Use of imprints for monoclonal antibody studies: suitability of air-dried preparations from lymphoid tissues with an immunohistochemical method.

Air-dried imprint preparations are conveniently produced from human lymphoid samples without the special methods required for snap-freezing tissues or rendering them into suspensions. T-cells, T-cell subsets (helper and suppressor), and HLA-DR-positive cells (B-lymphocytes, monocytic-histiocytic cells) can be identified in such imprints by the use of commercially obtained mouse hybridoma antibodies with a simple two-step immunoperoxidase method. Direct nuclear morphologic correlation with surface determinants is achieved by this method. Immunoreactivity is retained only eight to 10 days in such air-dried preparations, and attempts to prolong reactivity have been unsuccessful so far.

Demonstration of distinct antigenic profiles of small B-cell lymphomas by paraffin section immunohistochemistry.

The immunoperoxidase technique was used with antibodies against B-cell-associated antigens, including CD20, CD79a, CD10, CD23, CD43, cyclin D1, bcl-2, and kappa and lambda immunoglobulin light chains on formalin-fixed and B5-fixed tissue sections of follicular, small lymphocytic, mantle cell, and marginal zone lymphomas. Results obtained with paraffin section immunohistochemistry for CD20, CD10, CD23, and kappa and lambda light chains were compared with results obtained with flow cytometry or frozen section immunohistochemistry. Cells in all of the lymphoma types were positive for CD20 and CD79a. The antigenic profiles of the B-cell lymphomas demonstrated in paraffin sections were lymphoma type distinctive. Intrafollicular lymphocytes in follicular lymphomas were positive for CD10 and bcl-2. Small lymphocytic lymphomas expressed CD43 and CD23 and were negative for CD10 and cyclin D1. Mantle cell lymphomas characteristically expressed CD43 and cyclin D1 and were negative for CD23 and CD10. Marginal zone lymphomas were negative for CD23, CD10, and cyclin D1. All of the antibodies performed better in B5-fixed tissues, but formalin-fixed tissue immunophenotypes were always similar to those obtained on the B5-fixed tissue. These results were possible using well-fixed tissue, various antigen retrieval strategies, paraffin section reactive primary antibodies, and sensitive detection systems. Paraffin section immunohistochemistry on sections of routinely fixed tissue can be used similarly to flow cytometry and frozen section immunohistochemistry when classifying the lymphomas of small B lymphocytes.

Detection of Chlamydia trachomatis in Papanicolaou-stained cervical smears by an indirect immunoperoxidase method.

A two-step (indirect) immunoperoxidase method directed against Chlamydia trachomatis was developed. The method was then used to evaluate the specificity of cytologic changes suggestive of C. trachomatis in Papanicolaou smears of cervical specimens from women who were culture-negative for the organism. Positive immunoperoxidase staining was detected in 9 of 21 cases (43%) tested. Technical problems, especially background staining, precluded interpretation in the remainder of the cases. Cervical cytology, as demonstrated by immunoperoxidase staining, may, in some instances, be more sensitive than the culture. However, because the etiology of cytologic changes not specifically identified by immunoperoxidase staining may be due to other organisms or factors, immunoperoxidase procedures, as described, should not replace culture for confirmation of cytologic findings suggestive of C. trachomatis.

Overexpression of Syk tyrosine kinase in peripheral T-cell lymphomas.

Peripheral T-cell lymphomas (PTCLs) are fatal in the majority of patients and novel treatments, such as protein tyrosine kinase (PTK) inhibition, are needed. The recent finding of SYK/ITK translocations in rare PTCLs led us to examine the expression of Syk PTK in 141 PTCLs. Syk was positive by immunohistochemistry (IHC) in 133 PTCLs (94%), whereas normal T cells were negative. Western blot on frozen tissue (n=6) and flow cytometry on cell suspensions (n=4) correlated with IHC results in paraffin. Additionally, western blot demonstrated that Syk-positive PTCLs show tyrosine (525/526) phosphorylation, known to be required for Syk activation. Fluorescence in situ hybridization showed no SYK/ITK translocation in 86 cases. Overexpression of Syk, phosphorylation of its Y525/526 residues and the availability of orally available Syk inhibitors suggest that Syk merits further evaluation as a candidate target for pharmacologic PTK inhibition in patients with PTCL.

Gastrointestinal motor dysfunction in acquired selective cholinergic dysautonomia associated with infectious mononucleosis.

This report documents the disturbance in gastrointestinal motor function in a patient with selective cholinergic dysautonomia that occurred following acute infectious mononucleosis. Apart from the gut, other organs affected included the pupils, sweat glands, lacrimal and salivary glands, and urinary bladder. Autonomic function tests showed the preservation of sympathetic adrenergic functions in contrast to the generalized involvement of postganglionic parasympathetic and sympathetic cholinergic nerves, including denervation hypersensitivity of the pupil and urinary bladder to exogenous cholinergic agonists. Cardiac and abdominal vagal responses were abnormal. Colon myenteric plexus ganglion cells were normal by morphological and immunohistochemical studies, suggesting that the selective cholinergic dysautonomia was the most likely pathophysiologic process responsible for the observed motility disorder. This study documents the occurrence of selective cholinergic dysautonomia following a viral illness, the importance of the extrinsic neural control on the motor function of the gastrointestinal tract, and the usefulness of combined motility and autonomic function testing in the evaluation of patients with symptoms suggestive of gut dysmotility.