Histological characterization of liver involvement in systemic mastocytosis.

BACKGROUND AND AIMS: Systemic mastocytosis (SM) is characterized by the accumulation of atypical mast cells (MCs) in organs. Liver histology of SM has been marginally described and accurate histological classification is critical, given the consequences of aggressive SM diagnosis. We aimed to describe the histological features associated with liver SM using updated tools. METHODS: Using the database of the French Reference Centre for Mastocytosis, we retrospectively identified patients with a liver biopsy (LB) and a diagnosis of SM. All LB procedures were performed according to the local physician in charge and centrally reviewed by an expert pathologist. RESULTS: A total of 28 patients were included: 6 had indolent SM, 9 had aggressive SM, and 13 had SM with an associated hematologic neoplasm. Twenty-five (89%) patients presented hepatomegaly, and 19 (68%) had portal hypertension. The LB frequently showed slight sinusoid dilatation (82%). Fibrosis was observed in 3/6 indolent SM and in almost all advanced SM cases (21/22), but none of them showed cirrhosis. A high MC burden (>50 MCs/high-power field) was correlated with elevated blood alkaline phosphatase levels (p = .030). The presence of portal hypertension was associated with a higher mean fibrosis grade (1.6 vs. 0.8 in its absence; p = .026). In advanced SM, the presence of nodular regenerative hyperplasia (NRH) was associated with decreased overall survival (9.5 vs. 46.3 months, p = .002). CONCLUSIONS: MC infiltration induced polymorphic hepatic lesions and the degree of fibrosis is associated with portal hypertension. NRH identifies a poor prognosis subgroup of patients with advanced SM. Assessing liver histology can aid in SM prognostic evaluation.

Pathophysiologic implications of elevated prevalence of hereditary alpha-tryptasemia in all mastocytosis subtypes.

BACKGROUND: Mastocytosis and monoclonal mast cell (MC) activation syndrome (MMAS) are heterogeneous conditions characterized by the accumulation of atypical MCs. Despite the recurrent involvement of KIT mutations, the pathophysiologic origin of mastocytosis and MMAS is unclear. Although hereditary α-tryptasemia (HαT, related to TPSAB1 gene duplication) is abnormally frequent in these diseases, it is not known whether the association is coincidental or causal. OBJECTIVE: We evaluated the prevalence of HαT in all mastocytosis subtypes and MMAS and assessed the pathophysiologic association with HαT. METHODS: Clinical data, laboratory data, KIT mutations, TPSAB1 duplication (assessed by droplet digital PCR), and HαT prevalence were retrospectively recorded for all patients with mastocytosis and MMAS registered in the French national referral center database and compared to a control cohort. To increase the power of our analysis for advanced systemic mastocytosis (advSM), we pooled our cohort with literature cases. RESULTS: We included 583 patients (27 with MMAS and 556 with mastocytosis). The prevalence of HαT in mastocytosis was 12.6%, significantly higher than in the general population (5.7%, P = .002) and lower than in MMAS (33.3%, P = .02). HαT+ patients were more likely to have anaphylactic reactions and less likely to have cutaneous lesions than HαT- patients (43.0% vs 24.4%, P = .006; 57.7% vs 75.6%, respectively, P = .006). In the pooled analysis, the prevalence of HαT was higher in advSM (11.5%) than in control cohorts (5.2%, P = .01). CONCLUSION: Here we confirm the increase incidence of anaphylaxis in HαT+ mastocytosis patients. The increased prevalence of HαT in all subtypes of systemic mastocytosis (including advSM) is suggestive of pathophysiologic involvement.

Efficacy and Safety of Rituximab-Based Treatments in Angioedema With Acquired C1-Inhibitor Deficiency.

BACKGROUND: Angioedema (AE) due to acquired C1-inhibitor (C1-INH) deficiency (AAE-C1-INH) is related to excessive consumption of C1-INH or to anti-C1-INH antibodies, and is frequently associated with lymphoproliferative syndromes or monoclonal gammopathies. Standard of care for prophylactic treatment in this condition is not established. Rituximab may be effective to prevent attacks, especially if the lymphoid hemopathy is controlled, but data are scarce. OBJECTIVE: To evaluate efficacy of rituximab in AAE-C1-INH. METHODS: A retrospective multicenter study was carried out in France, including patients with AAE-C1-INH treated with rituximab between April 2005 and July 2019. RESULTS: Fifty-five patients with AAE-C1-INH were included in the study, and 23 of them had an anti-C1-INH antibody. A lymphoid malignancy was identified in 39 patients, and a monoclonal gammopathy in 9. There was no associated condition in 7 cases. Thirty patients received rituximab alone or in association with chemotherapy (n = 25). Among 51 patients with available follow-up, 34 patients were in clinical remission and 17 patients had active AE after a median follow-up of 3.9 years (interquartile range, 1.5-7.7). Three patients died. The presence of anti-C1-INH antibodies was associated with a lower probability of AE remission (hazard ratio, 0.29 [95% CI, 0.12-0.67]; P = .004). Relapse was less frequent in patients with lymphoma (risk ratio, 0.27 [95% CI, 0.09-0.80]; P = .019) and in patients treated with rituximab and chemotherapy (risk ratio, 0.31 [95% CI, 0.12-0.79]; P = .014). CONCLUSIONS: Rituximab is an efficient and well-tolerated therapeutic option in AE, especially in lymphoid malignancies and in the absence of detectable anti-C1-INH antibodies.

In Situ Patch Test and Repeated Open Application Test for Fixed Drug Eruption: A Multicenter Study.

BACKGROUND: Few studies have evaluated allergy workup in fixed drug eruption (FDE) in a large population. OBJECTIVE: To evaluate the sensitivity of a standardized allergy workup for diagnosing the cause of FDE, with a focus on in situ repeated open application tests (ROATs). METHODS: In a retrospective multicenter study, we analyzed the practice of conducting a complete allergy workup for the etiological diagnosis of FDE. It consisted of 3 steps: in situ patch tests (PTs) for all cases except pure mucosal involvement, followed by in situ ROAT if in situ PT results were negative, and finally a drug challenge (DC). The in situ ROAT involved daily application of the suspected drug on a previously affected FDE site for 7 days. RESULTS: Of 98 suspected FDE cases, 61 patients (median age 61 y; male-to-female ratio 1.8) with a complete allergy workup were included. In 4 cases, even the DC yielded negative results. Among the remaining 57 patients with a positive workup, implicated drugs included paracetamol (12 cases), ß-lactams (11 cases), imidazoles (9 cases, including 5 with metronidazole), nonsteroidal anti-inflammatory drugs (8 cases), iodinated contrast media (4 cases), cotrimoxazole (3 cases), and various other drugs in 10 patients. The diagnosis was confirmed by in situ PT in 17 of 54 cases (31.5%), in situ ROAT in 14 of 40 cases (35%) (with 4 cases showing remote reactivation of FDE sites), and DC in 26 cases. CONCLUSIONS: The sequential allergy workup involving successively in situ PT, in situ ROAT, and DC is a reliable and safe method for diagnosing the cause of FDE. In situ tests exhibited a sensitivity of over 50%.

Long-term prophylaxis in hereditary angioedema management: Current practices in France and unmet needs.

Background: Hereditary angioedema (HAE) is characterized by unpredictable and potentially life-threatening attacks of cutaneous and submucosal swelling. Over the past decade, new agents, based on a better understanding of the underlying biologic mechanisms of HAE, have changed the face of long-term prophylaxis (LTP). Objective: The objective was to describe current practices and unmet needs with regard to LTP for HAE in expert centers in France. Methods: The study was conducted in France in 2020. Based on their experience with patients with HAE who had visited their center at least once in the past 3 years, physicians from 25 centers who are expert in the management of HAE were requested to fill in a questionnaire that encapsulated their active patient list, criteria for prescribing LTP, and medications used. They were asked about potential unmet needs with currently available therapies. They were asked to express their expectations with regard to the future of HAE management. Results: Analysis was restricted to 20 centers that had an active patient file and agreed to participate. There were 714 patients with C1 inhibitor (C1-INH) deficiency, of whom 423 (59.2%) were treated with LTP. Altered quality of life triggered the decision to start LTP, as did the frequency and severity of attacks. Ongoing LTP included androgens (28.4%), progestins (25.8%), lanadelumab (25.3%), tranexamic acid (14.2%), intravenous C1-INHs (5.6%), and recombinant C1-INH (0.7%). Twenty-nine percent of the patents with LTP were considered to still have unmet needs. Physicians' concerns varied among therapies: poor tolerability for androgens and progestins, a lack of efficacy for tranexamic acid and progestins, dosage form, and high costs for C1-INHs and lanadelumab. Physicians' expectations encompassed more-efficacious and better-tolerated medications, easier treatment administration for the sake of improved quality of life of patients, and less-expensive therapies. Conclusion: Despite the recent enrichment of the therapeutic armamentarium for LTP, physicians still expressed unmet needs with currently available therapies.

COVID-19 as a trigger of acute attacks in people with hereditary angioedema.

Acute attacks could occur during the convalescent phase of COVID-19 illness, more commonly in patients with a history of frequent attacks. However it is unclear whether the acute attacks during the convalescent phase are specifically triggered by COVID-19 or not.

A challenging diagnosis of exercise-related transient abdominal pain.

A 17-year-old woman, high-performance triathlete, presented transient abdominal pain, face angioedema and sometimes syncope during exercise. Exercise-induced anaphylaxis was suspected at first. Allergic explorations with skin prick tests were negative but wheat flour specific IgE and recombinant rTri a14 (LTP) were weakly positive. However, wheat eviction did not improve the symptoms and stress test after wheat oral challenge did not show any signs of anaphylaxis. An abdominal ultrasound revealed peak expiratory velocities with a stenosis evaluated at 70 to 80 percent with turbulences in the celiac artery, confirmed by computed tomography angiogram. The diagnosis of exercise-induced median arcuate ligament syndrome (MALS) was retained and we discuss here the challenging diagnosis mimicking exercise-induced anaphylaxis.

Efficacy and survival of biologic agents in psoriasis: a practical real-life 12-year experience in a French dermatology department.

Background: Drug survival in a real-life setting is critical to long-term use of biologics for psoriasis. Objective: We describe our 12-year experience with biologics in psoriasis patients. Patients and Methods: All patients treated with biologics including infliximab, adalimumab (ADA), etanercept (ETA), and ustekinumab (UST) for psoriasis vulgaris between January 2005 and December 2016 were retrospectively analyzed. Results: In total, 545 treatment series were administered to 269 patients, including 211 treatment series with ADA, 135 with ETA, 77 with infliximab, and 122 with UST. ADA and ETA were initiated most often as first-line therapy; 65.3% of treatment sequences were discontinued. UST had the highest drug survival. The major reason for treatment termination was a loss of efficacy (44.9%). Definitive discontinuation increased with the number of biologic therapy sequences. Limitations: Subjects were not randomized to the different treatments. Conclusions: In a long-term real-life setting, drug survival of UST is better than that of TNF-a inhibitors for both biologic-naive and biologic-experienced patients with psoriasis.

Diagnostic biologique des angioedèmes bradykiniques : les recommandations du CREAK.

Bradykinin mediated angioedema (BK-AE) can be associated either with C1Inhibitor deficiency (hereditary and acquired forms), either with normal C1Inh (hereditary form and drug induced AE as angiotensin converting enzyme inhibitors…). In case of high clinical suspicion of BK-AE, C1Inh exploration must be done at first: C1Inh function and antigenemy as well as C4 concentration. C1Inh deficiency is significant if the tests are below 50 % of the normal values and controlled a second time. In case of C1Inh deficiency, you have to identify hereditary from acquired forms. C1q and anti-C1Inh antibody tests are useful for acquired BK-AE. SERPING1 gene screening must be done if a hereditary angioedema is suspected, even if there is no family context (de novo mutation 15 %). If a hereditary BK-AE with normal C1Inh is suspected, F12 and PLG gene screening is suitable.