the term prolymphocytic leukemia is inaccurate to define the stage of cell differentiation, and we suggest calling the disease preplasmacytic leukemia.
The immunological phenotypes of lymphocytes and myeloma cells in 48 patients with multiple myeloma (MM) were analyzed using a panel of monoclonal antibodies (mAbs). Myeloma cells were positive for OKT10, BL3, Pca1 and BA2. In a few cases, they were also positive for the B cell-associated antigens J5, B1 and I2. Eight of 48 cases had more than 15% J5-positive lymphocytes, and some lymphocytes in MM expressed plasma cell-associated antigens (Pca1, BL3, OKT10), suggesting a possible clonal involvement. These observations demonstrate the heterogeneity of surface antigen expression of myeloma cells and suggest that BL3, Pca1, BA2 and J5 may be useful mAbs for purging myeloma cells from bone marrow for autologous transplantation.
The peripheral blood lymphocytes from 42 patients with multiple myeloma (MM) and 13 patients with monoclonal gammopathy of undetermined significance (MGUS) were studied by three-color immunofluorescence (IF) using antibodies directed to a broad range of B-cell markers (CD19, CD20, CD21, CD24), CALLA (CD10), Pca-1 (a plasma cell marker), and to the high and low molecular weight isoforms of the leukocyte common antigen, CD45RA (p205/220) and CD45RO (p 180). CD45RA is expressed on pre-B and B cells, and a transition from CD45RA to CD45RO defines differentiation towards plasma cells. Peripheral blood mononuclear cells (PBMC) from patients with myeloma included a large subset of B-lineage cells (mean of 39% to 45%) that were CALLA+ and Pca-1+ in all patients studied, including newly diagnosed patients and patients undergoing chemotherapy. Southern blot analysis indicated the presence of monoclonal Ig rearrangements in PBMC and a substantial reduction in the germ-line bands consistent with the presence of a large monoclonal B-cell subset. Avoidance of purification methods involving depletion of adherent cells was essential for detection of the abnormal B cells. Phenotypically, this abnormal B-cell population corresponded to late B or early pre-plasma cells (20% to 80% of PBMC), as defined by the concomitant expression of low densities of CD19 and CD20, moderate densities of CALLA and Pca-1, and strong expression of CD45RO on all B cells, with weakly coexpressed CD45RA on a small proportion. Heterogeneity in the expression of CD45RA and CD45RO within the abnormal B-cell population from any given patient suggested multiple differentiation stages. Abnormal B cells similar to those in MM were also detected in MGUS, although as a lower proportion of PBMC (26%). Abnormal B cells from patients with MGUS expressed predominantly the CD45RO isoform, but had a lower proportion of CALLA+ and Pca-1+ cells than were found on B cells from MM. This work indicates that the large subset of circulating monoclonal B lymphocytes from myeloma patients are at a late stage in B-cell differentiation, continuously progressing towards the plasma cell stage.
Circulating monoclonal B cells in peripheral blood from patients with multiple myeloma or with monoclonal gammopathy of undetermined significance (MGUS) have previously been shown to express CD19, CD20, and Pca-1 and are predominantly CD45R0+, characterizing them as very late stage B cells. This work shows that the abnormal B cells are monoclonal as defined by their exclusive expression of either kappa or lambda light chain mRNA, and that the same type of light chain mRNA is expressed in both bone marrow plasma cells and blood B cells. These abnormal tumour-related circulating B cells express high densities of CD11b, a beta 2-integrin, which is expressed in a conformationally active state as defined by reactivity with monoclonal antibody 7E3. Normal peripheral blood B cells which do not bear CD11b acquire a high density after stimulation with pokeweed mitogen (PWM). At day 4 of culture, the expression of CD11b on normal CD19+ B cells was nearly comparable to that of the circulating myeloma late stage B cells. After PWM stimulation of circulating myeloma B cells the expression of CD11b was gradually lost during 4 days of culture, suggesting that its expression is dynamically regulated. Two patients with no phenotypically abnormal B cells in their blood at diagnosis acquired a large subset of CD11b+ B cells 4 weeks after initiation of chemotherapy. In most patients, a subset of the circulating myeloma B cells express a low density of CD5. The proportion of CD19+ B cells in the bone marrow expressing CD11b was much reduced compared with peripheral blood B cells, and CD11b was not detectable on plasma cells in the bone marrow, suggesting a sequential relationship of the B-cell subsets detected in our population of patients, involving gradual loss of CD11b concurrent with the loss of CD19 during B lineage differentiation. These cells appear to represent a continuously differentiating monoclonal B lineage culminating in the CD11b- plasma cell entrenched in the bone marrow. We speculate that the expression of conformationally active CD11b on the abnormal B cells in peripheral blood mononuclear cells of myeloma patients facilitates transendothelial migration of circulating myeloma B cells to the bone marrow.