Epidermal Langerhans cells after allogeneic bone marrow transplantation: depletion by chemotherapy conditioning regimen alone

Antithymocyte globulin affects the occurrence of acute and chronic graft-versus-host disease after a reduced-intensity conditioning regimen by modulating mixed chimerism induction and immune reconstitution

BACKGROUND

There have been no detailed analyses of the induction of donor cell-type chimerism, the onset and incidence of acute and chronic graft-versus-host disease (GVHD), and the immune recovery kinetics after reduced-intensity stem cell transplantation (RIST).

METHODS

To address these, with particular emphasis on the impact of the use of antithymocyte globulin (ATG) in RIST, we compared 39 consecutively registered patients who underwent RIST from an HLA-matched related donor and 33 patients who underwent conventional marrow-ablative transplantation.

RESULTS

The incidences of grades II to IV acute and chronic GVHD tended to be less in RIST with ATG than in either RIST without ATG or conventional marrow-ablative transplantation. In a multivariate analysis, the predictive factors for acute and chronic GVHD included, respectively, ATG and grades II to IV acute GVHD. In a chimerism analysis, the achievement of complete donor chimera in T-cell lineage was delayed in RIST without ATG compared with RIST with ATG (P=0.038), which might explain the observed delayed onset of acute GVHD in RIST with ATG compared with the other two regimens. The ratio of type 1 and 2 dendritic cells did not affect the development of GVHD, whereas the number of naive CD4+ T cells did. No difference was observed in the incidence of clinically definitive infection, including cytomegalovirus, among the three cohorts, regardless of the use of ATG.

CONCLUSIONS

We suggest that the conditioning regimen and immunosuppressive strategy after RIST should be carefully balanced against the risk of GVHD and of relapse of the basic disorder caused by the lack of a graft-versus-leukemia benefit.

Numerical, morphological and phenotypic changes in Langerhans cells in the course of murine graft-versus-host disease

BACKGROUND

In the course of graft-versus-host disease (GVHD) or diseases that histologically mimic GVHD (e.g. toxic epidermal necrolysis, Stevens-Johnson syndrome), it is known that epidermal Langerhans cells (LCs) are depleted from the epidermis. However, the mechanism and significance of LC depletion is not well known.

OBJECTIVES

To investigate the numerical, morphological and phenotypic changes in LCs and apoptosis of LCs in the course of GVHD using a non-irradiated mouse GVHD model.

METHODS

BALB/c nu/nu mice and C57BL/6 mice were used as recipients and donors, respectively. Recipient mice were injected with T-cell-enriched donor spleen cells. Skin samples were harvested at various times after the inoculation. The numerical and morphological changes were examined by an immunofluorescence study of epidermal sheets. Apoptosis was studied by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling method and flow cytometric analysis using annexin V. Phenotypic change was studied by flow cytometric analysis of epidermal cell suspensions. The mixed epidermal cell lymphocyte reaction (MELR) was performed to examine functional changes in the epidermal cells.

RESULTS

Five days after inoculation, a graft-versus-host reaction occurred. Epidermal LCs began to decrease from the sixth day. On the fifth day, the LCs became larger and had prominent dendrites. Immediately before the LCs began to decrease, many LCs became round in shape, with scanty dendrites. LC apoptosis was not observed in the epidermis either on the fifth or seventh day. Phenotypically, the expression of CD40, CD80, CD86 and major histocompatibility complex class II antigen on the LCs was upregulated on the fifth and seventh day. Epidermal cells from GVHD mice showed an increased allostimulatory capacity in the secondary MELR.

CONCLUSIONS

These results suggest that at early GVHD onset, most LCs may not undergo apoptosis in the epidermis but are phenotypically activated, resulting in further activation of alloreactive T cells and aggravation of the disease.

Myocutaneous flaps in patients with head and neck cancer retain their immunological capacities in an activated functional state

Free/pedicled myocutaneous flaps used as functional replacement after radical dissection of advanced stage squamous cell carcinomas of the oral cavity/oropharynx were examined by immunohistochemistry (APAAP-technique). Biopsies from eight patients were taken at the time of surgery and at 3 and 5 months post-operatively. Fifteen monoclonal antibodies were used to detect surface antigens as markers of phenotypic changes of immune competent cells. In post-operative biopsies all antigens investigated increased significantly. Significantly higher numbers of CD45RO+ (P < 0.01) and CD45RA+ (P < 0.001) leukocytes were detectable. The majority of these leukocytes were TcR alpha/beta +/CD3+ T-cells, which increased in the CD4 (P < 0.05) and the CD8 (P < 0.001) subset. In addition, B-cells (P < 0.05), granulocytes (P < 0.05), NK cells (CD16+ lymphocytic cells; P < 0.05) and mature macrophages (25F9+cells; P < 0.01) were increased. Intra- and subepidermally a significantly (P < 0.01) higher number of dendritic-/Langerhans cells (CD1a+) was detectable. In post-operative biopsies, the activation-associated antigens ICAM-1, VCAM and HLA-DR were expressed on significantly more mononuclear-/endothelial cells and on keratinocytes. Our findings indicate that the myocutaneous flaps still contained cells with immunological capacities.

Image analysis in dermatopathology

BACKGROUND/AIMS

Image analysis in dermatopathology has been used for DNA ploidy analysis, morphometry, stereology, and quantitative immunohistochemistry. The object is to review image analysis in dermatopathology and evaluate these modalities and their application in pigmented lesion pathology, for elucidation of tumor behaviour and architecture and as an aid in tumor identification and prognostication.

CONCLUSION

Image analysis in dermapathology has a huge potential. The techniques are difficult and at present mainly used in specialized centres.