Negative Skin Test Research Articles

A multicenter clinical study on the incidence and influencing factors of cephalosporin-induced anaphylaxis

To investigate the incidence and influencing factors of allergic reactions to cephalosporins. A cross-sectional study of 29 medical institutions in Zhejiang Province was conducted from April 2021 to June 2021. The incidence of allergic reactions to cephalosporins was investigated, and the influencing factors of cephalosporin-induced allergic reactions were analyzed by Poisson regression. A total of 56 155 patients were included in this study. The total incidence of allergic reactions to cephalosporin was 1.67‰, the highest incidence of anaphylaxis occurred for ceftizoxime (4.27‰), followed by ceftriaxone (3.49‰) and cefotaxime (2.40‰). There was no significant difference in the incidence of allergic reactions between patients with negative skin tests and those without skin tests (1.75‰ vs. 1.63‰, RR=1.07, 95%CI: 0.70-1.63, P>0.05). Poisson regression showed that body mass index (BMI) <18.5 kg/m2 (RR=2.43, 95%CI: 1.23-4.82, P<0.05) and history of β-lactam antibiotics allergy (RR=33.88, 95%CI: 1.47-781.12, P<0.05) increased cephalosporin-induced anaphylaxis. Compared with cefuroxime, the risk of allergic reactions was increased for ceftriaxone (RR=3.08, 95%CI: 1.70-5.59, P<0.01), ceftazidime (RR=1.89, 95%CI: 1.03-3.47, P<0.05), and ceftizoxime (RR=3.74, 95%CI: 1.64-8.50, P<0.01). Lower BMI and history of β-lactam antibiotics allergy increase the risk of cephalosporin allergic reactions. The routine skin test may not reduce the occurrence of allergic reactions to cephalosporins.

Antepartum vs postpartum amoxicillin oral challenge in pregnant patients with a reported penicillin allergy: A two-center prospective cohort study.

While 10% of pregnant individuals report a penicillin allergy, there is no established best practice for penicillin allergy delabeling in pregnancy. To better understand options for penicillin delabeling, we aimed to evaluate two penicillin allergy delabeling protocols in pregnancy regarding efficacy, adverse events, and patient satisfaction. From July 2019 to December 2022, we completed a two-center prospective cohort study, where each site recruited pregnant patients over 24 weeks gestational age with a reported penicillin allergy. One center offered antepartum amoxicillin oral challenges, either directly or after negative skin testing (i.e., antepartum oral challenge site). Our other centers completed a two-step approach with antepartum penicillin skin testing only and deferred oral challenges to the postpartum period (i.e., postpartum oral challenge site). Our primary outcome was the rate of penicillin allergy delabeling, defined as tolerating an antibiotic challenge with penicillin or amoxicillin. Univariate analyses were completed using chi-squared, Fisher's exact, and Wilcoxon rank tests. During the study period, 276 pregnant patients were assessed, with 207 in the antepartum oral challenge site and 69 in the postpartum oral challenge site. Among the 204 patients who completed antepartum oral challenges, 201 (98%) passed without reactions. Deferring oral challenges to the postpartum period led to a loss of follow-up for 37/53 (70%) of eligible individuals. Overall, 97% (201/207) of patients at the antepartum oral challenge site were delabeled from their penicillin allergy-compared to 38% (26/69) of patients referred to the postpartum oral challenge site (p < 0.0001). Three antepartum oral challenge reactions were noted, including two mild cutaneous reactions and a case of transient abdominal discomfort. Antepartum amoxicillin oral challenge is a more effective method to delabel pregnant patients from their penicillin allergy. Deferral of oral challenges to the postpartum period introduces a significant barrier for penicillin allergy delabeling.

ImmunoglobulinE in nasal secretions

Diagnosis of allergic disease is primarily verified by IgE blood serum analysis. Determination in nasal secretions is technically more difficult, particularly due to alow specimen volume and the method of sample collection. Nasal secretions are frequently collected by lavage, which allows qualitative diagnostics, whereas swabs with defined amounts of mucus enable quantitative analyses. In the case of negative skin and serum tests, detection of IgE in nasal mucus combined with nasal provocation testing aids differentiation between local allergic and nonallergic rhinitis.

Pitfalls of a Negative Tuberculin Skin Test When Used as a Screening Modality for Latent Tuberculosis Prior to Adalimumab Therapy: A Case Report

Pitfalls of a Negative Tuberculin Skin Test When Used as a Screening Modality for Latent Tuberculosis Prior to Adalimumab Therapy: A Case Report

Exploring antibiotic safety: A prospective observational study from a tertiary care public sector hospital

BackgroundAntibiotics are the most commonly used drugs to treat bacterial infections; however, these life-saving drugs can also cause adverse drug reactions. In several pharmacovigilance studies, adverse drug reactions are a cause of prolonged hospitalization. The development of hypersensitivity reactions even after a negative skin test and patch test makes antibiotic-associated adverse reactions unpredictable. Owing to the scarcity of data on antibiotic desensitization, these drugs are important for pharmacovigilance. Most of the previous studies conducted were retrospective and lacked data regarding the duration of adverse drug reactions. AimThis study aimed to examine adverse drug reactions associated with antibiotics and to provide knowledge on the duration of these reactions. MethodA prospective observational study was conducted on patients receiving antibiotics at a tertiary care hospital. The patients were followed until discharge, and causality and severity assessments were performed. Descriptive statistical analyses were performed to summarize the data. ResultsThe study results show the median duration of adverse drug reactions was two days, with an interquartile range of two to four days. Most (21,3%) of the reactions were caused by cephalosporins. The majority (44.7%) of the reactions were skin and subcutaneous tissue disorders. The majority (78.7%) of the reactions were moderately severe and were not responsible for prolonged hospital stay. ConclusionThe patients receiving antibiotics require close monitoring for early detection and management of adverse reactions to reduce the duration of hospital stay and the duration of adverse drug reactions.

The Role of Medical History and Allergic Tests in the Analysis of Antibiotic Allergy in the Pediatric Population

The Role of Medical History and Allergic Tests in the Analysis of Antibiotic Allergy in the Pediatric Population

Specific IgE and Basophil Activation Test by Microarray: A Promising Tool for Diagnosis of Platinum Compound Hypersensitivity Reactions.

Drug hypersensitivity reactions (DHRs) to platinum-based compounds (PCs) are on the rise, and their personalized and safe management is essential to enable first-line treatment for these cancer patients. This study aimed to evaluate the usefulness of the basophil activation test by flow cytometry (BAT-FC) and the newly developed sIgE-microarray and BAT-microarray in diagnosing IgE-mediated hypersensitivity reactions to PCs. A total of 24 patients with DHRs to PCs (20 oxaliplatin and four carboplatin) were evaluated: thirteen patients were diagnosed as allergic with positive skin tests (STs) or drug provocation tests (DPTs), six patients were diagnosed as non-allergic with negative STs and DPTs, and five patients were classified as suspected allergic because DPTs could not be performed. In addition, four carboplatin-tolerant patients were included as controls. The BAT-FC was positive in 2 of 13 allergic patients, with a sensitivity of 15.4% and specificity of 100%. However, the sIgE- and BAT-microarray were positive in 11 of 13 DHR patients, giving a sensitivity of over 84.6% and a specificity of 90%. Except for one patient, all samples from the non-allergic and control groups were negative for sIgE- and BAT-microarray. Our experience indicated that the sIgE- and BAT-microarray could be helpful in the endophenotyping of IgE-mediated hypersensitivity reactions to PCs and may provide an advance in decision making for drug provocation testing.

Polyethylene glycol hypersensitivity, patient outcomes in a 7-year retrospective study

BackgroundImmediate IgE-mediated hypersensitivity reactions to polyethylene glycol (PEG) are rare. Our understanding of PEG hypersensitivity is limited. ObjectiveTo evaluate the clinical characteristics and investigation outcomes of the largest cohort of patients with PEG allergy reported. MethodsA total of 44 patients investigated for suspected PEG allergy across 4 United Kingdom tertiary allergy centers between October 2013 and December 2020 were studied. Clinical characteristics, index reaction, and approaches to and outcomes of allergy investigations were analyzed. ResultsPEG hypersensitivity was confirmed in 42 of 44 cases. Macrogol laxatives were the most common index drugs reported (23%), followed by depo-medroxyprogesterone (19%), oral penicillin V (10%), and depo-methylprednisolone (10%). In general, 61% experienced grade III anaphylaxis. Intradermal testing (IDT) increased the diagnostic sensitivity from 51% to 85%. Five patients experienced systemic reactions during IDT. Of the 5 patients, 2 were skin prick test positive to a high molecular weight PEG. Three patients with negative skin test results had positive drug provocation test results. Seven patients with PEG allergy reported tolerance to H1-antihistamines containing PEG. Administration of messenger RNA COVID-19 or Oxford/AstraZeneca COVID-19 vaccines was tolerated in all 16 patients to whom they were administered. ConclusionPEG hypersensitivity is an uncommon cause of drug-induced anaphylaxis. Four index drugs accounted for two-thirds of the cases, and reactions to these drugs should prompt PEG hypersensitivity investigations. PEG IDT increases diagnostic yield. The role of skin prick test with higher molecular weight PEGs requires further attention. Further studies are required to understand PEG thresholds and PEG equivalent doses of various administration routes. COVID-19 vaccines were tolerated by all exposed.

Tuberculosis among children visiting friends & relatives.

Most paediatric tuberculosis (TB) cases in low-TB-incidence countries involve children born to migrant families. This may be partially explained by trips to their countries of origin for visiting friends and relatives (VFR). We aimed to estimate the risk of latent TB infection (LTBI) and TB in children VFR. We conducted a prospective multicentric observational study in Catalonia (Spain) from June 2017 to December 2019. We enrolled children aged < 15years with a negative tuberculin skin test (TST) at baseline and at least one parent from a high-TB-incidence country, and who had travelled to their parent's birth country for ≥21days. TST and QuantiFERON-TB Gold Plus (QFT-Plus) were performed within 8-12weeks post-return. LTBI was defined as a TST ≥5mm and/or a positive QFT-Plus. Five hundred children completed the study, equivalent to 78.2 person-years of follow-up (PYFU). Thirteen children (2.6%) were diagnosed with LTBI (16.6/per100 PYFU, 95%CI = 8.8-28.5), including two cases (0.4%) of TB (2.5/per100 PYFU, 95%CI = 0.3-9.3). LTBI incidence rates remained high after excluding BCG-vaccinated children (9.7/per100 PYFU, 95%CI = 3.9-20.0). Household tobacco smoke exposure was associated with LTBI (aOR = 3.9, 95%CI = 1.1-13.3). The risk of LTBI in children VFR in high-TB-incidence countries may equal, or perhaps even exceed, the infection risk of the native population. The primary associated risk factor was the presence of smokers in the household. Furthermore, the incidence rate of active TB largely surpassed that of the countries visited. Children VFR in high-TB-incidence countries should be targeted for diagnostic and preventive interventions.

Toxic epidermal necrolysis in a 37-year-old man with pneumonia: a case report

Apart from allergy, TEN can be caused by infection, such as M. pneumoniae infection. Aim of this case report is to present clinical manifestations of TEN with pneumonia. A 37-year-old man, came to the emergency room with cough and fever since 5 days before hospitalized. The patient received intravenous ceftriaxone (with negative skin test), paracetamol, and n-acetylcysteine. Three days earlier, the patient had gone to primary health center and got paracetamol and n-acetylcysteine. On the first day of treatment, erythematous macules were seen on the anterior and posterior thoracic region, also the patient had sore throat and dysphagia, treated with intravenous dipenhydramine, mefenamic acid, and cetirizine. On the following day, the lesions expanded with multiple bullae on the anterior and posterior thoracic region, and erosion on the labia (BSA 28%). Intravenous methylprednisolone was administered, also Kloderma® and Ikagen® cream, and Kenalog®. Mefenamic acid and paracetamol were discontinued. On the third day of treatment, the lesions expanded (BSA 38%) and the next day, BSA reached 91.5%. The SCORTEN was 1. The patient was referred for treatment at the burn center and IVIg therapy. After the eleventh day of treatment at the referral hospital, the patient was fully recovered. The managements of TEN are stop suspected drugs, wound care, fluid therapy, systemic corticosteroids, and IVIg therapy. Appropriate management of TEN gives complete recovery to patient.

Miliary Tuberculosis as Postmortem Diagnosis in Solid Organ Transplant Recipient: Case Report and Review of the Literature

The diagnosis of tuberculosis (TB) in solid organ transplant (SOT) recipients presents challenges that may lead to treatment delay. These include atypical clinical presentations, increased likelihood of negative tuberculin skin test or/and interferon-gamma release assays, and negative sputum smear results despite active disease. The treatment poses challenges due to pharmacokinetic interactions, allograft-related toxicity, and inadequate immune response. We report the case of a 70-year-old man after kidney transplantation in 2012. The patient was transferred from the urology unit with deteriorating renal function and presumed urosepsis. His pulmonary chest X-ray showed hilar pulmonary infiltrates. Computed tomography of the chest/abdomen/pelvis revealed mediastinal lymphadenopathy, pulmonary infiltrates, pulmonary effusion, and splenomegaly. His blood results showed pancytopenia and high inflammatory and renal markers. He was treated with broad-spectrum antibiotics covering bacterial, fungal, and viral infections. Despite initial clinical improvement, his kidney function deteriorated, and he required hemodialysis. His temperature continued to spike. On physical examination, he was confused and lethargic. He was scheduled to have a mediastinoscopy with lymph node biopsy, but he died the day before. The postmortem examination revealed miliary tuberculosis with tuberculosis of many organs: kidney transplant, native kidney, bone marrow, mediastinal lymph nodes, lungs, and spleen. The diagnosis of active TB in transplant recipients requires a high index of suspicion and invasive procedures. The majority of all cases of active TB after SOT are disseminated or occur at extrapulmonary sites. Only a small minority of patients have classic cavitary changes on pulmonary imaging.

Vitamin B12 Hypersensitivity: A Retrospective Multicenter Study

Vitamin B12 (Vit B12) deficiency affects approximately 20% of those above the age of 60 years in the United Kingdom and United States. If untreated, it leads to detrimental health outcomes. To investigate a cohort of patients with Vit B12 hypersensitivity (VB12H) referred to 3 UK allergy centers and design a pathway for the investigation of VB12H. A total of 29 patients seen between 2014 and 2022 underwent skin prick testing (1 mg/mL) with cyanocobalamin (CC) and hydroxycobalamin (HC) and intradermal testing (0.1 and 0.01 mg/mL). Patients with negative skin tests underwent a Vit B12 drug provocation test (DPT) with either the index or the alternative drug. Of 29 patients, 18 (62%) presented with immediate VB12H. Eight experienced anaphylaxis (4 to HC and 4 to CC) and had positive skin tests to the index drug. One patient reacted to oral and 7 patients to injectable Vit B12. Seven patients sensitized to one form of Vit B12-tolerated DPT with an alternative Vit B12. One patient with immediate VB12H reacted to polyethylene glycol (PEG) in oral cobalamin. Of 29 patients, 8 presented with delayed hypersensitivity reaction; 4 patients tolerated the intramuscular index formulation, whereas 2 patients tolerated the per oral formulation. One patient presented with symptoms consistent with symmetrical drug-related intertriginous and flexural exanthema. Three patients were referred because of cobalt allergy. Confirmed VB12H is rare. We propose a comprehensive evaluation protocol that includes Vit B12 skin tests and considers PEG allergy in patients presenting with VB12H.

The Association Between Malignancy, Immunodeficiency, and Atopy in IgE-Deficient Patients

Studies show that IgE-deficient patients (IgE <2.5 kU/L) have a high prevalence of malignancy, but relevant clinical and laboratory characteristics associated with this susceptibility have never been well characterized. To evaluate if there is an association between a malignancy diagnosis and other immunological parameters (atopy or other immune abnormalities) in IgE-deficient patients. We retrospectively analyzed medical records of 408 IgE-deficient adults seen at our institution between 2005 and2020. A malignancy diagnosis was found in 23.5% (96 of 408) of IgE-deficient patients. Among those who had allergy skin testing performed for allergic rhinitis-like symptoms, the nonatopic IgE-deficient patients (negative environmental skin tests) were more likely to have a malignancy diagnosis than the atopic group (odds ratio [OR]= 4.36, 95% confidence interval [CI]: 1.11-17.13, P= .03). The IgE-deficient individuals with an additional non-common variable immunodeficiency (non-CVID) humoral abnormality (n= 75; with low IgG, IgA, or IgM without meeting criteria for CVID) were more likely to have a malignancy diagnosis than those with only a selective IgE deficiency (n= 134; with normal IgA, IgM, and IgG) (OR= 2.79, 95% CI: 1.37-5.68, P= .005). Among the IgE-deficient patients, certain less well-defined immune abnormalities such as IgM deficiency (OR= 2.46, 95% CI: 1.13-5.36, P= .02), IgG2 deficiency (OR= 10.14, 95% CI: 1.9-54.1, P= .007), and CD4 lymphopenia (OR= 7.81, 95% CI: 2.21-27.63, P= .001) were associated with higher malignancy odds than those without these abnormalities. The odds of a malignancy diagnosis are not shared equally by all IgE-deficient patients. Prospective studies are needed to determine the utility of performing skin testing and measuring additional immunological parameters in assessing the long-term malignancy risk in IgE-deficient patients.

Identification of New Mycobacterium bovis antigens and development of a multiplexed serological bead-immunoassay for the diagnosis of bovine tuberculosis in cattle.

Serological assays for bovine tuberculosis diagnosis require the use of multiple Mycobacterium bovis specific antigens to ensure the detection of infected animals. In the present study, identification and selection process of antigens, based on data from published proteomic studies and involving the use of bioinformatics tools and an immuno-screening step, was firstly performed for identifying novel antigens that elicit an antibody response in M. bovis infection. Based on this approach, a panel of 10 M. bovis antigens [with known relevance (MPB70, MPB83, MPB70/83, and ESAT6/CFP10) and novel (Mb1961c, Mb1301c, Mb3871, Mb1403, Mb0592, and PE25/PPE41)] were constructed and thenused to develop a new multiplexed serological assay based on Luminex technology. The performance of the Luminex-bTB immunoassay was evaluated using sera from cattle with known tuberculosis status. Among the proteins whose ability to detect bovine tuberculosis was evaluated for the first time, PE25/PPE41 and Mb1403, but not Mb3871, showed good detection capacity. Following multiple antigen combination, the final Luminex-bTB immunoassay included seven antigens (MPB70, MPB83, MPB70/83, ESAT6/CFP10, PE25/PPE41, Mb1403, and Mb0592) and showed better global performance than the immunoassay using the four usual antigens (MPB70, MPB70/83, MPB83 and ESAT6/CFP10). The specificity and sensitivity values were, respectively, of 97.6% and 42.8% when the cut-off of two-positive antigens was used to classify samples as positive. With the use of the more-restrictive criterion of three-positive antigens, the specificity increased to 99.2% but the sensitivity decreased to 23.9%. The analysis of antigen profiles generated with the Luminex-bTB immunoassay showed that mainly serodominant proteins were recognized in samples from infected cattle. The detection of Mb1961c and Mb1301c appeared to be associated with presumed false-positive results. Moreover, sera from cattle originating from bTB-outbreaks but having inconclusive or negative skin test results were identified as positive by the Luminex-bTB immunoassay and showed an antigen pattern associated with M. bovis infection. The Luminex-bTB immunoassay including seven antigens may be useful as adjunct test for the detection of M. bovis-infected herds, and different cut-offs could be applied according to the bovine tuberculosis epidemiological context.

Neutrophil extracellular trap formation and gene programs distinguish TST/IGRA sensitization outcomes among Mycobacterium tuberculosis exposed persons living with HIV.

Persons living with HIV (PLWH) have an increased risk for tuberculosis (TB). After prolonged and repeated exposure, some PLWH never develop TB and show no evidence of immune sensitization to Mycobacterium tuberculosis (Mtb) as defined by persistently negative tuberculin skin tests (TST) and interferon gamma release assays (IGRA). This group has been identified and defined as HIV+ persistently TB, tuberculin and IGRA negative (HITTIN). To investigate potential innate mechanisms unique to individuals with the HITTIN phenotype we compared their neutrophil Mtb infection response to that of PLWH, with no TB history, but who test persistently IGRA positive, and tuberculin positive (HIT). Neutrophil samples from 17 HITTIN (PMNHITTIN) and 11 HIT (PMNHIT) were isolated and infected with Mtb H37Rv for 1h and 6h. RNA was extracted and used for RNAseq analysis. Since there was no significant differential transcriptional response at 1h between infected PMNHITTIN and PMNHIT, we focused on the 6h timepoint. When compared to uninfected PMN, PMNHITTIN displayed 3106 significantly upregulated and 3548 significantly downregulated differentially expressed genes (DEGs) (absolute cutoff of a log2FC of 0.2, FDR < 0.05) whereas PMNHIT demonstrated 3816 significantly upregulated and 3794 significantly downregulated DEGs following 6h Mtb infection. Contrasting the log2FC 6h infection response to Mtb from PMNHITTIN against PMNHIT, 2285 genes showed significant differential response between the two groups. Overall PMNHITTIN had a lower fold change response to Mtb infection compared to PMNHIT. According to pathway enrichment, Apoptosis and NETosis were differentially regulated between HITTIN and HIT PMN responses after 6h Mtb infection. To corroborate the blunted NETosis transcriptional response measured among HITTIN, fluorescence microscopy revealed relatively lower neutrophil extracellular trap formation and cell loss in PMNHITTIN compared to PMNHIT, showing that PMNHITTIN have a distinct response to Mtb.

Vaccination approach in patients with an allergic reaction to COVID-19 vaccines or at risk of developing allergic reactions

There is consensus that patients at risk of developing an allergic reaction to COVID-19 vaccines should be evaluated by an immunologist-allergist to determine whether vaccination should be recommended. We wanted to share our experiences in the management of these high-risk patients, from diagnostic tests in allergological evaluation to the vaccination process. Our retrospective cross-sectional study included patients who had previously developed an allergic reaction to COVID-19 vaccines or drugs and therefore were referred to our allergy and immunology clinic. Prick and intradermal tests were performed on all patients with methylprednisolone acetate (Depo-Medrol®, Pfizer) 40 mg/mL containing polyethylene Glycol (PEG) and triamcinolone acetonide (Kenacort®, Deva) 40 mg/mL containing polysorbate 80. While vaccination with desensitization was recommended for all patients with positive skin tests, split-dose vaccination was recommended for patients with negative skin tests. After explaining the risks and benefits, the choice of the vaccine (Pfizer/BioNTech or Sinovac/ CoronoVac) was left to the patients' discretion. A total of 41 patients, 10 males, and 31 females, with a mean age of 42.37 ± 14.177 years were included. Eighteen patients with a history of allergy after COVID-19 vaccines were analyzed according to the type of reaction and type of vaccine administered (Pfizer/BioNTech/Coronovac; Anaphylaxis: 4/1, Urticaria: 11/2). Moreover, there was a history of drug allergy in 23 patients who had not been vaccinated before. Skin tests with PEG were positive in a total of seven patients while skin tests with polysorbate 80 were negative in all patients. No allergic reaction developed in seven patients who underwent desensitization and in 34 patients who received a split dose. Considering the potentially life-saving benefits of vaccination in a global pandemic environment, it is a safe and effective method to administer vaccines to at-risk patients using desensitization or split dosing techniques, based on their sensitivity status determined through a PEG skin test. This approach allows for the avoidance of preventing access to vaccines, while still ensuring the safety of patients.

Comparative Evaluation of Specific Antibody against Mycobacterium tuberculosis ESAT-6 Recombinant Antigen in Healthy Subject with Positive and Negative Skin Test.

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (M. tuberculosis). The laboratory diagnosis of the disease includes various bacteriologic and immunologic methods. Despite the effectiveness of many of these methods in diagnosing active TB, their high cost and time-consuming nature have led researchers to adopt more accurate and rapid screening methods based on specific antigens for M. tuberculosis. The present study aimed to measure specific antibody serum levels against the early secretory antigenic target 6 kDa (ESAT-6) recombinant protein in healthy people and compare it to TB patients. The target population included 27 TB patients and 87 healthy individuals with no clinical TB symptoms. The healthy population was divided into two groups, including positive purified protein derivative (PPD) and negative PPD (35 and 52 people, respectively), using the Tuberculin skin test. The specific antibody level against the ESAT-6 recombinant antigen and the PPD protein was measured using an indirect Enzyme-Linked Immunosorbent Assay (ELISA) test. The results of the study showed that the majority of the healthy population with no symptoms of clinical TB and having negative skin test results did not have antibodies against the recombinant ESAT-6 (98%) and PPD (96%) antigens. On the other hand, there was a high level of the specific antibody of the ESAT-6 recombinant and PPD antigens in TB patients (77%). It is notable that in people with positive skin test results, the level of the antibody against the ESAT-6 recombinant antigen and PPD antigen was 94%. The results demonstrated that the ELISA method based on the measurement of antibodies against the ESAT-6 recombinant antigen can be a proper diagnostic method for rapid and accurate screening of healthy from infected people.

Abstract #1398759: Rituximab Therapy for Refractory Insulin Allergy in Type-1 Diabetes Mellitus

Hypersensitivity reactions to insulin have decreased significantly since the introduction of human insulin preparations, but up to 3% of diabetic patients can still be affected with both immediate and delayed reactions described. There were previous reports of rituximab use in severe, refractory insulin allergies in Type-1 Diabetes Mellitus (T1DM) prior to omalizumab treatment. Here, we describe another case of T1DM with severe insulin allergy that was successfully treated with rituximab monotherapy. A 40-year-old female presents to an Endocrinology clinic for care of her T1DM. She was diagnosed with T1DM at age 37, initially treated with multiple daily injections of insulin glargine and aspart, which were switched to pod pump therapy 6 months later. Within 2 years, she experienced painful and itchy rashes with erythema and wheals at the pod insertion sites that developed within 1 to 4 hours of pod placement. Barrier adhesives, topical and oral antihistamines, and topical glucocorticoids were ineffective. Over the next 12 months, she was trialed on insulin aspart, lispro, regular, and glulisine with similar results despite using syringe and pen injectors. Skin reactions lasted several days, with nodules and surrounding lipodystrophy. Inhaled human insulin was implemented but discontinued due to cough. She was referred to our drug allergy clinic, where testing that included a positive immediate intradermal insulin lispro test and negative m-cresol skin test was performed. Serum insulin-specific IgG antibody testing was positive, but IgE antibody was negative, suggesting the reaction was related to tissue-bound IgE. Skin biopsy revealed sub-lobular panniculitis. She was empirically started on metformin, dapagliflozin, and liraglutide to reduce insulin needs, with only mild improvement achieved. However, 4 doses of rituximab 100mg weekly as intravenous infusion significantly reduced her skin reactions with a durable response out to 18 months, when the injection site reactions recurred. Rituximab treatment was repeated weekly for 4 weeks. Her skin reactions improved again after this second round of immunotherapy, and the patient continues to do well 30 months afterward. Suspected patients with insulin allergy should have a thorough evaluation including immediate and delayed skin testing, serum IgE assessment, skin biopsy, and exclusion of other skin disorders. Treatment approaches include changing insulin preparations, changing injection technique and rotating sites, antihistamines, or even desensitizing with an insulin pump. Our case reinforces that systemic immunotherapy can be a viable option in refractory cases.

Live attenuated Leishmania infantum centrin deleted mutant (LiCen-/-) as a novel vaccine candidate: A field study on safety, immunogenicity, and efficacy against canine leishmaniasis

This study was designed to evaluate the safety, immunogenicity, and efficacy of a single dose of L. infantum (LiCen-/-) live attenuated candidate vaccine against canine leishmaniasis (CanL). Eighteen healthy domestic dogs with no anti-Leishmania antibodies and negative leishmanin skin test (LST) were randomly inoculated intravenously with either L. infantum (LiCen-/-) vaccine candidate in 10 dogs or phosphate-buffered saline (PBS) in 8 dogs. The safety, immunogenicity, and efficacy rate of L. infantum (LiCen-/-) vaccine candidate against CanL were evaluated by different criteria, including clinical manifestations, injection-site lesion, hematology and biochemistry values, anti-Leishmania antibodies using direct agglutination test (DAT), delayed-type hypersensitivity (DTH) using LST, and CD4+ and CD8+ T-cells subsets, as well as by measuring interferon (IFN-γ), interleukin (IL-23), IL-17, and IL-10 cytokines. Spleen aspiration and detection of Leishmania parasite using parasitological examinations (microscopy and culture) were performed in both vaccinated and control groups. Two months after intervention, each dog was challenged intraperitoneally (IP) with wide type (WT) L. infantum. Two-month follow-up post vaccination showed no clinical signs and serious side effects associated with the vaccination. A significant increase was found in the expression of IL-17, CD4+, and CD8+ gene transcripts in PBMCs, as well as increased levels of Th1 cytokines, and reduction of Th2 cytokine. The efficacy of the vaccine candidate was calculated to be 42.85%. While the time window for assessing the vaccine's effectiveness was too limited to draw any real conclusions but the preliminary results showed a moderate efficacy rate due to inoculation a single dose of L. infantum (LiCen-/-) vaccine candidate. Further investigations with more sample sizes and multiple doses of the vaccine candidate using natural challenges in the endemic areas of CanL are recommended.

Differentially expressed transcript isoforms associate with resistance to tuberculin skin test and interferon gamma release assay conversion.

A mechanistic understanding of uncommon immune outcomes such as resistance to infection has led to the development of novel therapies. Using gene level analytic methods, we previously found distinct monocyte transcriptional responses associated with resistance to Mycobacterium tuberculosis (Mtb) infection defined as persistently negative tuberculin skin test (TST) and interferon gamma release assay (IGRA) reactivity among highly exposed contacts (RSTR phenotype). Using transcript isoform analyses, we aimed to identify novel RSTR-associated genes hypothesizing that previous gene-level differential expression analysis obscures isoform-specific differences that contribute to phenotype. Monocytes from 49 RSTR versus 52 subjects with latent Mtb infection (LTBI) were infected with M. tuberculosis (H37Rv) or left unstimulated (media) prior to RNA isolation and sequencing. RSTR-associated gene expression was then identified using differential transcript isoform analysis. We identified 81 differentially expressed transcripts (DETs) in 70 genes (FDR <0.05) comparing RSTR and LTBI phenotypes with the majority (n = 79 DETs) identified under Mtb-stimulated conditions. Seventeen of these genes were previously identified with gene-level bulk RNAseq analyses including genes in the IFNγ response that had increased expression among LTBI subjects, findings consistent with a clinical phenotype based on IGRA reactivity. Among the subset of 23 genes with positive differential expression among Mtb-infected RSTR monocytes, 13 were not previously identified. These novel DET genes included PDE4A and ZEB2, which each had multiple DETs with higher expression among RSTR subjects, and ACSL4 and GAPDH that each had a single transcript isoform associated with RSTR. Transcript isoform-specific analyses identify transcriptional associations, such as those associated with resistance to TST/IGRA conversion, that are obscured when using gene-level approaches. These findings should be validated with additional RSTR cohorts and whether the newly identified candidate resistance genes directly influence the monocyte Mtb response requires functional study.