The diagnostic role of the in vitro drug-induced interferon-gamma release test in Stevens-Johnson syndrome

Allopurinol induced erythroderma

Allopurinol, a widely prescribed urate lowering agent is responsible for various adverse drug reactions, including erythroderma. A 45-year-old male patient was admitted with the complaints of fever, redness and scaling all over the body after 3-4 weeks of allopurinol treatment for asymptomatic hyperuricemia. Elevated liver enzymes were detected in his blood analysis. Skin biopsy was consistent with drug induced erythroderma. Allopurinol was stopped and steroids were started. Patient improved over a period of 2 weeks.

Recovered patients with Stevens-Johson syndrome and toxic epidermal necrolysis maintain long-lived IFN-γ and sFasL memory response

There is evidence that drug-specific T cells are involved in inducing keratinocyte apoptosis in acute stage of Steven-Johson syndrome (SJS) and Toxic epidermal necrolysis (TEN). However, there are few studies that have attempted to examine T cell memory responses over time. We sought to determine the duration of IFN-γ and sFasL memory response to causal drugs in patients with SJS and TEN after remission. Eight patients with previous SJS and TEN were enrolled. Memory T cells were measured by 10-day cultured IFN-γ enzyme-linked immunosorbent spot-forming cell (ELISpot) assay. Effector T-cell responses were measured by ex vivo IFN-γ ELISpot assay and sFasL ELISA. The sFasL-mediated toxicities of drug-stimulated PBMC supernatants against keratinocyte line were further investigated by MTT proliferation assay and Annexin-V staining. We observed significant cultured and ex vivo IFN-γ ELISpot responses against causal drugs in all 8 patients. In addition, the sFasL levels were specifically increased in the supernatant of PBMCs cultured with causal drugs from 6 of 8 patients. Drug-stimulated PBMC supernatants were cytotoxic against keratinocyte line, which was inhibited by anti-FasL mAb in a dose-dependent manner. Our findings confirmed that drug-specific IFN-γ and sFasL memory response against causal drugs could be sustained over several years and further suggest that patients should avoid causal drug re-exposure after the recovery of TEN and SJS.

In vitro release of interferon-gamma from peripheral blood lymphocytes in cutaneous adverse drug reactions

BACKGROUND

Cutaneous drug reactions are common but diagnostically challenging due to phenotypic heterogeneity and simultaneous exposure to multiple drugs. These limitations prompted the development of diagnostic tests.

AIMS

To evaluate the performance of an in vitro assay measuring interferon-gamma release from patients' lymphocytes in the presence of causative drugs for the diagnosis of drug reactions.

METHODS

Mononuclear cells derived from patients were incubated with and without suspected drugs, and increment of interferon-gamma levels was measured by ELISA. We performed a telephonic survey to evaluate the effect of stopping the drugs incriminated by the assay on cutaneous manifestations.

RESULTS

We assessed 272 patients who used 1035 medications. When assessed against the questionnaire data collected at least 6 months after stopping the causative drug, sensitivity was found to be 83.61% and specificity 92.67%. Likelihood ratio for a positive test is 11.40 and for a negative test 0.18. Positive predictive value is 75.37% and negative predictive value is 95.47%. The test was found to perform significantly better in females and in older patients.

CONCLUSIONS

Interferon-gamma release test is a useful adjunct tool in the diagnosis of cutaneous drug reactions.

Cutaneous adverse drug reactions to allopurinol: 10 year observational survey of the dermatology department--Cagliari University (Italy)

BACKGROUND

Allopurinol is extensively prescribed for conditions associated with urate excess, despite being responsible for severe cutaneous adverse drug reactions (ADR).

OBJECTIVE

A cross-sectional survey of allopurinol cases observed at the main Dermatology Department with inpatients facilities in southern Sardinia. (approx 560,836 inhabitants).

MATERIAL AND METHODS

Data collection of all consecutive patients referred for ADR between 2001 and 2010. Causality assessment followed the WHO Collaborating Centre for Drug Monitoring criteria; illness severity score was adopted for toxic epidermal necrolysis (SCORTEN).

RESULTS

Allopurinol was the culprit drug in 84 of 780 cutaneous ADR cases (10.7%; 8.4 cases/year). Mean age was 74 years, 58% of the patients were female, 95% of patients required hospitalization. Clinical forms were maculo-papular eruptions (34 cases), Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (31 cases), vasculitis (six cases), Drug Rash Eosinophilia and Systemic Symptoms (DRESS) (three cases), Acute Generalized Exanthematous Pustolosis (AGEP) (three cases), Pityriasis rosea-like eruption (three cases), lichenoid dermatitis (two cases), fixed drug eruption (one case), erythroderma (one case). The indication for allopurinol prescription was asymptomatic hyper-uricemia in 95% of the patients. Twelve patients were under allopurinol dosage adjustment according to creatinine clearance. Final causality assessment was definite for 12% of the cases and probable for the remaining 88%. Full recovery was achieved in 88% of subjects; ten SJS/TEN patients died (12% overall mortality; 32% mortality of the SJS/TEN cases).

CONCLUSION

Considering the populations size of Southern Sardinia, is plausible that 1.5/100,000 Sardinian will be affected by allopurinol related ADR per year. Advanced age, and inappropriate allopurinol prescription were the main conditions affecting morbidity and mortality.

Analysis of cytokine secretion from lymphocytes of patients with hypersensitivity reactions to contaminated heparins

BACKGROUND

Beginning in 2007, anaphylactoid reactions associated with unfractionated heparin (UFH) occurred and resulted in some fatalities. These reactions were reported to be linked to the complement and contact system activation induced by certain batches of UFH containing the adulterant oversulphated chondroitin sulphate (OSCS).

OBJECTIVES

Drug-specific secretion of selected cytokines from peripheral blood mononuclear cells (PBMC) of patients with hypersensitivity reactions to contaminated heparin was compared with the respective in vitro cytokine pattern of individuals with or without hypersensitivity to heparin, different glycosaminoglycans or other drugs.

METHODS

Study individuals (n = 13) were classified as follows: patients with hypersensitivity reactions to contaminated (OSCS) heparin (n = 3), noncontaminated heparin (n = 1) or other compounds (n = 3) and patients with ongoing heparin therapy without symptoms of intolerance (n = 2). Four healthy individuals served as controls. PBMC were incubated with six different glycosaminoglycan structures. Drug-specific intracellular interleukin (IL)-5, interferon (IFN)-γ and IL-10 production was investigated by flow cytometry, while secretion of IL-5, IL-2 and IFN-γ was analysed by enzyme-linked immunosorbent assay.

RESULTS

PBMC from individuals with hypersensitivity reactions to contaminated heparin secreted considerable amounts of IL-2 in vitro. There was a suggestion that ongoing heparin therapy and the Li-heparin in the vials may have an impact on the lymphocyte reactivity of PBMC.

CONCLUSIONS

The in vitro lymphocyte reactivity pattern of PBMC from individuals with hypersensitivity reactions to contaminated heparins was neither typical for an immune-mediated nor for a nonimmune-mediated reaction. Possible effects of heparins in the test system itself may require consideration.

Drug-specific in vitro release of IL-2, IL-5, IL-13 and IFN-gamma in patients with delayed-type drug hypersensitivity

BACKGROUND

The most prevalent drug hypersensitivity reactions are T-cell mediated. The only established in vitro test for detecting T-cell sensitization to drugs is the lymphocyte transformation test, which is of limited practicability. To find an alternative in vitro method to detect drug-sensitized T cells, we screened the in vitro secretion of 17 cytokines/chemokines by peripheral blood mononuclear cells (PBMC) of patients with well-documented drug allergies, in order to identify the most promising cytokines/chemokines for detection of T-cell sensitization to drugs.

METHODS

Peripheral blood mononuclear cell of 10 patients, five allergic to beta-lactams and five to sulfanilamides, and of five healthy controls were incubated for 3 days with the drug antigen. Cytokine concentrations were measured in the supernatants using commercially available 17-plex bead-based immunoassay kits.

RESULTS

Among the 17 cytokines/chemokines analysed, interleukin-2 (IL-2), IL-5, IL-13 and interferon-gamma (IFN-gamma) secretion in response to the drugs were significantly increased in patients when compared with healthy controls. No difference in cytokine secretion patterns between sulfonamide- and beta-lactam-reactive PBMC could be observed. The secretion of other cytokines/chemokines showed a high variability among patients.

CONCLUSION

The measurement of IL-2, IL-5, IL-13 or IFN-gamma or a combination thereof might be a useful in vitro tool for detection of T-cell sensitization to drugs. Secretion of these cytokines seems independent of the type of drug antigen and the phenotype of the drug reaction. A study including a higher number of patients and controls will be needed to determine the exact sensitivity and specificity of this test.

Erythema multiforme and related disorders

Erythema multiforme (EM) and related disorders comprise a group of mucocutaneous disorders characterized by variable degrees of mucosal and cutaneous blistering and ulceration that occasionally can give rise to systemic upset and possibly compromise life. The clinical classification of these disorders has often been variable, thus making definitive diagnosis sometimes difficult. Despite being often caused by, or at least associated with, infection or drug therapy, the pathogenic mechanisms of these disorders remain unclear, and as a consequence, there are no evidence-based, reliably effective therapies. The present article reviews aspects of EM and related disorders of relevance to oral medicine clinical practice and highlights the associated potential etiologic agents, pathogenic mechanisms and therapies.

Chlorpyrifos exacerbating pemphigus vulgaris: a preliminary report and suggested in vitro immunologic evaluation model

BACKGROUND

There is accumulating evidence on the role of pesticides in the etiology of pemphigus vulgaris (PV).

OBJECTIVE

To determine whether chlorpyrifos, an organophosphate pesticide, is involved in the immunopathology of PV.

METHODS

Normal human skin biopsy specimens incubated with progressively diluted chlorpyrifos solutions were used as indirect immunofluorescence substrates for sera from two PV patients previously exposed to the agent and from healthy controls. Involvement of T-cell lymphocytes was assessed by release of interferon-g in the presence of chlorpyrifos.

RESULTS

In one PV patient, immunofluorescence was strongly positive for the specimen incubated with the pesticide and weakly positive for the specimen incubated with medium alone. Immunofluorescence was negative in the patient under immunosuppression with prednisolone and in all controls. Both patients tested positive on interferon-g assay; controls tested negative.

CONCLUSIONS

Findings suggest an immunopathogenic role of chlorpyrifos in PV. Interferon-g cytokine assay with the pesticide combined with immunofluorescence tests may provide an in vitro diagnostic tool in suspected pesticide-induced/exacerbated pemphigus.

A 2-year-old girl with Stevens--Johnson syndrome/toxic epidermal necrolysis treated with intravenous immunoglobulin

Toxic epidermal necrolysis and Stevens-Johnson syndrome are severe skin reactions, usually to drugs, associated with a widespread destruction of the epidermis. Widespread purpuric macules and epidermal detachment of less than 10% of the body surface is indicative of Stevens-Johnson syndrome, whereas epidermal detachment between 10% and 30% is called Stevens-Johnson-toxic epidermal necrolysis overlap. Epidermal detachment involving more than 30% of the total body surface is designated as toxic epidermal necrolysis. These generalized reactions are known to occur in association with various drugs. Treatment is primarily supportive care, and there are no specific therapy regimens. Therapeutic modalities such as corticosteroids, cyclosporin, thalidomide, cyclophosphamide, and plasmapheresis, usually based on a symptomatic approach, have been tried in single patients or in small series. Intravenous immunoglobulin has recently been shown to provide rapid improvement in all three of these skin reactions. We report a 2-year-old girl who developed Stevens-Johnson syndrome-toxic epidermal necrolysis overlap after receiving ampicillin-sulbactam for an upper respiratory tract infection. She was treated successfully with a 4-day course of intravenous immunoglobulin.

Increased in Vitro Release of Interferon-Gamma from Ampicillin-Stimulated Peripheral Blood Mononuclear Cells in Stevens-Johnson Syndrome

Stevens-Johnson syndrome (SJS) was diagnosed in a 39-year-old woman, treated with ampicillin (4000-8000 mg daily), phenytoin (250 mg daily), and furosemide (20-40 mg daily) for 25, 21, and 20 d, respectively, before the appearance of the eruption. The lymphocyte stimulation test with the MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay on ampicillin, phenytoin, and furosemide showed a low value of stimulation index, which indicated negative reactivity. An in vitro IFN-gamma release test was conducted on the patient with SJS and on two healthy controls. IFN-gamma release increased by 52% following the in vitro challenge of the patient's peripheral blood mononuclear cells (PBMCs) with 15 microg/ml of ampicillin, but not with phenytoin or furosemide. Neither of the controls experienced increased IFN-gamma release. In the present case, increased in vitro IFN-gamma release was observed on ampicillin-stimulated PBMCs, which may indicate the role of ampicillin as the drug responsible for the induction of SJS, and may imply the role of IFN-gamma in the pathogenesis of SJS.

Difficult gout and new approaches for control of hyperuricemia in the allopurinol-allergic patient

A major obstacle to the treatment of hyperuricemia in patients allergic to allopurinol is the limited availability of suitable, equally effective, alternative, urate-lowering drugs. Conventional uricosuric drugs, including probenecid and sulfinpyrazone, are recommended for allopurinol- intolerant patients with gout and "underexcretion" hyperuricemia who have normal renal function and no history of nephrolithiasis. Therapeutic options in those in whom traditional uricosuric drugs are contraindicated, ineffective, or poorly tolerated include slow oral desensitization to allopurinol and cautious administration of oxipurinol. Allopurinol desensitization is useful particularly in those who have failed other treatment modalities. If available (as in Europe, South Africa, and Japan), benzbromarone may be tried in patients with gout and mild-to-moderate renal insufficiency. Recombinant urate oxidase can be used in the short-term prophylaxis and treatment of chemotherapy- associated hyperuricemia in patients with lymphoproliferative and myeloproliferative disorders. Hyperuricemia and gout occur with increased frequency in cyclosporine-treated allograft transplant recipients. The management of gout in these patients is complicated by two main factors: cyclosporine-induced renal impairment, and interactions with medications used to preserve the allograft.

Efficacy and safety of desensitization to allopurinol following cutaneous reactions

OBJECTIVE

To evaluate the long-term efficacy and safety of slow oral desensitization in the management of patients with hyperuricemia and allopurinol-induced maculopapular eruptions.

METHODS

A retrospective evaluation of an oral desensitization regimen using gradual dosage-escalation of allopurinol in 32 patients (30 with gout and 2 with chronic lymphocytic leukemia) whose therapy was interrupted because of a pruritic cutaneous reaction to the drug.

RESULTS

Twenty-one men and 11 women with a mean age of 63 years (range 17-83 years), a mean serum urate level of 618 micromoles/liter (range 495-750) (or, mean 10.4 mg/dl [range 8.3-12.6]), and a mean serum creatinine level of 249 micromoles/liter (range 75-753) (or, mean 2.8 mg/dl [range 0.8-8.5]) were studied. Desensitization failed in 4 patients because of unmanageable recurrent rash. Twenty-eight patients completed the desensitization procedure to a target allopurinol dosage of 50-100 mg/day, 21 without deviation from the protocol for a mean of 30.5 days (range 21-56 days) and 7 requiring dosage adjustments because of a recurrent rash over 53.8 days (range 40-189 days). Seven of these 28 patients developed late cutaneous reactions 1-20 months postdesensitization, 4 responding to dosage modification and 3 discontinuing the drug. Twenty-five of the 32 patients (78%) continued to take allopurinol; their mean duration of followup was 32.6 months (range 3-92 months) and the mean postdesensitization serum urate level was 318 micromoles/liter (range 187-452) (or, mean 5.3 mg/dl [range 3.0-7.5]).

CONCLUSION

The study confirms the long-term efficacy and safety of slow oral desensitization to allopurinol in patients with maculopapular eruptions, particularly in those with gout, who cannot be treated with uricosurics or other urate-lowering drugs. Although pruritic skin eruptions may recur both during and after desensitization, most of these cutaneous reactions can be managed by temporary withdrawal of allopurinol and dosage adjustment.

Acute generalized exanthematous pustulosis associated with polysensitivity to paracetamol and bromhexine: the diagnostic role of in vitro interferon-gamma release test

We report a patient with acute generalized exanthematous pustulosis (AGEP), which occurred 3 days after ingesting paracetamol and bromhexine. Both were immediately stopped and the rash resolved rapidly. To determine the offending drug responsible for AGEP, an in vitro drug-induced interferon (IFN)-gamma release test was performed using an ELISA technique. Increased IFN-gamma release was observed following in vitro challenge of the patient's lymphocytes with paracetamol or bromhexine (110% and 157% increase, respectively). In vitro challenge with paracetamol or bromhexine in a control patient, treated with paracetamol and bromhexine, did not induce an increase in IFN-gamma. These findings suggest that the patient with AGEP may have polysensitivity to both drugs. The ELISA assessment also demonstrates the relevance of in vitro cytokine release tests in the investigation of such dermatoses.