The autologous serum skin test: a screening test for autoantibodies in chronic idiopathic urticaria

Autologous whole blood injections to patients with chronic urticaria and a positive autologous serum skin test: a placebo-controlled trial

BACKGROUND

Patients with chronic urticaria (CU) frequently exhibit positive skin test reactions to autologous serum (ASST). Therapies aimed at inducing tolerance to circulating histamine-releasing factors in ASST+ CU patients, e.g. by treatment with autologous whole blood (AWB), have not yet been tested.

OBJECTIVE

To test whether ASST+ CU patients can benefit from repeated low-dose intramuscular injections of AWB.

METHODS

We characterized CU severity and duration, anti-Fc(epsilon)RI and anti-IgE expression, use of antihistamines, and quality of life in 56 CU patients (ASST+: 35, ASST-: 21) and assessed the therapeutic effects of 8 weekly AWB injections in a randomized, placebo-controlled, single-blind, parallel-group trial.

RESULTS

Numbers, size, intensity, and/or duration of CU symptoms, quality of life, as well as expression of anti-Fc(epsilon)RI or anti-IgE were similar in ASST+ and ASST- CU patients. However, CU in ASST+ patients was of longer duration and required markedly more antihistaminic medication. Interestingly, ASST+ patients, but not ASST- patients, showed significantly (1) reduced CU activity, (2) decreased use of antihistamines, and (3) improved quality of life after AWB treatment. Placebo treatment was ineffective in both groups, but differences of AWB and placebo treatment responses did not achieve statistical significance in either group, most likely due to the limited number of patients treated.

CONCLUSION

Our findings suggest that ASST+ CU is clinically different from other CU subforms and that ASST+ CU patients can benefit from AWB therapy.

Familial aggregation of aspirin-induced urticaria and leukotriene C synthase allelic variant

BACKGROUND

We have reported that in patients with chronic idiopathic urticaria (CIU) who reacted adversely to aspirin, the frequency of the (-444)C allele of the leukotriene C(4) synthase gene (LTC4S) was higher than in patients who tolerated aspirin well.

OBJECTIVES

To study the pattern of aspirin-induced urticaria (AIU) in two families, with special interest on the polymorphisms of LTC4S (AA, AC, CC) and the glutathione S-transferase M1 and P1 genes (GSTM1 and GSTP1).

METHODS

Of 74 patients with CIU and a history of aspirin hypersensitivity studied by us, two patients (probands) gave a family history of aspirin intolerance. Oral challenge tests with aspirin were carried out in members of these families. Genomic DNA samples were obtained from peripheral blood to study the polymorphisms of LTC4S, GSTM1 and GSTP1.

RESULTS

In family 1 the aspirin challenge test confirmed AIU in three of five (60%) individuals, but in family 2 only in two of seven (29%). In both families, the variant genotypes of LTC4S (AC or CC) were present in the parents, but only one of them had CIU. In family 1, with both parents healthy, the three children had AIU; in two it was associated with variant LTC4S genotype. In family 2, urticaria following aspirin ingestion was present only with variant LTC4S genotype. In patients of both families with positive aspirin challenge test, deletion of the GSTM1 gene was present.

CONCLUSIONS

AIU aggregates in families inheriting the LTC4S(-444)C allele. Segregation of aspirin sensitivity in these families does not follow a clear Mendelian pattern. A common deletion of GSTM1, one of several enzymes involved in conjugation of a wide range of electrophilic substances with glutathione, was present in all individuals ascertained to have AIU.

Angioedema

Although first described more than 130 years ago, the pathophysiology, origin, and management of the several types of angioedema are poorly understood by most dermatologists. Although clinically similar, angioedema can be caused by either mast cell degranulation or activation of kinin formation. In the former category, allergic and nonsteroidal anti-inflammatory drug-induced angioedema are frequently accompanied by urticaria. Idiopathic chronic angioedema is also usually accompanied by urticaria, but can occur without hives. In either case, an autoimmune process leading to dermal mast cell degranulation occurs in some patients. In these patients, histamine-releasing IgG anti-FcepsilonR1 autoantibodies are believed to be the cause of the disease, removal or suppression by immunomodulation being followed by remission. Angiotensin-converting enzyme inhibitor-induced angioedema is unaccompanied by hives, and is caused by the inhibition of enzymatic degradation of tissue bradykinin. Hereditary angioedema, caused by unchecked tissue bradykinin formation, is recognized biochemically by a low plasma C'4 and low quantitative or functional C'1 inhibitor. Progress has now been made in understanding the molecular genetic basis of the two isoforms of this dominantly inherited disease. Recently, a third type of hereditary angioedema has been defined by several groups. Occurring exclusively in women, it is not associated with detectable abnormalities of the complement system. Angioedema caused by a C'1 esterase inhibitor deficiency can also be acquired in several clinical settings, including lymphoma and autoimmune connective tissue disease. It can also occur as a consequence of specific anti-C'1 esterase autoantibodies in some patients. We have reviewed the clinical features, diagnosis, and management of these different subtypes of angioedema.

LEARNING OBJECTIVE

After completing this learning activity, participants should be aware of the classification, causes, and differential diagnosis of angioedema, the molecular basis of hereditary and non-hereditary forms of angioedema, and be able to formulate a pathophysiology-based treatment strategy for each of the subtypes of angioedema.

In chronic idiopathic urticaria autoantibodies against Fc epsilonRII/CD23 induce histamine release via eosinophil activation

BACKGROUND

Chronic idiopathic urticaria is a common skin disorder characterized by recurrent, transitory, itchy weals for more than 6 weeks. An autoimmune origin has been suggested based on the findings of auto-antibodies (Abs) directed against either the alpha subunit of the high-affinity IgE receptor or the IgE molecule in nearly half of the patients.

OBJECTIVE

To identify other autoantigen targets in patients with chronic idiopathic urticaria.

METHODS

We used pooled IgG derived from 133 patients with chronic idiopathic urticaria to screen a random peptide library to identify disease-relevant autoantigen peptides. Among the identified peptides, one was recognized by the vast majority of patients' sera. Abs against this peptide were affinity purified from the patients' sera and assayed for their ability to induce histamine release from basophils.

RESULTS

We identified a peptide that showed similarity with the low-affinity IgE receptor (Fc epsilonRII/CD23) expressed on lymphomonocytes and eosinophils. Anti-peptide IgG Abs purified from the patients' sera bound cell surface CD23 and were able to induce histamine release from basophils. This effect appeared to be mediated by the release of major basic protein from eosinophils upon engagement of CD23. The same effects were obtained with the sera from mice immunized with the CD23 peptide.

CONCLUSION

Our results indicate that patients with chronic idiopathic urticaria have Abs against CD23 and that eosinophils, which infiltrate the skin of these patients, play a crucial role in maintaining the disease through the release of major basic protein upon engagement of the low-affinity IgE receptor by such auto-Abs.

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

BACKGROUND

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.

OBJECTIVES

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Autoantibodies to the high-affinity IgE receptor in children with chronic urticaria

BACKGROUND

Chronic urticaria (CU) in childhood remains a challenge for investigation, and its etiology is largely unknown. Autoantibodies to the high-affinity IgE receptor (FcepsilonRI) are believed to play a role in the pathogenesis of this disease in adults.

OBJECTIVE

To determine the prevalence of autoantibodies to FcepsilonRIalpha on basophils in children with CU vs atopic eczema dermatitis syndrome (AEDS).

METHODS

Eighty children with CU were compared with 38 children with AEDS. In addition to complete blood cell counts and total IgE measurements, CAP-RASTs to egg, codfish, soy, milk, and peanut were performed. Stool samples were examined for parasites, and autologous serum skin testing and a functional anti-FcepsilonRIalpha assay were conducted to detect autoantibodies.

RESULTS

No significant differences were observed between children with CU and controls in mean basophil or eosinophil counts. Twenty (26%) of 77 children with CU and 31 (82%) of 38 with AEDS had positive CAP-RAST results (P < .001). Only 2.5% of the children with CU and 0% with AEDS had stool samples positive for parasites (P = .005). Anti-FcepsilonRIalpha autoantibodies were positive in 37 (47%) of 78 children with CU and in none of 33 with AEDS. Non-IgG histamine-releasing factors were found in 10 (13%) of 78 children with CU.

CONCLUSIONS

Children have a similar prevalence of autoantibodies to the FcepsilonRIalpha as has been previously published for adults. Few have type I allergies, and parasite infestation is also uncommon. Further studies are required to investigate the predictive value of the autoantibodies in these children with respect to clinical profile, requirements for medications other than antihistamines, and remission rates.

Lack of correlation between Helicobacter pylori infection and autologous serum skin test in chronic idiopathic urticaria

BACKGROUND

There are controversial reports about the direct role of Helicobacterpylori infection in chronic idiopathic urticaria. The indirect role of H. pylori infection in the induction of pathogenetic antibodies is not fully elucidated either. This study aims to reveal the association of H. pylori infection with autologous serum skin test positivity in chronic idiopathic urticaria (CIU) patients.

METHODS

A total of 47 patients (35 women, 12 men, age range 17-65 years) diagnosed as CIU were included in the study. Autologous serum skin test was performed on all patients. The patients were examined with a commercially available ELISA test for H. pylori-specific antibodies. Gastroscopy with mucosal biopsy and rapid urease tests were proposed to verify the presence of H. pylori infection.

RESULTS

Helicobacter pylori infection was detected in 33 of the 47 patients (70%). No significant relation was found between the autologous serum skin test positivity and the serological and histopathological presence of H. pylori infection.

CONCLUSION

The results of our study suggest that chronic H. pylori infection does not appear to have a role in the induction of autoantibodies in CIU.

Plasma of patients with chronic urticaria shows signs of thrombin generation, and its intradermal injection causes wheal-and-flare reactions much more frequently than autologous serum

BACKGROUND

Several aspects of the pathogenesis of chronic urticaria (CU) remain contradictory. Autologous serum skin tests (ASSTs) and in vitro histamine release assays seem to look into distinct aspects of the disease, and the specificity of ASST has been questioned.

OBJECTIVE

We compared the autologous plasma skin test (APST) with ASST to detect autoreactivity in patients with CU. The clotting process was investigated as well by measuring in vivo thrombin generation.

METHODS

A total of 96 adults with CU underwent ASST; 71 of them underwent APST with Na citrate-anticoagulated plasma. Prothrombin fragment 1+2 plasma levels were measured by a sandwich ELISA in Na citrate-anticoagulated plasmas from 28 patients and 27 controls.

RESULTS

Fifty-one of 96 (53%) patients scored positive on ASST, whereas 61 of 71 (86%) patients scored positive on APST (21/30 [70%] ASST-negative and 40/41 [98%] ASST-positive). Plasma prothrombin fragment 1+2 was higher in patients than controls (3.06 [SD 3.36] vs 0.80 [0.34]; P < .001) and in ASST-positive/APST-positive than in ASST-negative/APST-positive patients (3.89 [SD 3.68] vs 1.33 [1.64]; P = 0.058) and was directly related to urticaria severity (r = 0.37; P < .05).

CONCLUSION

Most patients with CU are positive on APST-Na citrate. CU is associated with the generation of thrombin, a serine protease able to activate mast cells and to cause relevant increase in permeability of endothelium. APST and ASST only partially depend on the presence of circulating antibodies to FcepsilonRI or to IgE.

CLINICAL IMPLICATIONS

These findings provide new insights into the pathogenesis of CU and suggest new therapeutic opportunities for treating this disease.

Autologous serum skin test reactivity in patients with non-allergic asthma

BACKGROUND

Inflammatory alterations of respiratory airways have been found in patients with non-allergic asthma, but the triggering event has not been defined. An autoimmune activation of inflammatory cells has been hypothesized.

OBJECTIVE

To evaluate whether histamine-releasing factors are present in sera from non-allergic asthmatics.

METHODS

Twenty-four patients with non-allergic asthma underwent in vivo autologous serum skin test (ASST) and in vitro basophil histamine release assay using autologous basophils as well as basophils from normal donors. Twenty-seven subjects with respiratory allergy and three normal subjects were chosen as control.

RESULTS

ASST was positive in 14/24 non-allergic asthmatics (58%) whereas it was negative in all 30 control subjects (P<0.001). The serum of only one ASST-positive patient out of 12 (8.4%) induced in vitro histamine release from autologous basophils. The serum from another ASST-positive patient induced histamine release from membrane IgE-stripped autologous basophils. Sera from either non-allergic asthmatics or from control subjects did not provoke significant histamine release from basophils from three normal donors.

CONCLUSION

Skin reactivity to autologous serum is common among non-allergic asthmatics, indicating the presence of circulating histamine-releasing factors. However, only in a minority of patients in vitro functional evidence of histamine-releasing autoantibodies (anti-FcepsilonRI or anti-IgE) was obtained. The presence of circulating histamine-releasing factors might contribute to initiation/maintenance of inflammation in respiratory airways of non-allergic asthmatics.

A high-affinity natural autoantibody from human cord blood defines a physiologically relevant epitope on the FcepsilonRIalpha

Natural Abs represent the indigenous immune repertoire and are thus present at birth and persist throughout life. Previously, human autoantibodies to the alpha domain of the high-affinity IgE receptor (FcepsilonRIalpha) have been isolated from Ab libraries derived from normal donors and patients with chronic urticaria. To investigate whether these anti-FcepsilonRIalpha Abs are present in the germline repertoire, we constructed a phage Fab display library from human cord blood, which represents the naive immune repertoire before exposure to exogenous Ags. All isolated clones specific to the FcepsilonRIalpha had the same sequence. This single IgM Ab, named CBMalpha8, was strictly in germline configuration and had high affinity and functional in vitro anaphylactogenic activity. Inhibition experiments indicated an overlapping epitope on the FcepsilonRIalpha recognized by both CBMalpha8 and the previously isolated anti-FcepsilonRIalpha Abs from autoimmune and healthy donors. This common epitope on FcepsilonRIalpha coincides with the binding site for IgE. Affinity measurements demonstrated the presence of Abs showing CBMalpha8-like specificity, but with a significantly lower affinity in i.v. Ig, a therapeutic multidonor IgG preparation. We propose a hypothesis of escape mutants, whereby the resulting lower affinity IgG anti-FcepsilonRIalpha Abs are rendered less likely to compete with IgE for binding to FcepsilonRIalpha.

Urticaria: selected highlights and recent advances

Urticaria has been called a vexing problem and remains so today. The most important part of the diagnostic evaluation remains a comprehensive and detailed history and physical examination, supplemented with limited laboratory testing. Although acute urticaria has been relatively well understood for some time, significant and important recent advances in under-standing the pathogenesis of chronic urticaria are beginning to provide insight in this challenging field, notably the identification of many of these patients with an autoimmune etiology. Antihistamines of various types continue to represent the keystone of symptomatic treatment, with adjunctive support from medications of other classes, such as antileukotrienes, adrenergics, and immunosuppressive and anti-inflammatory agents (including steroids and cyclosporine). Although some progress has been made at improving symptomatic control of urticaria, further research and discovery are necessary before there can yet be an effective impact on the underlying course and natural history of this condition.

Autoantibodies to the high-affinity IgE receptor in chronic urticaria: how important are they?

PURPOSE OF REVIEW

Eighty to 90% of patients with chronic urticaria have no specific external cause for their disease, which is therefore labeled 'chronic idiopathic urticaria'. We now know, however, that as many as 30-50% of patients have evidence of an autoantibody to the high-affinity receptor for IgE (FcepsilonRI), which may be pathogenic. The exact prevalence and role of these autoantibodies is still under investigation.

RECENT FINDINGS

The frequency of autoantibodies to FcepsilonRI in chronic urticaria has been estimated at 30-50%, but extensive epidemiological studies have not been done. Recent work has confirmed that autoantibodies to FcepsilonRI can be functional, meaning that they can cause histamine release from basophils in vitro. Evidence increasingly suggests that such autoantibodies are also functional in vivo, but conclusive evidence is still lacking. Approximately 50% of cases of urticaria still have no known cause, but recent studies have demonstrated that some of these patients may have intrinsic abnormalities of basophils or mast cells.

SUMMARY

The recent evidence that is discussed in this review helps to clarify the role of autoantibodies in some cases of urticaria, but also points towards other non-autoimmune mechanisms that might be pathogenic. Further investigation in these areas will help us to understand the cause of urticaria in cases that are still classified as 'idiopathic'.

Urticaria and angioedema

Urticaria and angioedema are commonly encountered complaints in children. Although the diagnosis is clear, establishing an etiology, especially with respect to chronic urticaria, can be challenging. A significant proportion of chronic urticarial cases are now considered to have an autoimmune etiology. This article reviews progress in the field of urticaria and angioedema including developments in pathogenesis, description of laboratory testing, and review of medications. Urticaria and angioedema can usually be controlled by avoidance of triggers, a variety of supportive medications, and reassurance.

Validation of basophil histamine release against the autologous serum skin test and outcome of serum-induced basophil histamine release studies in a large population of chronic urticaria patients

BACKGROUND

Endogenous histamine-releasing factors (HRFs) are involved in 30-60% of patients with chronic urticaria (CU). Evidence for their existence comes from in vivo studies of autoreactivity with the autologous serum skin test (ASST), in vitro immunoassays demonstrating autoantibodies against the immunoglobulin E (IgE) or the high affinity IgE receptor (FcepsilonRI) and serum-induced histamine release (HR) from basophils and mast cells. We have examined the correlation between the ASST and a new basophil histamine-releasing assay (the HR-Urtikaria test) in a group of well-characterized CU patients and subsequently determined the frequency of HR-Urticaria-positive sera from a larger population of CU patients.

SUBJECTS

Group 1 consisted of 28 patients with CU (16 were ASST-positive) 20 patients with atopic dermatitis, 24 patients with allergy to birch and nine healthy controls. Group 2 consisted of 873 unselected CU patients.

METHODS

White blood cells containing 1-2% basophils from a healthy nonatopic donor were incubated with patients sera in the presence of interleukin (IL)-3. Histamine was measured by the glass fibre method.

RESULTS

Using the ASST as the true outcome, the HR-Urticaria test showed a sensitivity and specificity of 75% in group 1 using a cut-off value for HR of >16.5%. None of the controls was positive in the HR-Urticaria test. In group 2, we found no difference in the frequency of positives between male (34.6%, n = 254) and female adults (35.1%, n = 576) but twice as many females as males were tested.

CONCLUSIONS

Our studies have shown that the HR-Urticaria test has a good sensitivity and specificity for endogenous HRFs demonstrated by the ASST in patients with CU and that about one-third of unselected patients with CU have a positive result.

Helicobacter pylori immunoproteomes in case reports of rosacea and chronic urticaria

Rosacea and chronic urticaria are two common skin disorders existing in idiopathic forms. A role of Helicobacter pylori bacterium infection in the aetiopathogenesis of rosacea or chronic urticaria has been suggested although still controversial. The aim of the present study was to establish a relationship between H. pylori infection and rosacea chronic urticaria by means of an immunoproteomic investigation. We analyzed immunoglobulin A (IgA)-, IgG-, and IgE-mediated immune-responses against H. pylori antigens and we identified some bacterial immunoresponsive proteins. A general IgA- and IgE-mediated immune response against antioxidative bacterial proteins was observed. A correlation between the bacterial occurrence and skin diseases pathogenesis is discussed.

Assessment of platelet activity as expressed by plasma levels of platelet factor 4 and beta-thromboglobulin in patients with chronic idiopathic urticaria

Blood platelet significance in inflammation is recognized but poorly characterized in urticaria. It is known that platelets are activated during inflammatory processes and are involved in modulating inflammatory and immune response via various mediator release. The aim of our study was to investigate the functional state of platelets, expressed by release reaction of C-X-C chemokines such as platelet factor 4 (PF-4) and beta-thromboglobulin (beta-TG) in chronic idiopathic urticaria (CIU). Plasma levels of PF-4 and beta-TG, which are established markers of in vivo platelet activation and which play important role in inflammatory processes, were measured by enzyme-linked immunosorbent assay in 19 patients with CIU and in 25 healthy subjects. Mean plasma PF-4 level in CIU patients and control subjects was 5.01 +/- 1.67 and 4.13 +/- 2.05 IU/ml, respectively, whereas that for beta-TG was 29.3 +/- 14.0 and 25.2 +/- 12.6 IU/ml, respectively. In our small study, there have been no significant differences found between the members of the control and CIU group regarding plasma levels of PF-4 and beta-TG. Further studies should be performed to elucidate whether any systemic platelet activation occurs in CIU.

No evidence of increased serum substance P levels in chronic urticaria patients with and without demonstrable circulating vasoactive factors

The neuropeptide substance P is a possible candidate as histamine-releasing factor in some patients with chronic ordinary urticaria (COU), particularly in those with evidence of a nonautoantibody circulating histamine-releasing factor. In this study, serum substance P levels were measured by enzyme immunoassay in 117 COU patients, 40 atopic subjects and 24 normal subjects. In vivo and in vitro assays for histamine-releasing factors, autologous serum skin test (ASST) and basophil histamine release (BHR) assay, respectively, were performed in all COU patients. Mean serum substance P concentration was not significantly different in COU patients and in normal subjects; however, significantly higher levels were detected in atopic subjects than in COU patients (P < 0.003). ASST and BHR assays allowed us to distinguish different subsets of COU patients. Mean serum substance P concentration did not vary significantly in the different subsets of patients. Nevertheless, interestingly three patients with positive ASST and negative BHR assay showed very high substance P levels. These results suggest that substance P does not play an important role as histamine-releasing factor in COU in general but only in occasional patients in whom it might act as a trigger of urticarial symptoms.

Chronic idiopathic urticaria: infiltrating cells and related cytokines in autologous serum-induced wheals

The term chronic autoimmune urticaria (CAIU) is used for chronic urticaria in subjects who present a whealing response to the intradermal injection of autologous serum, suggesting the presence of pathogenic antibody activities. In this study, we examined 28 chronic urticaria subjects with positive autologous serum skin test (ASST), all of whom presented autologous serum-induced lesions at different evolutive stages. Punch biopsies were taken from lesional skin of six subjects at 10', eight subjects at 30', six subjects at 60', and four subjects each at 24 and 48 h. Immunological studies focussed on infiltrating cell immunophenotype and related cytokines, chemokines and chemokine receptors, adhesion molecules. Immunohistochemical staining was performed to measure expression of CD3, CD4, CD8, tryptase, eosinophil cationic protein, myeloperoxidase, basophil granular protein, IL-4, IL-5, IL-8, CCR3 and CXCR3, ICAM-1, VCAM and ELAM. Control staining was done on unaffected skin from the patients and normal skin from four healthy donors. The main infiltrating population was represented by neutrophils, seen focally in both unaffected skin (P = 0.001) and healthy controls (P = 0.003). IFN-gamma and IL-5 were expressed focally in autologous wheals. Significant staining for IL-4 was seen at 30'. CCR3 and CXCR3 were expressed less in autologous wheals than in uninvolved skin (P < 0.0001; P = 0.002). Cellular adhesion molecules (CAMs) reached their highest expression at 30' and 60' in induced lesions, and they showed strong expression also in unaffected skin (ICAM-1: P < 0.0001). Our data show that the immunoinflammatory features of ASST-induced wheals involve a prevalent role of lymphocytes (with a mixed Th1/Th2 response), with strong neutrophil infiltration and activity and involvement of the chemokine pathway. We interpreted the finding of inflammatory cells and mediator up-regulation in uninvolved CIU skin as a sign of prolonged and widespread "urticarial status".

The autologous serum skin test in the follow-up of patients with chronic urticaria

BACKGROUND

The presence of anti-FcepsilonRI and anti-IgE autoantibodies in a subset of patients with chronic urticaria suggests their aetiopathogenetic role. In clinical practice, the presence of these antibodies is usually considered when the autologous serum skin test (ASST) is positive.

AIMS

To evaluate if the positive ASST follows up the activity of chronic urticaria.

METHODS

Autologous serum skin test and thyroid autoantibody detection were performed in 82 patients with chronic urticaria and repeated 1 year later, when the vast majority of patients were symptom-free. Twenty patients with Hashimoto thyroiditis (HT), who had never suffered from urticaria, represented the control group.

RESULTS

At the start of the study, the prevalence of positive ASST was 46.6%. The association of HT-urticaria was 29.3%. ASST was positive in 62 and 39% of patients with and without HT, respectively (P > 0.05 ns). One year later, 28 of 34 patients with a positive ASST were symptom-free, but 50% of them were positive for ASST. The ASST was positive in 86.7 and 8% of patients with and without HT, respectively (P < 0.001). In the control group, ASST was always negative.

CONCLUSIONS

The co-existence of autoimmune thyroiditis with chronic urticaria seems to induce a significant difference in the persistence of a positive ASST. Consistent with previous reports, a positive ASST correlates with disease exacerbation in chronic urticaria patients without thyroiditis. In patients with thyroiditis and urticaria, positive ASST persists even after the urticaria has disappeared, thus questioning whether a positive ASST to be a surrogate marker of the functional role of anti-FcepsilonRI and anti-IgE autoantibodies.

Prevalence of autoantibodies against structure specific recognition protein 1 in systemic lupus erythematosus

Antibodies (Abs) against the structure specific recognition protein 1 (SSRP1) were reported in a small systemic lupus erythematosus (SLE) series but not in other systemic autoimmune diseases. The aim of the study was to confirm the selective presence of anti-SSRP1 Abs in a larger SLE series and to evaluate their relationship with disease activity and other immune markers. Anti-SSRP1 Abs were investigated by a 'home made' ELISA in: 120 SLE, 65 rheumatoid arthritis (RA), 51 systemic sclerosis (SSc), 23 Churg-Strauss syndrome (CSS) and 40 idiopathic autoimmune urticaria (IAU) patients and 190 healthy controls. Sera from MRL lpr/lpr and Balb-c mice were also tested. Anti-SSRP1 Abs were detected in 43 SLE (35.8%), nine SSc (17.6%), eight RA (12.3%), six IAU (15%), three CSS (13%) patients and five healthy controls (2.6%). Antibody prevalence and titers were significantly higher in SLE patients than in sera from both normal and disease controls. Anti-SSRP1 Ab activity was also detected in sera from MRL lpr/lpr but not Balb-c mice. The antibodies did not correlate with the disease activity evaluated as the ECLAM index score and were more prevalent in patients without renal involvement. No correlation was found with other serum autoantibodies. Our results confirm that anti-SSRP1 Abs are associated with but not specific for the lupus disease.

Autoimmune urticaria

A growing body of evidence shows that at least 40% of patients with unexplained (idiopathic) chronic urticaria have clinically relevant functional autoantibodies to the high-affinity IgE receptor on basophils and mast cells. The term "autoimmune urticaria" is used for this subgroup of patients presenting with continuous ordinary urticaria. This article reviews the evidence for the autoimmune hypothesis and other nonantibody serum histamine-releasing factors in the etiopathogenesis of urticaria; defines autoimmune urticaria; looks at how autoimmune urticaria fits into existing classifications of urticaria; proposes diagnostic criteria that may be useful to the clinician; and reviews the management implications for patients with this subset of chronic disease.

Urticaria and angioedema: an overview

Persistent or frequent episodes of urticaria are difficult to evaluate and treat. The best test to identify most patients with a specific underlying cause (eg, physical trigger, allergen, systemic disease) likely is the taking of a careful and detailed history and performance of a physical examination by a specialist who is knowledgeable in urticarial disease. Further study of the pathogenesis and treatment of urticaria is crucial. Given the limited efficacy of presently approved antihistamine treatments and the significant side effects of steroids and cyclosporine, there is a pressing need to evaluate other anecdotally supported urticaria treatments in randomized, controlled trials.

Clinical and laboratory parameters in predicting chronic urticaria duration: a prospective study of 139 patients

BACKGROUND

Despite the disabling nature of chronic urticaria (CU), little is known about the disease's duration or the efficacy of adopting aggressive therapeutic regimens such as cyclosporine A.

OBJECTIVES

The aim of this study was to evaluate whether parameters such as angioedema, autologous serum test, anti-thyroid antibodies, and total IgE could predict both CU duration and severity.

PATIENTS AND METHODS

One hundred and thirty-nine patients suffering from CU were prospectively followed over a 5-year period for disease duration, severity and the presence of angioedema. Also investigated was the association between these clinical parameters and the subsequent detection of autologous serum test, anti-thyroid antibodies, and total IgE.

RESULTS

CU lasted over 1 year in more than 70% of cases and in 14% it still existed after 5 years. Angioedema co-existed or appeared during the course of CU in 40% of patients and was associated with disease duration. Autologous serum test and anti-thyroid antibodies were found positive in 28 and 12% of patients, respectively, compared to none of normal individuals, P = 0.001. CU duration was associated with the presence of both autologous serum test and anti-thyroid antibodies; however, autologous serum test and not anti-thyroid antibodies was found in association with CU severity.

CONCLUSION

We demonstrate for the first time that CU duration is associated with clinical parameters such as severity and angioedema, and with laboratory parameters such as autologous serum test and anti-thyroid antibodies. The ability to predict CU duration may facilitate decisions regarding the possible early initiation of cyclosporine A as a means by which to reduce disease severity and duration.

Basophil CD63 expression assay on highly sensitized atopic donor leucocytes-a useful method in chronic autoimmune urticaria

BACKGROUND

The autoimmune subclass of chronic idiopathic urticaria (CU) has been characterized by the occurrence of biologically relevant IgG antibodies against the IgE molecule or the alpha chain of the high-affinity Fcepsilon receptor (FcepsilonRIalpha) on basophils and mast cells. These antibodies are usually detected by autologous serum skin testing and confirmed by histamine release studies, immunoblotting, or enzyme-linked immunosorbent assay, but not always.

OBJECTIVES

To detect autoantibodies to the FcepsilonRIalpha in sera of CU patients by a modified serum-induced basophil activation test measured by flow cytometry (FCM) and to evaluate the relationship between the in vitro functional test, the autologous serum skin test (ASST), and the serum levels of IgE, eosinophil cationic protein (ECP) and antithyroid antibodies.

METHODS

Sera of 30 patients with CU and 26 patients with systemic autoimmune diseases (systemic lupus erythematosus, dermatomyositis) were tested for CD63 activation marker expression on basophils by FCM. Leucocytes from two highly sensitized atopic donors (D(A1,) D(A2)) and one non-atopic donor (D(NA)) were incubated with patients' sera and double-labelled with anti-IgE and anti-CD63 antibodies. Subsequently, the percentage of CD63-expressing basophils was determined by using FCM. In all CU patients an ASST was carried out and the serum IgE, and ECP levels and antithyroid antibodies were evaluated.

RESULTS

Twelve patients had a positive ASST and 14 patients a positive CD63 expression assay. There was a strong correlation between the ASST and CD63 assay. Sera from patients with systemic autoimmune diseases did not raise positive CD63 expression on basophils. There was a moderate negative correlation between the occurrence of atopic serum markers (IgE, ECP) and the ability of sera to induce CD63 expression on basophil cells of D(A2) (P < 0.05). The female sex was preponderant and antithyroid antibodies were more frequent.

CONCLUSIONS

Our new technical observation demonstrates that basophils of highly sensitized atopic donors can be successfully used without priming with IL-3 for the in-vitro flow cytofluorimetric diagnosis of CU. With this investigation the characterization of the autoimmune origin of CU is based on an objective in vitro technique.

Monomeric IgE stimulates NFAT translocation into the nucleus, a rise in cytosol Ca2+, degranulation, and membrane ruffling in the cultured rat basophilic leukemia-2H3 mast cell line

Mast cells are key regulators in allergy and inflammation, and release histamine, cytokines, and other proinflammatory mediators. In the classical view, IgE acts merely to prime mast cells, attaching to FcepsilonRs but not evoking any cell signaling response until cross-linked by the presence of a multivalent allergen. However, several recent studies have reported that IgE alone can promote cell survival and cytokine production in the absence of cross-linking by allergen. In this study we demonstrate that acute addition of monomeric IgE elicits a wide spectrum of responses in the rat basophilic leukemia-2H3 mast cell line, including activation of phospholipases Cgamma and D, a rise in cytosol Ca(2+), NFAT translocation, degranulation, and membrane ruffling within minutes. Calcium transients persist for hours as long as IgE is present resulting in the maintained translocation of the transcription factor NFAT to the nucleus. Removal of IgE reverses the signaling processes. Our results indicate that, far from simply preparing the cells for a response to allergen, monomeric IgE can stimulate signaling pathways that lead to degranulation, membrane ruffling, and NFAT translocation. The mechanism of activation is likely to be via aggregation of the FcepsilonR1 because activation by IgE can be inhibited with monovalent hapten.

Multiple NSAID intolerance in chronic idiopathic urticaria is correlated with delayed, pronounced and prolonged autoreactivity

Autologous serum skin test (ASST) reactivity is positive in up to 60% of patients with chronic idiopathic urticaria (CIU). About 21 to 30% of patients with CIU have intolerance to acetyl salicylic acid (ASA) and/or other chemically unrelated non-steroidal anti-inflammatory drugs (NSAIDs). To investigate the relationship between ASA/NSAID intolerance and ASST reactivity, a case-control study was performed in 110 patients with CIU and 60 healthy controls. A positive ASST was defined as an erythematous wheal with a diameter of > 5 mm more than the saline-induced response. Patients were assessed at 10-minute intervals for a minimum of three hours. ASA/NSAID intolerance was ascertained by a placebo controlled-provocation test with offending drug (s). Forty-two patients with CIU (38.2%) had autoreactivity whereas only two of the controls (3.3%) displayed early and weak skin responses (P<.0001). ASA/NSAID intolerance was demonstrated in 30 (27.3%) patients with CIU. The prevalences of autoreactivity were 93.3% (28/30) and 17.5% (14/80) in patients with and without ASA/NSAID intolerance, respectively (P<.001). Thirteen of the 25 ASST-positive patients (52%) who had single (n: 7) or multiple (n: 6) NSAID intolerance showed early (before or at 30 min) and mild autoreactivity of short duration, whereas 15 of the remaining 17 ASST-positive patients (88.2%) who all had multiple NSAID intolerance showed delayed (later than 30 min) and prolonged autoreactivity (P<.05). These findings suggest that a common mechanism may be responsible for the pathogeneses of both delayed autoreactivity and multiple NSAID intolerance in CIU. It might be further speculated that delayed, prolonged, and pronounced autoreactivity may be a possible predictor for multiple NSAID sensitivity in CIU.

Assessment of histamine-releasing activity of sera from patients with chronic urticaria showing positive autologous skin test on human basophils and mast cells

BACKGROUND

All previous studies agree that only a proportion of sera from patients with chronic urticaria (CU) positive on the autologous serum skin test (ASST) are able to induce histamine release in vitro. A non-specific release of bradykinins during clotting of blood samples has been suggested; however, ASST seems rather specific and some data point to the existence of a mast cell-specific histamine-releasing factor.

OBJECTIVE

To assess whether, and to what extent, the use of both human basophils and mast cells increases the sensitivity of in vitro histamine release assays (HRAs) in ASST-positive patients with CU.

METHODS

The histamine-releasing activity of sera from 93 patients with CU selected on the basis of strong skin reactivity on ASST was assessed in vitro on basophils from 1 (n=86), 2 (n=31), or 3 (n=20) normal donors, and on mast cells from 1 (n=3), 2 (n=3), or 3 (n=87) normal donors.

RESULTS

Sera from 88/93 (95%) patients induced significant histamine release from mast cells or basophils on at least one HRA. 76/93 (82%), 45/90 (50%), 22/80 (28%), and 6/12 (50%) sera were able to induce significant histamine release from cells of 2/5, 3/5, 4/5 and 5/5 donors, respectively.

CONCLUSION

Sera from nearly all ASST-positive patients with CU are able to induce histamine release in vitro. However, the serum from each single patient seems to show its maximal activity on autologous mast cells in vivo, and functional in vitro tests show much variability and seem less sensitive than ASST in the detection of patients with histamine-releasing factors in their blood.

The urticaria spectrum: recognition of clinical patterns can help management

Urticaria has diverse clinical presentations and causes. The implication of classifying urticaria primarily by clinical presentation rather than aetiology is that management can be focused on specific clinical problems without extensive investigations. Management pathways may involve nonpharmacological measures and drug interventions, which can be grouped into first-, second- and third-line therapies. Stronger, but potentially more risky, second- and third-line approaches may be justified for patients who do not respond to first-line therapy with antihistamines even though it may not be possible to define a specific aetiology, such as autoimmune urticaria, with confidence.

Chronic idiopathic urticaria

PURPOSE OF REVIEW

Chronic idiopathic urticaria has long been a demoralizing disease, baffling allergists and dermatologists alike, to the detriment of the patient. Recent findings, however, have shed light on causation in many, though not all, of these patients. The purpose of this review is to bring the reader up to date on the current position regarding aetiology and pathogenesis and the strength of the evidence. The review also seeks to point up rational approaches to diagnosis and treatment in the light of these developments.

RECENT FINDINGS

Chronic idiopathic urticaria encompasses at least two subgroups. One of these is the now well-established entity of autoimmune chronic urticaria, due to autoantibodies against either the high-affinity IgE receptor Fc epsilon R1 or, less commonly, IgE. These patients, who co-segregate with chronic idiopathic urticaria patients having an increased frequency of antithyroid autoantibodies, represent 30-50% of the patients previously designated as having chronic idiopathic urticaria. Convenient routine diagnostic tests for this subset remain elusive. The remaining 50% of patients with chronic idiopathic urticaria remain truly 'idiopathic', although the condition in some may have an autoimmune basis, autoantibodies having eluded current techniques for detection. Selected patients with autoimmune urticaria may benefit from immunotherapy.

SUMMARY

It is now known that in 30-50% of patients with chronic idiopathic urticaria, the condition has an autoimmune basis, although confirmation of the diagnosis in these patients is not straightforward. In selected patients, attempts to establish this diagnosis are worthwhile since there are important therapeutic implications.

Chronic Urticaria

Chronic urticaria is a common condition that can be very disabling when severe. A cause for chronic idiopathic urticaria (CIU) is only infrequently identified. Potential causes include reactions to food and drugs, infections (rarely) and, apart from an increased incidence of thyroid disease, uncomplicated urticaria is not usually associated with underlying systemic disease or malignancy. About one-third of patients with CIU have circulating functional autoantibodies against the high affinity IgE receptor or against IgE, although it is not known why such antibodies are produced, or how the presence of such antibodies alters the course of the disease or response to treatment. There are only a few publications relating to childhood urticaria, but it is probably similar to the adult form, except that adult urticaria is more common. The diagnosis is based on patient history and it is vital to spend time documenting this in detail. Extensive laboratory tests are not required in the vast majority of patients. Chronic urticaria resolves spontaneously in 30-55% of patients within 5 years, but it can persist for many years. Treatment is aimed firstly at avoiding underlying causative or exacerbating factors. Histamine H1 receptor antagonists remain the mainstay of oral treatment for all forms of urticaria. The newer low-sedating antihistamines desloratadine, fexofenadine, levocetirizine and mizolastine should be tried first. Sedating antihistamines have more adverse effects but are useful if symptoms are causing sleep disturbance. Low-dose dopexin is effective and especially suitable for patients with associated depression. There is controversy as to whether the addition of an histamine H2 receptor antagonist or a leukotriene antagonist is helpful. For CIU, second-line agents include ciclosporin (cyclosporine) [which is effective in approximately 75% of patients], short courses of oral corticosteroids, intravenous immunoglobulins and plasmapheresis, although the last two were found to be beneficial in small trials only. Treatments for CIU with only limited or anecdotal supportive evidence include sulphasalazine, methotrexate, stanazol, rofecoxib and cyclophosphamide. The efficacy of photo(chemo)therapy is controversial. Physical urticarias may respond to H1 receptor antagonists, although in delayed pressure urticaria, and cold, solar and aquagenic urticaria, the response may be disappointing. Second-line agents for physical urticarias vary depending on the urticaria and most have limited supportive evidence. The potential for spontaneous resolution, the variation in the disease activity and the unpredictable nature of the disease makes the efficacy of treatments difficult to assess.

Effect of high-dose intravenous immunoglobulin in delayed pressure urticaria

BACKGROUND

Delayed pressure urticaria (DPU) is difficult to treat. High-dose intravenous immunoglobulin (IVIG) has been found to be effective in treating patients with autoimmune chronic urticaria.

OBJECTIVES

To report the effect of IVIG on eight patients with severe unremitting DPU.

METHODS

IVIG was administered at a dose of 2 g kg-1 over 2-3 days on an in-patient basis. The response to treatment was assessed subjectively and recorded as remission, improved or unchanged. An autologous serum skin test (ASST) was performed in seven patients.

RESULTS

Three of eight patients achieved remission; two after one infusion and one after three infusions. Two patients improved. Three patients remained unchanged; of these, two declined further treatment after two infusions, and one failed to improve after six infusions at monthly intervals. Four of seven patients had positive ASST; three responded to IVIG. Two developed delayed positive ASST; both responded to IVIG. Of three patients with negative ASST, two responded.

CONCLUSIONS

IVIG induced remission or improved symptoms in five of eight patients with DPU with severe unremitting disease who had failed to respond to other therapies or were controlled only with systemic corticosteroids. Those who responded did so with three or fewer infusions. ASST is not a reliable predictor of response to IVIG.

Comparison of chronic autoimmune urticaria with chronic idiopathic urticaria

BACKGROUND

Chronic urticaria has been described in patients with Helicobacter pylori infection. Despite numerous studies, the correlation between H. pylori infection and chronic urticaria is doubtful. Our study was performed to determine the prevalence of H. pylori infection in autoimmune urticaria and in patients suffering from autoimmune urticaria and autoimmune thyroiditis.

METHODS

The authors widely investigated 48 patients. The examinations were extended principally to autologous serum skin test, antithyroid antibodies, and the presence of H. pylori infection as well as detection of antibodies against H. pylori.

RESULTS

Out of the 48 patients, 26 were regarded as having autoimmune origin. The prevalence of antithyroid antibodies was different in the two groups of patients with urticaria. There were 11 patients (42.3%) in the autoimmune group compared with three patients (13.6%) in the nonautoimmune group with antithyroid peroxidase antibody (P = 0.03). The difference in the prevalence of H. pylori infection was significant between autoimmune urticaria with and without thyroid autoimmunity (90.9% vs. 46.7%; P = 0.02). Autoimmune thyroiditis was connected with CagA +H. pylori strains, as the H. pylori- specific IgG antibodies revealed significant differences in a prevalence of 120 kDa (P < 0.05).

CONCLUSIONS

The authors observed a relationship between autoimmune urticaria and autoimmune thyroiditis. The results strengthen the possibility of cross-reactivity being triggered between CagA plus H. pylori strains and some other organ-specific autoimmune diseases such as autoimmune urticaria and autoimmune thyroiditis. This indicates a possible role of H. pylori in triggering autoimmune urticaria in at least a select group of patients.

Chronic urticaria: a role for newer immunomodulatory drugs?

Chronic urticaria is now recognized as an autoreactive disorder in a substantial fraction of patients. A serologic mediator of whealing has been demonstrated in 50-60% of patients with chronic urticaria, and autoantibodies against the high affinity IgE receptor or IgE have been detected in about half of these patients. The demonstration that chronic urticaria is frequently autoimmune has encouraged a more aggressive therapeutic approach, with the use of immunomodulatory drugs.A step-by-step approach to the management of chronic urticaria is proposed, based on our personal experience and review of current medical literature, identified through Medline research and hand searching in medical journals. The non- or low-sedating H(1) receptor antagonists (antihistamines), such as cetirizine, fexofenadine, loratadine, mizolastine and, more recently, levocetirizine, desloratadine and ebastine, represent the basic therapy for all chronic urticaria patients. Older sedating antihistamines, such as hydroxyzine and diphenhydramine, may be indicated if symptoms are severe, are associated with angioedema, and if the patient is anxious and disturbed at night.Corticosteroid therapy with prednisone or methylprednisolone can be administered for a few days (7-14) if urticarial symptoms are not controlled by antihistamines and a rapid clinical response is needed. In cases of relapse after corticosteroid suspension, leukotriene receptor antagonists, such as montelukast and zafirlukast, should be tried. In our experience, remission of urticarial symptoms can be achieved in 20-50% of chronic urticaria patients unresponsive to antihistamines alone. When urticaria is unremitting and is not controlled by combined therapy with antihistamines and leukotriene receptor antagonists, prolonged corticosteroid therapy may be needed. Long-term corticosteroid therapy should be administered at the lowest dose able to control urticarial symptoms, in order to minimize adverse effects. In a few patients, however, high-dose corticosteroid therapy may have to be administered for long periods. In these patients, immunosuppressive treatment with low-dose cyclosporine can be started. This type of treatment has a corticosteroid-sparing effect and is also generally effective in patients with severe, unremitting urticaria, but requires careful monitoring of cyclosporine plasma concentration and possible adverse effects. Other immunomodulating drugs that have been tried in chronic urticaria patients include hydroxychloroquine, dapsone, sulfasalazine and methotrexate, but their efficacy has not been proven in large controlled studies. Warfarin therapy may also be considered in some patients with chronic urticaria and angioedema unresponsive to antihistamines.

High prevalence of IgG and IgA antibodies to 19-kDa Helicobacter pylori-associated lipoprotein in chronic urticaria

BACKGROUND

Chronic urticaria has been described in patients with Helicobacter pylori infection. We studied the titer of IgG and IgA type antibodies against H. pylori in patients with and without urticaria of unknown etiology. We also investigated the prevalence of antibodies against H. pylori-associated lipoprotein 20 (lpp20) in patients with and without chronic urticaria.

METHODS

The concentration of anti-H. pylori antibodies (IgG and IgA) was determined by the RIDA test. The level of anti-lpp20 antibodies was determined by Western blot using various H. pylori antigens (from 19 to 120 kDa).

RESULTS

Patients with chronic urticaria and H. pylori infection (subgroup 1, n = 33) had high IgG and IgA titers whereas all patients with chronic urticaria and without H. pylori infection (subgroup 2, n = 23) were seronegative (P = 0.0128 for IgG and P = 0.003 for IgA). Titers in subgroup 1 did not differ significantly from a control group (n = 33) with severe H. pylori-associated gastritis without urticaria. The prevalence of the anti-lpp20 antibodies was significantly higher in subgroup 1 compared to the control group (93.9 vs 21.2%, P < 0.0001 for IgG, and 46.1 vs 6.3%, P < 0.0029 for IgA).

CONCLUSIONS

We suggest that IgG and IgA antibodies to H. pylori-associated lpp20 may play role in the pathogenesis of chronic urticaria.

Intolerance to nonsteroidal anti-inflammatory drugs might precede by years the onset of chronic urticaria

BACKGROUND

Recent studies have found that most otherwise normal subjects with a history of acute urticaria induced by several nonsteroidal anti-inflammatory drugs (NSAIDs) show a wheal-and-flare reaction on intradermal injection of autologous serum. This phenomenon has been previously observed in patients with chronic urticaria (CU) and suggests a possible common background in CU and NSAID-induced urticaria. A relationship between these 2 conditions is further suggested by the fact that up to 30% of patients with CU have a worsening of their skin disorders after the ingestion of chemically unrelated NSAIDs.

OBJECTIVE

I sought to assess whether otherwise normal subjects with multiple or single NSAID intolerance show a propensity to have CU.

METHODS

Two hundred eighty otherwise normal patients with an unequivocal history of acute urticaria induced by NSAIDs seen during the last 10 years were studied. On the basis of both clinical history and oral challenge tests with at least 2 alternative NSAIDs, the patients were classified as having single or multiple NSAID intolerance. All the patients were re-evaluated within the end of 2002, 1 to 10 years after the first visit, to assess the onset of CU. One hundred allergic adults without a history of CU and of drug allergy followed up for 1 to 10 years were used as control subjects.

RESULTS

One hundred fifty-nine and 121 patients were finally considered as having single or multiple NSAID intolerance, respectively. At the follow-up visit, 93 (33%) of 280 patients had CU. The prevalence of CU was very similar in subjects with single or multiple NSAID intolerance (48/159 [30%] vs 45/121 [37%], respectively; P = not significant). Only 1 (1%) of 100 atopic control subjects had CU during the follow-up period (P <.001). Among single NSAID reactors, patients who had CU had a significantly higher prevalence of intolerance to aspirin than those who did not have CU (36/48 [75%] vs 41/111 [37%], P <.001), whereas the latter had a markedly higher prevalence of intolerance to pyrazolone drugs (52/111 [47%] vs 10/48 [21%], P <.01). Altogether, only 12 (15%) of 82 patients intolerant to drugs other than aspirin versus 36 (47%) of 77 aspirin reactors had CU (P <.001).

CONCLUSION

NSAID intolerance might precede the onset of CU by years. Both multiple and single NSAID reactors with a history of aspirin-induced urticaria seem at higher risk for CU than patients with a history of single intolerance to NSAIDs other than aspirin.

Chronic urticaria: impact of allergic inflammation

Urticaria is defined by weals (hives), with or without angioedema, that appear and peak in minutes to hours, usually disappear within 24 h, and are accompanied by pruritus that worsens during the night. Urticaria is caused by cutaneous mast cell degranulation, attributed to immunological, nonimmunological, and idiopathic causes. Chronic idiopathic urticaria (CIU) is the diagnosis when the pathophysiological mechanism of persistent urticaria remains unclear; up to half of patients with CIU have functional autoantibodies directed against the high-affinity receptor for IgE (FcepsilonRI) or against IgE itself, which appear to induce mast cell degranulation. Systemic histamine H1-receptor antagonists, such as desloratadine, are central to the management of CIU. The efficacy and safety of desloratadine, 5 mg once daily, was studied in a double-blind, randomized, placebo-controlled, multicentre trial that included 190 patients, ages 12 and above, with at least a 6-week history of CIU and experiencing a flare of at least moderate severity. Desloratadine was superior to placebo in controlling pruritus and total symptoms after the first dose, and its superiority was maintained throughout the full 6 weeks of the study. Measures of sleep, daily activity, therapeutic response, and global CIU status were also significantly improved with desloratadine after the first dose and maintained throughout the study.

Blood basophil numbers in chronic ordinary urticaria and healthy controls: diurnal variation, influence of loratadine and prednisolone and relationship to disease activity

BACKGROUND

The basopenia of chronic urticaria relates to histamine releasing autoantibodies in the serum of patients with autoimmune urticaria. This reduction in circulating basophils may be due to active recruitment into weals. If so, it might be expected that numbers in blood would be reduced when urticaria is active and increased after treatment. The primary aim of this study was to look at diurnal variation of basophil numbers in patients with chronic ordinary urticaria (not physical or vasculitic) in relation to disease activity and the effect of treatment with antihistamines and corticosteroids, and to compare the results with healthy controls. A secondary aim was to compare a standard manual counting method with automated basophil counts and to look at numbers of other circulating leucocytes that might be relevant to urticaria pathogenesis.

METHODS

Manual basophil counts using a toluidine blue stain and automated 5-part differentials (Coulter Gen. S) were performed at 4-hourly intervals from 08.00 to 20.00 in 10 healthy controls (six women, age 24 to 63 years) and seven chronic urticaria patients (five women, 24 to 50 years). All chronic urticaria patients had severe daily or almost daily urticaria. Only one of six chronic urticaria sera showed in vitro basophil histamine releasing activity. Counts were performed without treatment, after a week of taking loratadine 10 mg daily and after 3 days of adding prednisolone at 0.6 mg/kg/day (maximum 40 mg). Daily urticarial activity scores (UAS) were derived from weal numbers and itch, maximum 7.

RESULTS

There was no significant overall diurnal variation of basophil numbers in healthy controls or chronic urticaria patients. Mean (SE) manually counted basophil were higher in healthy controls than chronic urticaria (43.4/ microL (2.1) vs. 4.4 (0.8), P < 0.001). Basophil counts were reduced in healthy controls on steroids (19.2 (1.9), P < 0.001) but increased in chronic urticaria (8.9 (1.9), P < 0.001). Loratadine did not influence them. UAS fell on treatment (3.3 (0.4) baseline, 1.4 (0.5) on loratadine and 0.5 (0.2) on prednisolone with loratadine, P < 0.001). There was a negative linear correlation between basophil numbers and UAS in untreated chronic urticaria patients (P = 0.001, Spearman rank correlation). Manual and automated basophil counts showed poor agreement. Lymphocyte numbers were lower in chronic urticaria than healthy controls. Neutrophils increased whereas lymphocytes and eosinophils decreased in all subjects on prednisolone. They were unaffected by loratadine.

CONCLUSION

The results are consistent with the hypothesis that circulating basophils may be recruited from blood into urticarial weals during disease activity. Automated counts are not suitable for assessing basophil numbers in chronic urticaria. The relevance of reduced lymphocyte numbers in chronic urticaria needs to be explored.

Clinical and aetiological aspects in urticaria and angio-oedema

BACKGROUND

Urticaria is a common disorder that affects as many as 20% of all people at some time during their lifetime.

OBJECTIVES

To analyse the prevalence of various forms of urticaria according to an aetiological and clinical classification, we carried out a 4-year study in an outpatient clinic.

METHODS

The study was carried out on 562 consecutive patients (178 males and 384 females; mean age 35.4 +/- 16), who had been referred to our unit for the study of urticaria and angio-oedema. Baseline investigations included: the patient's family and personal history of allergy; duration of symptoms, presence of associated symptoms and objective signs of the current episode; clinical, laboratory and instrumental investigations; assessment of response to antihistamine treatment.

RESULTS

A family history of atopy was present in 35% of patients and a personal history of allergy in 24%. We subdivided urticaria and angio-oedema into several groups on the basis of their clinical and aetiological aspects. Of the 562 patients, 424 (76%) presented with ordinary urticaria (43 acute urticaria, 311 chronic urticaria, 70 episodic urticaria), 80 (14%) physical urticaria, 49 (9%) angio-oedema without weals, six (1%) IgE-mediated contact urticaria and three (0.5%) urticarial vasculitis. In 64 cases (11%) urticaria/angio-oedema was associated with one or more symptoms. We identified 394 cases (82%) of idiopathic urticaria, 42 (9%) of immunological urticaria, 29 (6%) of non-immunological urticaria and 17 (3%) of urticaria secondary to infections. Of the treated subjects, 54% showed a good response to treatment with antihistamines.

CONCLUSIONS

Our data provide an overview of urticaria/angio-oedema in a large series of patients, based on clinical-aetiological aspects, and related to recent diagnostic guidelines.

Classification of anti-FcepsilonRI and anti-IgE autoantibodies in chronic idiopathic urticaria and correlation with disease severity

BACKGROUND

Circulating autoantibodies against FcepsilonRI, IgE, or both occur in approximately one third of patients with chronic idiopathic urticaria (CIU), but not all autoantibodies initiate histamine release.

OBJECTIVE

We sought to classify patients with CIU into subsets on the basis of serum bioactivity and immunoreactivity and to examine the relationship between newly defined subtype and disease severity.

METHODS

Sera from patients with CIU (n = 78), dermog-raphism (n = 15), and cholinergic urticaria (n = 10) and sera from healthy subjects (n = 39) were analyzed by means of Western blot analysis for anti-FcepsilonRI autoantibodies and for histamine release from basophils and dermal mast cells. In vivo reactivity of autologous serum was tested by means of intradermal injection, and CIU severity was determined on the basis of clinical interview.

RESULTS

We classified sera from patients with CIU into 5 subsets: immunoreactive histamine-releasing anti-FcepsilonRI autoantibodies (n = 20 [26%]); immunoreactive anti-FcepsilonRI autoantibodies without histamine-releasing activity (n = 12 [15%]); anti-IgE-like autoantibodies (n = 7 [9%]); serum containing a mast cell-specific histamine-releasing factor (n = 7 [9%]); and sera with no identifiable factor (n = 32 [41%]). Patients with serum histamine-releasing activity had more severe urticaria than patients without such activity. Positive skin test responses to autologous sera were associated with histamine-releasing anti-FcepsilonRI autoantibodies but not with non-histamine-releasing anti-FcepsilonRI autoantibodies. Neither healthy subjects nor patients with dermographism or cholinergic urticaria had his-tamine-releasing anti-FcepsilonRI autoantibodies.

CONCLUSION

These data support the specificity of functional anti-FcepsilonRI autoantibodies to CIU. The identification of distinctive subsets of patients suggests that other pathogenic mechanisms occur in CIU in addition to direct ligation of FcepsilonRI by autoantibodies causing dermal mast cell degranulation. Elucidating these mechanisms might lead to new treatments for CIU.