Immunoreactivity of tumor-associated glycoprotein (TAG-72) in normal, hyperplastic, and neoplastic colon.

Monoclonal antibody B72.3 recognizes tumor-associated glycoprotein (TAG-72) and has been widely used to identify malignant epithelial cells in cytologic and histologic preparations. We investigated TAG-72 expression in normal, hyperplastic, and neoplastic adult colon tissues. Formalin-fixed, paraffin-embedded samples of normal (43), hyperplastic (20), and neoplastic (70) colonic tissue were studied with B72.3 using the avidin-biotin complex immunoperoxidase method. TAG-72 expression was detected in 100% of the invasive carcinomas, in 84% of the normal colon samples, in 100% of the hyperplastic polyps, and in 93% of the adenomatous or mixed hyperplastic-adenomatous lesions. Among cases expressing TAG-72 immunoreactivity, the extent of staining varied from 100% of cells in normal and hyperplastic lesions to 10% to 100% in neoplastic lesions. A consistent supranuclear (presumably Golgi) staining pattern was observed in all tissues with the exception of carcinoma and some adenomas; in these cases, staining localized to the luminal surface and intraluminal mucin and/or was diffusely cytoplasmic. From these data, it is clear that TAG-72 is expressed in both benign and neoplastic cells of the human adult colon, although different patterns of expression may distinguish malignant transformation. Furthermore, carcinoma cells less consistently express TAG-72, so that small biopsies or cytologic specimens may be falsely negative due to sampling errors.

A comparative analysis of cytoplasmic mu (C mu) expression in acute lymphoblastic leukemia by molecular and immunologic techniques. Identification of leukemia cases expressing C mu mRNA transcripts in the absence of detectable C mu proteins.

Among acute lymphoblastic leukemias derived from the B-cell lineage, the subset of cases expressing cytoplasmic mu heavy chain proteins (C mu) in the absence of surface immunoglobulin has been designated pre-B-cell acute lymphoblastic leukemia. This group, traditionally identified using immunologic smear techniques, has been associated with a poor prognosis in some series. In a comparative study, 25 cases of B-lineage acute lymphoblastic leukemia were analyzed for C mu expression using molecular and immunologic techniques. RNA derived from cryopreserved blast cells was hybridized in both Northern and slot-blot analyses using a probe (pBZ311) containing four exons of the human immunoglobulin heavy chain mu constant region gene. Expression of C mu proteins was assessed simultaneously by slide immunofluorescence and flow cytometric techniques in all samples. These studies were correlated with immunoglobulin heavy and light chain gene rearrangements, cell-surface immunophenotype, cytogenetics, and other clinicopathologic features. C mu mRNA transcripts were detected in 14 of 25 cases, whereas C mu proteins were detected in only 9 of these cases using flow cytometric techniques. Only four of these nine cases were positive by slide immunofluorescence techniques. These studies imply that molecular and flow cytometric techniques may be a more sensitive means to assess C mu expression. The identification of five cases that expressed C mu mRNA transcripts in the absence of detectable C mu proteins also suggests that molecular techniques may be valuable in identifying a unique subgroup of pre-B-cell acute lymphoblastic leukemia cases that contain C mu mRNA transcripts, but lack C mu proteins.

Flow cytometric analysis of lymphoma and lymphoma-like disorders.

The use of flow cytometry (FC) represents the most recent advance in the phenotypic analysis of lymphocyte subsets, and has emerged as a valuable adjunct in the diagnosis of malignant non-Hodgkin's lymphoma (NHL). In a review of over 200 cases of nodal and extranodal suspected lymphomas studied in the Immunophenotyping Laboratory at the University of New Mexico, the diagnostic utility of FC was assessed. Among cases of NHL, FC was able to confirm a morphologic diagnosis of lymphoma and determine B or T cell lineage in greater than 85% of the samples submitted. Difficulty in lineage determination in the remaining cases of morphologic NHL was multifactorial. Among cases of reactive lymph nodes and Hodgkin's disease, FC showed no characteristic patterns, although several cases exhibited phenotypic profiles suggestive of B or T cell clonality. When combined with routine morphologic review and accompanied by other specialized diagnostic techniques when necessary, the use of FC represents a precise and reproducible method for rapidly and easily studying lymphoproliferative disorders in solid tissue.

Serologic responses to Schistosoma japonicum: evaluation of total and parasite-specific immunoglobulins during the course of murine infection.

Mice with a primary infection of Schistosoma japonicum develop high levels of both total immunoglobulins and parasitic-specific antibodies, beginning about 1.5 wk after the onset of oviposition in the host. Radial immunodiffusion demonstrated an 18-fold, fivefold, and threefold increase in the levels of IgG1, IgM, and IgA, respectively, during the course of infection. Schistosoma japonicum-specific antibodies, as measured by an enzyme-linked immunoabsorbent assay, appeared and increased at about the same time as total immunoglobulins, and were predominantly of the IgG1 and IgM classes. The specific/ELISA response to a purified antigen from S. japonicum SEA was distinct from the total specific response to crude SEA. Hemagglutinating antibodies increased at 5 wk PI and remained at high levels for the duration of infection. Specific, circulating IgE measured by PCA appeared 6 wk PI, reaching a peak at 9 wk, and persisted at moderate levels throughout the infection period.