In-vivo and ex-vivo tests for culprit drugs identification in severe cutaneous adverse drugs reactions.

Drug causality assessment in severe cutaneous adverse reactions (SCARs) remains challenging. We investigated the usefulness of in-vivo drug patch tests (PT), ex-vivo interferon (IFN)-γ enzyme-linked immunospot (ELISpot) assay, and lymphocyte transformation test (LTT) in 30 SCARs patients within the past 36 months. Drug PT yielded a 20% positivity rate (n = 6), while IFN-γ ELISpot and LTT showed positive rates of 56.67% (n = 17) and 41.38% (n = 12), respectively. Combining the three tests resulted in an overall positive rate of 66.67% (n = 20) of cases. IFN-γ ELISpot offered additional positivity, especially with oxypurinol. Employing a combined diagnostic approach may enhance the chances of obtaining a positive result.

Involvement of autologous myeloid dendritic cells in the evaluation of immediate hypersensitivity reactions to betalactams.

BACKGROUND: Amoxicillin (AX) and clavulanic acid (CLV) are the betalactam antibiotics (BLs) most used to treat bacterial infections, although they can trigger immediate hypersensitivity reactions (IDHRs). The maturation analysis of monocyte-derived dendritic cells (moDCs) and their capacity to induce proliferative response of lymphocytes are useful to test the sensitisation to a drug, although without optimal sensitivity. Nevertheless, this can be improved using directly isolated DCs such as myeloid DCs (mDCs). METHODS: mDCs and moDCs were obtained from 28 allergic patients (AP), 14 to AX, 14 to CLV and from 10 healthy controls (HC). The expression of CCR7, CD40, CD80, CD83, and CD86 was analysed after stimulation with both BLs. We measured the capacity of these pre-primed DCs to induce drug-specific activation of different lymphocyte subpopulations, CD3+, CD4+, CD8+, CD4+Th1, and CD4+Th2, by flow cytometry. RESULTS: Higher expression of CCR7, CD40, CD80, CD83, and CD86 was observed on mDCs compared to moDCs from AP after stimulating with the culprit BL. Similarly, mDCs induced higher proliferative response, mainly of CD4+Th2 cells, compared to moDCs, reaching up to 67% of positive results with AX, whereas of only 25% with CLV. CONCLUSIONS: mDCs from selective AP efficiently recognise the culprit drug which trigger the IDHR. mDCs also trigger proliferation of lymphocytes, mainly those with a Th2 cytokine pattern, although these responses depend on the nature of the drug, mimicking the patient's reaction.

Characteristics of mild and severe apalutamide-related cutaneous adverse events in patients with prostate cancer: A review of the literature.

Apalutamide is an antiandrogen used to treat prostate cancer. Although it sometimes induces mild cutaneous adverse events and occasionally severe ones, clinical differences between severe and mild cases remain unclear. To assess the risks in patients experiencing apalutamide-related cutaneous adverse events (ARCAEs), we aimed to characterize severe and mild ARCAEs in terms of onset time and lymphocyte transformation test (LTT) for apalutamide. We reviewed 41 ARCAE cases: 24 from our institute and 17 from the literature, comprising (i) eight severe cases including six with toxic epidermal necrolysis, one with acute generalized exanthematous pustulosis, and one with drug reaction with eosinophilia and systemic symptoms, and (ii) 33 mild cases. Patients with evere cases developed ARCAEs significantly earlier than patients with mild cases (5.2 vs 9.6 weeks). No severe cases appeared ≥8 weeks after initiation of apalutamide. LTTs showed positive results in two of seven mild cases (28.6%) and four of four severe cases (100.0%). In conclusion, we found that severe ARCAEs are characterized by earlier onset and LTT positivity. Dermatologists and urologists should pay special attention to patients who develop ARCAEs <8 weeks after initiating apalutamide and/or show positive LTT results.

Hypersensitivity to metals in metal-on-metal hip arthroplasty: a prospective study of one hundred and thirty five lymphocyte transformation tests.

BACKGROUND: Metal allergy remains a controversial topic in the orthopaedic community. It is not known if or to what degree metal sensitivity contributes to inflammatory soft tissue failures, unexplained residual pain, or clinical complications after total joint replacement with metal prostheses. METHODS: We investigated the efficacy of the lymphocyte transformation test (LTT) in predicting adverse outcomes in patients after receiving a metal joint replacement. Our study cohort consists of 135 metal-on-metal hip resurfacing arthroplasty cases performed between 2013 and 2015. All study patients had an LTT preoperatively. We retrospectively analyzed clinical outcomes and failures for our cohort. RESULTS: There was no difference in LTT reactivity between men and women. Of the 135 patients tested, 46 (34.1% of cohort) tested positive to at least one of the materials comprising their implant, and 78 patients (57.8%) had at least one reactive score to any component of the LTT. After a minimum follow-up of two years, we did not observe an allergic response to the implant in any patients. There were no failures requiring revision. We observed a 2.2% rate of moderate residual pain; no patients with residual pain tested positive for metal sensitivity. When patients with moderate-high LTT reactivity (30.4% of cohort) were compared to the remainder of the study group, there was no difference in HHS or UCLA activity score. There was no correlation between blood metal ion levels and LTT reactivity. CONCLUSION: We were unable to prove any predictive value of the LTT. We failed to identify hypersensitivity to metals in patients with metal-on-metal hip resurfacing arthroplasty.

Lymphocyte transformation tests predict delayed-type allergy to piperacillin/tazobactam in patients with cystic fibrosis.

BACKGROUND: Antibiotic treatment is crucial for patients with chronic bacterial infections. Suspected drug allergies often lead to inconsistent therapies and challenging clinical management for patients and caregivers. The objective of this study was to evaluate the value of lymphocyte transformation tests in comparison to skin tests for the prediction of delayed-type allergic reactions. METHODS: This prospective, observational study tested the diagnostic value of skin prick tests, intradermal tests (reading: 15 min and 72 h) and lymphocyte transformations tests for the prediction of allergic reactions in CF patients with physician reported allergy to piperacillin/tazobactam, meropenem and ceftazidime. The tests were performed directly before a 14d intravenous drug challenge. RESULTS: We performed 33 drug challenges in 29 subjects. 21 drug challenges were negative (63 %); 12 lead to a reaction (37 %), of those 2 were immediate and 10 were delayed-type. 100 % of the skin prick tests were negative. 97 % (33/34) of the intradermal tests with early reading and 100 % of the intradermal tests with late reading yielded negative results. 5/11 patients who experienced a delayed-type reaction during the drug challenge had a positive lymphocyte transformations test. All 17 patients who did not react had a negative lymphocyte transformations test. For piperacillin/tazobactam, 4/5 patients who experienced a delayed-type reaction during the drug challenge had positive lymphocyte transformations tests. Hence, for piperacillin/tazobactam, the sensitivity of the lymphocyte transformation test for prediction of reactions was 80.0 % and the specificity 100 %. CONCLUSION: We demonstrate that the lymphocyte transformation test predicts delayed-type allergy to piperacillin/tazobactam in contrast to skin tests.

A 14-year-old boy with severe erythema multiforme due to amoxicillin.

The most common cause of erythema multiforme (EM) in children is infectious diseases which account for approximately 90% of cases. Drug eruptions are another common cause. Here we are reporting about a male patient aged 14 years with lymphadenitis who developed severe diffuse erythema during the course of treatment with medications including several antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs). Based on the pathological findings of the skin biopsy, the skin rash was due to EM. Upon investigating the underlying cause of EM, viral antibody was positive for Coxsackie A6, lymphocyte transformation testing (LTT) was positive for one of the NSAIDs, and the patch test (PT) was positive for amoxicillin. Based on the pattern of distribution of the skin rash, the cause of EM was considered to be drug-induced eruption due to amoxicillin. In this case, we did not derive a diagnosis of drug eruption without investigating the possibility of drug induction, because most cases of EM in children are induced by infection and the antibody against Coxsackie A6 was elevated. To diagnose the possibility of amoxicillin-induced EM, it was important to distinguish between the distribution patterns of infectious versus drug-induced EM and to evaluate the possibility of drug induction by both LTT and PT. If the diagnosis of amoxicillin-induced EM, had not been made, the potential recurrence of EM with amoxicillin could have occurred.

[Stevens-Johnson syndrome in a patient with positive lymphocyte transformation test]. / Síndrome de Stevens-Johnson en una paciente con prueba positiva de transformación linfocitaria.

BACKGROUND: Stevens-Johnson syndrome is a severe drug reaction. Sulfonamides have been associated with drug reactions, complications, sequelae, even death. CASE REPORT: A 40-year-old female patient with a medical history of endometriosis and recently diagnosed chronic inflammatory ulcerative colitis. She was treated at the Allergology service of the San Juan de Dios Hospital of the Costa Rican Social Security Fund, and after 20 days of treatment with sulfasalazine she had a severe drug reaction on the skin, compatible with Stevens-Johnson syndrome. The lymphocyte transformation test was positive, confirming sulfasalazine as the causative agent. CONCLUSION: The lymphocyte transformation test is a useful method that can confirm the causative agent and prevent important complications in the future.

ANTECEDENTES: El síndrome de Stevens-Johnson es una reacción medicamentosa severa. Las sulfamidas se han asociado con reacciones medicamentosas, complicaciones, secuelas, incluso la muerte. REPORTE DE CASO: Paciente femenina de 40 años, con antecedentes médicos de endometriosis y colitis ulcerativa crónica inflamatoria de reciente diagnóstico. Fue atendida en el servicio de Alergología del Hospital San Juan de Dios de la Caja Costarricense del Seguro Social, y luego de 20 días de tratamiento con sulfasalazina tuvo una reacción medicamentosa severa en la piel, compatible con síndrome de Stevens-Johnson. La prueba de transformación linfocitaria resultó positiva, con lo que se confirmó la sulfasalazina como el agente causal. CONCLUSIÓN: La prueba de transformación linfocitaria es un método útil que puede confirmar el agente causal y prevenir complicaciones importantes a futuro.

IFN-γ secretion of PBMC from non-drug-allergic control persons: Considerations for the validity of a positive lymphocyte transformation test.

BACKGROUND: The lymphocyte transformation test (LTT) is used for the in vitro detection of a drug sensitization in assumed drug allergic patients. It is based on the detection of antigen (drug)-specific activation of T cells indicated by e.g. proliferation or cytokine secretion. However, occasional stimulatory effects of the drug unrelated to specific drug-allergic mechanisms can only be detected if a larger number of non-drug allergic control persons are tested with this specific drug. In this respect, the overall specificity of the LTT with ELISA read-out is summarized in several review articles, but the impact of a specific drug on the specificity has not yet been analyzed in a larger set of control persons. OBJECTIVE: Do amoxicillin, cefuroxime and clindamycin induce an interferon (IFN)-y or interleukin (IL)-5 secretion of PBMC from control persons using the LTT with ELISA read-out? METHODS: We performed LTTs with amoxicillin, cefuroxime and clindamycin and determined drug-specific IFN-γ and IL-5 secretion measured by ELISA read-out. We included PBMC from 60 non-drug allergic control persons, who were unexposed to the tested drug at the time of blood donation. RESULTS: PBMC from 12 out of 23 control persons tested with amoxicillin gave a positive stimulation index (SI > 3.0) for IFN-γ resulting in a specificity of 47.8%. The corresponding specificity was 75% for cefuroxime (5/20 if SI > 3.0) and 58.8% for clindamycin (7/17, if SI > 2.0), respectively. In a next step, we calculated the Δ IFN-γ concentration by subtracting the background IFN-γ concentration in the unstimulated sample from the stimulated sample. After stimulation with amoxicillin, a mean concentration of 21.0 pg/mL IFN-γ was secreted. The less outlier prone median concentration was 7.4 pg/mL and much higher than for cefuroxime (1.7 pg/mL) and clindamycin (1.0 pg/mL). Remarkably, IL-5 concentrations were below the detection limit (< 1 pg/mL) for all drugs in all control persons who responded to TT. CONCLUSION: Consideration of these observations may be helpful since a positive LTT result in a control patient may challenge the validity of a positive LTT result in the same experiment for a patient with assumed drug allergy.

Immune-Mediated Organ-Specific Reactions to COVID-19 Vaccines: A Retrospective Descriptive Study.

Severe acute respiratory syndrome coronavirus 2 caused the global COVID-19 pandemic and public health crisis, and it led to the rapid development of COVID-19 vaccines, which can cause rare and typically mild hypersensitivity reactions (HRs). Delayed HRs to COVID-19 vaccines have been reported, and the excipients polyethylene glycol (PEG)2000 and polysorbate 80 (P80) are the suspected culprits. Skin patch tests do not help in diagnosing delayed reactions. We aimed to perform lymphocyte transformation tests (LTT) with PEG2000 and P80 in 23 patients with suspected delayed HRs. Neurological reactions (n = 10) and myopericarditis reactions (n = 6) were the most frequent complications. Seventy-eight percent (18/23) of the study patients were admitted to a hospital ward, and the median time to discharge was 5.5 (IQR, 3-8) days. Some 73.9% of the patients returned to baseline condition after 25 (IQR, 3-80) days. LTT was positive in 8/23 patients (5/10 neurological reactions, 2/4 hepatitis reactions and 1/2 rheumatologic reactions). All myopericarditis cases had a negative LTT. These preliminary results indicate that LTT with PEGs and polysorbates is a useful tool for identifying excipients as causal agents in HRs to COVID-19 vaccines and can play an important role in risk stratification in patients with HRs.

In vitro diagnostic testing for drug allergy in children.

Diagnosing Drug Hypersensitivity Reactions (DHRs) could be a complicated process especially in children, since allergic-like manifestation at this age is more often the expression of concomitant infections rather than a actual DHRs. In vivo tests are usually suggested as a first step; however, prick and intradermal tests could be painful and have shown different sensitivity and specificity among published studies. In some cases, in vivo tests such as Drug Provocation test (DPT) could be even contraindicated. Therefore, the need for in vitro testing is compelling, to add useful information along the diagnostic pathway and to limit the need of DPT. In this review, we analyze the different types of in vitro tests, focusing on those used more widely such as specific IgE and on those that are still for research settings, such as basophil activation test and lymphocyte transformation test, but that have shown some useful diagnostic potential.

Nivolumab-induced acute tubular injury: A case report.

Nivolumab belongs to immune checkpoint inhibitors (ICIs). ICIs-induced kidney injury is rare and acute interstitial nephritis (AIN) is the majority. A 58-year-old woman had gastric cancer treated with nivolumab. Her serum creatinine (Cr) increased to 5.94 mg/dL post 2 cycles of nivolumab and co-administered with acemetacin. A kidney biopsy showed acute tubular injury (ATI). Nivolumab rechallenge was done and Cr worsened again. The lymphocyte transformation test (LTT) indicated a strong positive for nivolumab. Although rare, ATI due to ICIs could not be ruled out, and LTT is a tool to identify the culprit.