Chronic Autoimmune Urticaria Research Articles

Dermatologic Manifestations in the Antiphospholipid Syndrome

Skin manifestations are very frequent in the antiphospholipid syndrome (APS) and may be the presenting symptom of the disease. Taking into account the impact of early diagnosis on APS outcome, recognition and interpretation of these skin manifestations is paramount. Most skin lesions are the result of blood-flow impairment in the skin microvascular system. Livedo reticularis, livedo racemosa, retiform purpura and livedoid vasculopathy are frequent manifestations of the disease. Although all these terms are used to describe net-like-pattern vascular lesions, their clinical distinction is important because of the different clinical implications of each. APS may present skin lesions very similar to those of Degos disease; however, it remains unclear how many patients with this rare vasooclusive disease present antiphospholipid antibodies (aPL). Although numerous case reports have emphasized the strong association between primary anetoderma, which is characterized by the loss of the dermal elastic fibers, and aPL, this condition seems to be a rare finding in APS. Nonetheless, many authors consider it mandatory to seek underlying aPL in patients presenting with primary anetoderma. Patients with APS may also present unspecific skin manifestations, such as superficial thrombophlebitis and post-phlebitic ulcers, due to the involvement of the venous territory. Thrombocytopenic purpura has been detected in some cases and seems to be more frequent in the SLE-related APS subset. Dermographism and chronic urticaria have been related to APS, with suspicion of an autoimmune origin. However, the potential relationship between chronic autoimmune urticaria and APS needs further confirmation and should be specifically analyzed in future studies on skin manifestations in APS. Keywords: Antiphospholipid syndrome, skin, Degos' disease, autoimmune

Etiological approach to chronic urticaria

Background:In 1769, William Cullen introduced the word “urticaria” (transient edematous papules, plaque with itching). Urticaria affects 15-25% of people at least once in their life time. It is a clinical reaction pattern triggered by many factors causing the liberation of vasoactive substances such as histamine, prostaglandins and kinins. Urticaria is classified according to its duration into acute (< 6 weeks duration) and chronic (>6 weeks duration). Various clinical investigations may be initiated to diagnosis the cause.Aims:To evaluate the types of chronic urticaria with reference to etiology from history and investigations.Materials and Methods:A total of 150 patients with chronic urticaria of more than six weeks were studied. Autologous serum skin test (ASST) was performed after physical urticarias were excluded. Standard batteries of tests were performed after ASST in all patients; and other specific investigations were done where necessary. Skin prick test was done in idiopathic urticaria.Results:The study sample consisted of 62 male and 88 female patients with a mean age of 21-40 years. About 50% of patients showed an ASST positive reaction, 3.9% were positive for antinuclear antibody (ANA), IgE titer was elevated in 37%, H. pylori antibodies was positive in 26.7%. Thyroid antibodies were positive in 6.2%. Giardia and entamoeba histolytica was reported in 3.3% on routine stool examination and on urinalysis 8% had elevated WBC counts; 12% showed para nasal sinusitis, with maxillary sinusitis of 7.3%. Random blood sugar was high in 5.3%. Four patients had ASOM, two had positive KOH mount for dermatophytes, abdominal USG showed cholecystitis in two patients. Recurrent tonsillitis was noted in two patients. Urticaria following intake of NSAIDs was observed in four patients and with oral contraceptive pills in one patient. Contact urticaria to condom (latex) was seen in one patient. Cholinergic (4.7%) and dermographic (4.7%) urticaria were the predominant physical urticarias. Prick test was performed in idiopathic urticaria with maximum reactions to food antigens (25%) where brinjal was the commonest, 9% to dust in which spider web was the most common, 8% to pollen where parthenium and amaranthus were the commonest, followed by A. flavus in fungi, pigeon in epithelia and cockroach in insects.Conclusion:Nearly half of the patients had chronic autoimmune urticaria on the basis of ASST. A significant number of them had serological makers of autoimmune activity. ASST provides an easy, inexpensive investigation in CU and helps direct attention to underlying systemic auto immune diseases. The presence of these auto antibodies was significantly associated with more frequent and longer lasting urticarial attacks. Exhaustive work ups with extensive laboratory diagnostics, challenge tests, and prick testing should be reserved for individual cases following detailed history.

Chronic autoimmune urticaria: treatment with omalizumab

We report the case of a child with diagnosis of chronic urticaria/angioedema and its evolution upon omalizumab treatment. Our patient is a 12-years-old female who suffered for 14 months severe chronic urticaria/angioedema. She had a poor response to the highest doses of combined therapy with 3 antihistamines, steroids and anti-leukotrienes and great impairment of her quality of life. An autologous serum skin test was positive until 1:100 dilutions, leading to the diagnosis of chronic autoimmune urticaria. Due to the lack of response to treatment, therapy with omalizumab was administered. A notable reduction in symptoms toward the third dose was observed. After 12 months of this treatment, the patient is asymptomatic and has a negative autologous serum test. Omalizumab could be a therapeutic option for patients with autoimmune urticaria unresponsive to other treatments.

Plasma levels of metalloproteinase-9 are elevated in patients with chronic autoimmune urticaria

Plasma levels of metalloproteinase-9 are elevated in patients with chronic autoimmune urticaria

Pathogenesis of chronic urticaria

Chronic urticaria is defined as the presence of urticaria (hives) for at least 6 weeks with the assumption that it occurs daily or close to it. If we eliminate physical urticarias and urticarial vasculitis from consideration, the remainder can be divided into autoimmune chronic urticaria (45%) and idiopathic chronic urticaria (55%). The autoimmune subgroup is associated with the IgG anti-IgE receptor alpha subunit in 35-40% of patients and IgG anti-IgE in an additional 5-10%. These autoantibodies have been shown to activate blood basophils and cutaneous mast cells in vitro with augmentation of basophil activation by complement and release of C5a, in particular. Binding methods (immunoblot and ELISA) yield positives in many autoimmune diseases as well as occasional normal subjects or patients with other forms of urticaria but most such sera are non-functional. Activation of basophils or mast cells causing histamine release is quite specific for chronic urticaria and defines the autoimmune subgroup. Although pathogenicity is not formally proven, the antibodies cause wealing upon intradermal injection, and removal of the autoantibody leads to remission. A cellular infiltrate is seen to be characterized by mast cell degranulation and infiltration of CD4+ T lymphocytes, monocytes, neutrophils, eosinophils, and basophils. The intensity of the infiltrate and clinical severity of the disease (including accompanying angio-oedema) is more severe in the autoimmune subpopulation. This latter group also has a higher evidence of human leucocyte antigen DR alleles associated with autoimmunity and a 25% incidence of antithyroid antibodies with diagnosed hypothyroidism in some. Hypo-responsiveness of patients' basophils to anti-IgE and hyperresponsiveness to serum defines another subpopulation (at least 50%) that overlaps the idiopathic and autoimmune subgroups. Hypo-responsiveness to anti-IgE has been shown to be associated with elevated levels of cytoplasmic phosphatases that inhibit degranulation. Reversal of the abnormality is seen with disease remission. Further work will be needed to distinguish whether this is a cause or a consequence of persistent urticaria and to further assess the relationship (or lack thereof) of altered responsiveness (decreased or increased) with the presence or absence of activating autoantibodies.

A non‐responsive chronic autoimmune urticaria in a 12‐year‐old autistic girl treated with cyclosporin

A non‐responsive chronic autoimmune urticaria in a 12‐year‐old autistic girl treated with cyclosporin

Advances in mechanisms of asthma, allergy, and immunology in 2008

This review summarizes selected articles appearing in 2008 in the Journal. Articles chosen include those improving our understanding of mechanisms of allergic diseases by focusing on human basophil, mast cell, and eosinophil biology; IgE and its high-affinity receptor on various cells; novel properties of omalizumab; airways remodeling; and genetics. Articles from other journals have been included to supplement the topics presented.

Presence of IgG Anti-IgE Autoantibodies in Chronic Urticaria and Atopic Dermatitis

RATIONALE: Autoantibodies specific for IgE have been detected in multiple disease states. In chronic urticaria (CU) a subset of patients have an autoimmune etiology with auto-antibodies against IgE, FceRI or FceRII. IgE autoantibodies have also been described in atopic dermatitis (AD). It has been suggested that these autoantibodies may inhibit the inflammatory cascade. The autoantibodies may bind to the surface of mast cells and basophils initiating a signal transduction cascade that results in the secretion of histamine and other mediators and the amplification of ongoing allergic reactions. The goal was to develop and standardize a quantitative assay for these autoantibodies.METHODS: IgG antibodies specific for IgE are quantified a non-competitive ELISA. The assay calibration curve was based on standards prepared from a humanized monoclonal anti-IgE. The test was evaluated with sera from autoimmune CU (n = 97), idiopathic CU (n = 142), AD (n = 75) patients and healthy controls (n = 61).RESULTS: A population of healthy controls was used to determine the cutoff for the assay. The 95% cutoff was 60ng/mL. The assay demonstrated high reproducibility (intra- (7.4%) and inter-assay (10%)) and good linearity (inter-dilutional coefficient of variation of 14%). This study confirmed the presence of autoantibodies in healthy individuals (mean = 16.1). Patients with autoimmune CU and AD had higher rates of samples with elevated anti-IgE, 20.6% and 29.3% compared to healthy controls (3.3%) and idiopathic CU patients (4.9%).CONCLUSIONS: A quantitative assay can be useful for the detailed evaluation of autoantibodies against IgE in diseases such as autoimmune chronic urticaria, atopic dermatitis, allergic rhinitis, and idiopathic rhinitis. RATIONALE: Autoantibodies specific for IgE have been detected in multiple disease states. In chronic urticaria (CU) a subset of patients have an autoimmune etiology with auto-antibodies against IgE, FceRI or FceRII. IgE autoantibodies have also been described in atopic dermatitis (AD). It has been suggested that these autoantibodies may inhibit the inflammatory cascade. The autoantibodies may bind to the surface of mast cells and basophils initiating a signal transduction cascade that results in the secretion of histamine and other mediators and the amplification of ongoing allergic reactions. The goal was to develop and standardize a quantitative assay for these autoantibodies. METHODS: IgG antibodies specific for IgE are quantified a non-competitive ELISA. The assay calibration curve was based on standards prepared from a humanized monoclonal anti-IgE. The test was evaluated with sera from autoimmune CU (n = 97), idiopathic CU (n = 142), AD (n = 75) patients and healthy controls (n = 61). RESULTS: A population of healthy controls was used to determine the cutoff for the assay. The 95% cutoff was 60ng/mL. The assay demonstrated high reproducibility (intra- (7.4%) and inter-assay (10%)) and good linearity (inter-dilutional coefficient of variation of 14%). This study confirmed the presence of autoantibodies in healthy individuals (mean = 16.1). Patients with autoimmune CU and AD had higher rates of samples with elevated anti-IgE, 20.6% and 29.3% compared to healthy controls (3.3%) and idiopathic CU patients (4.9%). CONCLUSIONS: A quantitative assay can be useful for the detailed evaluation of autoantibodies against IgE in diseases such as autoimmune chronic urticaria, atopic dermatitis, allergic rhinitis, and idiopathic rhinitis.

Determination of Autologus Serum Skin Test and its Association with Clinical and Immunological Markers in Adult Patients with Chronic Urticaria Treated at the Regional Unit of Immunology at the "Dr. Enrique Tejera" Hospital from April to September 2007.

RATIONALE: Urticaria is a common clinical entity, is called Chronic Urticaria (CU) if the clinic persists for more than 6 weeks. In those patients who were identified a positive Autologus Serum Skin Test (ASST), it was proposed the term Chronic Autoimmune Urticaria (CAU), describing in them a greater relationship with other autoimmune phenomena.

Chronic autoimmune urticaria: where we stand?

It is well-recognized that 30-40% of chronic idiopathic urticaria is autoimmune in nature. Chronic autoimmune urticaria is caused by anti-FcεRI and less frequently, by anti-IgE autoantibodies that lead to mast cell and basophil activation, thereby giving rise to the release of histamine and other proinflammatory mediators. Activation of the classical complement pathway and formation of C5a are important in dermal mast cell activation. C5a is also a neutrophil and eosinophil chemoattractant. Chronic autoimmune urticaria has been found to be associated with autoimmune thyroid disease. The autologous serum skin test is used as a screening test for chronic autoimmune urticaria and has a sensitivity and specificity of about 70 and 80%, respectively. The current gold standard diagnostic test is the basophil histamine release assay. The treatment of chronic autoimmune urticaria, as in chronic idiopathic urticaria, is with H1 antihistamines. Oral corticosteroids may be used during acute flares. Refractory cases have been shown to respond to cyclosporine and other immunomodulators. The prevalence of chronic autoimmune urticaria in Singapore is similar to that reported in Western countries at about 42%. The presence of thyroid autoimmunity appears to be higher than reported, with 22.5% of patients with chronic idiopathic urticaria here, exhibiting presence of thyroid autoantibodies.

Treatment of chronic autoimmune urticaria with omalizumab

Approximately 45% of patients with chronic urticaria have an IgG autoantibody directed to the alpha-subunit of the high-affinity IgE receptor (chronic autoimmune urticaria, CAU) leading to cutaneous mast cell and basophil activation. Treatment of allergic asthma with omalizumab produces rapid reduction in free IgE levels and subsequent decrease in Fc epsilon RI expression on mast cells and basophils. If this occurs in CAU, cross-linking of IgE receptors by autoantibody would be less likely, reducing cell activation and urticaria/angioedema. To investigate the efficacy of omalizumab in patients with CAU symptomatic despite antihistamine therapy. Twelve patients with CAU, identified by basophil histamine release assay and autologous skin test, with persistent symptoms for at least 6 weeks despite antihistamines, were treated with placebo for 4 weeks followed by omalizumab (>or=0.016 mg/kg/IU mL(-1) IgE per month) every 2 or 4 weeks for 16 weeks. Primary efficacy variable was change from baseline to the final 4 weeks of omalizumab treatment in mean Urticaria Activity Score (UAS, 0-9 scale). Changes in rescue medication use and quality of life were assessed. Mean UAS declined significantly from baseline to the final 4 weeks of omalizumab treatment (7.50 +/- 1.78 to 2.66 +/- 3.31, -4.84 +/- 2.86, P = .0002). Seven patients achieved complete symptom resolution. In 4 patients, mean UAS decreased, but urticaria persisted. One patient did not respond. Rescue medication use was reduced significantly, and quality of life improved. No adverse effects were reported or observed. This exploratory proof of concept study suggests omalizumab is an effective therapy for CAU resistant to antihistamines.

Defective functions of circulating CD4 +CD25 + and CD4 +CD25 − T cells in patients with chronic ordinary urticaria

Patients with chronic ordinary urticaria (CU) are divided into two groups: 30-50% have chronic autoimmune urticaria, and the remainder have chronic idiopathic urticaria. CD4(+)CD25(+) regulatory T (Treg) cells play critical roles in maintaining peripheral tolerance and preventing autoimmunity, but the characteristics of Treg cells have not yet been defined in CU. To identify whether CD4(+) T cells play an important immunoregulatory role in the etiology of CU, we determined the frequencies and functions of circulating CD4(+)CD25(+) and CD4(+)CD25(-) T cells in CU patients and healthy control subjects, with special focus on the characteristics of CD4(+)CD25(+) T cells. Peripheral blood mononuclear cells (PBMCs) were obtained from CU and healthy controls in this study. The frequency of CD4(+)CD25(+) T cells in PBMCs was detected by flow cytometry. The expression levels of forkhead box P3 (FOXP3) and transforming growth factor-beta (TGF-beta) in CD4(+)CD25(+) T cells were detected by real-time PCR. Furthermore, the suppressive function of CD4(+)CD25(+) T cells was analyzed. Additionally, the Th1/Th2 cytokine secretory profile in mitogen-stimulated CD4(+)CD25(-) T cells was measured by ELISA. An increased frequency of CD4(+)CD25(+) T cells was observed in CU patients (n=19) compared to control subjects (n=7). No significant difference was detected in the expression levels of FOXP3 or TGF-beta between CU patients (n=14) and control subjects (n=7). Strikingly, the suppressive capacity of CD4(+)CD25(+) Treg cells from 2 of 5 CU patients was partially defective. We also found that cytokine production from CD4(+)CD25(-) T cells was significantly reduced in CU patients (n=9) compared to healthy donors (n=11). Our data demonstrate that CD4(+)CD25(+) and CD4(+)CD25(-) T cells in PBMCs exhibit defective functions in CU patients.

Autoimmune Disease and Chronic Urticaria in Adult Patients in Lithuania

This study investigates the causes of chronic urticaria (CU) in adults referred to our department in Vilnius, Lithuania. 101 patients with CU were studied (82 females, 19 males), mean age 43.7 ± 14.5 years old. Assessment included skin prick tests (SPT), total serum IgE, specific food IgE, complete blood count, erythrocyte sedimentation rate (ESR), total serum IgA/IgM/IgG levels, autologous serum skin tests (ASST) and Helicobacter pylori urease tests. Antinuclear antibodies (ANA) were assessed if autoimmune disease was suspected. Autoimmune thyroiditis was diagnosed by thyroid peroxidase antibodies (TPO). Increased IgE levels were found in 31 (30.7%) patients, 5 of whom had a positive SPT to inhalant allergens. Specific IgE to food allergens in patients with elevated IgE were negative. Elevated ESR was in 2 patients, one with SLE, and one with a dental infection. Total IgA, IgG, IgM levels were unremarkable. 8 (7.9%) patients had positive Helicobacter pylori tests. Positive antinuclear antibodies were found in 4 patients including 1 with SLE, 1 positive on ASST, and 2 with autoimmune thyroiditis. Elevated TPO were found in 30 (29.7%) patients only 10 of whom had impaired thyroid function. 33 (32.7%) patients had positive ASST, 6 (19.4%) with increased IgE (only one atopic) and 14 (46.6%) patients with autoimmune thyroiditis. Sensitivity to NSAIDs occurred in 9 (8.9%) patients, 4 (44.4%) with positive ASST. The most common cause of CU was autoimmunity. About one-third of CU patients had positive ASST or autoimmune thyroiditis.

Treatment of Chronic Autoimmune Urticaria with Omalizumab

Treatment of Chronic Autoimmune Urticaria with Omalizumab

Autologous serum therapy in chronic urticaria: Old wine in a new bottle

Chronic urticaria (CU) is one of the most challenging and frustrating therapeutic problems faced by a dermatologist. A recent demonstration of abnormal type 1 reactions to intradermal autologous serum injections in some CU patients has led to the characterization of a new subgroup of "autoimmune chronic urticaria". This has rekindled interest in the age-old practice of autologous blood injections as a theoretically sound treatment option in these patients. To evaluate the efficacy of repeated autologous serum injections (ASIs) in patients with recalcitrant chronic urticaria. A cohort of 62 (32 females) CU patients with a positive autologous serum skin test (ASST) (group 1) was prospectively analyzed for the efficacy of nine consecutive weekly autologous serum injections with a postintervention follow-up of 12 weeks. Another group of 13 (seven females) CU patients with negative ASST (group 2) was also treated similarly. In both groups, six separate parameters of disease severity and activity were recorded. Demographic and disease variables were comparable in both groups. The mean duration of disease was 1.9 +/- 0.3 years (range = 3 months to 32 years) in group 1 and 1.5 +/- 0.2 years (range = 3 months to 10 years) in group 2. In the ASST (+) group, 35.5% patients were completely asymptomatic at the end of the follow-up while an additional 24.2% were markedly improved. In the ASST (-) group, these figures were 23 and 23% respectively. The intergroup difference for complete subsidence was statistically significant (P < 0.05). In both groups, the most marked reduction was seen in pruritus and antihistamine use scores followed by the size and frequency of the wheals. Autologous serum therapy is effective in a significant proportion of ASST (+) patients with CU. A smaller but still substantial number of ASST (-) patients also benefited from this treatment.

Cutis marmorata telangiectatica congenita and chronic autoimmune urticaria in a young man

A 20-year-old man with mental impairment, was referred to us for evaluation of recurring idiopathic urticaria episodes, characterized by a diffuse spreading of wheals and severe itching lacking response to traditional antihistamines. Upon physical examination, he showed a persistent, generalized, reticular, red-bluish vascular skin pattern in association with diffuse arborizing telangiectasias. Such lesions were present from an early age. Laboratory and instrumental tests, performed in order to exclude any condition associated with livedo did not evidence pathological results. He was found to be positive for antinuclear autoantibodies (ANA; 1:640). Histopathologically, numerous dilated capillary vessels associated with sparse extravasated erythrocytes were observed in the upper dermis. We performed an autologous serum skin test (ASST), which resulted in a positive, suggesting an autoimmune basis of the condition. On the basis of clinical and histopathological findings, and in the absence of other clinical and laboratory data suggesting other neoplastic, immunological or systemic diseases, the diagnosis of cutis marmorata telangiectatica congenita (CMTC) associated with chronic autoimmune urticaria (CAIU) was made. CMTC is a rare congenital vascular disorder, consisting in an anomalous, persistent, red-bluish marbling of the skin, that can be associated with a wide spectrum of cutaneous and extracutaneous anomalies. In our case, neither physical examination nor instrumental investigation demonstrated any of these anomalies, with the exception of cognitive impairment. We report this case because of the rarity of a diagnosis of CMTC in an adult patient, because this condition has almost always previously been diagnosed in infancy, or it comes to observation because of the presence of associated disorders, as in our case for chronic urticaria.

Cellular adhesion molecules in chronic urticaria: modulation of serum levels occurs during levocetirizine treatment

Some antihistamines are capable of reducing levels of adhesion molecules in wealing tissues of patients with chronic urticaria (CU). To determine if 6 weeks of therapy with levocetirizine 5 mg once daily would also induce any decrease in serum levels of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, endothelial leucocyte adhesion molecule-1 (ELAM-1) or P-selectin in subjects with CU and chronic autoimmune urticaria. Thirty-six patients with CU (18 with positive and 18 with negative autologous serum skin test) were studied, together with 10 control healthy subjects. All patients received levocetirizine 5 mg daily. Serum soluble cellular adhesion molecule (CAM) levels were determined by immunoenzymatic assay before and after the end of the study period. Disease activity was recorded according to the EAACI/GA(2)LEN/EDF scoring system. After levocetirizine therapy CAM levels decreased in patients with CU, significantly in the cases of ELAM-1 and P-selectin. Patients' clinical scores improved during regular antihistamine therapy. Levocetirizine 5 mg daily demonstrated a broad anti-inflammatory effect in patients with CU. The significant decrease in serum levels of ELAM-1 and P-selectin might reflect the inhibitory activity on neutrophil rolling and extravasation towards inflamed skin.

Cellular Infiltrate and Related Cytokines, Chemokines, Chemokine Receptors and Adhesion Molecules in Chronic Autoimmune Urticaria: Comparison between Spontaneous and Autologous Serum Skin Test Induced Wheal

In recent years, the demonstration of circulating functional autoantibodies against the high affinity IgE receptor or against IgE themselves in about one-third of patients with chronic idiopathic urticaria has suggested that an autoimmune mechanism might be involved in the pathogenesis of the disease--the so-called chronic autoimmune urticaria (CAIU). In this study we compare findings from serum-induced and spontaneous wheals with regard to immunohistochemical markers of disease activity and discuss whether autologous serum skin test (ASST) may be regarded as an in vivo experimental model of the physiological stimulus causing urticaria skin condition, or if it does not reproduce the whole of the mechanisms operating in the development of spontaneous wheals. By means of immunohistochemical technique, we analyzed specimens from just-developed spontaneous wheals and from serum-evoked wheals of six CAIU patients, to glean information on cellular infiltrate and related cytokines, chemokines, chemokine receptors and adhesion molecules. According to the results of our study, spontaneous urticaria lesions seem to be sustained by a characteristic inflammation pattern where neutrophils, adhesion molecules, IL-8 and chemokine receptors play a main role in flogosis triggering and, consequently, disease development. On the contrary, ASST-induced wheals seem to imply different activities mainly represented by basophil granulocytes and related molecules, i.e. IL-4. Although it represents an efficacious diagnostic instrument to screen CAIU patients, ASST is not an exhaustive model of the many immunopathogenic pathways operating in the development of urticaria lesions, especially with regard to systemic activation networks.

Significant correlation between the CD63 assay and the histamine release assay in chronic urticaria

Antibodies directed to the alpha subunit of the high affinity IgE receptor and the IgE molecule are proposed to be of pathogenetic relevance in a group of patients with chronic urticaria (CU). The diagnosis of autoimmune chronic urticaria (ACU) is difficult; the autologous serum skin test (ASST) seems to be a useful screening test, but reliable, additional confirmatory methods are needed. To assess the diagnostic value of a modified serum-induced basophil activation test, the CD63 expression assay, in the diagnosis of ACU by comparing the results of the CD63 assay with the results of the histamine release (HR) test, the ASST and serum levels of soluble CD40 ligand (sCD40L). Using basophils from an atopic (DA) and a nonatopic (DNA) donor the activity of sera of 72 patients with CU were measured in HR assay by enzyme-linked immunosorbent assay and in CD63 expression assay by flow cytometry. An ASST was carried out in all patients; in 30 of the 72 patients sCD40L was detected and correlations were derived between the different assays. Sera of 20 normal controls and 26 patients with systemic autoimmune diseases were also tested in the HR assay and in the CD63 expression assay. Histamine-releasing activity was detected in the sera of 51% (DA) and 32% (DNA) of CU patients and 57% (DA) and 28% (DNA) of sera upregulated CD63 expression on the surface of basophils from the different donors. There was a significant correlation between the HR and the CD63 assays carried out on both donors, but the ASST showed a strong correlation with the HR assay only for basophils from the DA. The serum level of sCD40L was significantly higher in patients with CU compared with controls, but the difference between the autoimmune and the nonautoimmune groups was not significant. The CD63 expression assay seems to be a reliable functional test in the diagnosis of ACU, particularly if highly sensitive donor basophils are used, but the determination of the sCD40L serum level was not sufficient to differentiate between the autoimmune and the nonautoimmune patient groups.

Effects of calcineurin inhibitors on an in vitro assay for chronic urticaria

Chronic urticaria is a common skin disorder, which causes considerable morbidity. In approximately 40% of cases, patients have an autoimmune disorder in which functional antibodies cause degranulation of mast cells and basophils, and C5a complement augments this in varying amounts from patient to patient. Since the calcineurin inhibitor ciclosporin has been used in chronic autoimmune urticaria, we examined the effect of ciclosporin and other drugs on the release of histamine from basophils when stimulated by sera from patients with chronic autoimmune urticaria. Leucocytes from healthy donors were isolated and incubated in varying concentrations of ciclosporin, ascomycin, methotrexate, diphenhydramine or hydroxyzine for 30 min prior to stimulation with serum from urticaria patients known to have functional immunoglobulin (Ig)G antibodies directed against the alpha subunit of the IgE receptor. Histamine release was then measured. Pre-incubating cells with ciclosporin and ascomycin produced dose-dependent inhibition of histamine release when cells were stimulated by sera of urticaria patients, by purified IgG from these sera, but not by C5a. Inhibition was not prevented by C5a receptor blocking antibodies. No inhibition was seen with methotrexate, diphenhydramine or hydroxyzine. This is the first demonstration of inhibition of histamine release by calcineurin inhibitors employing sera of patients with chronic autoimmune urticaria. These drugs may work by interfering with intracellular signalling in cells following cross-linking of the IgE receptor, but not following stimulation of the C5a receptor.