Mycosis Fungoides in Children and Adolescents: A Series of 23 Cases. / Micosis fungoide en niños y adolescentes: descripción de una serie de 23 casos.

BACKGROUND: Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma in adults and children. The prevalence has increased in some countries, but no descriptive studies of MF in the pediatric population have been done in Colombia to date. METHODS: A combined prospective-retrospective study of 128 patients with a diagnosis of MF confirmed by the dermatology department and dermatopathology laboratory of Universidad de Antioquia between 2008 and 2017. We describe the clinical and histopathologic variants, response to treatment, and progression of the disease in 23 patients under 18 years of age. RESULTS: The pediatric cases of MF accounted for 18% of all the cases on record. The median age of onset of lesions was 9 years, the median age at diagnosis was 11 years, and the median time between onset of lesions and diagnosis was 2 years. All patients were in early stages of the disease. Hypopigmented MF was the most common clinical presentation (in 52.2%), followed by classical MF (in 30.4%). Folliculotropic MF was identified in 17.4%. All patients were treated with topical corticosteroids and phototherapy. One patient received chemotherapy while still in the early stage of disease. Complete remission was achieved in 59.1% and a partial response in 40.9%. Only 2 patients remained asymptomatic for 5 years. CONCLUSION: We found hypopigmented MF to be the most common clinical presentation in patients under 18 years of age. The disease did not progress to advanced stages in any of the patients, although recurrence after treatment interruption was common.

Human spleen contains different subsets of dendritic cells and regulatory T lymphocytes.

Most knowledge about dendritic cells (DCs) and regulatory T cells in humans has been gathered from circulating cells but little is known about their frequency and distribution in lymphoid organs. This report shows the frequency, phenotype and location of DCs and regulatory T cells in deceased organ donors' spleens. As determined by flow cytometry, conventional/myeloid DCs (cDCs) CD11c(high)HLA-DR(+)CD123(-/low) were 2.3 +/- 0.9% and LIN(-) HLA-DR(+)CD11c(high) 2.1 +/- 0.3% of total spleen cells. Mature CD11c(high)HLA-DR(+)CD83(+) were 1.5 +/- 0.8% and 1.0 +/- 1.6% immature CD11c(high)HLA-DR(+)CD83(-) cDC. There were 0.3 +/- 0.3% plasmacytoid DCs (pDC) CD11c(-/low)HLA-DR(+)CD123(high) and 0.3 +/- 0.1% LIN(-)HLA-DR(+)CD123(high). Cells expressing cDCs markers, BDCA-1 and BDCA-3, and pDCs markers BDCA-2 and BDCA-4 were observed in higher frequencies than DCs with other phenotypes evaluated. CD11c(+), CD123(+) and CD83(+) cells were located in subcapsular zone, T cells areas and B-cell follicles. CD4(+)CD25(high) Tregs were 0.2 +/- 0.2% and CD8(+)CD28(-) comprised 11.5 +/- 8.1% of spleen lymphocytes. FOXP3(+) cells were found in T- and B-cell areas. The improvement in cell separation, manipulation and expansion techniques, will facilitate the manipulation of donor spleen cells as a part of protocols for induction and maintenance of allograft tolerance or treatment of autoimmune diseases.

Enhanced allograft survival and modulation of T-cell alloreactivity induced by inhibition of MMP/ADAM enzymatic activity.

Recent studies have shown significantly increased expression of matrix metalloproteinases (MMP) and disintegrin-type metalloproteinases (ADAM) during allograft rejection. In this regard, our previous studies have demonstrated contrasting roles for MMP-2 and MMP-9 during allograft rejection: MMP-2-deficiency enhanced allograft survival while MMP-9-deficiency decreased allograft survival. The aim of this study was to determine the effect of broad-spectrum MMP/ADAM inhibition on the pathogenesis of allograft rejection. Toward this, heterotopic BALB/c cardiac allografts were transplanted into C57BL/6 recipients treated with MMP/ADAM inhibitors, GM6001 or doxycycline. Systemic MMP/ADAM inhibition significantly enhanced allograft survival. Functioning allografts recovered from MMP/ADAM inhibitor-treated recipients showed lower cellular infiltration and tissue remodeling than rejected allografts recovered from control recipients. In addition, decreased chemotaxis of CD4+ and CD8+ T cells, B cells and macrophages was observed in vitro in the presence of MMP/ADAM inhibitors. Enhanced T-cell alloreactivity was also observed ex vivo in MMP/ADAM inhibitor-treated recipients and in vitro in the presence of MMP/ADAM inhibitors. These observations were associated with enhanced cytokine, chemokine and growth factor production. These results indicate that MMPs and ADAMs play a critical role in the pathogenesis of allograft rejection and may represent novel therapeutic targets for the treatment and/or prevention of this disease.