[Complement activation products (C3a and C5b-9) as markers of activity of dermatomyositis. Comparison with usual biochemical parameters]. / Productos de activación del complemento (C3a y C5b-9) como marcadores de actividad de la dermatomiositis. Comparación con parámetros bioquímicos tradicionales.

INTRODUCTION: Dermatomyositis (DM) is an autoimmune disease included in the group of idiopathic inflammatory myopathies. Markers of disease activity are needed for clinical control in order to facilitate adjustment of immunomodulatory therapy. We analyzed the relationship between complement activation products (CAP) and the activity of dermatomyositis and its usefulness in the follow-up of the disease and the prediction of recrudescences related to usual biochemical parameters. MATERIAL AND METHODS: We studied 16 patients with DM that were followed periodically. In each appointment the degree of cutaneous and muscular activity was assessed and such disease activity was correlated with plasma levels of C3a and C5b-9, measured by ELISA. RESULTS: Though we obtained certain correlation between disease activity and plasma levels of C3a and C5b-9, the strength of such correlation was not superior to that obtained by usual biochemical markers. C3a was shown to be the most sensitive marker (100 %) with a sufficient specificity (83.3 %) in the capability to predict recrudescences. CONCLUSIONS: C3a and, to a lesser extent C5b-9, would be useful in the identification of patients with especially active DM as well as in predicting disease recrudescences. Nevertheless they are not superior to the rest of biochemical markers as indicators of current activity.

Productos de activación del complemento (C3a y C5b-9) como marcadores de actividad de la dermatomiositis. Comparación con parámetros bioquímicos tradicionales / Complement activation products (C3a and C5b-9) as markers of activity of dermatomyositis. Comparison with usual biochemical parameters

Introducción. La dermatomiositis (DM) es una enfermedad de origen autoinmune, incluida en el grupo de las miopatías inflamatorias idiopáticas. En el control clínico de este proceso se precisan marcadores que permitan determinar el grado de actividad de la enfermedad, facilitando así el ajuste a la terapia inmunomoduladora. Se analiza la relación entre los productos de activación del complemento (PAC) y la actividad de la DM y su utilidad en el seguimiento de la enfermedad y en la predicción de las reagudizaciones en relación a los parámetros bioquímicos habituales. Material y métodos. Se estudiaron 16 pacientes con DM, que fueron seguidos periódicamente. En cada revisión se estableció el grado de actividad cutánea y muscular del proceso, y se correlacionó dicha actividad con los niveles plasmáticos de C3a y C5b-9, determinados mediante técnica de ELISA. Resultados. Si bien se obtuvo cierta correlación entre la actividad del proceso y los niveles plasmáticos de C3a y C5b-9, la intensidad de dicha correlación no superó la obtenida por los marcadores bioquímicos tradicionales. En la capacidad de predicción de reagudizaciones, C3a se mostró como el marcador más sensible (100 %), con una especificidad suficiente (83,3 %). Conclusiones. C3a y en menor medida C5b-9 serían de utilidad en la identificación de pacientes con DM especialmente activas, así como en la predicción de reagudizaciones del proceso. Sin embargo, no tienen una utilidad superior al resto de marcadores bioquímicos como marcadores de actividad actual

Introduction. Dermatomyositis (DM) is an autoimmune disease included in the group of idiopathic inflammatory myopathies. Markers of disease activity are needed for clinical control in order to facilitate adjustment of immunomodulatory therapy. We analyzed the relationship between complement activation products (CAP) and the activity of dermatomyositis and its usefulness in the follow-up of the disease and the prediction of recrudescences related to usual biochemical parameters. Material and methods. We studied 16 patients with DM that were followed periodically. In each appointment the degree of cutaneous and muscular activity was assessed and such disease activity was correlated with plasma levels of C3a and C5b-9, measured by ELISA. Results. Though we obtained certain correlation between disease activity and plasma levels of C3a and C5b-9, the strength of such correlation was not superior to that obtained by usual biochemical markers. C3a was shown to be the most sensitive marker (100 %) with a sufficient specificity (83.3 %) in the capability to predict recrudescences. Conclusions. C3a and, to a lesser extent C5b-9, would be useful in the identification of patients with especially active DM as well as in predicting disease recrudescences. Nevertheless they are not superior to the rest of biochemical markers as indicators of current activity

Depósitos del complejo de ataque de membrana en la alopecia areata / Membrane attack complex deposits in alopecia areata

El sistema del complemento es un complejo formado por más de 28 proteínas plasmáticas, cuya activación secuencial en cascada tiene como resultado un producto final, el complejo de ataque de membrana (MAC ó C5b-9) y unas fracciones protéicas derivadas de la fragmentación de los diferentes componentes del complemento. Estos productos de activación del complemento, además de desarrollar diferentes funciones biológicas, se han implicado en la patogenia de diversas enfermedades autoinmunes, incluso en algunas de ellas se ha demostrado que el grado de activación del sistema del complemento está relacionado con la actividad del proceso. Objetivo de estudio: Hasta el momento no se han realizado estudios similares en la alopecia areata (AA), por lo cual el objetivo de este trabajo fue detectar la posible existencia de depósitos de MAC en biopsias cutáneas de AA. Material y métodos: Para ello dispusimos de 16 muestras: 9 de ellas pertenecientes al borde de placas alopécicas de cuero cabelludo de pacientes con diferentes formas clínicas de AA, seis, a diferentes áreas pilosas de individuos control aparentemente sanos y una, a cuero cabelludo de otro paciente control afecto de lupus eritamatoso discoide (LED). La técnica utilizada fue el sistema de inmunodetección biotina-estreptavidina (Bio.Genex) y los anticuerpos monoclonales C5b-9 de Dakopatts (Dinamarca). Resultados: En 8 de 9 biopsias de AA, se hallaron depósitos de MAC en la membrana basal (MB) de muchos folículos, fundamentalmente en la porción inferior y en el promontorio. Respecto a los controles, solo en 2 de las 6 biopsias de piel normal se detectaron depósitos de MAC en la zona de la MB adyacente a la glándula sebácea y en el LED, se observaron depósitos densos de MAC a lo largo de la MB de prácticamente todos los folículos pilosos observados. Conclusión: Los depósitos de MAC parecen ser más frecuentes en las lesiones de AA que en piel normal, pero menos intensos que en el LED. Por tanto, podríamos decir que probablemente el MAC está implicado en la patogenia de la AA y quizá también interviene en el desarrollo normal del ciclo folicular (AU)

Tissue expression and subcellular localization of the pro-survival molecule Bcl-w.

Anti-apoptotic members of the Bcl-2 family, such as Bcl-w, maintain cell viability by preventing the activation of the cell death effectors, the caspases. Gene targeting experiments in mice have demonstrated that Bcl-w is required for spermatogenesis and for survival of damaged epithelial cells in the gut. Bcl-w is, however, dispensable for physiological cell death in other tissues. Here we report on the analysis of Bcl-w protein expression using a panel of novel monoclonal antibodies. Bcl-w is found in a diverse range of tissues including colon, brain and testes. A survey of transformed cell lines and purified hematopoietic cells demonstrated that Bcl-w is expressed in cells of myeloid, lymphoid and epithelial origin. Subcellular fractionation and confocal laser scanning microscopy demonstrated that Bcl-w protein is associated with intracellular membranes. The implications of these results are discussed in the context of the phenotype of Bcl-w-null mice and recent data that suggest that Bcl-w may play a role in colon carcinogenesis.

Pro-apoptotic apoptosis protease-activating factor 1 (Apaf-1) has a cytoplasmic localization distinct from Bcl-2 or Bcl-x(L).

How Bcl-2 and its pro-survival relatives prevent activation of the caspases that mediate apoptosis is unknown, but they appear to act through the caspase activator apoptosis protease-activating factor 1 (Apaf-1). According to the apoptosome model, the Bcl-2-like proteins preclude Apaf-1 activity by sequestering the protein. To explore Apaf-1 function and to test this model, we generated monoclonal antibodies to Apaf-1 and used them to determine its localization within diverse cells by subcellular fractionation and confocal laser scanning microscopy. Whereas Bcl-2 and Bcl-x(L) were prominent on organelle membranes, endogenous Apaf-1 was cytosolic and did not colocalize with them, even when these pro-survival proteins were overexpressed or after apoptosis was induced. Immunogold electron microscopy confirmed that Apaf-1 was dispersed in the cytoplasm and not on mitochondria or other organelles. After the death stimuli, Bcl-2 and Bcl-x(L) precluded the release of the Apaf-1 cofactor cytochrome c from mitochondria and the formation of larger Apaf-1 complexes, which are steps that presage apoptosis. However, neither Bcl-2 nor Bcl-x(L) could prevent the in vitro activation of Apaf-1 induced by the addition of exogenous cytochrome c. Hence, rather than sequestering Apaf-1 as proposed by the apoptosome model, Bcl-2-like proteins probably regulate Apaf-1 indirectly by controlling upstream events critical for its activation.

An immunohistopathologic study in cutaneous necrotizing vasculitis.

In order to investigate the importance of timing in the immunophenotypical characteristics of the inflammatory infiltrate and in the adhesion molecules expression in cutaneous necrotizing vasculitis (CNV) we carried on an immunohistopathologic study. An avidin-biotin-streptavidin peroxidase technique was performed on 21 lesional skin biopsy specimens obtained sequentially at 0 to 24, 72 and 120 hours from seven patients with a CNV presenting as palpable purpura. A panel of monoclonal antibodies specific for inflammatory cells (T lymphocytes, polymorphonuclear leukocytes, macrophages, dendritic cells) and different adhesion molecules (E-selectin, ICAM-1, VCAM-1, LFA-1, VLA-4) was used. Moreover, HECA-450 monoclonal antibody was used to identify cutaneous lymphocyte antigen (CLA) in the inflammatory infiltrate. In all cases, polymorphonuclear leukocytes predominated in the early phase of CNV and their number decreased significantly with time (p = 0.0001). The T lymphocytes were present from the beginning and their number remained stable or increased slightly in time (p = 0.1), thus becoming predominant in the perivascular infiltrate in older lesions. Macrophages were scattered on interstitium since the early phase and they showed a time-dependent increase (p = 0.0003). E-selectin (ELAM-1) expression was detected at the first biopsy and it decreased depending on the age of the evolving vasculitis (p = 0.0033). The expression of CLA decreased also with time in 5 of the 7 cases (p = 0.0001). Our study supports the existence of an unique histopathologic pattern in CNV, in which the inflammatory infiltrate varies with time at the expense of the number of polymorphonuclear cells and macrophages.

The conserved SOCS box motif in suppressors of cytokine signaling binds to elongins B and C and may couple bound proteins to proteasomal degradation.

The suppressors of cytokine signaling (SOCS) family of proteins act as intracellular inhibitors of several cytokine signal transduction pathways. Their expression is induced by cytokine activation of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway and they act as a negative feedback loop by subsequently inhibiting the JAK/STAT pathway either by direct interaction with activated JAKs or with the receptors. These interactions are mediated at least in part by the SH2 domain of SOCS proteins but these proteins also contain a highly conserved C-terminal homology domain termed the SOCS box. Here we show that the SOCS box mediates interactions with elongins B and C, which in turn may couple SOCS proteins and their substrates to the proteasomal protein degradation pathway. Analogous to the family of F-box-containing proteins, it appears that the SOCS proteins may act as adaptor molecules that target activated cell signaling proteins to the protein degradation pathway.

Bim: a novel member of the Bcl-2 family that promotes apoptosis.

Certain members of the Bcl-2 family inhibit apoptosis while others facilitate this physiological process of cell death. An expression screen for proteins that bind to Bcl-2 yielded a small novel protein, denoted Bim, whose only similarity to any known protein is the short (nine amino acid) BH3 motif shared by most Bcl-2 homologues. Bim provokes apoptosis, and the BH3 region is required for Bcl-2 binding and for most of its cytotoxicity. Like Bcl-2, Bim possesses a hydrophobic C-terminus and localizes to intracytoplasmic membranes. Three Bim isoforms, probably generated by alternative splicing, all induce apoptosis, the shortest being the most potent. Wild-type Bcl-2 associates with Bim in vivo and modulates its death function, whereas Bcl-2 mutants that lack survival function do neither. Significantly, Bcl-xL and Bcl-w, the two closest homologues of Bcl-2, also bind to Bim and inhibit its activity, but more distant viral homologues, adenovirus E1B19K and Epstein-Barr virus BHRF-1, can do neither. Hence, Bim appears to act as a 'death ligand' which can only neutralize certain members of the pro-survival Bcl-2 sub-family.

T-cell population of primary and secondary cutaneous B-cell lymphomas does not express the cutaneous lymphocyte-associated antigen (CLA).

Primary cutaneous B-cell lymphomas (CBCL) are a group of malignant lymphomas with apparently distinct clinicopathological and immunophenotypical features. As in other B-cell lymphomas, the accompanying benign cell population in CBCL includes a variable number of T lymphocytes whose role is not well understood. In the present study we characterized the immunophenotype of these T cells and compared it with that of the reactive T-cell population in specific skin involvement by noncutaneous B-cell malignancies. Our results indicated that most T cells in both primary and secondary B-cell lymphomas were CLA+ memory/effector helper T cells which differed from the currently known CLA+ memory/effector helper T lymphocytes of the skin-associated lymphoid tissue (SALT) system. However, the endothelial CLA ligand, E-selectin, was expressed on dermal vessels. These results suggest that a B cell environment and/or a lack of epidermal involvement promote(s) the recruitment into the skin of a different, apparently less specific, subset of memory helper T cells from those seen in T-cell-mediated dermatoses.

Uncommon cutaneous manifestations of lupus erythematosus.

Cutaneous manifestations of lupus erythematosus (LE) are, usually, characteristic enough to permit an easy diagnosis. However, some patients may present less typical lesions, associated or not to the classic ones. Therefore, irrespectively of the variety of LE (acute, subacute and chronic), in absence of the typical butterfly rash, erythematosquamous papules or plaques, or any of the characteristic cutaneous alterations, it is important (even though not always easy) to recognize the uncommon and/or atypical changes of the skin.

Cell adhesion molecule expression in cutaneous lesions of dermatomyositis.

Chronic inflammation seems to play a major role in skin and muscle cell damage in dermatomyositis. Adhesion molecules and their ligands are fundamental in regulating inflammation. We have carried out an immunohistochemical analysis of different activation-inducible adhesion markers in 15 biopsy specimens from dermatomyositis skin lesions. Consistent findings were the increased expression of intercellular adhesion molecule-1 (ICAM-1) on endothelial cells, inflammatory cells and focally grouped keratinocytes in contact with subepidermal inflammatory infiltrates. Immunoreactivity for vascular cell adhesion molecule-1 (VCAM-1) was predominant on endothelial cells of the upper reticular dermis and dermal stellate-shaped cells. E-selectin (endothelial leukocyte adhesion molecule-1) immunoreactivity was less extensive, detected mostly on segments of vessels of the papillary dermis and upper reticular dermis, and sometimes independent of inflammation. This pattern of adhesion molecule expression is similar to that described in other immunemediated dermatoses. The up-regulation of the adhesion molecules appears to play a role in the development and perpetuation of dermatomyositis skin lesions.

Chlamydia trachomatis antibodies in serum and ejaculate of male patients without acute urethritis.

In a prospective study, the prevalence of specific antibodies against Chlamydia trachomatis in serum and seminal plasma evaluated by a genus specific immunofluorescence test in 101 men without acute urethritis was investigated. The results were compared to the clinical diagnosis, cell culture of urethral swabs, demonstration of DNA particles by Polymerase Chain Reaction (PCR) in the ejaculate and signs of genital inflammation by counting peroxidase-positive leukocytes and elastase level in semen. The objective was to evaluate the significance of chlamydial antibodies in genital infection. Serum specific IgG and IgA antibodies were found in 26% and 15%, respectively; seminal IgG and IgA antibodies were present in 6% and 7%, respectively. Serum specific antibodies were not associated with the clinical diagnosis of infection nor with C. trachomatis cell culture, PCR findings, peroxidase positive leukocytes or PMN-elastase level. It is concluded that serum antibodies are not useful in detecting a chlamydial infection. Seminal plasma antibodies were not correlated with the clinical diagnosis of infection, positive cell culture, PMN-elastase levels and leukocytes in semen. However, a significant correlation was found for positive PCR in the ejaculate (p < 0.001 for IgG, p < 0.05 for IgA, p < 0.001 when combined). Though seminal antibodies may be more useful in detecting ascended or occult chlamydial infection, their significance remains unclear, their absence does not exclude chlamydial infection. In particular, the biological significance of locally derived IgA needs further evaluation.

Membrane attack complex deposits in cutaneous lesions of dermatomyositis.

BACKGROUND AND DESIGN: The presence of membrane attack complex of complement (MAC) deposits in the intramuscular vasculature of biopsy specimens taken from patients with dermatomyositis (DM) has been implicated in the pathogenesis of this myopathy. The purpose of this study was to investigate the presence of MAC deposition in the skin lesions of patients with DM. Using immunohistochemical methods, we examined 22 biopsy specimens from lesional skin, six biopsy specimens from uninvolved skin, and 12 muscle biopsy specimens from patients with DM for the presence of MAC and vitronectin and CD59, two regulatory proteins of complement. RESULTS: The deposition of MAC was demonstrated in a large percentage of biopsy specimens obtained from the lesional skin of patients with DM. Deposits were found along the dermoepidermal junction in 19 (86%) of 22 biopsy specimens. Deposits on the vessel walls of the dermis were found in 17 (77%) of 22 biopsy specimens; but only in six of these biopsy specimens (27%) were deposits present in more than 10% of blood vessels. In contrast, deposits along the dermoepidermal junction and the vessel walls of the dermis were absent in specimens from uninvolved skin. In 12 muscle biopsy specimens obtained simultaneously from these patients, MAC deposits were found on the vessel walls in nine (75%), but only in six (50%) were deposits found in more than 10% of the intramuscular vessels. The pattern of vitronectin immunoreactivity in skin and muscle biopsy specimens obtained from patients with DM was similar to MAC deposits. The expression of CD59 was normal in all skin and muscle biopsy specimens. CONCLUSIONS: The deposition of MAC was found in a high percentage of biopsy specimens from the lesional skin of patients with DM; it was absent in uninvolved skin. These findings suggest that the complement system may be involved in the pathogenesis of the skin lesions of DM.

Immunopathologic study of skin lesions in dermatomyositis.

To determine the phenotype of skin infiltrates in affected and uninvolved skin from patients with dermatomyositis, immunohistochemical studies with 10 murine monoclonal antibodies were carried out on 25 skin biopsy specimens. Dermal infiltrates consisted predominantly of HLA-DR-expressing macrophages and T lymphocytes, especially of the CD4 subset. B lymphocytes, as defined by positive staining for Leu-12, were absent. Epidermal Langerhans cells were absent or decreased in some areas of affected skin but the total number was normal. OKT6+ cells were present in some dermal mononuclear infiltrates in close contact with lymphocytes. We observed reduced HLA-DR positivity of dermal capillary endothelia. These findings are apparently different from dermatomyositis muscle infiltrates but are similar to those in skin affected by cutaneous lupus erythematosus. Our observations support the concept that, in autoimmune diseases, cellular infiltrates may be more organ-specific than disease-specific.

[The Winer dilated pore]. / El poro dilatado de Winer.

Dilated pore (Winer) is a not uncommon adnexal benign tumor with follicular differentiation. Clinically the lesion looks like a giant comedo, usually located on the facial area of the elderly. Due to annular elevation of the borders, differential diagnosis needs to be made with basal cell epithelioma and senile sebaceous adenoma. The histology shows a typical infundibular dilatation with subinfundibular atrophy of hair structures. The authors report two typical cases of this badly known but not infrequent lesions.