Histotopography of highly glycosylated lymphocytes and stromal cells in lymph nodes of patients with B-chronic lymphocytic leukaemia

Abstract

Malignant transformation of lymphopoiesis in lymph nodes (LN) is accompanied by structural rearrangement of the LN stroma and changes in the glycosylation of membrane and cytoplasmic proteins. For the histochemical detection of transforming lymphoid cells and remodeled LN stroma, we used the tomato lectin Lycopersicon esculentum, which is able to bind to surface and cytoplasmic glycoproteins of the majority of LN cells. The study aimed to investigate the characteristics of cell architectonics with a high level of protein glycosylation in the LN of patients with B-chronic lymphocytic leukаemia (B-CLL). The study material were biopsy specimens of supraclavicular and cervical LNs from patients of the First Republican Clinical Hospital of the Ministry of Health of the Udmurt Republic with a confirmed diagnosis of B-CLL (16 patients), aged 49-73 years, obtained prior to treatment with their informed voluntary consent. LN biopsies from the same body regions of 12 individuals aged 48-70 years with reactive LN hyperplasia served as control samples. Paraffin sections of 7 µm thick LN were stained with FITC-conjugated tomato lectin and fluorescent dye propidium iodide (IP) and examined using a Nikon Eclipse200 microscope equipped with a luminescence unit and digital camera. Analysis of LN preparations from patients with B-CLL revealed significant changes in the histotopography of cells and extracellular structures with a high degree of glycosylation. Follicles in the cortex were replaced by an array of small lymphocytes against a background of proliferating centers containing lymphocytes with dispersed packing of IP-labelled chromatin. In this area we also observed a uniform network of thin lectin-labelled reticular fibres and a large number of small blood vessels. Macrophage-like cells, clearly identifiable in the germinal centres of follicles in control, were absent in B-CLL. Their increased number and intensity of luminescence was observed in the subcapsular sinus area and in the paracortical area around collagen bundles formed by conduits, as well as around connective tissue trabeculae of the brain substance. The differences observed in the histological topography of highly glycosylated LN cells in B-CLL suggest that the proposed staining method is informative and facilitates the diagnosis of this disease in histological studies.