Pathogenesis of graft versus host disease.
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Epithelium↗
Biomedical subjects
S A Dilly
Publications and source records attributed to S A Dilly.
Changes in rectal leucocytes after allogeneic bone marrow transplantation.
Using immunohistological techniques the number of leucocytes present in the epithelium and lamina propria of the rectal mucosa were assessed in 16 allogeneic bone marrow transplant recipients, with and without evidence of graft-versus-host disease (GVHD), and compared with a non-transplant group of patients. Samples were obtained between 15 and 198 days after transplant. In marrow recipients without GVHD, compared with non-transplant cases, there was a decrease in T lymphocytes in the lamina propria due to a reduction in the helper-inducer (T4+) subset with no change in suppressor-cytotoxic (T8+) cells or epithelial leucocytes. In GVHD, the number of T lymphocytes increased both in the lamina propria and epithelium due to an increase in T8+ cells with no change in T4+ cells. Lymphocytes did not express the activation markers detected by Tac, OKT10 or HLA-DR. Macrophages and natural killer cells were not changed after transplant or in GVHD. Epithelial HLA-DR expression was detected in seven out of eight in the GVHD group, three out of eight in the non-GVHD transplant group and two out of eight in the non-transplant cases. These findings show several differences from those we have observed in cutaneous and hepatic GVHD. Although elevated numbers of T8+ cells are common to GVHD in all three sites, the precise role of these cells in producing epithelial damage is not clear.
Adolescent↗
The cellular composition of human lymph nodes after allogenic bone marrow transplantation: an immunohistological study.
Using immunohistological techniques, the cellular composition of lymph nodes was assessed in 18 patients who had died 15 to 326 days after allogeneic bone marrow transplantation for leukaemia. The lymph nodes showed reduced cellularity of the cortex and paracortex, dilated sinuses and no lymphoid follicles. The majority of leucocytes were T lymphocytes with an inversion of the normal T4:T8 ratio. No cells were detected expressing immature cortical thymocyte antigens, using NA1/34 and OKT10, but an excess of T11 (E rosette receptor)+ cells over the sum of T4+, T8+ and HNK1+ cells raised the possibility of the presence of immature cells. B lymphocytes were extremely rare and present as clusters in only two patients. Despite this, plasma cells were prominent in many cases and their number increased with time post transplant. The predominant immunoglobulin heavy chain class was IgA in seven cases, IgG in three cases, IgM in two cases and IgE in one case with no relationship between dominant class and days post transplant. In patients with graft-versus-host disease (GvHD), there was a significantly lower T4:T8 ratio but no increase in expression of lymphocyte activation markers. Pyknotic leucocytes were present in half of the cases with GvHD and none of the other cases. No differences were detected in patients who had received marrow purged with monoclonal antibodies (Campath-I or UCHT1). Chimeric studies on three recipients of one haplotype matched marrow, using a monoclonal antibody specific for HLA-A2 and A28 antigens, showed a significant influx of donor cells by 56 days but this did not appear to be an immediate prelude to full morphological reconstitution.
Adolescent↗
Peritoneal cystic mesothelioma: an electron microscopic and immunohistochemical study of two male patients.
The clinical, pathological, and ultrastructural features of two cases of peritoneal cystic mesothelioma occurring in men were studied. The results of immunohistochemical staining for CAM 5.2, epithelial membrane antigen, carcinoembryonic antigen, and Factor VIII related antigen are reported for the first time and compared with the staining results of two peritoneal cystic lymphangiomas. Although resembling cystic lymphangioma by light microscopy, cystic mesothelioma may have a greater tendency for local recurrence. Staining for CAM 5.2 or epithelial membrane antigen may facilitate the differentiation of these two entities.
Adult↗
Microcorrosion casting of the human respiratory acinus.
Microcorrosion casts demonstrating the respiratory acini of human lungs were produced using Tensol Cement No. 70 (a methyl methacrylate mixture). Lung casts were made from foetuses of 19 weeks' gestation to term, a child of 5 years and two adults. Tensol Cement No. 70 was found to infuse the most peripheral airspaces without tissue penetration and could be airdried. Attempts using Batson's medium were hampered by permeation of the airway walls and inability to withstand airdrying. Despite the use of autopsy material, good cell impressions were seen. At 19 weeks' gestation, the respiratory acinus is simple with only two or three generations of rather tubular respiratory bronchioles. In later intra-uterine development, the number of generations of intra-acinar airways increases and the most peripheral airspaces expand to form initially shallow but later cup-shaped saccules. At all ages, the proximal airways of the acinus have regularly-spaced deep cell impressions suggesting a cuboidal/columnar epithelium while the distal airspaces have less frequent shallow cell impressions suggesting a flattened epithelium. Measurements of the maximum diameter of the most peripheral airspaces show an approximate doubling of size between 19 weeks' gestation and term and a further doubling by the age of 5 years.
Adult↗
Leukaemic infiltration of the anus.
A case of biopsy-proven anal involvement in acute promyelocytic leukaemia is presented with management by local conservative measures and remission induction with chemotherapy. A brief review of the literature is given.
Adult↗
An immunohistological study of human hepatic graft-versus-host disease.
Using immunohistological techniques, leucocytes were enumerated in portal tracts and bile duct epithelium in bone marrow transplant recipients with and without evidence of hepatic graft versus host disease (GvHD) and compared with normal subjects. Samples were obtained 8-169 days after transplantation. In marrow recipients without graft versus host disease (GvHD), inducer and suppressor/cytotoxic lymphocytes were reduced in number in the portal tracts compared with normal subjects. In GvHD, suppressor/cytotoxic lymphocytes were increased relative to non-GvHD recipients, but did not exceed normal values, while inducer cell numbers remained low. Natural killer cells (HNK1+) were not found in normal subjects, were present in small numbers in non-GvHD transplant cases and significantly increased in GvHD. The total number of portal tract leucocytes was not elevated in GvHD and the changes in the relative proportions of cells were similar to those that have been observed in the peripheral blood after transplantation. There was no increase in the number of lymphocytes expressing the activation markers Tac, T10 and HLA-DR nor in the number of leucocytes within the bile duct epithelium itself. These findings differ from those we have previously obtained in a similarly treated group of patients with cutaneous GvHD where lymphocytes were increased in the epithelium and stroma and expressed activation markers. Like the epidermis of the skin, however, the bile duct epithelium showed increased staining for HLA-DR antigens in all cases, but focal staining was also present in four of the seven marrow recipients without GvHD. The significance of these findings is discussed.
Adolescent↗
Scanning electron microscope study of the development of the human respiratory acinus.
Plastic corrosion casts were made of lungs from fetuses aged from 19 weeks' gestation to term and of lungs from a child and two adults to study the development of the respiratory acinus. To achieve reliable infusion of the most peripheral airspaces a high viscosity plastic was used that is not known to have been employed previously for corrosion casting of lungs. The casts were examined in the scanning electron microscope and showed the increase both in number and in length of the airways distal to the terminal bronchiole and also the change in shape and complexity of the most peripheral airspaces as the lung matures. The terminal airspaces change from short, simple, tubular endings at 19 weeks' gestation to short, shallow saccules from around 30 weeks' gestation to full term and contrast with the deep cup shaped alveoli in the adult. Measurements of the size of the terminal airspace at various stages of development are presented. This new approach, allowing three dimensional study of the peripheral airspaces of the developing lung, will be useful for investigating the lung pathology of neonates.
Adult↗