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.

Impact of dupilumab on patch test results and allergic contact dermatitis: A prospective multicenter study.

BACKGROUND: Limited and conflicting data have been reported on the impact of dupilumab (DUPI) on patch test (PT) results and its efficacy against allergic contact dermatitis (ACD). OBJECTIVE: This study was undertaken to analyze PT reactivities and relevance during treatment with DUPI to determine whether they could detect ACD in patients with uncontrolled or worsened atopic dermatitis (AD) who were receiving this agent. METHODS: This prospective, multicenter study examined 76 DUPI-treated patients who had undergone PTs. The relevant information was collected during 3 visits. RESULTS: Overall, 36 patients (47%) had ≥1 positive PT reaction, and 142 PT results were positive. Twenty-three patients (30%) had ≥1 positive and clinically relevant PT result. Five of them had clinical eczema improvement after allergen avoidance. We compared the PT results of 36 patients before and during DUPI therapy, representing 1230 paired PT allergens, of which 1022 were the same, 34 were positive, 44 were lost, and 130 were uninterpretable. LIMITATIONS: Because the number of patients included remains limited, our findings should be confirmed with a larger sample. CONCLUSION: Our results confirmed the usefulness of PTs for patients receiving DUPI, with good PT reproducibility. We suggest that all DUPI-treated patients with AD developing partial responses or experiencing symptom worsening should undergo PTs to look for contact sensitization.

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%.

Assessing delayed penicillin hypersensitivity using the PENFAST+ score.

Introduction: Approximately 10% of individuals report a suspected allergy to penicillin, but according to allergy work-ups, only 10%-15% of them are truly allergic. A clinical decision score, the PEN-FAST, was developed and validated to identify adults with low-risk penicillin allergy. Objectives: The objective of this study was to improve the performance of the PEN-FAST score, particularly for those with delayed hypersensitivity (HS), by improving the negative predictive value. Methods: STEP 1: Retrospective evaluation of the PEN-FAST score in patients with proven immediate and delayed penicillin allergy. STEP 2: Identification of additional criteria among Step 1 patients misclassified by PEN-FAST score. Development of the PEN-FAST+ score using multivariable logistic regression in a prospective cohort of patients with a suspicion of HS to penicillin. STEP 3: Comparison of diagnostic performances of PEN-FAST and PEN-FAST+ scores. Results: The PEN-FAST score showed limitations in predicting the relapse of immediate skin HS or delayed maculopapular exanthema, with 28.6% and 38.4% of patients misclassified, respectively. We identified two potential additional criteria: skin rash lasting more than 7 days and immediate reaction occurring in less than 1 h (generalized or localized on palmoplantar area or scalp itching/heat feeling). A total of 32/252 (12.7%) patients were confirmed to be allergic to penicillin. With PEN-FAST, 37% of patients (n = 10) with delayed allergic penicillin HS were misclassified. With PEN-FAST+, 3 patients with delayed HS confirmed by a ST (11.1%) were misclassified. The AUC was significantly higher for PEN-FAST+ than PEN-FAST (85% vs. 72%, p = 0.03).

Over diagnosis of bradykinin angioedema in patients treated with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers.

Background: Bradykinin angioedemas are a potentially serious side effect of angiotensin-converting enzyme inhibitors (ACEI) and more controversially of angiotensin II receptor blockers (ARB). Their challenging diagnosis is based on the absence of any recurrence after more than 6 months of drug discontinuation; otherwise mast-cell driven angioedemas as a differential diagnosis must be considered. Objective: The aim of this study was to determine the prevalence of recurrent angioedema in patients referred for ACEI/ARB-induced bradykinin angioedema, after more than 6 months of drug discontinuation. Methods: We included ACEI/ARB-treated patients referred for angioedema(s) without hives and unresponsive to antihistamines, after they discontinued ACEI/ARB for at least 6 months. Any C1-inhibitor deficiency was excluded. The primary endpoint was the prevalence of patients with recurrent angioedema after more than 6 months of drug discontinuation and/or developing hives during follow-up. The secondary endpoint was the identification of epidemiological factors associated with any final diagnosis. Results: Thirty-eight of 93 patients (41%) with a suspicion of ACEI/ARB-induced bradykinin angioedema still had recurrent angioedema (n = 27) or developed hives (n = 2) or both (n = 9) after 6 months of drug discontinuation. Good response to icatibant and facial but not oral localization were predictive for the final diagnosis of ACEI/ARB-induced bradykinin angioedema and mast-cell driven angioedema, respectively. Conclusion: In patients referred for acquired angioedema without wheals occurring during ACEI/ARB therapy, 59% finally had a diagnosis of ACEI/ARB-induced bradykinin angioedema whereas 41% were rather diagnosed with mast-cell driven angioedema. The overdiagnosis of ACEI/ARB-induced bradykinin angioedema may deteriorate the management of severe cardiovascular conditions.

Omalizumab Drug Survival in Chronic Urticaria: A Retrospective Multicentric French Study.

BACKGROUND: Omalizumab (OMA) dramatically improves disease control and quality of life in patients with chronic urticaria (CU). OBJECTIVE: We aimed to evaluate the discontinuation patterns of OMA and their determinants in a cohort of French patients with CU. METHODS: We conducted a retrospective multicenter study in 9 French tertiary referral hospitals. All patients diagnosed with either spontaneous (CSU) and/or inducible (CIndU) CU who received at least 1 injection of OMA between 2009 and 2021 were included. We analyzed OMA drug survival and investigated possible determinants using Kaplan-Meier curves and log-rank tests. RESULTS: A total of 878 patients were included in this study; 48.8% had CSU, 10.1% CIndU, and 41.1% a combination of both. OMA was discontinued in 408 patients, but the drug was later reintroduced in 50% of them. The main reason for discontinuing treatment was the achievement of a well-controlled disease in 50% of patients. Half of the patients were still being treated with OMA 2.4 years after the initiation of treatment. Drug survival was shorter in patients with CIndU and in those with an autoimmune background. In atopic patients, OMA was discontinued earlier in patients achieving a well-controlled disease. A longer OMA drug survival was observed in patients with a longer disease duration at initiation. CONCLUSION: In French patients with CU, the drug survival of OMA appears to be longer than that observed in previous studies conducted elsewhere, highlighting discrepancies in prescription and reimbursement possibilities. Further studies are warranted to develop customized OMA treatment schemes based on individual patterns.

Allergic contact dermatitis from essential oil in consumer products: Mode of uses and value of patch tests with an essential oil series. Results of a French study of the DAG (Dermato-Allergology group of the French Society of Dermatology).

OBJECTIVE: To analyse the clinical characteristics and sensitivity of an essential oil patch test series (EOS) in patients sensitized to their own essential oils (EOs). METHOD: We analysed the clinical data and patch test results obtained with the European baseline series (BSE) and an EOS, as well as the mode of use of EOs, through a questionnaire included in the patient file. RESULTS: The study included 42 patients (79% women, average age 50 years) with allergic contact dermatitis (ACD), 8 patients required hospitalization. All patients were sensitized to the EO they used, primarily lavender (Lavandula augustifolia, 8000-28-0), tea tree (Melaleuca alternifolia leaf oil, 68647-73-4), ravintsara (Cinnamomum camphora oil, 92201-50-8), and 2 cases were attributed to helichrysum (helichrysum italicum flower absolute, 90045-56-0). 71% had positive patch tests to fragrance mix I or II, 9 only to the EOS and 4 only with their personal EO. Interestingly, 40% of patients did not spontaneously mention the use of EOs, and only 33% received advice on their use at the time of purchase. CONCLUSION: Patch tests with the BSE, limonene and linalool HP, and oxidized tea tree oil is sufficient to detect most EO-sensitized patients. The most important is to test the patient's own used EOs.

Successful treatment of JAK1-associated inflammatory disease.

BACKGROUND: Gain-of-function variants of JAK1 drive a rare immune dysregulation syndrome associated with atopic dermatitis, allergy, and eosinophilia. OBJECTIVES: This study sought to describe the clinical and immunological characteristics associated with a new gain-of-function variant of JAK1 and report the therapeutic efficacy of Janus kinase (JAK) inhibition. METHODS: The investigators identified a family affected by JAK1-associated autoinflammatory disease and performed clinical assessment and immunological monitoring on 9 patients. JAK1 signaling was studied by flow and mass cytometry in patients' cells at basal state or after immune stimulation. A molecular disease signature in the blood was studied at the transcriptomic level. Patients were treated with 1 of 2 JAK inhibitors: either baricitinib or upadacitinib. Clinical, cellular, and molecular response were evaluated over a 2-year period. RESULTS: Affected individuals displayed a syndromic disease with prominent allergy including atopic dermatitis, ichthyosis, arthralgia, chronic diarrhea, disseminated calcifying fibrous tumors, and elevated whole blood histamine levels. A variant of JAK1 localized in the pseudokinase domain was identified in all 9 affected, tested patients. Hyper-phosphorylation of STAT3 was found in 5 of 6 patients tested. Treatment of patients' cells with baricitinib controlled most of the atypical hyper-phosphorylation of STAT3. Administration of baricitinib to patients led to rapid improvement of the disease in all adults and was associated with reduction of systemic inflammation. CONCLUSIONS: Patients with this new JAK1 gain-of-function pathogenic variant displayed very high levels of blood histamine and showed a variable combination of atopy with articular and gastrointestinal manifestations as well as calcifying fibrous tumors. The disease, which appears to be linked to STAT3 hyperactivation, was well controlled under treatment by JAK inhibitors in adult patients.

The immunological effects of intradermal particle-based vaccine delivery using a novel microinjection needle studied in a human skin explant model.

For intradermal (ID) immunisation, novel needle-based delivery systems have been proposed as a better alternative to the Mantoux method. However, the penetration depth of needles in the human skin and its effect on immune cells residing in the different layers of the skin has not been analyzed. A novel and user-friendly silicon microinjection needle (Bella-muTM) has been developed, which allows for a perpendicular injection due to its short needle length (1.4-1.8 mm) and ultrashort bevel. We aimed to characterize the performance of this microinjection needle in the context of the delivery of a particle-based outer membrane vesicle (OMV) vaccine using an ex vivo human skin explant model. We compared the needles of 1.4 and 1.8 mm with the conventional Mantoux method to investigate the depth of vaccine injection and the capacity of the skin antigen-presenting cell (APC) to phagocytose the OMVs. The 1.4 mm needle deposited the antigen closer to the epidermis than the 1.8 mm needle or the Mantoux method. Consequently, activation of epidermal Langerhans cells was significantly higher as determined by dendrite shortening. We found that five different subsets of dermal APCs are able to phagocytose the OMV vaccine, irrespective of the device or injection method. ID delivery using the 1.4 mm needle of a OMV-based vaccine allowed epidermal and dermal APC targeting, with superior activation of Langerhans cells. This study indicates that the use of a microinjection needle improves the delivery of vaccines in the human skin.

Multicenter prospective observational study of dupilumab-induced ocular events in atopic dermatitis patients.

BACKGROUND: Although ocular adverse events are frequent in AD patients treated with dupilumab, their characterization remains limited due to a lack of prospective studies with a systematic ophthalmological examination. OBJECTIVE: To examine the incidence, characteristics and risk factors of dupilumab-induced ocular adverse events. METHODS: A prospective, multicenter, and real-life study in adult AD patients treated with dupilumab. RESULTS: At baseline, 27 out of 181 patients (14.9%) had conjunctivitis. At week 16 (W16), 25 out of 27 had improved their conjunctivitis and 2 remained stable and 34 out of 181 patients (18.7%) had dupilumab-induced blepharoconjunctivitis: either de novo (n = 32) or worsening of underlying blepharoconjunctivitis (n = 2). Most events (27/34; 79.4%) were moderate. A multivariate analysis showed that head and neck AD (OR = 7.254; 95%CI [1.938-30.07]; p = 0.004), erythroderma (OR = 5.635; 95%CI [1.635-21.50]; p = 0.007) and the presence of dry eye syndrome at baseline (OR = 3.51; 95%CI [3.158-13.90]; p = 0.031) were independent factors associated with dupilumab-induced blepharoconjunctivitis. LIMITATIONS: Our follow-up period was 16 weeks and some late-onset time effects may still occur. CONCLUSION: This study showed that most dupilumab-induced blepharoconjunctivitis cases are de novo. AD severity and conjunctivitis at baseline were not found to be associated risk factors in this study.