ABSTRACT
Programmed cell death 1 (PD-1) is a premier cancer drug target for immune checkpoint blockade (ICB). Because PD-1 receptor inhibition activates tumor-specific T-cell immunity, research has predominantly focused on T-cell-PD-1 expression and its immunobiology. In contrast, cancer cell-intrinsic PD-1 functional regulation is not well understood. Here, we demonstrate induction of PD-1 in melanoma cells via type I interferon receptor (IFNAR) signaling and reversal of ICB efficacy through IFNAR pathway inhibition. Treatment of melanoma cells with IFN-α or IFN-ß triggers IFNAR-mediated Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling, increases chromatin accessibility and resultant STAT1/2 and IFN regulatory factor 9 (IRF9) binding within a PD-1 gene enhancer, and leads to PD-1 induction. IFNAR1 or JAK/STAT inhibition suppresses melanoma-PD-1 expression and disrupts ICB efficacy in preclinical models. Our results uncover type I IFN-dependent regulation of cancer cell-PD-1 and provide mechanistic insight into the potential unintended ICB-neutralizing effects of widely used IFNAR1 and JAK inhibitors.
Subject(s)
Immune Checkpoint Inhibitors , Interferon Type I , Melanoma , Programmed Cell Death 1 Receptor , Receptor, Interferon alpha-beta , Signal Transduction , Programmed Cell Death 1 Receptor/metabolism , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Melanoma/drug therapy , Melanoma/immunology , Melanoma/genetics , Melanoma/metabolism , Humans , Receptor, Interferon alpha-beta/metabolism , Receptor, Interferon alpha-beta/genetics , Immune Checkpoint Inhibitors/pharmacology , Immune Checkpoint Inhibitors/therapeutic use , Signal Transduction/drug effects , Animals , Cell Line, Tumor , Mice , Interferon Type I/metabolism , STAT1 Transcription Factor/metabolism , Interferon-Stimulated Gene Factor 3, gamma Subunit/metabolism , Interferon-Stimulated Gene Factor 3, gamma Subunit/genetics , Interferon-beta/metabolism , Gene Expression Regulation, Neoplastic/drug effects , Janus Kinases/metabolism , Mice, Inbred C57BL , Interferon-alpha/pharmacology , Interferon-alpha/metabolism , FemaleABSTRACT
Darier disease (DD) is a rare severe acantholytic skin disease caused by mutations in the ATP2A2 gene that encodes for the sarco/endoplasmic reticulum calcium ATPase isoform 2 (SERCA2). SERCA2 maintains endoplasmic reticulum calcium homeostasis by pumping calcium into the ER, critical for regulating cellular calcium dynamics and cellular function. To date, there is no treatment that specifically targets the disease mechanisms in DD. Dantrolene sodium (Dl) is a ryanodine receptor antagonist that inhibits calcium release from ER to increase ER calcium levels and is currently used for non-dermatological indications. In this study, we first identified dysregulated genes and molecular pathways in DD patient skin, demonstrating downregulation of cell adhesion and calcium homeostasis pathways, as well as upregulation of ER stress and apoptosis. We then show in various in vitro models of DD and SERCA2 inhibition that Dl aided in the retention of ER calcium and promoted cell adhesion. In addition, Dl treatment reduced ER stress and suppressed apoptosis. Our findings suggest that Dl specifically targets pathogenic mechanisms of DD and may be a potential treatment.
ABSTRACT
Exudates of nonhealing wounds contain drivers of pathogenicity. We utilized >800 exudates from nonhealing and healing wounds of diverse etiologies, collected by 3 different methods, to develop a wound-specific, cell-based functional biomarker assay. Human dermal fibroblast proliferation served as readout to (i) differentiate between healing and nonhealing wounds, (ii) follow the healing process of individual patients, and (iii) assess the effects of therapeutics for chronic wounds ex vivo. We observed a strong correlation between wound chronicity and inhibitory effects of individual exudates on fibroblast proliferation, with good diagnostic sensitivity (76-90%, depending on the sample collection method). Transition of a clinically nonhealing to a healing phenotype restored fibroblast proliferation and extracellular matrix formation while reducing inflammatory cytokine production. Transcriptional analysis of fibroblasts exposed to ex vivo nonhealing wound exudates revealed an induction of inflammatory cytokine and chemokine pathways and the unfolded protein response, indicating that these changes may contribute to the pathology of nonhealing wounds. Testing the wound therapeutics, PDGF and silver sulfadiazine, yielded responses in line with clinical experience and indicates the usefulness of the assay to search for and profile new therapeutics.
ABSTRACT
Introduction: The COVID vaccination program with new types of vaccinations and early reports of allergic reactions to vaccines led to vaccination hesitancy in patients with allergies. In this study, we aimed to characterize patients who present at an allergy center with specific questions regarding risk assessment to COVID vaccines in comparison to regular allergy center patients. Methods: A total of 50 patient charts of patients with risk assessment for COVID vaccination (COV group) and 50 regular allergy center patients (ALL group) were assessed for documented allergies, comorbidities, total IgE, and tryptase levels and hospital anxiety and depression score (HADS). Skin prick testing (SPT) with additives of COVID vaccines [polyethylene glycol (PEG), polysorbate] were performed if indicated based on medical history. Results: Patients who presented for examination prior to a possible COVID vaccination were mostly female (86%) and had more frequently reported allergic reactions to drugs in the past, but only in a minor group (28%) were the reactions qualified as anaphylaxis. The group COV patients scored significantly higher in the HADS for anxiety and depression than the regular group ALL patients. The same trend was observed when data were corrected for gender. It is worth noting that patients without any prior contact to COVID vaccines scored comparable regarding anxiety to patients with prior reaction to COVID vaccinations, but significantly higher in the depression score. In 19 patients (38%) who met the indications for SPT for the suspicious contents PEG and Polysorbate 80, the tests did not show a positive result. Furthermore, 84% of patients underwent the prick test, but only 15% of patients who received consultation alone agreed to vaccination at our center. No vaccination-related event was documented in these patients. Discussion: In conclusion, vaccination hesitancy was frequently elicited by negative experiences with drugs and putative drug allergies. Female patients predominate in this patient group, and the anxiety and depression scores were significantly elevated. Allergological workup, including SPT, led to a high rate of subsequent vaccinations, whereas a discussion with the patients about risks and individualized advice for vaccination without testing only rarely resulted in documented vaccinations.
Subject(s)
COVID-19 Vaccines , COVID-19 , Vaccination Hesitancy , Vaccination , Adult , Aged , Female , Humans , Male , Middle Aged , Anxiety/psychology , COVID-19/prevention & control , COVID-19/psychology , COVID-19 Vaccines/adverse effects , Depression , Hypersensitivity/psychology , Mental Health , Skin Tests , Vaccination/psychology , Vaccination Hesitancy/psychologyABSTRACT
Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer. Inhibitors targeting the programmed cell death 1 (PD-1) immune checkpoint have improved MCC patient outcomes by boosting antitumor T cell immunity. Here, we identify PD-1 as a growth-promoting receptor intrinsic to MCC cells. In human MCC lines and clinical tumors, RT-PCR-based sequencing, immunoblotting, flow cytometry, and immunofluorescence analyses demonstrated PD-1 gene and protein expression by MCC cells. MCC-PD-1 ligation enhanced, and its inhibition or silencing suppressed, in vitro proliferation and in vivo tumor xenograft growth. Consistently, MCC-PD-1 binding to PD-L1 or PD-L2 induced, while antibody-mediated PD-1 blockade inhibited, protumorigenic mTOR signaling, mitochondrial (mt) respiration, and ROS generation. Last, pharmacologic inhibition of mTOR or mtROS reversed MCC-PD-1:PD-L1-dependent proliferation and synergized with PD-1 checkpoint blockade in suppressing tumorigenesis. Our results identify an MCC-PD-1-mTOR-mtROS axis as a tumor growth-accelerating mechanism, the blockade of which might contribute to clinical response in patients with MCC.
Subject(s)
Carcinoma, Merkel Cell , Skin Neoplasms , Humans , B7-H1 Antigen , Carcinoma, Merkel Cell/drug therapy , Carcinoma, Merkel Cell/genetics , Programmed Cell Death 1 Receptor , Reactive Oxygen Species , Skin Neoplasms/drug therapy , Skin Neoplasms/genetics , TOR Serine-Threonine KinasesABSTRACT
Cancer-associated immune dysfunction is a major challenge for effective therapies. The emergence of antibodies targeting tumor cell-surface antigens led to advancements in the treatment of hematopoietic malignancies, particularly blood cancers. Yet their impact is constrained against tumors of hematopoietic origin manifesting in the skin. In this study, we employ a clonality-supervised deep learning methodology to dissect key pathological features implicated in mycosis fungoides, the most common cutaneous T-cell lymphoma. Our investigations unveil the prominence of the IL-32ß-major histocompatibility complex (MHC)-I axis as a critical determinant in tumor T-cell immune evasion within the skin microenvironment. In patients' skin, we find MHC-I to detrimentally impact the functionality of natural killer (NK) cells, diminishing antibody-dependent cellular cytotoxicity and promoting resistance of tumor skin T-cells to cell-surface targeting therapies. Through murine experiments in female mice, we demonstrate that disruption of the MHC-I interaction with NK cell inhibitory Ly49 receptors restores NK cell anti-tumor activity and targeted T-cell lymphoma elimination in vivo. These findings underscore the significance of attenuating the MHC-I-dependent immunosuppressive networks within skin tumors. Overall, our study introduces a strategy to reinvigorate NK cell-mediated anti-tumor responses to overcome treatment resistance to existing cell-surface targeted therapies for skin lymphoma.
Subject(s)
Lymphoma, T-Cell, Cutaneous , Mycosis Fungoides , Skin Neoplasms , Humans , Mice , Female , Animals , Up-Regulation , Killer Cells, Natural , Lymphoma, T-Cell, Cutaneous/pathology , Proteins , Skin Neoplasms/genetics , Skin Neoplasms/pathology , Histocompatibility Antigens , Major Histocompatibility Complex , Histocompatibility Antigens Class I , Tumor MicroenvironmentSubject(s)
Keratosis , Skin Abnormalities , Humans , Tumor Necrosis Factor-alpha , Interleukin-23 , Acantholysis/diagnosisABSTRACT
BACKGROUND: Targeted therapy (TT) of BRAF V600 mutated unresectable melanoma with inhibitors of the MAPK pathway achieves response rates of up to 76%, but most patients develop secondary resistance. Albeit TT is strikingly efficacious during the first days of treatment, even in advanced cases, long-term survival is highly unlikely, especially in patients with unfavorable baseline characteristics like elevated lactate dehydrogenase (LDH). In patients treated with anti-PD-1 immune checkpoint inhibitors, elevated baseline metastatic growth rate (MGR) was the most important prognostic factor. Here, we aimed at investigating the prognostic impact of MGR in patients with unresectable melanoma receiving TT. METHODS: Clinical records of 242 patients with at least one measurable target lesion (TL) receiving TT at seven skin cancer centers were reviewed. Baseline MGR was determined measuring the largest TL at baseline and at one earlier timepoint. RESULTS: Overall survival (OS) and progression-free survival (PFS) were significantly impaired in patients with an MGR > 3.9 mm/month (median OS: 11.4 vs. 35.5 months, P < 0.0001; median PFS: 4.8 vs. 9.2 months, P < 0.0001). Multivariable analysis of OS and PFS revealed that the prognostic impact of elevated MGR was independent of LDH, presence of brain and liver metastases, tumor burden, and line of treatment. The prognostic significance of elevated MGR was highest in patients with normal LDH. CONCLUSIONS: Baseline MGR is an important independent prognostic marker for OS and PFS in melanoma patients treated with TT. Its implementation in clinical routine is easy and could facilitate the prognostic stratification.
Subject(s)
Melanoma , Skin Neoplasms , Humans , Melanoma/drug therapy , Melanoma/genetics , Melanoma/metabolism , Proto-Oncogene Proteins B-raf/genetics , Prognosis , Skin Neoplasms/drug therapy , Skin Neoplasms/genetics , Skin Neoplasms/pathology , Progression-Free Survival , Retrospective Studies , MutationABSTRACT
In patients infected with severe acute respiratory syndrome coronavirus 2, vasculopathic changes of the skin are associated with a severe prognosis. However, the pathogenesis of this vasculopathy is not conclusively clarified. In this study, 25 prospectively collected skin samples from patients with COVID-19-related skin lesions were examined for vasculopathic changes and, in case of vasculitis, were further analyzed with electron microscopy and immunohistochemistry. Vasculopathy was observed in 76% of all COVID-19-related inflammatory skin lesions. Visual endothelial changes without manifest leukocytoclastic vasculitis were found in 60% of the COVID-19-related skin lesions, whereas leukocytoclastic vasculitis was diagnosed in 16%. In the cases of vasculitis, there were extensive spike protein depositions in microvascular endothelial cells that colocalized with the autophagosome proteins LC3B and LC3C. The autophagy protein complex LC3-associated endocytosis in microvascular endothelial cells seems to be an important pathogenic factor for severe acute respiratory syndrome coronavirus 2-related vasculitis in the skin. On ultrastructural morphology, the vasculitic process was dominated by intracellular vesicle formation and endothelial cell disruption. Direct presence of severe acute respiratory syndrome coronavirus 2 particles in the skin was not observed. Therefore, our results suggest that instead of direct viral infection, dermal vasculitic lesions in COVID-19 are caused by severe acute respiratory syndrome coronavirus 2 spike protein deposition followed by endothelial damage with activation of autophagy.
Subject(s)
COVID-19 , Vasculitis, Leukocytoclastic, Cutaneous , Vasculitis , Humans , SARS-CoV-2 , COVID-19/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Endothelial Cells/metabolism , AutophagosomesABSTRACT
Darier disease (DD) is a rare, inherited multi-organ disorder associated with mutations in the ATP2A2 gene. DD patients often have skin involvement characterized by malodorous, inflamed skin and recurrent, severe infections. Therapeutic options are limited and inadequate for the long-term management of this chronic disease. The aim of this study was to characterize the cutaneous immune infiltrate in DD skin lesions in detail and to identify new therapeutic targets. Using gene and protein expression profiling assays including scRNA sequencing, we demonstrate enhanced expression of Th17-related genes and cytokines and increased numbers of Th17 cells in six DD patients. We provide evidence that targeting the IL-17/IL-23 axis in a case series of three DD patients with monoclonal antibodies is efficacious with significant clinical improvement. As DD is a chronic, relapsing disease, our findings might pave the way toward additional options for the long-term management of skin inflammation in patients with DD.
Subject(s)
Darier Disease , Humans , Darier Disease/genetics , Darier Disease/metabolism , Darier Disease/pathology , Interleukin-17/genetics , Interleukin-17/metabolism , Interleukin-23/metabolism , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism , Skin/pathology , Th17 Cells/metabolismABSTRACT
BACKGROUND: Recurring therapy resistant hives, accompanied by IgM-gammopathy, fever and joint pain can indicate Schnitzler syndrome, a rare autoimmune disorder. There is currently no approved treatment, but complete remission of symptoms can be induced with IL-1 antagonists. CASE PRESENTATION: A patient with a history of chronic urticaria presented frequently at the outpatient clinic with severe hives and was treated unsuccessfully with antihistamines and omalizumab. After several years, additional symptoms such as joint pain, recurrent fever, and IgM-gammopathy developed. After the diagnostic criteria for Schnitzler syndrome were met, treatment with anakinra was initiated and resulted in an improvement of the symptoms. Shortly after the first injection, the patient developed large and painful erythematous lesions at the injection sites, leading to discontinuation of treatment and a rapid recurrence of symptoms. Subsequently, treatment with a longer-acting IL-1 antagonist (canakinumab) was initiated, resulting in a complete remission of symptoms. CONCLUSION: This case report demonstrates that patients with urticarial symptoms that are not relieved by typical treatments should prompt repeated reassessments of the diagnosis, even years later, because gammopathy and other diagnostic criteria for Schnitzler syndrome can occur with a delay.
ABSTRACT
BACKGROUND: Extracorporeal photopheresis (ECP) has emerged as a systemic first-line immunomodulatory therapy in leukaemic cutaneous T-cell lymphoma (L-CTCL) and is now beginning to be utilized in other T-cell-mediated diseases. Although ECP has been used for nearly 30â years, its mechanisms of action are not sufficiently understood, and biomarkers for response are scarce. OBJECTIVES: We aimed to investigate the immunomodulatory effects of ECP on cytokine secretion patterns in patients with L-CTCL, to help elucidate its mechanism of action. METHODS: A total of 25 patients with L-CTCL and 15 healthy donors (HDs) were enrolled in this retrospective cohort study. Concentrations of 22 cytokines were simultaneously quantified by using multiplex bead-based immunoassays. Neoplastic cells in patients' blood were evaluated by flow cytometry. RESULTS: Firstly, we observed a distinct cytokine profile pattern difference between L-CTCLs and HDs. There was a significant loss of tumour necrosis factor (TNF)-α, and significant increase of interleukins (IL)-9, IL-12 and IL-13 in the sera of patients with L-CTCL compared with HDs. Secondly, patients with L-CTCL who received ECP were classified as treatment responders and nonresponders according to the quantitative reduction of malignant burden in their blood. We evaluated cytokine levels in culture supernatants from patients' peripheral blood mononuclear cells (PBMCs) at baseline and 27 weeks after ECP initiation. Strikingly, PBMCs purified from ECP responders released statistically higher concentrations of innate immune cytokines IL-1α, IL-1ß, granulocyte-macrophage colony-stimulating factor (GM-CSF) and TNF-α in comparison with ECP nonresponders. In parallel, responders showed clearance of erythema, reduction of malignant clonal T cells in the blood, and a potent boost of relevant innate immune cytokines in individual patients with L-CTCL. CONCLUSIONS: Taken together, our results demonstrate that ECP stimulates the innate immune network, and facilitates redirection of the tumour-biased immunosuppressive microenvironment towards proactive antitumour immune responses. The alterations of IL-1α, IL-1ß, GM-CSF and TNF-α can be used as biomarkers of response to ECP in patients with L-CTCL.
Subject(s)
Lymphoma, T-Cell, Cutaneous , Photopheresis , Skin Neoplasms , Humans , Cytokines , Photopheresis/methods , Granulocyte-Macrophage Colony-Stimulating Factor , Tumor Necrosis Factor-alpha , Retrospective Studies , Leukocytes, Mononuclear , Lymphoma, T-Cell, Cutaneous/pathology , Immunity, Innate , Skin Neoplasms/therapy , Biomarkers , Tumor MicroenvironmentABSTRACT
BACKGROUND: In Hymenoptera venom allergy serologically double-sensitized patients, it is often difficult to identify the culprit insect for venom immunotherapy (VIT). OBJECTIVES: To evaluate if basophil activation tests (BATs) performed not only with venom extracts but additionally with single component-resolved diagnostics could differentiate between sensitized and allergic individuals and how the test results influenced the physicians' decision regarding VIT. METHODS: BATs were performed with bee and wasp venom extracts and with single components (Api m 1, Api m 10, Ves v 1, and Ves v 5) in 31 serologically double-sensitized patients. RESULTS: In 28 finally included individuals, 9 BATs were positive and 4 negative for both venoms. Fourteen of 28 BATs showed positive results for wasp venom alone. Two of 10 BATs positive for bee venom were only positive to Api m 1 and 1 of 28 BATs only to Api m 10, but not for whole bee venom extract. Five of 23 BATs positive for wasp venom were only positive for Ves v 5 but negative for wasp venom extract and Ves v 1. Finally, VIT with both insect venoms was recommended in 4 of 28 individuals, with wasp venom alone in 21 of 28 patients and with bee venom alone in 1 of 28. In 2 cases no VIT was recommended. CONCLUSIONS: BATs with Ves v 5, followed by Api m 1 and Api m 10, were helpful for the decision for VIT with the clinically relevant insect in 8 of 28 (28.6%) patients. A BAT with components should therefore be additionally carried out in cases with equivocal results.
Subject(s)
Arthropod Venoms , Bee Venoms , Hymenoptera , Hypersensitivity , Insect Bites and Stings , Venom Hypersensitivity , Humans , Animals , Allergens , Wasp Venoms , Basophil Degranulation Test , Immunoglobulin E , Hypersensitivity/diagnosis , Hypersensitivity/therapy , Insect Bites and Stings/diagnosis , Insect Bites and Stings/therapyABSTRACT
Primary cutaneous B-cell lymphomas (CBCL) are a heterogeneous group of B-cell lymphomas without evidence of extracutaneous disease at the time of diagnosis. The 2022 World Health Organization classification of mature lymphoid neoplasms differentiates the indolent primary cutaneous marginal zone lymphoproliferative disorder, primary cutaneous follicle center lymphoma and Epstein-Barr virus-positive mucocutaneous ulcer, from the more aggressive primary cutaneous diffuse large B-cell lymphoma, leg-type and intravascular large B-cell lymphoma. The new updates in the 2022 classification are based on recent scientific advances in the understanding and characterization of these entities. This article aims to review the main clinical, cellular and molecular features of the five CBCL subsets along with their management and treatment. The exponentially growing evidence for new treatment options for systemic B-cell lymphomas raises expectations for the field of CBCL as well. However, specific prospective high quality research on CBCL is still crucial to further define their management and update international guidelines.
Subject(s)
Epstein-Barr Virus Infections , Lymphoma, Large B-Cell, Diffuse , Skin Neoplasms , Humans , Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/diagnosis , Epstein-Barr Virus Infections/therapy , Herpesvirus 4, Human , Lymphoma, Large B-Cell, Diffuse/diagnosis , Lymphoma, Large B-Cell, Diffuse/pathology , Lymphoma, Large B-Cell, Diffuse/therapy , Prospective Studies , Skin Neoplasms/diagnosis , Skin Neoplasms/therapyABSTRACT
Urticaria is a disease triggered by mast cells and characterized by recurrent symptoms such as wheals and/or angioedema. Most patients benefit from treatment with antihistamines (AH) or, if not effective enough, from additional therapy with omalizumab, which leads to significant symptom relief. Here we present a patient with therapy-resistant chronic spontaneous urticaria treated with AH, omalizumab, and glucocorticosteroids. The subsequent recommended therapy according to the current guideline, cyclosporine A, was contraindicated in this patient. Therefore, therapy with dupilumab was initiated, resulting in a complete control of symptoms. In this case report, we present a case of successful dual therapy with omalizumab and dupilumab.
ABSTRACT
Rapid and reliable fungal identification is crucial to delineate infectious diseases, and to establish appropriate treatment for onychomycosis. Compared to conventional diagnostic methods, molecular techniques are faster and feature higher accuracy in fungal identification. However, in current clinical practice, molecular mycology is not widely available, and its practical applicability is still under discussion. This study summarizes the results of 16,094 consecutive nail specimens with clinical suspicion of onychomycosis. We performed PCR/sequencing on all primary nail specimens for which conventional mycological diagnostics remained inconclusive. In specimens with a positive direct microscopy but negative or contaminated culture, molecular mycology proved superior and specified a fungal agent in 65% (587/898). In 75% (443/587), the identified pathogen was a dermatophyte. Positive cultures for dermatophytes, yeasts and non-dermatophyte molds (NDMs) were concordant with primary-specimen-DNA PCR/sequencing in 83% (10/12), 34% (22/65) and 45% (76/169), respectively. Among NDMs, agreement was high for Fusarium spp. (32/40; 80%), but low for Penicillium spp. (5/25; 20%) and Alternaria spp. (1/20; 5%). This study underlines the improvement in diagnostic yield by fungal primary-specimen-DNA PCR/sequencing in the event of a negative or contaminated culture, as well as its significance for the diagnosis of dermatophyte and non-dermatophyte onychomycosis. Molecular mycology methods like PCR and DNA sequencing should complement conventional diagnostics in cases of equivocal findings, suspected NDM onychomycosis or treatment-resistant nail pathologies.
ABSTRACT
COVID-19 vaccines contain additives such as Polyethylenglycol-2000 (PEG2000; mRNA vaccines) or Polysorbat 80 (vector vaccines), which have been described previously as culprits for anaphylactic events. This retrospective study included 46 individuals, who were referred to Comprehensive Allergy Center at the Department Dermatology and Venereology, Kepler University Hospital, Linz, Austria, with suspected allergic reactions to the first COVID-19 vaccine dose with either mRNA or vector-based vaccines. Patients underwent detailed anamnesis, clinical examination, and in most cases, skin prick testing using pure additive substances (PEG - different molecular weights, Polysorbate 80). Out of 46, 7 patients' reactions were classified as possibly anaphylactic and graded according to Ring & Messmer. Forty patients out of 46 were assessed with skin prick tests for potential allergens in COVID-19 vaccines. Only 1 patient showed an immediate positive prick test to PEG2000. Second-dose vaccination with mRNA or vector-based vaccines were tolerated well in all patients, including the individual with a positive skin prick test against PEG2000. The currently available COVID-19 vaccines have an overall low allergic potential and may be administered safely in patients with suspected allergic reactions to the first dose.