Proliferation kinetics of the dermal infiltrate in cutaneous malignant lymphomas

Summary To obtain information about the role of local proliferation in the pathogenesis of dermal infiltrate in malignant cutaneous lymphomas, we determined the percentage of ³H-thymidine-labeled infiltrating cells (³H-index).A linear correlation was found between proliferative activity and clinical stage in mycosis fungoides, i.e., the ³H-index is moderately elevated in stage I and high in stage III.The ³H-index is within normal range in dermal infiltrate of Sézary syndrome, diffuse lymphocytic lymphoma, as well as in lymphocytoma benigna cutis.In parapsoriasis en plaques two groups can be distinguished: in the smallplaque variant (chronic superficial dermatitis) the ³H-index is low, whereas the large-plaque variant (prereticulotic poikiloderma) shows strong proliferative activity.Thus, determination of proliferative activity seems to give new insights into the pathogenesis of dermal infiltrate in cutaneous lymphomas.Zusammenfassung Um die Bedeutung der lokalen Zellproliferation im dermalen Infiltrat bei cutanen malignen Lymphomen zu untersuchen, bestimmten wir den Prozentsatz der ³H-Thymidin-markierten Infiltratzellen (³H-Index.Zwischen dem klinischen Stadium der Mycosis fungoides und der Proliferationsaktivität des dermalen Infiltrats besteht eine lineare Beziehung; im Stadium I ist die Proliferation niedrig, im Stadium III sehr hoch.Nicht erhöht ist der ³H-Index im dermalen Infiltrat beim Sézary-Syndrom, diffusen lymphocytischen Lymphom sowie bei Lymphocytoma benigna cutis.Bei der Parapsoriasis en plaques müssen zwei Formen unterschieden werden: bei der kleinfleckigen Form (chronic superficial dermatitis) ist der ³H-Index niedrig, während die großfleckige Form (Präretikulotisches Poikiloderm) eine starke Proliferationsaktivität aufweist.Die Untersuchung des Proliferationsverhaltens gibt neue Einblicke in die Pathogenese des dermalen Infiltrats cutaner Lymphome.     

Isoenzyme studies in human leukemia-lymphoma cell lines--1. Carboxylic esterase

The isoenzyme patterns of carboxylic esterase (E.C. 3.1.1.1) were studied in 74 proven human leukemia-lymphoma and 12 normal B-lymphoblastoid cell lines. These cell lines have been extensively phenotyped using poly- and monoclonal antibodies. Esterase isoenzymes were separated by isoelectric focusing and visualized by histo-cytochemical techniques. No leukemia-specific or (except for monocytes) blood cell type-specific isoenzyme or isoenzyme pattern could be detected. The monocytic element in some cell lines was characterized by a strong isoenzyme band which could be selectively and completely inhibited by sodium fluoride. The enzyme phenotypes were stably expressed in all subcultures of a given cell line and did not appear to have any cell cycle dependency. The leukemia-lymphoma cell lines have been subclassified into four major groups according to immunological parameters: T-cell, B-cell, myelomonocytic and non-T, non-B-cell. On the basis of immunological data the T-cell lines were assigned to five stages of differentiation. The number and staining intensity of the isoenzymes increased with differentiation of the T-cells paralleling the expression of immunological markers. The B-cell leukemia-lymphoma cell lines were divided into pre B-, B-, Burkitt lymphoma, multiple myeloma and hairy cell leukemia cell lines. Substantial variability among the isoenzyme patterns was detected ranging from immature profiles of pre B-cell lines to complete isoenzyme repertoires of multiple myeloma cell lines. No significant difference was seen between the isoenzymes of mature B-cell lines and normal B-lymphoblastoid cell lines. The most prominent feature seen in myelomonocytic cell lines was the monocytic band indicating a monocytic origin and separating the 'monocytoid' from the 'pure myeloid' cell lines. Considerable heterogeneity in the isoenzyme patterns was observed in the non-T, non-B cell groups which comprised erythroleukemia cell lines and cell lines arrested at a very early stage of lymphoid differentiation. These latter cell lines together with some T- and B-cell lines shared the common characteristics of positivity for cALLA, TdT and Ia antigens and an immature, incomplete isoenzyme profile. The results support the notions of maturation arrest and normal gene expression in leukemic cell populations. Furthermore, the importance of biochemical studies as part of the multiple marker analysis could be demonstrated.