Similarities and differences in autoinflammatory diseases with urticarial rash, cryopyrin-associated periodic syndrome and Schnitzler syndrome.

Cryopyrin-associated periodic syndromes (CAPS) and Schnitzler syndrome (SchS) are autoinflammatory diseases that present with urticaria-like rashes. CAPS is characterized by periodic or persistent systemic inflammation caused by the dysfunction of the NLRP3 gene. With the advent of IL-1-targeted therapies, the prognosis of CAPS has improved remarkably. SchS is considered an acquired form of autoinflammatory syndrome. Patients with SchS are adults of relatively older age. The pathogenesis of SchS remains unknown and is not associated with the NLRP3 gene. Previously, the p.L265P mutation in the MYD88 gene, which is frequently detected in Waldenström macroglobulinemia (WM) with IgM gammopathy, was identified in several cases of SchS. However, because persistent fever and fatigue are symptoms of WM that require therapeutic intervention, it is a challenge to determine whether these patients truly had SchS or whether advanced WM was misidentified as SchS. There are no established treatments for SchS. The treatment algorithm proposed with the diagnostic criteria is to use colchicine as first-line treatment, and systemic administration of steroids is not recommended due to concerns about side effects. In difficult-to-treat cases, treatment targeting IL-1 is recommended. If targeted IL-1 treatment does not improve symptoms, the diagnosis should be reconsidered. We hope that the efficacy of IL-1 therapy in clinical practice will serve as a stepping stone to elucidate the pathogenesis of SchS, focusing on its similarities and differences from CAPS.

Schnitzler Syndrome: the paradigm of an acquired adult-onset auto-inflammatory disease.

Schnitzler Syndrome is a rare acquired auto-inflammatory syndrome defined by an urticarial eruption and a monoclonal gammopathy, mainly of the IgM kappa isotype. It shares many clinical and biological features with other autoinflammatory disorders such as NLRP3-auto-inflammatory disorders (NLRP3-AID, formerly cryopyrin associated periodic syndromes or CAPS) or adult-onset Still disease (AOSD). Hence, recurrent fever, urticarial rash with a neutrophilic infiltrate on skin biopsy (i.e. neutrophilic urticarial dermatosis or NUD) and a significant elevation of blood inflammation markers are commonly found in Schnitzler Syndrome as well as in NLRP3-AID or AOSD. IL-1ß plays a crucial role in the pathogenesis and explains the clinical symptoms of Schnitzler Syndrome. This is emphasized by the spectacular effectiveness of IL-1 blocking therapies, especially anakinra. IL-1 blocking therapies are efficient on the inflammation-linked symptoms but not on the monoclonal component. The evolution is chronic and about 15-20% of patients may develop lymphoproliferative disease, in particular Waldenström disease, a proportion similar to patients with IgM monoclonal gammopathy of undetermined significance, and more rarely AA-amyloidosis.

Incomplete Schnitzler Syndrome.

Schnitzler syndrome (SS) is a rare autoinflammatory disease that presents with chronic urticaria and monoclonal immunoglobulin (Ig) M or G, accompanied by fever, abnormal bone remodeling, skin biopsy with a neutrophilic dermal infiltrate, leukocytosis, or elevated C-reactive protein. It is usually refractory to antihistamines and immunosuppression. We present a case report of clinical SS without monoclonal Ig with robust response to interleukin-1 inhibitor anakinra. This suggests the possible existence of an incomplete form of SS and underlines the risk of false negative diagnosis in individuals with such "incomplete SS".

Hereditary systemic autoinflammatory diseases and Schnitzler's syndrome.

The systemic autoinflammatory diseases are disorders of the innate immune system distinguished by severe inflammation resulting from dysregulation of the innate immune system. Hereditary fever syndromes, such as FMF, TNF receptor-associated periodic syndrome, cryopyrin-associated periodic syndromes and mevalonate kinase deficiency, were the first group of systemic autoinflammatory diseases for which a genetic basis was established, between 1999 and 2001. Currently according to the latest report of the international union of immunological societies, 37 separate monogenic disorders were classified as autoinflammatory. In addition to the abovementioned monogenic conditions, we describe Schnitzler's syndrome, a well-defined, acquired autoinflammatory condition without a clear genetic basis. For the purposes of this review, we discuss several conditions defined by the latest consensus process as systemic autoinflammatory diseases. We focus on those disorders where recent studies have contributed to further phenotypic characterization or had an impact on clinical management.

Schnitzler Syndrome With Delirium and Vertigo: The Utility of Neurologic Manifestations in Diagnosis.

Schnitzler syndrome (SS) is an autoinflammatory dermatosis that often goes undiagnosed for 5-6 years. Patients typically carry a diagnosis of urticaria; however, their cutaneous symptoms fail to respond to typical urticaria therapies and lack symptoms such as pruritus. Additionally, patients with SS may see multiple providers for nonspecific complaints of fever, lymphadenopathy, arthralgias, and bone pain. A correct diagnosis is paramount, as close to 20% of patients may develop a lymphoproliferative disorder and appropriate treatment may ameliorate all symptoms.1 We report 2 cases of SS misdiagnosed as urticaria for years in order to illuminate diagnostic pearls, histopathological findings, and treatment modalities. Additionally, we highlight the importance of neurologic disturbances in this rare but important differential diagnosis of urticaria.

J Drugs Dermatol. 2017;16(6):625-627.

The inflammasomes in autoinflammatory diseases with skin involvement.

During the past years, significant progress in the understanding of the complexity, regulation, and relevance of innate immune responses underlying several inflammatory conditions with neutrophilic skin involvement has been made. These diseases belong to the novel class of autoinflammatory diseases, and several are caused by mutations in genes regulating the function of innate immune complexes, termed inflammasomes, leading to enhanced secretion of the proinflammatory cytokine IL-1ß. Consequently, targeting of IL-1ß has proven successful in the treatment of these diseases, and the identification of related pathogenic mechanisms in other more common skin diseases characterized by autoinflammation and neutrophilic tissue damage also provides extended opportunities for therapy by interfering with IL-1 signaling.

Urticarial vasculitis and Schnitzler syndrome.

Both urticarial vasculitis and Schnitzler syndrome are serious diseases but a recently gained better understanding of their underlying pathomechanism allows better treatment options than only a decade ago.

[Schnitzler syndrome]. / Schnitzler-Syndrom.

Schnitzler syndrome is a rare systemic inflammatory disease characterized by the presence of chronic urticarial skin rash and a monoclonal immunoglobulin M (IgM) gammopathy, combined with further, variable disease symptoms. The term refers to a young disease entity which has recently gained increasing acknowledgement and attention, also due to the availability of interleukin-1 (IL-1) blockade as an effective therapeutic option. Insights into the pathophysiology of the disease have resulted in the assumption of Schnitzler syndrome being a special form of an autoinflammatory disease with late onset or an acquired genesis. This article provides an overview on the clinical appearance, current knowledge of pathophysiology and available therapeutic options.

[Schnitzler syndrome: diagnostics and treatment]. / Schnitzler-syndrom: diagnostika a lécba.

BACKGROUNDS: The most important diagnostic criteria for Schnitzler syndrome include chronic urticaria, the presence of monoclonal IgM immunoglobulin, marked inflammation (leukocytosis, elevated CRP and erythrocyte sedimentation rate), subfebrile temperatures or fevers and bone and joint pains. It is a rare idiopathic disease that may lead to potentially life-threatening complications such as development of secondary amyloidosis or transformation into malignant lymphoproliferation. Schnitzler syndrome should be included in differential diagnostics of chronic urticaria and fevers of unknown origin. The diagnostic algorithm is based on clinical presentation and serum and urine electrophoreses to detect monoclonal components. Blockade of interleukin-1 (IL-1), key cytokine in the pathogenesis of the disease, dominates current therapeutic protocols. Anakinra (Kineret), recombinant human IL-1 receptor antagonist, is the most widely used treatment option. According to literature, disease remission was obtained in all treated patients. Therefore, anakinra represents a significant diagnostic possibility to differentiate Schnitzler syndrome from e.g. monoclonal gammopathy of unknown significance (MGUS) associated with urticaria of different aetiology. Biological therapy with rilonacept (Arcalyst) and canakinumab (Ilaris) represents a new treatment alternative for patients, allowing prolonged dosing intervals of 1 and 8 weeks, respectively (compared to 24 hours with anakinra). The review article also presents findings of various imaging methods (conventional radiography, computed tomography, traditional bone scintigraphy) and photographs of patients with Schnitzler syndrome before and after anakinra therapy. DESIGN: The aim of the review is to draw attention to the existence of this rare autoinflammatory and potentially premalignant condition, present a simple diagnostic algorithm and provide an overview of therapeutic options for the patients. CONCLUSIONS: Malign potential of Schnitzler syndrome, possible development into systemic amyloidosis and the fact that patients are frequently referred to oncology clinics for differential diagnostics of monoclonal gammopathy, are the main reasons why clinical oncologists should be aware of Schnitzler syndrome.

Dramatic response to IL1-RA treatment in longstanding multidrug resistant Schnitzler's syndrome: a case report and literature review.

We report a case of longstanding multidrug resistant Schnitzler's syndrome that finally went into clinical remission upon treatment with anakinra and review the literature concerning IL1-RA treatment for Schnitzler's syndrome. A now 71-year-old patient presenting with recurring episodes of urticaria and fever and secondary weight loss for the past 16 years as well as arthralgia, hearing loss. The patient has anemia, leucocytosis with neutrophilia, thrombocytosis, elevated C-reactive protein and erythrocyte sedimentation rate, lymphadenopathy and a monoclonal IgM kappa band that later became oligoclonal with two IgM kappa bands and one IgM lambda band. The patient was treated with moderate effect with combination of prednisolone, azathioprine, and colchicine. In March 2009, anakinra 100 mg daily sc was added during a disease flare. Within 24 h after the first injection, both the urticaria and the fever disappeared and have not recurred. For the past 6 months, the patient has been in clinical and biochemical remission. Colchicine has been stopped while the azathioprine and prednisolone doses are being reduced. Twenty-four patients with Schnitzler's syndrome, including three patients with a variant of Schnitzler's syndrome and three patients with a Schnitzler-like syndrome, have been successfully treated with anakinra. Nevertheless, seven out of seven patients, that either interrupted or used anakinra every other day, had relapse of their symptoms within 24-48 h; anakinra was restarted in all patients with the same clinical efficiency. The current case history and the literature review already suggest an important role for IL-1 as a mediator in the pathophysiology of Schnitzler's syndrome.

[Adult-onset Still's disease, Schnitzler syndrome, and autoinflammatory syndromes in adulthood]. / Adulter Morbus Still, Schnitzler-Syndrom und autoinflammatorische Syndrome im Erwachsenenalter.

Adult-onset Still's disease (AoSD), Schnitzler syndrome, and cases of adult-onset autoinflammatory syndromes [10-15% of cases of familial Mediterranean fever (FMF) and tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS)] are characterized by a genetic predisposition, with increased interleukin (IL)-1beta and IL-18 production and TNF-alpha signaling, respectively. As a result, periodic fever and inflammation at barrier tissues (synovial tissues, serous membranes, and the skin) are encountered in such patients. Pathophysiological insights into these diseases have renewed interest in research on IL-1beta in rheumatic diseases and have opened new therapeutic avenues. Recently published studies have shown that patients with Schnitzler syndrome, methotrexate-refractory AoSD, and colchicine-refractory FMF or contraindications to colchicines in FMF respond well to treatment with the soluble IL-1 receptor antagonist anakinra. For TRAPS patients, the p75 TNF-alpha receptor/Fc-IgG1 fusion protein etanercept is the treatment of first choice.

The Schnitzler syndrome: chronic urticaria and monoclonal gammopathy--an autoinflammatory syndrome?

Schnitzler syndrome describes the simultaneous occurrence of monoclonal gammopathy and chronic urticaria with at least two additional minor symptoms (arthralgia, bone pain, fever of uncertain origin, hepato- or splenomegaly, lymphadenopathy, increased erythrocyte sedimentation rate, leukocytosis/thrombocytosis or increased bone density). Schnitzler syndrome is not wellknown and very likely under-recognized. Comprehensive diagnostic examinations are necessary to rule out other diseases, especially those of hematologic origin. Close interdisciplinary collaboration is mandatory. The etiology of Schnitzler syndrome is unclear, but the rapid response to the interleukin-1 receptor inhibitor anakinra underlines the pivotal role which the proinflammatory cytokine interleukin-1 may play in the pathophysiology of this potentially autoinflammatory disorder.

[Schnitzler syndrome--report on a fourteen-year course of the disease and an overview of information on the disease]. / Schnitzleruv syndrom--popis ctrnáctiletého prubehu nemoci a prehled informací o této nemoci.

Schnitzler syndrome is a rare disease characterised by chronic urticaria and the presence of monoclonal IgM immunoglobulin, and by other symptoms. We report ourexperience with 14-year treatment of a patient. The first medical examination in our workplace was at the beginning of 1995 and the patient was diagnosed with the disease in 1996 (at the age of 52). Antihistaminics, the first medication used to relieve the symptoms of urticaria, had no subjective or objective effect. After the detection of osteolytic-osteosclerotic changes in the pelvic region, in areas with intense pain, we started treatment with pamidronate (90 mg at 28-day intervals), and the pain disappeared completely within 3 months of application of the drug. When the bisphosphonate therapy was interrupted, the pain recurred and receded completely after renewal of bisphosphonate administration. After the diagnosis, we gave the patient high doses of dexametazone (40 mg day 1-4, 10-13 and 20-23, at 28-day cycles). However, the therapy suppressed urticaria only on the days dexametasone was administered and the effect did not last when the drug was discontinued. Therefore we moved to continuous daily doses of prednisone (10-30 mg, depending on the intensity of problems), which was the only therapy with a long-term effect which was relatively well tolerated at the same time. Based on the excellent effect of 2-chlordeoxyadenosine in Waldenström's macroglobulinaemia, three cycles of this therapy were administered to the patient in 1996 (0.1 mg/kg/day, 7 days, at 28-day intervals). After the first infusion, urticarious lesions disappeared, but the positive effect on skin eruptions was limited in time and lasted only 14 days after the last infusion, i.e. the medication proved ineffective from a long-term point of view. The first improvement lasting for a longer period of time (partial remission) was achieved by regular application of interferon alpha (3 QU 3 times a week). However, adverse effects of interferon alpha prevailed after two years and the therapy was discontinued. Similarly phototherapy using the PUVA method resulted in partial regression of urticarious symptoms. Subsequently tested cyclosporine A (5 mg/kg/day) brought no benefit. Thalidomide (100 mg in the evening) administered on a continuous basis relieved pruritus and improved sleep disturbed by pruritus. However, adverse effects prevailed after 4 months and the therapy had to be discontinued, too. In 2005, we were hoping to achieve positive results with the most effective treatment for multiple myeloma of the time, a combination of bortezomib (1.3 mg/m2 i.v. on day 1, 4, 8 and 11, thalidomide 100 mg daily and dexametazon 20 mg p.o. on days 1-4 and 8-11 in 21-day cycles --VTD). A total of 4 complete cycles and 4 cycles with bortezomib reduced by 50% were applied. Urticarious eruptions were reduced by at least 50% in the course of the therapy, and also the concentration of monoclonal immunoglobin decreased temporarily by more than 50%. However, after the therapy was discontinued, the symptoms returned with their original intensity, which means that VTD regime did not provide a long-term therapeutic response. In 2007, we started the anakinra (Kineret) therapy. Skin symptoms disappeared after the first injection and a dose of 100 mg/ day has kept the patient free of skin symptoms for 12 months by now. Also the CRP value which had been constantly high returned to normal, and haemoglobin values increased to achieve physiological range. In the course of 14 years, we confirmed partial therapeutic effect of glucocorticoids administered on a continuous basis, as well as a partial therapeutic effect of interferon alpha, thalidomide and PUVA, but all the therapies had to be discontinued due to adverse effects. A major turn, i.e. the complete disappearance of skin symptoms and normalisation of CRP and haemoglobin values, only came with anakinra which has become the drug of the first choice for the above syndrome.

Schnitzler syndrome: beyond the case reports: review and follow-up of 94 patients with an emphasis on prognosis and treatment.

OBJECTIVE: Schnitzler syndrome is a rare disorder characterized by a chronic urticarial rash and monoclonal gammopathy, accompanied by intermittent fever, arthralgia or arthritis, bone pain, and lymphadenopathy. Our objectives are to systematically review disease characteristics of Schnitzler syndrome and collect follow-up information to gain insight into treatment efficacy and long-term prognosis. METHODS: PubMed and MEDLINE databases (1966-2006) were searched, using the key words "Schnitzler syndrome," and the combination of "urticaria" with "monoclonal gammopathy," "immunoglobulin M (IgM)," or "paraproteinemia," as well as secondary references. Data on a total of 94 patients who met the criteria for Schnitzler syndrome were reviewed. Questionnaires sent to all authors retrieved additional follow-up data on 43 patients, resulting in a mean follow-up of 9.5 years after onset of symptoms, and a follow-up of 20 years or more in 10 patients. RESULTS: Symptoms, signs, and laboratory findings as found in the 94 patients are reviewed in detail. There have been promising developments in therapeutic options, especially antiinterleukin-1 treatment, which induced complete remission in all 8 patients treated so far. To date, no spontaneous complete remissions have been reported. Patients with Schnitzler syndrome showed no increased mortality during the present follow-up. However, they had a 10-year risk of 15% of developing a lymphoproliferative disorder, most notably Waldenström's macroglobulinemia. Three cases of type amyloid A (AA) amyloidosis associated with Schnitzler syndrome were reported. CONCLUSIONS: Schnitzler syndrome is a disabling disorder which affects multiple systems and which can be considered as an autoinflammatory syndrome. There are new, effective treatment options, but close monitoring remains warranted because of the increased risk of lymphoproliferative disease.

The Schnitzler syndrome. Four new cases and review of the literature.

The Schnitzler syndrome is characterized by a chronic urticarial eruption with a monoclonal IgM gammopathy. The other signs of the syndrome include intermittent elevated fever, joint and/or bone pain with radiologic evidence of osteosclerosis, palpable lymph nodes, enlarged liver and/or spleen, elevated erythrocyte sedimentation rate, and leukocytosis. The mean delay to diagnosis is more than 5 years, and this syndrome is of concern to internists and many medical specialists. Patients with this syndrome are often initially considered to have lymphoma or adult-onset Still disease, which are the main differential diagnoses. However, hypocomplementic urticarial vasculitis, systemic lupus erythematosus, cryoglobulinemia, acquired C1 inhibitor deficiency, hyper IgD syndrome, chronic infantile neurologic cutaneous and articular (CINCA) syndrome, and Muckle-Wells syndrome should also be excluded, because diagnosis relies on a combination of clinical and biologic signs and there is no specific marker of the disease. The disease pursues a chronic course, and no remissions have yet been reported. Disabling skin rash, fever, and musculoskeletal involvement are the most frequent complications. Severe anemia of chronic disease is another serious complication. The most harmful complication, however, is evolution to an authentic lymphoplasmacytic malignancy, which occurs in at least 15% of patients. This hematologic transformation can occur more than 20 years after the first signs of the disease, thus patients deserve long-term follow-up. Treatment is symptomatic and unsatisfactory. The skin rash is unresponsive to treatment, and nonsteroidal antiinflammatory drugs, antihistamines, dapsone, colchicine, and psoralens and ultraviolet A (PUVA) therapy give inconstant results. Fever, arthralgia, and bone pain often respond to nonsteroidal antiinflammatory drugs. In some patients, these symptoms and/or the presence of severe inflammatory anemia require steroids and/or immunosuppressive treatment, which ameliorate inflammatory symptoms but do not change the course of the skin rash.

Schnitzler's syndrome: no evidence for autoimmune basis in two patients.

We report two cases of Schnitzler's syndrome in which anti-interleukin-1alpha autoantibodies and functional autoantibodies against the high affinity IgE receptor (FcepsilonRIalpha) or against IgE were absent. One patient responded well to TL-01 phototherapy, a treatment which may be considered in patients with Schnitzler's syndrome if, as is usually the case, they are unresponsive to antihistamine therapy.