Low percentages of regulatory T cells in common variable immunodeficiency (CVID) patients with autoimmune diseases and its association with increased numbers of CD4+CD45RO+ T and CD21low B cells

Background: Common variable immunodeficiency (CVID) is a heterogeneous group of primary antibody deficiencies defined by marked reductions in serum IgG, IgA and/or IgM levels and recurrent bacterial infections. Some patients are associated with defects in T cells and regulatory T cells (Tregs), resulting in recurrent viral infections and early-onset autoimmune disease. Methods: We analyzed whether there is an association between Tregs cells (CD4+CD25+CD127low and CD4+CD25+FoxP3+); memory T cells (CD4+CD45RO+); memory B cells (CD19+CD27-IgD-); and CD21low B cells (CD19+CD38lowCD21low); as well as autoimmune manifestations in 36 patients with CVID (25 women and 11 men, mean age 24 years), all by flow cytometry. Results: Fourteen patients presented with autoimmune diseases (AI) (39%), including 11 with autoimmune thrombocytopenia (ITP) (31%); two with vitiligo (6%); one with systemic lupus erythematosus (LES) (3%); and one with multiple sclerosis (MS) (3%). CVID patients with AI had a reduced proportion of Tregs (both CD4+CD25+CD127low and FoxP3+ cells) compared with healthy controls. CVID patients with AI had expanded CD21low B cell populations compared with patients who did not have AI. A correlation between increased CD4+CD45RO T cell populations and reduced Tregs was also observed. Conclusions: Our results showed that 39% of patients with CVID had AI and reduced Tregs populations. Research in this area might provide noteworthy data to better understand immune dysfunction and dysregulation related to CVID

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Sarcoma histiocítico. Estudio inmunohistoquímico de 6 casos / Immunohistochemical study of 6 cases of histocytic sarcoma

Introducción. El sarcoma histiocítco (SH) es una neoplasia poco frecuente con características morfológicas e inmunohistoquímicas de diferenciación histiocítica. Material y métodos. Presentamos 6 casos de SH. Se estudiaron cortes con hematoxilina y eosina y con inmunohistoquímica para CD45, CD163, CD68, lisozima, CD21, EMA, CD1a, S-100, CD20, Ki-67, HMB45 y CK AE1-3. Resultados. Cuatro pacientes fueron hombres y dos mujeres (edad promedio, 25,7 años; rango, 8 meses-64 años). Dos tumores se originaron en ganglios linfáticos, y los demás fueron extraganglionares (glándula parótida, meninges, tejidos blandos de tibia derecha y yeyuno). Los tumores estaban compuestos por células epitelioides medianas a grandes, pleomórficas, con abundante citoplasma eosinófilo, núcleos irregulares y nucléolos prominentes con áreas fusiformes focales y citofagocitosis. Las mitosis variaron con una media de 10 por campo de ×40. Un tumor presentó infiltrado inflamatorio prominente. Todos los tumores fueron positivos a CD45, CD163 y CD68 (KP1 y PGM-1), y 5 expresaron lisozima. Dos tumores fueron focal y débilmente positivos para S-100 y uno para CD1a; todos fueron negativos al CD 20, CD21, HMB45 y a CKAE1-3. Discusión. Para el diagnóstico de SH debe utilizarse CD45 además de dos antígenos asociados a macrófagos y ausencia de marcadores B, T, de melanoma y citoqueratinas(AU)

Introduction. Histiocytic sarcoma (HS) is a rare malignant neoplasm showing the morphologic and immunohistochemical features of histiocytic differentiation. Material and methods. We present 6 cases of HS diagnosed in 4 female and 2 male patients with ages ranging from 8 months to 64 years (medium age of 25.7 years). Sections were stained with hematoxylin and eosin and immunohistochemistry was performed using CD45, CD163, CD68, lysozyme, CD21, EMA, CD1a, S-100, CD20, Ki-67, HMB45 and CK AE1-3. Results. Two tumours arose from lymph nodes and 4 were extranodal (parotid gland, meninges, soft tissues and jejunum); all were composed of sheaths of medium to large pleomorphic epithelioid cells with abundant eosinophilic cytoplasm, irregular nuclei and prominent nucleoli with focal spindle cell features and cytophagocytosis. Mitotic features varied from case to case with a medium of 10 per 10 HPF. All tumours were positive for CD45, CD163 and CD68 (KP1 and PGM-1), 5 expressed lysozyme, 2 showed weak focal positivity for S-100 and 1 for CD1a. All were negative for CD 20, CD21, HMB45 and CK AE1-3. Discussion. It is important that the diagnosis of HS be based on immunohistochemical markers that should include CD45 plus two specific macrophage-associated antigens and the lack of the B-cell, T-cell, as well as cytokeratins and melanoma markers(AU)

Angioma esplénico de célula litoral. Correlación radiopatológica en dos casos / Splenic littoral cell angioma. Radiopathological correlation in two cases

Presentamos dos casos de angiomas de células litorales (ACL), variante de angioma esplénico recientemente descrita, originada en las células que tapizan los sinusoides de la pulpa roja (célula litoral).Las características histopatológicas e inmunohistoquímicas de esta neoplasia confirman su origen en la célula litoral con un origen intermedio entre célula endotelial e histiocítica y que permiten su consideración como entidad patológica diferenciada de los hemangiomas.Los hallazgos de imagen son indistinguibles de los de otras neoplasias vascularares esplénicas, destacando el papel de la resonancia magnética (RM) (AU)