PAPA, PASH and PAPASH Syndromes: Pathophysiology, Presentation and Treatment

Pyoderma gangrenosum (PG) is a neutrophilic dermatosis usually manifesting as skin ulcers with undermined erythematous-violaceous borders. It may be isolated, associated with systemic conditions or occurring in the context of autoinflammatory syndromes such as PAPA (pyogenic arthritis, PG and acne), PASH (PG, acne and suppurative hidradenitis) or PAPASH (pyogenic arthritis, acne, PG and suppurative hidradenitis). From a physiopathological point of view, all these conditions share common mechanisms consisting of over-activation of the innate immune system leading to increased production of the interleukin (IL)-1 family and 'sterile' neutrophil-rich cutaneous inflammation. From a genetic point of view, a number of mutations affecting the proteins of the inflammasome complex (the molecular platform responsible for triggering autoinflammation) or the proteins that regulate inflammasome function have been described in these disorders. As these debilitating entities are all associated with the over-expression of IL-1 and tumour necrosis factor (TNF)-α, biological drugs specifically targeting these cytokines are currently the most effective treatments but, given the emerging role of IL-17 in the pathogenesis of these syndromes, IL-17 antagonists may represent the future management of these conditions.

Detection of Low-Molecular-Weight Mast Cell-Activating Factors in Serum From Patients With Chronic Spontaneous Urticaria

BACKGROUND AND OBJECTIVES

Functionally active autoantibodies to IgE and to the high-affinity IgE receptor (FcεRI) can be detected in serum in about 40% of patients with chronic spontaneous urticaria (CSU). Recent studies showed that serum from patients with CSU can induce activation of mast cells, irrespective of whether they carry high-affinity IgE receptors. To evaluate mast cell activation induced by factors in the serum of CSU patients with a molecular weight lower than that of autoantibodies.

METHODS

Eight CSU patients and 5 healthy controls were evaluated. Whole serum and serum fractionated at 100, 50, and 30 kDa were used to stimulate in vitro LAD2 mast cells. The enzymatic activity of β-hexosaminidase was evaluated in supernatants and cell pellets as a measure of mast cell degranulation.

RESULTS

Mean (SEM) release of mast cell β-hexosaminidase induced by whole serum from CSU patients was higher than that induced by serum from the healthy controls (14.4 [2.7%] vs 5.1 [2.4%]; P=.027). In addition, serum fractions below 100 kDa and below 50 kDa from CSU patients induced mast cell degranulation that was significantly higher than that induced by the corresponding fractions in sera from healthy controls (10.2% [1.4%] vs 3.8% [1.9%] [P=.024] and 10.1% [1.2%] vs 3.9% [1.7%] [P=.012], respectively). In 4 CSU patients, we evaluated serum fractions <30 kDa, which retained their capacity to activate mast cells (11.0% [0.7%]).

CONCLUSIONS

This study shows that sera from CSU patients may contain low-molecular-weight mast cell-activating factors other than autoantibodies. These factors could be an additional mechanism contributing to the pathogenesis of CSU.

Chronic urticaria: a focus on pathogenesis

Chronic urticaria is a spontaneous or inducible group of diseases characterized by the occurrence of wheals (and, in about half of cases, angioedema) for more than 6 weeks. These are rather frequent conditions that may severely affect patients’ quality of life and sometimes represent a challenge for doctors as well. The causes of chronic urticaria are still poorly defined, although there is growing evidence that different biologic systems including immunity, inflammation, and coagulation may take part in the pathomechanism eventually leading to mast cell and basophil degranulation and hence to wheal formation. This review will discuss the main findings that are (slowly) shedding light on the pathogenesis of this disorder.

Acquired Complement Regulatory Gene Mutations and Hematopoietic Stem Cell Transplant-Related Thrombotic Microangiopathy

Hematopoietic stem cell transplant-related thrombotic microangiopathy (HSCT-TMA) is a severe complication whose pathophysiology is unknown. We describe 6 patients in which the disease was associated with complement regulatory gene abnormalities received from their respective donors. It is suggested that mutated and transplanted monocyte-derived cells are responsible for production of abnormal proteins, complement dysregulation, and, ultimately, for the disease. This observation might have important drawbacks as far as HSCT-TMA pathophysiology and treatment are concerned.

Autoinflammation in pyoderma gangrenosum and its syndromic form (pyoderma gangrenosum, acne and suppurative hidradenitis)

BACKGROUND

Pyoderma gangrenosum (PG) is a rare skin disease characterized clinically by ulcers with undermined borders, and histologically by neutrophil-rich infiltrates. PG may occur alone, in syndromic forms or associated with systemic diseases, such as inflammatory bowel disease and haematological or rheumatological disorders.

OBJECTIVES

To determine a specific genetic background related to autoinflammation for PG.

METHODS

We assessed autoinflammation by evaluating the cytokine profile and genes involved in classic autoinflammatory diseases in 13 patients with PG and in seven patients with the syndromic form, known as PASH (pyoderma gangrenosum, acne and suppurative hidradenitis).

RESULTS

In skin samples, the expression of interleukin (IL)-1β and its receptors, IL-17 and its receptor, and tumour necrosis factor-α and its receptors were significantly higher in both PG (P = 0·001) and in PASH (P < 0·001) than in controls. The chemokines IL-8; chemokine (C-X-C motif) ligand 1/2/3; chemokine (C-X-C motif) ligand 16; and RANTES (regulated on activation, normal T-cell-expressed and secreted) were also overexpressed. Cases of PG and PASH showed mutations in the autoinflammatory genes MEFV, NLRP3, NLRP12, NOD2, LPIN2 and PSTPIP1.

CONCLUSIONS

Overexpression of cytokines/chemokines, along with genetic changes, supports the hypothesis that PG and its syndromic form, PASH, are a spectrum of polygenic autoinflammatory conditions.

D-Dimer Plasma Levels Parallel the Clinical Response to Omalizumab in Patients with Severe Chronic Spontaneous Urticaria

Omalizumab is very effective in the majority of patients with severe chronic spontaneous urticaria (CSU), but its mechanism of action is still unclear. In CSU the coagulation cascade is activated with an intensity that parallels the disease severity, and elevated plasma D-dimer levels are associated with a poor response to both antihistamines and cyclosporin. We measured D-dimer plasma levels before and after the first administration of omalizumab in 32 patients with severe CSU. A number of clinical and laboratory parameters were recorded, including the urticaria activity score, presence of angioedema, disease duration, C-reactive protein, anti-nuclear, and anti-thyroid antibodies. Baseline D-dimer levels were elevated in 19 (59%) cases. Omalizumab induced a complete response in 25 patients (78%), in most cases already after the first administration. At baseline, 14/25 responders had increased D-dimer plasma levels versus 5/7 non-responders. All responders showed a dramatic decrease of D-dimer plasma levels after the first administration of the drug (from 1,024 ± 248 [mean ± SE] to 251 ± 30 ng/mL; p = 0.003). In contrast, non-responders did not show any reduction in D-dimer levels after omalizumab administration (from 787 ± 206 to 1,230 ± 429 ng/mL; p = ns). In conclusion, plasma levels of D-dimer are frequently elevated in patients with severe CSU before omalizumab administration and decrease according to the clinical response of the disease to the drug, suggesting a possible effect of omalizumab on coagulation activation and fibrin degradation in a subset of CSU patients.

Pyoderma gangrenosum and its syndromic forms: evidence for a link with autoinflammation

Pyoderma gangrenosum is a rare inflammatory neutrophilic dermatosis manifesting as painful ulcers with violaceous, undermined borders on the lower extremities. It may occur in the context of classic syndromes like PAPA (pyogenic arthritis, pyoderma gangrenosum and acne) and SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis), as well as in a recently described entity named PASH (pyoderma gangrenosum, acne and suppurative hidradenitis). Pyoderma gangrenosum has recently been included within the spectrum of autoinflammatory diseases, which are characterized by recurrent episodes of sterile inflammation, without circulating autoantibodies and autoreactive T cells. In PAPA syndrome, different mutations involving the PSTPIP1 gene, via an increased binding affinity to pyrin, induce the assembly of inflammasomes. These are molecular platforms involved in the activation of caspase 1, a protease that cleaves inactive prointerleukin (pro-IL)-1β to its active isoform IL-1β. The overproduction of IL-1β triggers the release of a number of proinflammatory cytokines and chemokines, which are responsible for the recruitment and activation of neutrophils, leading to neutrophil-mediated inflammation. In SAPHO syndrome, the activation of the PSTPIP2 inflammasome has been suggested to play a role in inducing the dysfunction of the innate immune system. Patients with PASH have recently been reported to present alterations of genes involved in well-known autoinflammatory diseases, such as PSTPIP1, MEFV, NOD2 and NLRP3. Pyoderma gangrenosum and its syndromic forms can be regarded as a single clinicopathological spectrum in the context of autoinflammation.

Prothrombotic biomarkers in patients with rheumatoid arthritis: the beneficial effect of IL-6 receptor blockade

OBJECTIVES

The pro-inflammatory cytokine interleukin (IL)-6 is involved in the pathogenesis of both rheumatoid arthritis (RA) and cardiovascular events. We evaluated the correlation of prothrombotic biomarkers, in particular those of thrombin generation, with inflammatory and clinical parameters in RA patients treated with tocilizumab, an IL-6 receptor (IL-6R) inhibitor. Naïve and maintenance patients were compared.

METHODS

We studied 15 RA patients undergoing tocilizumab infusions at a University Outpatient Clinic. Eight received tocilizumab for the first time and were evaluated at baseline. Seven were in maintenance therapy (9 to 77 months). All 15 patients were evaluated four weeks after the last administration of tocilizumab. At each time, we assessed disease activity score 28 (DAS28), erythrocyte sedimentation rate (ESR) and plasma levels of C-reactive protein (CRP), IL-6, soluble (s)IL-6R, tumour necrosis factor-alpha (TNF-alpha), prothrombin fragment F1+2 and fibrin fragment D-dimer. Forty healthy subjects served as basal controls.

RESULTS

At baseline, RA patients showed a moderate-to-high disease activity and median ESR of 51 mm/1(st) hour (interquartile range 25-63). Plasma levels of CRP (p=0.0001), IL-6 (p=0.043), sIL-6R (p=0.003), TNF-alpha (p=0.0001), F1+2 (p=0.0001) and D-dimer (p=0.002) were higher than those of healthy controls. After four weeks we observed reduction of DAS28 (p=0.0001), ESR (p=0.0001), CRP (p=0.014), TNF-alpha (p=0.006), F1+2 (p=0.009) and D-dimer (p=0.04). No differences were observed between naïve and maintenance patients.

CONCLUSIONS

The reduction of prothrombotic biomarkers parallels the reduction of inflammatory parameters and clinical symptoms in RA patients treated with tocilizumab, both four weeks after the first administration and during maintenance therapy.

Adverse drug reactions and organ damage: The skin

Cutaneous adverse drug reactions are frequent, affecting 2-3% of hospitalized patients and in one twentieth of them are potentially life-threatening. Almost any pharmacologic agent can induce skin reactions, and certain drug classes, such as non-steroidal anti-inflammatory drugs, antibiotics and antiepileptics, have drug eruption rates ranging from 1% to 5%. Cutaneous drug reactions recognize several different pathomechanisms: some skin manifestations are immune-mediated like allergic reactions while others are the result of non immunological causes such as cumulative toxicity, photosensitivity, interaction with other drugs or different metabolic pathways. Cutaneous adverse drug reactions can be classified into two groups: common non-severe and rare life-threatening adverse drug reactions. Non-severe reactions are often exanthematous or urticarial whereas life-threatening reactions typically present with skin detachment or necrosis of large areas of the body and mucous membrane involvement, as in the Stevens-Johnson syndrome or toxic epidermal necrolysis. Clinicians should carefully evaluate the signs and symptoms of all cutaneous adverse drug reactions thought to be due to drugs and immediately discontinue drugs that are not essential. Short cycles of systemic corticosteroids in combination with antihistamines may be necessary for widespread exanthematous rashes, while more aggressive corticosteroid regimens or intravenous immunoglobulins associated with supportive treatment should be used for patients with Stevens-Johnson syndrome or toxic epidermal necrolysis.

Thrombotic microangiopathy without renal involvement: two novel mutations in complement-regulator genes

ESSENTIALS: The differential diagnosis among thrombotic microangiopathies (TMAs) is challenging. We studied a case of TMA with neurologic symptoms, no renal impairment and normal ADAMTS-13 levels. Two novel mutations in complement factor I and thrombomodulin genes were identified. Complement-regulator genes can be involved in TMAs with normal ADAMTS-13 regardless of renal damage.

BACKGROUND

Thrombotic microangiopathies (TMAs) often represent a challenge for clinicians, because clinical, laboratory, and even genetic features are not always sufficient to distinguish among different TMAs.

OBJECTIVES

The aim of this study was to investigate the pathogenetic mechanisms underlying an acute case of TMA with features of both thrombotic thrombocytopenic purpura (TTP) and atypical hemolytic uremic syndrome (aHUS).

PATIENTS/METHODS

We report the case of a 49-year-old woman who developed an acute TMA with neurologic involvement and no renal impairment. ADAMTS-13, von Willebrand factor, and complement-system biochemical characterization was performed on acute phase samples. Exome sequencing and direct Sanger sequencing of previously aHUS-associated genes were performed. The functional consequences of the thrombomodulin (THBD) mutation were investigated by in vitro expression studies.

RESULTS

Despite a clinical diagnosis of TTP, the patient had normal ADAMTS-13 levels and increased VWF antigen levels with ultra-large von Willebrand factor multimers. C3, C4, and complement factors H and I (CFI) were normal. Molecular analysis confirmed two novel heterozygous mutations in CFI (c.805G>A, p.G269S) and THBD (c.1103C>T, p.P368L), and in vitro expression studies showed a reduction in the generation of activated thrombin-activatable fibrinolysis inhibitor (TAFIa) caused by mutated THBD. This proinflammatory condition, associated with the p.G269S mutation in CFI, probably leads to a complement-mediated endothelial activation, with a relevant prothrombotic potential in case of transient environmental triggers.

CONCLUSIONS

This study identified the first case of acute TMA without renal involvement but with neurological damage carrying two novel mutations in complement-regulator genes, highlighting the possible role of the complement system as a common pathogenetic mechanism in TMAs.

Assessment of Anti-Tissue Type Plasminogen Activator Antibodies in Patients With Prosthetic Heart Valve Thrombosis: The ATA Trial

BACKGROUND

Thrombolysis is an effective treatment strategy for prosthetic valve thrombosis (PVT). Recombinant tissue-type plasminogen activator (rt-PA) is widely used as a thrombolytic agent. Infusion of rt-PA may trigger the production of anti-tissue plasminogen activator (tPA) antibodies (ATAs). We aimed to evaluate the possible relationship between ATA levels and PVT formation, and the role of baseline ATA levels on outcomes of thrombolytic therapy in patients with PVT.

METHODS

This prospective, single-center cohort study included 28 patients with PVT undergoing thrombolysis and 31 controls with normal prostheses. Plasma samples were collected from patients with PVT at baseline and at 15th, 30th, 90th, and 180th days after thrombolysis and from controls at baseline only. The ATA levels were assessed in human plasma by an enzyme-linked immunosorbent assay.

RESULTS

Baseline ATA-immunoglobulin (Ig) G and IgM were significantly higher in patients with PVT than in controls. The levels of IgM and IgG peaked at 15th and 30th days after rt-PA infusion, respectively. Subtherapeutic international normalized ratio and baseline ATA-IgM were independent predictors of PVT. Thrombolysis failed in 6 patients (21%) in whom baseline IgM levels were significantly higher than successfully lysed patients. Rethrombosis occurred in 9 patients (32%) in whom baseline IgG levels were significantly higher than those without rethrombosis. There was a moderate positive correlation between baseline and 15th-day IgM levels and the dose of rt-PA needed for successful lysis.

CONCLUSION

The ATA levels tended to be higher in patients with PVT at the time of initial diagnosis compared to controls without PVT. In addition, such patients with PVT and high ATA levels may be at high risk for failed thrombolysis or rethrombosis.

Cytokine and Chemokine Profile in Amicrobial Pustulosis of the Folds: Evidence for Autoinflammation

Autoinflammation has recently been suggested in the pathogenesis of neutrophilic dermatoses but systematic studies on their cytokine profile are lacking. Notably, amicrobial pustulosis of the folds (APF), classified among neutrophilic dermatoses, has been studied only in small case series. In our University Hospital, we conducted an observational study on 15 APF patients, analyzing their clinical and laboratory features with a follow-up of 9 months to 20 years. Skin cytokine pattern of 9 of them was compared to that of 6 normal controls. In all patients, primary lesions were pustules symmetrically involving the skin folds and anogenital region with a chronic-relapsing course and responding to corticosteroids. Dapsone, cyclosporine, and tumor necrosis factor blockers were effective in refractory cases. In skin samples, the expressions of interleukin (IL)-1β, pivotal cytokine in autoinflammation, and its receptors I and II were significantly higher in APF (P = 0.005, 0.018, and 0.034, respectively) than in controls. Chemokines responsible for neutrophil recruitment such as IL-8 (P = 0.003), CXCL 1/2/3 (C-X-C motif ligand 1/2/3) (P = 0.010), CXCL 16 (P = 0.045), and RANTES (regulated on activation, normal T cell expressed and secreted) (P = 0.034) were overexpressed. Molecules involved in tissue damage like matrix metalloproteinase-2 (MMP-2) (P = 0.010) and MMP-9 (P = 0.003) were increased. APF is a pustular neutrophilic dermatosis with a typical distribution in all patients. The disorder may coexist with an underlying autoimmune/dysimmune disease but is often associated only with a few autoantibodies without a clear autoimmunity. The overexpression of cytokines/chemokines and molecules amplifying the inflammatory network supports the view that APF has an important autoinflammatory component.

Paradoxical Autoinflammatory Skin Reaction to Tumor Necrosis Factor Alpha Blockers Manifesting as Amicrobial Pustulosis of the Folds in Patients With Inflammatory Bowel Diseases

The therapy of inflammatory bowel disease, particularly with tumor necrosis factor (TNF) blockers, may be associated with a number of cutaneous adverse effects, including psoriasis-like, eczema-like, and lichenoid eruptions. Other rare skin complications are neutrophilic dermatoses such as amicrobial pustulosis of the folds (APF), which is a chronic relapsing pustular disorder classified in this spectrum.The authors analyzed clinical, histopathologic, and cytokine expression profiles of 3 inflammatory bowel disease patients with APF triggered by adalimumab (patient 1) and infliximab (patients 2 and 3).All 3 patients presented with sterile pustules involving the cutaneous folds, genital regions, and scalp 6 months after starting adalimumab (patient 1) and 9 months after starting infliximab (patients 2 and 3). Histology was characterized by epidermal spongiform pustules with a dermal neutrophilic and lymphocytic infiltrate. Tumor necrosis factor blocker withdrawal associated with topical and systemic corticosteroids induced complete remission of APF in all 3 patients. The expressions of interleukin (IL)-1 beta and its receptors as well as TNF alpha and its receptors were significantly higher in APF than in controls. Also IL-17, leukocyte selectin, and chemokines, such as IL-8, [C-X-C motif] chemokine ligand 1/2/3 (C = cysteine, X = any amino acid), [C-X-C motif] chemokine ligand 16 (C = cysteine, X = any amino acid), and RANTES (regulated on activation, normal T cell expressed and secreted) were significantly overexpressed. Finally, the authors found significant overexpression of both metalloproteinases 2/9 and their inhibitors 1/2.The observation of 3 patients with APF following anti-TNF therapy expands not only the clinical context of APF but also the spectrum of anti-TNF side effects. Overexpression of cytokines/chemokines and molecules amplifying the inflammatory network supports the view that APF is autoinflammatory in origin.

Increased risk of venous thromboembolism in patients with bullous pemphigoid. The INVENTEP (INcidence of VENous ThromboEmbolism in bullous Pemphigoid) study

Activation of blood coagulation has been demonstrated in bullous pemphigoid (BP), a rare autoimmune blistering disease, potentially leading to a prothrombotic state. In order to evaluate the incidence of venous thromboembolism (VTE) in BP, a cohort study was carried out on 432 BP patients (59% females; median age 76 years, interquartile range [IQR]: 68-82). At diagnosis, autoimmune bullous skin disorder intensity score (ABSIS) was calculated. VTE incidence was standardised with rates of the general population. Multivariable Cox proportional hazard model was used to estimate the hazard ratio of VTE according to ABSIS and concomitant risk factors. During a median follow-up of 4.2 years, 31 objectively-diagnosed VTE events were recorded. The incidence rate of VTE (per 1000 patient-years) was 17.2 overall (95% confidence interval [CI]: 11.1-23.2), 56.7 (95%CI: 33.0-80.4) during acute phase (22 VTE) and 6.3 (95%CI: 2.8-11.3) during remission (9 VTE). The standardised incidence ratio was 4.06 (95%CI: 2.73-5.65), higher during the acute phase (14.86, 95%CI: 9.20-21.88) than during remission (1.48, 0.66-2.63). The adjusted hazard ratio of VTE was 2.74 (95%CI: 1.07-7.04) for ABSIS > 48 vs ABSIS < 28, and 2.56 (95%CI: 1.00-6.70) in patients with ≥ 2 concomitant risk factors. In conclusion, BP patients have a 15-fold increased VTE risk during acute phase, proportional to disease severity and heightened by concomitant risk factors.

Activation of Blood Coagulation in Two Prototypic Autoimmune Skin Diseases: A Possible Link with Thrombotic Risk

Coagulation activation has been demonstrated in two prototypic autoimmune skin diseases, chronic autoimmune urticaria and bullous pemphigoid, but only the latter is associated with increased thrombotic risk. Two markers of coagulation activation (prothrombin fragment F1+2 and fibrin fragment D-dimer) were measured by immunoenzymatic methods in plasma samples from 30 patients with active chronic autoimmune urticaria, positive for autologous serum skin test, 30 patients with active bullous pemphigoid and 30 healthy subjects. In skin biopsies, tissue factor expression was evaluated by both immunohistochemistry and in situ hybridization. F1+2 and D-dimer levels were higher in active chronic autoimmune urticaria (276.5±89.8 pmol/L and 5.56±4.40 nmol/L, respectively) than in controls (145.2±38.0 pmol/L and 1.06±0.25 nmol/L; P=0.029 and P=0.011) and were much higher in active bullous pemphigoid (691.7±318.7 pmol/L and 15.24±9.09 nmol/L, respectively) (P<0.0001). Tissue factor positivity was evident in skin biopsies of both disorders with higher intensity in bullous pemphigoid. F1+2 and D-dimer, during remission, were markedly reduced in both disorders. These findings support the involvement of coagulation activation in the pathophysiology of both diseases. The strong systemic activation of coagulation in bullous pemphigoid may contribute to increase the thrombotic risk and provides the rationale for clinical trials on anticoagulant treatments in this disease.

Expression of cytokines, chemokines and other effector molecules in two prototypic autoinflammatory skin diseases, pyoderma gangrenosum and Sweet's syndrome

Pyoderma gangrenosum (PG) and Sweet's syndrome (SS) are two inflammatory skin diseases presenting with painful ulcers and erythematous plaques, respectively; both disorders have a debilitating clinical behaviour and PG is potentially life-threatening. Recently, PG and SS have been included among the autoinflammatory diseases, which are characterized by recurrent episodes of sterile inflammation, without circulating autoantibodies and autoreactive T cells. However, an autoinflammatory pattern clearly supporting this inclusion has never been demonstrated. We studied 16 patients with PG, six with SS and six controls, evaluating, using a sandwich-based protein antibody array method, the expression profile of inflammatory effector molecules in PG, SS and normal skin. The expressions of interleukin (IL)-1 beta and its receptor I were significantly higher in PG (P = 0·0001 for both) and SS (P = 0·004-0·040) than in controls. In PG, chemokines such as IL-8 (P = 0·0001), chemokine (C-X-C motif) ligand (CXCL) 1/2/3 (P = 0·002), CXCL 16 (P = 0·003) and regulated upon activation normal T cell expressed and secreted (RANTES) (P = 0·005) were over-expressed. In SS, IL-8 (P = 0·018), CXCL 1/2/3 (P = 0·006) and CXCL 16 (P = 0·036) but not RANTES were over-expressed, suggesting that chemokine-mediated signals are lower than in PG. Fas/Fas ligand and CD40/CD40 ligand systems were over-expressed in PG (P = 0·0001 for Fas, P = 0·009 for Fas ligand, P = 0·012 for CD40, P = 0·0001 for CD40 ligand), contributing to tissue damage and inflammation, while their role seems to be less significant in SS. Over-expression of cytokines/chemokines and molecules amplifying the inflammatory network supports the view that PG and SS are autoinflammatory diseases. The differences in expression profile of inflammatory effectors between these two disorders may explain the stronger local aggressiveness in PG than SS.

Association of pyoderma gangrenosum, acne, and suppurative hidradenitis (PASH) shares genetic and cytokine profiles with other autoinflammatory diseases

The association of pyoderma gangrenosum, acne, and suppurative hidradenitis (PASH) has recently been described and suggested to be a new entity within the spectrum of autoinflammatory syndromes, which are characterized by recurrent episodes of sterile inflammation, without circulating autoantibodies and autoreactive T-cells. We conducted an observational study on 5 patients with PASH syndrome, analyzing their clinical features, genetic profile of 10 genes already known to be involved in autoinflammatory diseases (AIDs), and cytokine expression pattern both in lesional skin and serum. In tissue skin samples, the expressions of interleukin (IL)-1β and its receptors I and II were significantly higher in PASH (P = 0.028, 0.047, and 0.050, respectively) than in controls. In PASH patients, chemokines such as IL-8 (P = 0.004), C-X-C motif ligand (CXCL) 1/2/3 (P = 0.028), CXCL 16 (P = 0.008), and regulated on activation, normal T cell expressed and secreted (RANTES) (P = 0.005) were overexpressed. Fas/Fas ligand and cluster of differentiation (CD)40/CD40 ligand systems were also overexpressed (P = 0.016 for Fas, P = 0.006 for Fas ligand, P = 0.005 for CD40, and P = 0.004 for CD40 ligand), contributing to tissue damage and inflammation. In peripheral blood, serum levels of the main proinflammatory cytokines, that is, IL-1β, tumor necrosis factor-α, and IL-17, were within the normal range, suggesting that in PASH syndrome, the inflammatory process is mainly localized into the skin. Four out of our 5 PASH patients presented genetic alterations typical of well-known AIDs, including inflammatory bowel diseases, and the only patient lacking genetic changes had clinically evident Crohn disease. In conclusion, overexpression of cytokines/chemokines and molecules amplifying the inflammatory network, along with the genetic changes, supports the view that PASH syndrome is autoinflammatory in origin.

Enhanced tissue factor expression by blood eosinophils from patients with hypereosinophilia: a possible link with thrombosis

Thrombotic risk is increased in eosinophil-mediated disorders, and several hypotheses have been proposed to link eosinophilia and thrombosis. In particular, eosinophils have been described as source of tissue factor (TF), the main initiator of blood coagulation; however, this aspect is still controversial. This study was aimed to evaluate whether TF expression varies in eosinophils isolated from normal subjects and patients with different hypereosinophilic conditions. Eosinophils were immunologically purified from peripheral blood samples of 9 patients with different hypereosinophilic conditions and 9 normal subjects. Western blot analysis and real-time polymerase chain reaction (RT-PCR) were performed to test eosinophil TF expression. For comparison, TF expression was evaluated in monocytes from blood donors and in human endothelial (ECV304) and fibroblast (IMR90) cell lines. Western blot analysis revealed a major band of 47,000 corresponding to native TF in homogenates of purified eosinophils with a higher intensity in the 9 patients than in the 9 controls (p<0.0001). According to RT-PCR cycle threshold (Ct), TF gene expression was higher in eosinophils from patients than in those from controls, median (range) 35.10 (19.45-36.50) vs 37.17 (35.33-37.87) (p = 0.002), and was particularly abundant in one patient with idiopathic hypereosinophilic syndrome and ischemic heart attacks (Ct: 19.45). TF gene expression was moderate in monocytes, Ct: 31.32 (29.82-33.49) and abundant in endothelial cells, Ct: 28.70 (27.79-29.57) and fibroblasts, Ct: 22.77 (19.22-25.05). Our results indicate that human blood eosinophils contain variable amounts of TF. The higher TF expression in patients with hypereosinophilic disorders may contribute to increase the thrombotic risk.

Complement functional tests for monitoring eculizumab treatment in patients with atypical hemolytic uremic syndrome

BACKGROUND

Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy characterized by hemolysis, platelet consumption, and renal injury. Eculizumab, a mAb that blocks complement activity, has been successfully used in aHUS.

OBJECTIVES

To optimize eculizumab therapy in aHUS patients by monitoring complement functional tests and markers of disease activity.

PATIENTS/METHODS

We studied 18 patients with aHUS (10 males; eight females; age range, 2-40 years) treated with eculizumab to induce and/or maintain disease remission. Patients were followed up for a cumulative observation period of 160 months, during which blood samples were obtained at various time intervals to measure complement activity (Wieslab for the classical, alternative and mannose-binding lectin complement pathways) and the parameters of disease activity (haptoglobin and lactate dehydrogenase serum levels, and platelet count). The intravenous eculizumab doses of 12-33 mg kg(-1) were initially administered every week, with the interval between doses being gradually extended to 2 weeks, 3 weeks and 4 weeks on the basis of strict laboratory and clinical control.

RESULTS

Complement activity was normal before eculizumab treatment, regardless of the state of the disease (activity or remission). It was completely suppressed 1 week, 2 weeks and 3 weeks after the last eculizumab infusion (mean values ± standard deviation: 1% ± 1% to 3% ± 5% for both the classical and alternative pathways; P = 0.0001 vs. baseline), and partially suppressed after 4 weeks (22% ± 26% and 16% ± 27%; P = 0.0001 vs. baseline). The increase in the time interval between eculizumab infusions did not change disease activity markers.

CONCLUSIONS

Monitoring complement tests can allow a safe reduction in the frequency of eculizumab administration in aHUS while keeping the disease in remission.

Salvage therapy with high dose Intravenous Immunoglobulins in acquired Von Willebrand Syndrome and unresponsive severe intestinal bleeding

A 91-year-old woman affected with acquired Von Willebrand (VW) syndrome and intestinal angiodysplasias presented with severe gastrointestinal bleeding (hemoglobin 5 g/dl). Despite replacement therapy with VW factor/factor VIII concentrate qid, bleeding did not stop (eleven packed red blood cell units were transfused over three days). High circulating levels of anti-VW factor immunoglobulin M were documented immunoenzimatically. Heart ultrasound showed abnormalities of the mitral and aortic valves with severe flow alterations. When intravenous immunoglobulins were added to therapy, prompt clinical and laboratory responses occurred: complete cessation of bleeding, raise in hemoglobin, VW factor antigen, VW ristocetin cofactor and factor VIII levels as well as progressive reduction of the anti-VWF autoantibody levels.

Pulmonary embolism in elderly patients: prognostic impact of the Cumulative Illness Rating Scale (CIRS) on short-term mortality

BACKGROUND

Pulmonary embolism (PE) is associated with high short-term mortality in elderly patients, even when hemodynamically stable.

METHODS

One hundred and seventy hemodynamically stable patients with confirmed PE (41<65years and 129≥65years) were prospectively followed for one month in order to assess whether comorbidities can predict short-term mortality in elderly patients. Upon admission, patients' clinical characteristics (including instrumental and laboratory parameters) were evaluated, and two clinical scores were calculated: the Cumulative Illness Rating Scale (CIRS), commonly used to evaluate comorbidities in elderly patients, and the Pulmonary Embolism Severity Index (PESI).

RESULTS

Fifteen patients (all elderly) died within one month from their PE diagnosis (mortality rate=8.8%; 95%CI:4.6-13.1%). In these non survivors, arterial partial oxygen pressure (p<0.0001) and saturation (p<0.0001), pH (p=0.001) and systolic blood pressure (p=0.017) at admission were significantly lower than in survivors, whereas their respiratory rate (p<0.0001), white blood cells (p<0.0001), lactate dehydrogenase (p<0.0001), troponin T (p=0.001) and D-dimer (p=0.023) were significantly higher. CIRS correlated with PESI (rho=0.54, p<0.0001), and was higher in non-survivors (p=0.002). The age- and sex-adjusted odds ratio of 1-month mortality was 1.91 (95%CI:1.24-2.95) for every 1-point increase in CIRS. The AUC was 0.78 (95%CI:0.67-0.89) for the logistic model containing CIRS, and 0.88 (95%CI:0.79-0.96) for that containing PESI (p=0.059).

CONCLUSIONS

In elderly patients with PE, CIRS demonstrated a fairly good performance in predicting short-term mortality. Its easiness and suitability for use in common clinical practice make CIRS a potentially useful prognostic score for short-term mortality in these patients.

Chronic urticaria and coagulation: pathophysiological and clinical aspects

Chronic urticaria (CU) is a widespread skin disease, characterized by the recurrence of transient wheals and itch for more than 6 weeks. Besides autoimmune mechanisms, coagulation factors, in particular tissue factor and thrombin, might also participate in the disease pathophysiology. Tissue factor expressed by eosinophils can induce activation of blood coagulation generating thrombin which in turn can increase vascular permeability both directly, acting on endothelial cells, and indirectly, inducing degranulation of mast cells with release of histamine, as demonstrated in experimental models. D-dimer, a fibrin degradation product, generated following activation of the coagulation cascade and fibrinolysis, has been found to be increased during urticaria exacerbations; moreover, it has been proposed as a biomarker of severity and resistance to H1-antihistamines in CU patients. The possible role of coagulation in CU is also supported by case reports, case series and a small controlled study showing the efficacy of anticoagulant therapy in this disease. The purpose of this review was to summarize the available data on the possible contribution of coagulation to the pathophysiology of CU focusing on clinical aspects and possible future therapeutic developments.

Eosinophil cationic protein levels parallel coagulation activation in the blister fluid of patients with bullous pemphigoid

BACKGROUND

Bullous pemphigoid (BP) is an autoimmune blistering disease due to autoantibodies against two hemidesmosomal antigens, namely BP180 and BP230, and characterized by coagulation activation both at cutaneous and systemic levels. Skin-infiltrating eosinophils contribute to bulla formation and, upon activation, are supposed to initiate the coagulation cascade.

OBJECTIVE

The aim of this study was to investigate whether the activation of eosinophils and coagulation are linked in BP.

METHODS

We evaluated the correlation between eosinophil cationic protein (ECP) levels and concentrations of the prothrombotic markers F1 + 2 and D-dimer in blister fluid and blood samples of 30 BP patients. Thirty healthy subjects were used as normal controls.

RESULTS

ECP, F1 + 2 and D-dimer plasma levels were significantly higher in BP patients than in normal subjects. A significant correlation was found between ECP plasma levels and blood eosinophil count (r = 0.54, P = 0.002). F1 + 2 plasma levels positively correlated with disease severity, expressed as the percentage of body surface area involved (r = 0.36, P = 0.048). A striking increase in ECP (288.8 ± 45.2 ng/mL), F1 + 2 (31 409.9 ± 2929.4 pmol/L) and D-dimer levels (342 798.3 ± 44 206 ng/mL) was found in blister fluid from BP patients. In blister fluid, ECP levels were significantly higher than in peripheral blood (P < 0.0001) and were positively correlated with the levels of both F1 + 2 (r = 0.4, P = 0.02) and D-dimer (r = 0.5, P = 0.0045).

CONCLUSIONS

ECP levels are strikingly elevated in blister fluids from BP patients and correlate with markers of coagulation activation, supporting the view that eosinophils initiate the coagulation cascade at skin level.

Discontinuation of eculizumab maintenance treatment for atypical hemolytic uremic syndrome: a report of 10 cases

Atypical hemolytic uremic syndrome (aHUS) is a life-threatening thrombotic microangiopathy, and as many as 70% of patients with aHUS have mutations in the genes encoding complement regulatory proteins. Eculizumab, a humanized recombinant monoclonal antibody targeting C5, has been used successfully in patients with aHUS since 2009. The standard maintenance treatment requires life-long eculizumab therapy, but the possibility of discontinuation has not yet been tested systematically. We report the safety of discontinuing eculizumab treatment in 10 patients who stopped treatment with the aim of minimizing the risk of adverse reactions, reducing the risk of meningitis, and improving quality of life while also reducing the considerable treatment costs. Disease activity was monitored closely at home by means of urine dipstick testing for hemoglobin. During the cumulative observation period of 95 months, 3 of the 10 patients experienced relapse within 6 weeks of discontinuation, but then immediately resumed treatment and completely recovered. Our experience supports the possibility of discontinuing eculizumab therapy with strict home monitoring for early signs of relapse in patients with aHUS who achieve stable remission.

Immune-mediated inflammatory reactions and tumors as skin side effects of inflammatory bowel disease therapy

All drugs currently used for treating patients with inflammatory bowel disease (IBD - including Crohn's disease and ulcerative colitis) have the potential to induce skin lesions ranging from mild eruptions to more serious and widespread clinical presentations. The number of cutaneous adverse reactions due to IBD therapies is progressively increasing and the most frequently involved drugs are thiopurines and biologics like tumor necrosis factor (TNF)-α antagonists. The main drug-induced cutaneous manifestations are non-melanoma skin cancer (NMSC), notably basal cell and squamous cell carcinomas, and viral skin infections for thiopurines and psoriasiform, eczematoid and lichenoid eruptions as well as skin infections and cutaneous lupus erythematosus for biologics. Cutaneous manifestations should be promptly recognized and correctly diagnosed in order to quickly establish an adequate therapy. The main treatment for NMSC is surgical excision whereas the management of immune-mediated inflammatory skin reactions varies from topical therapy for mild presentations to the shift to another drug alone or in combination with corticosteroids for extensive eruptions.

Choosing treatment options for patients with relapsed/refractory multiple myeloma

Multiple myeloma (MM) is a clonal plasma cell disorder that is still incurable using conventional treatments. Over the last decade, advances in front-line therapy have led to an increase in survival, but there are still some doubts in the case of relapsed/refractory disease. We searched the PubMed database for articles on treatment options for patients with relapsed/refractory MM published between 1996 and 2013. These treatments included hematopoietic cell transplantation (HCT), rechallenges using previous chemotherapy regimens, and trials of new regimens. The introduction of new agents such as the immunomodulatory drugs (IMIDs) thalidomide and lenalidomide, and the first-in-its-class proteasome inhibitor bortezomib, has greatly improved clinical outcomes in patients with relapsed/refractory MM, but not all patients respond and those that do may eventually relapse or become refractory to treatment. The challenge is therefore to select the optimal treatment for each patient by balancing efficacy and toxicity. To do this, it is necessary to consider disease-related factors, such as the quality and duration of responses to previous therapies, and the aggressiveness of the relapse, and patient-related factors such as age, comorbidities, performance status, pre-existing toxicities and cytogenetic patterns. The message from the trials reviewed in this article is that the new agents may be used to re-treat relapsed/refractory disease, and that the sequencing of their administration should be modulated on the basis of the various disease and patient-related factors. Moreover, our understanding of the pharmacology and molecular action of the new drugs will contribute to the possibility of developing tailored treatment.

Treatment of refractory chronic urticaria: current and future therapeutic options

Chronic urticaria is a distressing disease that affects up to 1 % of the general population at a time point in life and may severely worsen the quality of life. First-line treatment has been based on antihistamines, and presently relies on the use of non-sedating, second-generation antihistamines; following the recommendations of the recent international guidelines, in patients who do not respond to antihistamines at licensed doses, the daily dosage of these drugs can be increased up to fourfold. Nonetheless, a significant proportion of patients with chronic urticaria remain poorly controlled; in these cases, alternative therapeutic approaches have to be considered. This article critically reviews all of the third- and fourth-line treatment options suggested for patients whose disease is refractory to antihistamines, including systemic corticosteroids, leukotriene receptor antagonists, several different anti-inflammatory drugs (dapsone, sulfasalazine, hydroxychloroquine), various immunosuppressive drugs (calcineurin inhibitors, methotrexate, cyclophosphamide, azathioprine, mycophenolate mofetil), intravenous immunoglobulin, and newer treatment options, such as omalizumab and other biologic drugs. In addition, the article examines possible future treatment options based on recent findings about pathogenic mechanisms, and considers the treatment of antihistamine-unresponsive urticaria in special conditions such as children and pregnancy/lactation. The evidence supporting the use of several of the discussed drugs is presently limited and thus insufficient to recommend their routine use; as a consequence, such compounds should be considered only in specific cases and in adequate settings.

Ongoing contact activation in patients with hereditary angioedema

Hereditary angioedema (HAE) is predominantly caused by a deficiency in C1 esterase inhibitor (C1INH) (HAE-C1INH). C1INH inhibits activated factor XII (FXIIa), activated factor XI (FXIa), and kallikrein. In HAE-C1INH patients the thrombotic risk is not increased even though activation of the contact system is poorly regulated. Therefore, we hypothesized that contact activation preferentially leads to kallikrein formation and less to activation of the coagulation cascade in HAE-C1INH patients. We measured the levels of C1INH in complex with activated contact factors in plasma samples of HAE-C1INH patients (N=30, 17 during remission and 13 during acute attack) and healthy controls (N=10). We did not detect differences in enzyme-inhibitor complexes between samples of controls, patients during remission and patients during an acute attack. Reconstitution with C1INH did not change this result. Next, we determined the potential to form enzyme-inhibitory complexes after complete in vitro activation of the plasma samples with a FXII trigger. In all samples, enzyme-C1INH levels increased after activation even in patients during an acute attack. However, the levels of FXIIa-C1INH, FXIa-C1INH and kallikrein-C1INH were at least 52% lower in samples taken during remission and 70% lower in samples taken during attack compared to samples from controls (p<0.05). Addition of C1INH after activation led to an increase in levels of FXIIa-C1INH and FXIa-C1INH (p<0.05), which were still lower than in controls (p<0.05), while the levels of kallikrein-C1INH did not change. These results are consistent with constitutive activation and attenuated depletion of the contact system and show that the ongoing activation of the contact system, which is present in HAE-C1INH patients both during remission and during acute attacks, is not associated with preferential generation of kallikrein over FXIa.

Current and emerging treatment options for patients with relapsed myeloma

Multiple myeloma (MM) is a neoplastic disorder. It results from proliferation of clonal plasma cells in bone marrow with production of monoclonal proteins, which are detectable in serum or urine. MM is clinically characterized by destructive bone lesions, anemia, hypercalcemia and renal insufficiency. Its prognosis is severe, with a median survival after diagnosis of approximately 3 years due to frequent relapses. Treatments for patients with relapsed/refractory MM include hematopoietic cell transplantation, a rechallenge using a previous chemotherapy regimen or a trial of a new regimen. The introduction of new drugs such as thalidomide, lenalidomide and bortezomib has markedly improved MM outcomes. When relapse occurs, the clinician's challenge is to select the optimal treatment for each patient while balancing efficacy and toxicity. Patients with indolent relapse can be first treated with a 2-drug or a 3-drug combination. Patients with more aggressive relapse often require therapy with a combination of multiple active agents. Autologous stem cell transplantation should be considered as salvage therapy at first relapse for patients who have cryopreserved stem cells early in the disease course. The aim of this review is to provide an overview on the pharmacological and molecular action of treatments used for patients with relapsed/refractory multiple myeloma.

Acquired C1-inhibitor deficiency and lymphoproliferative disorders: a tight relationship

Angioedema due to the acquired deficiency of C1-inhibitor is a rare disease known as acquired angioedema (AAE), which was first described in a patient with high-grade lymphoma and is frequently associated with lymphoproliferative diseases, including expansion of B cell clones producing anti-C1-INH autoantibodies, monoclonal gammopathy of uncertain significance (MGUS) and non-Hodgkin lymphoma (NHL). AAE is clinically similar to hereditary angioedema (HAE), and is characterized by recurrent episodes of sub-cutaneous and sub-mucosal edema. It may affect the face, tongue, extremities, trunk and genitals. The involvement of the gastrointestinal tract causes bowel sub-occlusion with severe pain, vomiting and diarrhea, whereas laryngeal edema can be life-threatening. Unlike those with HAE, AAE patients usually have late-onset symptoms, do not have a family history of angioedema and present variable response to treatment due to the hyper-catabolism of C1-inhibitor. Reduced C1-inhibitor function leads to activation of the classic complement pathway with its consumption and activation of the contact system leading to the generation of the vasoactive peptide bradykinin, which increases vascular permeability and induces angioedema. Lymphoprolipherative diseases and AAE are tightly linked with either angioedema or limphoprolyferation being the first symptom. Experimental data indicate that neoplastic tissue and/or anti-C1-inhibitor antibodies induce C1-inhibitor consumption, and this is further supported by the observation that cytotoxic treatment of the lymphoproliferative diseases associated with AAE variably reverses the complement impairment and leads to a clinical improvement in angioedema symptoms.

Prothrombotic state and impaired fibrinolysis in bullous pemphigoid, the most frequent autoimmune blistering disease

Bullous pemphigoid (BP) is a potentially life-threatening autoimmune blistering disease that is burdened with an increased risk of cardiovascular events. In BP, there is an interplay between inflammation and coagulation both locally, which contributes to skin damage, and systemically, which leads to a prothrombotic state. Fibrinolysis is an important defence mechanism against thrombosis, but has only been studied locally in BP and no systemic data are available. The aim of this observational study was to evaluate systemic fibrinolysis and coagulation activation in patients with BP. We measured parameters of fibrinolysis and coagulation by immunoenzymatic methods in plasma from 20 patients with BP in an active phase and during remission after corticosteroid treatment. The controls were 20 age- and sex-matched healthy subjects. Plasma levels of plasminogen activator inhibitor type 1 (PAI-1) antigen, PAI-1 activity and tissue plasminogen activator (t-PA) antigen were significantly higher in the BP patients with active disease than in healthy controls (P = 0·0001 for all), as were the plasma levels of the fibrin fragment d-dimer and prothrombin fragment F1+2 (P = 0·0001 for both). During remission after treatment, levels of PAI-1 antigen and PAI-1 activity decreased significantly (P = 0·008 and P = 0·006, respectively), and there was also a significant decrease in plasma levels of d-dimer (P = 0·0001) and F1+2 (P = 0·0001). Fibrinolysis is inhibited in patients with active BP, due mainly to an increase in plasma levels of PAI-1. Corticosteroids not only induce the regression of BP lesions, but also reduce the inhibition of fibrinolysis, which may contribute to decreasing thrombotic risk.

Hypereosinophilic syndrome, Churg-Strauss syndrome and parasitic diseases: possible links between eosinophilia and thrombosis

Throughout the past decade, a possible role of eosinophils in blood coagulation and thrombosis has been suggested. We conducted a Pubmed (MEDLINE) search of case and series referring to any kind of thrombotic events described in three conditions characterised by persistent blood eosinophilia, i.e. the hypereosinophilic syndrome (HES), the Churg Strauss syndrome (CSS), and parasitic infestations from 1966 to date. One hundred and ninety-two articles were found regarding thrombotic events in HES and CSS, and 209 cases of thrombosis were extracted. One hundred and seventy- seven articles dealing with parasitic diseases and thrombosis were found, but only 15 manuscripts reporting thrombosis of unknown origin in 22 patients were selected. In HES, arterial thromboses were more frequent than in CSS (p=0.006), representing almost half of the cases (45%), while venous and mixed artero-venous thrombosis were respectively 28% and 27%. In contrast, in CSS there was a predominance of venous thrombosis (56%, p=0.006), with arterial thrombosis representing 38% of total thrombotic events, and mixed thrombosis being the least frequent (4%). The higher incidence of arterial thrombosis in HES patients can be explained by the common cardiac involvement (64% of patients). In the 22 patients with parasitoses and thrombosis, 15 had arterial thrombosis (68%) and 7 had venous thrombosis (32 %). Literature analysis shows that there are numerous reports of thrombotic events in patients with eosinophil-related disorders supporting a role for eosinophils in thrombosis. This observation raises the problem of prevention and treatment of thromboembolism particularly in HES and CSS patients.

Serum eotaxin levels in patients with chronic spontaneous urticaria

Eotaxin is a potent agonist for CC chemokine receptor 3 that can attract eosinophils at sites of inflammation. Given the potential role of eosinophils in chronic spontaneous urticaria (CU), we measured serum eotaxin levels together with C-reactive protein in 100 CU patients who were characterized according to autologous serum skin test (ASST) and disease severity. Serum eotaxin concentration was significantly higher in CU patients (median 140.1 pg/ml, range 33.7-718.7 pg/ml) than in 45 healthy controls (median 108.9 pg/ml, range 45.5-409.4 pg/ml) (p = 0.032) Serum eotaxin concentration was not significantly different in ASST-positive and ASST-negative patients as well as in patients with different urticaria activity scores. However, eotaxin levels tended to be higher in patients with intense symptoms. In the 7 patients observed during CU exacerbation and during remission, eotaxin serum levels tended to decrease during remission, although statistical significance was not reached (median concentration decreased from 170.0 pg/ml to 123.8 pg/ml). CRP levels were not significantly different in CU patients and healthy subjects, although there was a trend towards higher levels in the former population. Furthermore, in the 7 patients observed during CU exacerbation and during remission, CRP levels decreased significantly during remission (median concentration dropped from 4.1 microg/ml to 0.7 microg/ml, p = 0.015). No significant correlation was found between eotaxin and CRP serum levels. These findings indicate that serum eotaxin levels are increased in CU patients, although they do not reflect strictly disease activity. A role for eotaxin in eosinophil attraction and activation in CU can be envisaged.