Common Skin Diseases

This continuation of the discussion of common skin dermatoses includes the diagnosis and treatment of warts, seborrheic dermatitis, rosacea, seborrheic and actinic keratoses, and common skin malignancies. Skin cancers affect innumerable guises and may derive from various tissues. The family physician should be familiar with the more common types and be alert to the possibility of rarer kinds.     

Omalizumab therapy is associated with reduced circulating basophil populations in asthmatic children

Basophils have been implicated in promoting the early development of T_H2 cell responses in some murine models of T_H2 cytokine‐associated inflammation. However, the specific role of basophils in allergic asthma remains an active area of research. Recent studies in animal models and human subjects suggest that IgE may regulate the homeostasis of human basophil populations. Here, we examine basophil populations in children with severe asthma before and during therapy with the IgE‐directed monoclonal antibody omalizumab. Omalizumab therapy was associated with a significant reduction in circulating basophil numbers, a finding that was concurrent with improved clinical outcomes. The observation that circulating basophils are reduced following omalizumab therapy supports a mechanistic link between IgE levels and circulating basophil populations, and may provide new insights into one mechanism by which omalizumab improves asthma symptoms.     

The underestimated role of basophils in Ph+ chronic myeloid leukaemia

Chronic myeloid leukaemia (CML) is a hematopoietic neoplasm defined by the chromosome translocation t(9;22) and the related oncogene, BCR‐ABL1. In most patients, leukaemic cells can be kept under control using BCR‐ABL1‐targeting drugs. However, many patients relapse which remains a clinical challenge. In particular, patients with advanced (accelerated or blast phase) CML have a poor prognosis. So far, little is known about molecular and cellular interactions and features that contribute to disease progression and drug resistance in CML. One key prognostic factor at diagnosis is marked basophilia. However, although basophils are well‐known multifunctional effector cells, their impact in CML remains uncertain. In this article, we discuss the potential role of basophils as active contributors to disease evolution and progression in CML. In particular, basophils serve as a unique source of inflammatory, angiogenic and fibrogenic molecules, such as vascular endothelial growth factor or hepatocyte growth factor. In addition, basophils provide vasoactive substances, like histamine as well as the cytokine‐degrading enzyme dipeptidyl‐peptidase IV which may promote stem cell mobilization and the extramedullary spread of stem and progenitor cells. Finally, basophils may produce autocrine growth factors for myeloid cells. Understanding the role of basophils in CML evolution and progression may support the development of more effective treatment concepts.     

Use of a rat basophil leukemia (RBL) cell-based immunological assay for allergen identification,clinical diagnosis of allergy,and identification of anti-allergy agents for use in immunotherapy

Abstract

Food allergy is an important public health problem that affects an estimated 8% of young children and 2% of adults. With an increasing interest in genetically-engineered foods, there is a growing need for development of sensitive and specific tests to evaluate potential allergenicity of foods and novel proteins as well as to determine allergic responses to ensure consumer safety. This review covers progress made in the field of development of cell models, specifically that involving a rat basophil leukemia (RBL) cell-based immunoassay, for use in allergen identification, diagnosis, and immunotherapy. The RBL assay has been extensively employed for determining biologically relevant cross-reactivities of food proteins, assessing the effect of processing on the allergenicity of food proteins, diagnosing allergic responses to whole-food products, and identifying anti-allergy food compounds. From the review of the literature, one might conclude the RBL cell-based assay is a better test system when compared to wild-type mast cell and basophil model systems for use in allergen identification, diagnosis, and analyses of potential immunotherapeutics. However, it is important to emphasize that this assay will only be able to identify those allergens to which the human has already been exposed, but will not identify a truly novel allergen, i.e. one that has never been encountered as in its preferred (humanized) configuration.     

Recent advances in understanding basophil-mediated Th2 immune responses

Basophils, the least common granulocytes, represent only ~0.5% of peripheral blood leukocytes. Because of the small number and some similarity with mast cells, the functional significance of basophils remained questionable for a long time. Recent studies using newly-developed analytical tools have revealed crucial and non-redundant roles for basophils in various immune responses, particularly Th2 immunity including allergy and protective immunity against parasitic infections. In this review, we discuss the mechanisms how basophils mediate Th2 immune responses and the nature of basophil-derived factors involved in them. Activated basophils release serine proteases, mouse mast cell protease 8 (mMCP-8), and mMCP-11, that are preferentially expressed by basophils rather than mast cells in spite of their names. These proteases elicit microvascular hyperpermeability and leukocyte infiltration in affected tissues, leading to inflammation. Basophil-derived IL-4 also contributes to eosinophil infiltration while it acts on tissue-infiltrating inflammatory monocytes to promote their differentiation into M2 macrophages that in turn dampen inflammation. Although basophils produce little or no MHC class II (MHC-II) proteins, they can acquire peptide-MHC-II complexes from dendritic cells via trogocytosis and present them together with IL-4 to naive CD4 T cells, leading to Th2 cell differentiation. Thus, basophils contribute to Th2 immunity at various levels.     

A new approach to the isolation and characterization of wheat flour allergens

Background The incidence of food allergy to wheat is increasing. Its diagnosis depends on the purity of major allergens and their inclusion in tests. Isolation and characterization of wheat allergens are therefore of utmost importance. Objective To purify and identify wheat flour allergens most frequently recognized by patients' IgE antibodies and to study their allergenicity. Methods Water/salt‐soluble extracts from wheat flour were prepared and separated using a combination of ultrafiltration, isoelectric focusing and liquid chromatography. Purified proteins were analysed by immunoblotting using pooled sera from patients with atopic dermatitis who possessed IgE specific to wheat. Wheat proteins found to bind IgE were subsequently identified by matrix‐assisted laser desorption/ionisation‐time of flight mass spectrometry. The frequency and intensity of IgE binding of isolated proteins were tested using individual sera from patients and controls. Results We developed a procedure that allows isolation of wheat allergens from natural sources. Twenty‐seven potential wheat allergens have been successfully identified; of these, the following seven are newly reported in food allergy: endogenous α‐amylase/subtilisin inhibitor, trypsin/α‐amylase inhibitor (AAI) CMX1/CMX3, thaumatin‐like protein (TLP), xylanase inhibitor protein‐1, β‐glucosidase, class II chitinase and 26 kDa endochitinase. TLP and wheatwin were shown to activate patients' basophils to a similar extent as two well‐known allergens, lipid transfer protein (Tri a 14) and AAI 0.19 (Tri a 28.0101). Conclusion and Clinical Relevance Our new approach enables the isolation of water/salt‐soluble wheat allergens in their native form in amounts sufficient both for biological testing (in vivo and in vitro) and for physicochemical characterization. Such studies will lead to a more detailed knowledge of allergenicity of wheat proteins and to improved accuracy of diagnostic tests. Cite this as: P. ?otkovský, J. Sklená?, P. Halada, J. Cinová, I. ?etinová, A. Kainarová, J. Goliá?, K. Pavlásková, S. Honzová and L. Tu?ková, Clinical & Experimental Allergy, 2011 (41) 1031–1043.     

Comparisons of neutrophil‐, monocyte‐, eosinophil‐, and basophil‐ lymphocyte ratios among various systemic autoimmune rheumatic diseases

This study was aimed to evaluate levels of neutrophil‐ (NLR), monocyte‐ (MLR), eosinophil‐ (ELR), and basophil‐lymphocyte ratio (BLR) and their association with inflammatory markers in systemic autoimmune rheumatic diseases (SARDs). A total of 1139 SARD patients and 170 healthy individuals were enrolled. Clinical and laboratory data were extracted. NLR and MLR were significantly increased, but BLR decreased in most SARD patients (p < 0.05). ELR were significantly decreased in systemic lupus erythematosus (SLE) patients, but increased in those with other SARDs (p < 0.001). In SLE patients, C‐reactive protein (CRP) showed positive correlation with NLR, MLR, and BLR. IgG negatively correlated with NLR, and did positively with ELR. IgM negatively correlated with NLR and MLR. In those with rheumatoid arthritis (RA), ankylosing spondylitis (AS), and osteoarthritis (OA), NLR and MLR positively correlated with erythrocyte sedimentation rate (ESR) and CRP. In primary Sjögren's syndrome (pSS) patients, ESR showed positive correlation with NLR and MLR. IgA had positive correlation with BLR. In polymyositis/dermatomyositis (PM/DM) patients, ESR and CRP positively correlated with NLR. Additionally, significant correlations were also found between CRP and BLR, IgG and ELR, IgM and ELR. In systemic sclerosis (SSc) patients, clear correlations were only observed between CRP and NLR or MLR. In mixed connective tissue disease (MCTD) patients, NLR positively correlated with ESR and CRP, while NLR and MLR did negatively with IgM. In polymyalgia rheumatic (PMR) patients, MLR positively correlated with CRP, while ELR did negatively with IgG. This study demonstrated increased NLR and MLR and deceased BLR in most SARDs, decreased ELR in SLE and increased ELR in other SARDs. Furthermore, NLR and MLR may be useful tools to reflect inflammatory status of SARDs.     

Acute basophilic leukaemia and translocation t(X;6)(p11;q23)

We report two infants with acute basophilic leukaemia associated with a t(X;6)(p11;q23) as the sole abnormality. Morphologic evidence of basophilic lineage was provided by light and electron microscopy. Both patients also had a similar presentation on diagnosis, characterized by clinical signs consistent with a hyperhistaminaemia syndrome, i.e. urticarian rashes and gastro-intestinal disorders evocative of peptic ulcer. Immunophenotypes differed in the two patients, one expressing CD24, CD13 and CD33, whereas only CD117 was found in the other.
Basophilic acute leukaemia, a rare group among acute leukaemias, might be nonrandomly associated with a specific chromosomal abnormality, t(X;6)(p11;q23). This new entity might also be identifiable by an uncommon clinical presentation and occurrence in infancy.