DRUG-INDUCED IN-VITRO STIMULATION OF PERIPHERAL LYMPHOCYTES

In-Vitro Approaches to Predict and Study T-Cell Mediated Hypersensitivity to Drugs

Mitigating the risk of drug hypersensitivity reactions is an important facet of a given pharmaceutical, with poor performance in this area of safety often leading to warnings, restrictions and withdrawals. In the last 50 years, efforts to diagnose, manage, and circumvent these obscure, iatrogenic diseases have resulted in the development of assays at all stages of a drugs lifespan. Indeed, this begins with intelligent lead compound selection/design to minimize the existence of deleterious chemical reactivity through exclusion of ominous structural moieties. Preclinical studies then investigate how compounds interact with biological systems, with emphasis placed on modeling immunological/toxicological liabilities. During clinical use, competent and accurate diagnoses are sought to effectively manage patients with such ailments, and pharmacovigilance datasets can be used for stratification of patient populations in order to optimise safety profiles. Herein, an overview of some of the in-vitro approaches to predict intrinsic immunogenicity of drugs and diagnose culprit drugs in allergic patients after exposure is detailed, with current perspectives and opportunities provided.

Blastic Transformation Induced on the Lymphocytes «in vitro» by an Exudate of Reticulum Cell Sarcoma

The blood lymphocyte culture «in vitro» has been employed in order to investigate (a) the presence of neoplastic antigens in reticulum cell sarcoma exudates, and (b) the ability of patients with reticulum cell proliferative diseases (reticulum cell sarcoma, reticulum cell reticulosis) to give immune reactions to such antigens. Lymphocytes from a patient with reticulum cell reticulosis showed a 7.3% transformation to blast cells in the presence of the pleural exudate from a reticulum cell sarcoma patient. However, this same exudate did not induce transformation of lymphocytes from two other patients with reticulum cell sarcoma nor of normal lymphocytes. Lymphocytes from the exudate donor patient did show a small percentage transformation in the presence as well as in the absence of the exudate (2.3, and 2.1%, respectively). With the purpose of identification of the transformating factor, fractionation studies were performed yielding a carbohydrate-rich, partially dialyzable mucoprotein. The conclusion is drawn that lymphocytes from the patient with reticulum cell reticulosis were immunologically reactive to a neoplastic antigen contained in the reticulum cell sarcoma exudate, and possibly produced by the proliferating reticulum cells.

Phenytoin Hypersensitivity Reaction: Hepatic necrosis

A 47-year-old black male treated with phenytoin for generalized seizures developed a generalized maculopapular rash approximately three weeks after starting therapy. In addition, fever, jaundice, diffuse lymphadenopathy, and elevated liver function enzymes resulted. A liver biopsy revealed hepatic necrosis. Treatment with oral prednisone 60 mg/d led to a resolution of the patient's clinical symptomatology and a normalization of his liver function enzymes in approximately two weeks. An updated review of the literature involving phenytoin-induced hepatic dysfunction is discussed, as well as both the postulated mechanisms causing the reaction, and therapeutic modalities of treatment.

In vitro testing for diagnosis of idiosyncratic adverse drug reactions: Implications for pathophysiology

Idiosyncratic drug reactions (IDRs) represent a major health problem, as they are unpredictable, often severe and can be life threatening. The low incidence of IDRs makes their detection during drug development stages very difficult causing many post-marketing drug withdrawals and black box warnings. The fact that IDRs are always not predictable based on the drug's known pharmacology and have no clear dose-effect relationship with the culprit drug renders diagnosis of IDRs very challenging, if not impossible, without the aid of a reliable diagnostic test. The drug provocation test (DPT) is considered the gold standard for diagnosis of IDRs but it is not always safe to perform on patients. In vitro tests have the advantage of bearing no potential harm to patients. However, available in vitro tests are not commonly used clinically because of lack of validation and their complex and expensive procedures. This review discusses the current role of in vitro diagnostic testing for diagnosis of IDRs and gives a brief account of their technical and mechanistic aspects. Advantages, disadvantages and major challenges that prevent these tests from becoming mainstream diagnostic tools are also discussed here.

Pathogenic Mechanisms and In Vitro Diagnosis of AERD

Aspirin-exacerbated respiratory disease (AERD) refers to chronic rhinosinusitis, nasal polyposis, bronchoconstriction, and/or eosinophilic inflammation in asthmatics following the exposure to nonsteroidal anti-inflammatory drugs (NSAIDs). A key pathogenic mechanism associated with AERD is the imbalance of eicosanoid metabolism focusing on prostanoid and leukotriene pathways in airway mucosa as well as blood cells. Genetic and functional metabolic studies on vital and non-vital cells pointed to the variability and the crucial role of lipid mediators in disease susceptibility and their response to medication. Eicosanoids, exemplified by prostaglandin E(2) (PGE(2)) and peptidoleukotrienes (pLT), are potential metabolic biomarkers contributing to the AERD phenotype. Also other mediators are implicated in the progress of AERD. Considering the various pathogenic mechanisms of AERD, a multitude of metabolic and genetic markers is suggested to be implicated and were introduced as potential biomarkers for in vitro diagnosis during the past decades. Deduced from an eicosanoid-related pathogenic mechanism, functional tests balancing PGE(2) and pLT as well as other eicosanoids from preferentially vital leukocytes demonstrated their applicability for in vitro diagnosis of AERD.

Safety assessment in pediatric studies

It typically takes many years before an association of a drug with a rare, serious adverse reaction is established. As related to pediatric drug use, evidence is even more erratic, as most drugs are used off labels. To enhance child safety, there is an urgent need to develop robust and rapid methods to identify such associations in as timely a manner as possible. In this chapter, several novel methods, both clinically based pharmacoepidemiological approaches and laboratory-based methods, are described.

Do the national survey results reflect the state of drug-induced liver injury in a single local city in which there is no hospital having Members of the Board of Councilors of the Japan Society of Hepatology? Results of a questionnaire survey conducted in a local city

AIM

  This survey aims at clarifying if there are common features of drug-induced liver injury (DILI) in local areas and in the national surveys, and the degree of dissemination of the new diagnostic criteria (JDDW scale) proposed during the Japan Digestive Disease Week (JDDW) in 2004 and Manual for Serious Side-Effects of DILI (Manual) published in April 2008.

METHODS

  An anonymous questionnaire for DILI was conducted for 6 weeks starting on 20 October 2008. The participants were 179 medical doctors. One hundred and fifty-seven of them belonged to the Medical Association of Nakatsu City (population: 86 000 persons), which is located in northern Kyushu, and 22 physicians working in a core hospital, Nakatsu Municipal Hospital.

RESULTS

  Seventy-four percent of the responding doctors with 13 various specialties had experienced DILI cases. The three most frequent causative drugs were antibiotics, folk medicines and drugs for the circulatory system. DILI associated with folk medicines was encountered mostly after 2000. The doctors' recognition of the JDDW scale and Manual were as low as 17% and 29%, respectively.

CONCLUSION

  This survey revealed that the results of the national investigations conducted by the Japan Society of Hepatology (JSH) reflect the current state of DILI in local areas in which there is no hospital with Members of the Board of Councilors of the JSH. Widespread utilization of the Manual and JDDW scale by local doctors must be facilitated for early diagnosis of DILI and the prevention of severe conditions.

Hypersensitivity pneumonitis caused by Penicillium citrinum, not Enoki spores

BACKGROUND

Flammulina velutipes is called the Enoki mushroom in Japanese and is cultivated indoors. Mushroom workers face occupational exposure to a tremendous number of fungi and organic antigens capable of causing hypersensitivity pneumonitis (HP). One worker employed at an Enoki farm developed HP due to Penicillium citrinum. This study investigated new cases of HP among the workers cultivating Enoki.

METHODS

Serum Krebs von der Lungen-6 (KL-6), surfactant protein (SP)-A and SP-D were measured. Lymphocyte stimulation tests (LST) and double immunodiffusion tests (DIT) were performed to identify P. citrinum. Workers showing high levels of KL-6, SP-A, or SP-D and a high LST value or positive DIT were identified and then were further examined by chest computed tomography, bronchoalveolar lavage and transbronchial lung biopsy. The initial patient and new HP patients were defined as the HP group and the other participants were defined as the non-HP group.

RESULTS

Forty-eight Enoki workers participated in the study. Four of nine workers who met the criteria for further examinations were diagnosed as having HP due to P. citrinum. In comparison between non-HP group and HP group, KL-6, SP-D and LST values were significantly higher in HP group. There was a strong correlation between KL-6 and SP-D. DIT had high sensitivity and high specificity.

CONCLUSIONS

KL-6, SP-D, LST, and DIT were useful for detecting HP patients. KL-6 was the most useful predictor of HP in this study. DIT was useful not only as a predictor of HP but also as a detector of the causative antigen.

Therapeutic effects for hypersensitivity pneumonitis induced by Japanese mushroom (Bunashimeji)

BACKGROUND

Bunashimeji-related hypersensitivity pneumonitis is found among workers who cultivate the mushroom in indoor facilities. An evaluation of protective measures was initiated using the outcomes of clinical, immunological, and radiological findings.

METHODS

Twenty-two patients presented with symptoms of HP; all were employed cultivating Bunashimeji mushrooms in indoor facilities. After hospitalization, 6 of 22 patients quit their job to avoid exposure to spores (Avoidance group). Sixteen patients continued to work used a mask for 3 months, and were then divided into two subgroups: Mask alone (seven patients) and mask plus oral prednisolone (Mask + PSL) (nine patients). The erythrocyte sedimentation rate (ESR), serum Krebs von der Lungen-6 (KL-6), surfactant protein-D (SP-D), lymphocyte stimulation test (LST), ground-glass scores in chest high-resolution computed tomography (HRCT), and bronchoalveolar lavage (BAL) were assessed before and after treatment.

RESULTS

Complete avoidance resulted in a significant decrease in LST. There was a significant decrease after PSL treatment in serum KL-6, SP-D, and total cell counts in the BAL fluid in the Mask + PSL group. In the Mask alone group, serum KL-6, SP-D, ground-glass scores in chest HRCT and total cell counts in BAL fluid showed high levels compared with the other two groups.

CONCLUSIONS

Complete cessation was the best treatment for hypersensitivity pneumonitis. The use of a mask was ineffective for patients with a high serum KL-6 and SP-D concentration and severe ground-glass opacity on chest HRCT. Initial treatment with PSL is recommended for these patients with high levels of total cell counts in BAL fluid.

High expression of eosinophil chemoattractant ecalectin/galectin-9 in drug-induced liver injury

BACKGROUND

Ecalectin/galectin-9 (ECL/GL9) is an eosinophil chemoattractant isolated from T lymphocytes. Drug-induced liver injury (DILI), often caused by an allergic mechanism, is occasionally accompanied by eosinophilic infiltration. In this study, we intended to determine whether DILI can induce augmentation of ECL/GL9 expression. Further, we investigated whether this augmentation is associated with tissue eosinophilia.

METHODS

We examined the expression of ECL/GL9 in biopsy specimens of DILI using the immunohistochemical technique. A rabbit anti-ECL/GL9 antibody was produced by immunizing rabbits with synthetic peptide corresponding to a molecular epitope of ECL/GL9. Thereafter, immunohistochemical staining with the use of this antibody was performed on 16 DILI needle biopsy specimens, and on biopsy specimens of chronic viral hepatitis, liver cirrhosis, and normal liver tissues as controls.

RESULTS

In all cases of DILI specimens, but not in control liver specimens, a clear positive staining for ECL/GL9 was observed. Such positive staining was noted on Kupffer cells, fibroblasts, and histiocytes, but not on lymphocytes or hepatocytes. However, the intensity of immunolabeling did not correlate with the extent of eosinophile leukocyte infiltration.

CONCLUSION

High expression of ECL/GL9 is suggested to be a specific finding of DILI. However, tissue eosinophilia in DILI cannot be explained by the augmentation of ECL/GL9 expression.

Hypersensitivity pneumonitis induced by spores of Penicillium citrinum in a worker cultivating Enoki mushroom

A 47-year-old Japanese woman was admitted to our hospital with a 2-week history of dry cough and shortness of breath. She had been engaged in Enoki mushroom production for 22 years. Chest X-ray and chest computed tomography (CT) scan showed bilateral fine-nodular shadows and ground glass opacity. Bronchoalveolar lavage fluid demonstrated an increase of total cell counts with predominant lymphocytosis. Pathological specimens obtained by video-assisted thoracoscopic surgery revealed alveolitis and noncaseating granuloma with giant cells. Lymphocyte stimulation test showed positive responses with Enoki mushroom, culture medium, and Penicillium citrinum. On double immunodiffusion test, a precipitation line was observed between patient's serum and Penicillium citrinum antigen. She was found to have hypersensitivity pneumonitis caused by Penicillium citrinum. This is the first report of mushroom worker's lung caused by Penicillium citrinum.

Hypersensitivity Pneumonitis due to Bunashimeji Mushrooms in the Mushroom Industry

BACKGROUND

Detection of hypersensitivity pneumonitis (HP) in employees involved in the Bunashimeji mushroom industry is difficult. The level of precipitating antibody is not related with the prediction of progression and resolution of HP. The aims of this study were to examine the actual prevalence of HP in the Bunashimeji industry and the clinical differences among selected employees.

METHODS

One hundred and fourteen employees worked in Bunashimeji enterprises. These subjects were divided into the following subgroups: office workers, pickers/packers with mask and pickers/packers without mask. We measured serum Krebs von der Lungen-6 (KL-6), surfactant protein (SP)-A and SP-D, and examined the stimulation index (SI) due to Bunashimeji spores. Chest high-resolution computed tomography (HRCT), pulmonary function tests and bronchoalveolar lavage (BAL) were performed for select employees who showed positive SI values (>200%) to examine the clinical differences.

RESULTS

The proportion of respiratory symptoms was significantly higher in the pickers/packers than that in the office workers. The picker/packer group had high serum KL-6 concentrations and SI compared with the office worker group. Thirty select employees were divided into the following three subgroups: HP, select employees without HP, and SI <400% and KL-6 <500 U/ml , using high SI levels (>400%) and positive serum KL-6 concentration (>500 U/ml). Four exhibited ground glass opacities with centrilobular fine nodules on HRCT, and 8 had high numbers of lymphocytes in the BAL fluid. The BAL findings and serum KL-6 concentrations showed significant differences among the three groups.

CONCLUSIONS

Four employees were evaluated as having HP. Serum KL-6 and SP-D may be related to the resolution of HP in addition to SI and chest HRCT.

Lymphocyte transformation test for medicinal herbs yields false-positive results for first-visit patients

We performed lymphocyte transformation tests (LTTs) for toki (angelicae radix) and ogon (scutellariae radix) on first-visit patients who had never taken Kampo medicines. LTTs for both herbs were positive in 12 of 14 patients, suggesting that LTTs for these herbs are unreliable for the diagnosis of Kampo medicine-induced liver injury.

Herbal medicine and false-positive results on lymphocyte transformation test

In vitro mitogenic activity of 16 herbs and 3 Kampo (herbal medicine) formulae have been reported in experimental studies. It is not known how many herbs and Kampo formulae in total have mitogenic activity. Lymphocyte transformation test (LTT) is generally utilized to diagnose drug-induced liver injury. In LTT, mitogenic activity is assessed by measuring 3H-thymidine incorporation. The objective of the present study was to determine which herbs and which Kampo formulae caused false-positivity on LTT. We examined 2496 summaries of all admission records from 1979 to 1999 in our department. We selected patients in whom liver injuries were diagnosed as definitely unrelated to Kampo medication. In these patients, LTT was performed for some herbs contained in the suspect Kampo medicines, resulting in positive LTT for 17 herbs: Evodiae Fructus (Goshuyu), Zizyphi Fructus (Taiso), Ginseng Radix (Ninjin), Zingiberis Rhizoma (Shokyo), Hoelen (Bukuryo), Aconiti Tuber (Bushi), Angelicae Radix (Toki), Cnidii Rhizoma (Senkyu), Rehmanniae Radix (Jio), Ephedrae Herba (Mao), Anemarrhenae Rhizoma (Chimo), Cinnamomi Cortex (Keihi), Bupleuri Radix (Saiko), Artemisiae Capillari Spica (Inchinko), Persicae Semen (Tonin), Moutan Cortex (Botanpi) and Paeoniae Radix (Shakuyaku). These results were considered false-positive, because the results were observed in the "definitely unrelated" patients. Mitogenic activity inherent to some herbs and Kampo formulae may sometimes cause false-positivity on LTT in clinical situations. These examples suggest that LTT for Kampo formulae may be unreliable as a diagnostic method for drug-induced liver injury.

Hypersensitivity pneumonitis induced by spores of Lyophyllum aggregatum

OBJECTIVES

Lyophyllum aggregatum (LA) is called Shimeji in Japanese and is eaten commonly as a mushroom. Shimeji mushrooms are cultivated in an indoor environment all year round. This study aimed to clarify the clinical features of hypersensitivity pneumonitis (HP) induced by LA.

PATIENTS AND SETTING

Ten patients showed mild respiratory symptoms including dry cough, sputum, and low-grade fever. We tried to characterize the clinical features and the findings using chest high-resolution CT (HRCT), pulmonary function tests (PFTs), and BAL fluid (BALF) tests in patients with HP induced by LA. HP was diagnosed from clinical features, HRCT findings, BALF findings, lung histology, and lymphocyte stimulation tests (LSTs) for LA.

RESULTS

Laboratory findings showed mean (+/- SD) elevated levels of C-reactive protein (0.78 +/- 1.3 mg/dL), erythrocyte sedimentation rate (48 +/- 23 mm/h), and gamma-globulin (26.9 +/- 7.6%). PFTs revealed a slight decrease in the percentage diffusing capacity of the lung for carbon monoxide, possibly due to the presence of epithelial granulomas in the alveoli. Although 4 of 10 patients showed normal findings on the chest radiograph (CXR), chest HRCT findings of all patients showed centrilobular small nodules and diffuse ground-glass opacities. The BALF testing revealed an increase in total cell counts, showing predominantly activated T lymphocytes. The CD4/CD8 cell ratio was significantly decreased (0.5 +/- 0.3). The results of the LSTs were positive in seven of seven cases.

CONCLUSIONS

Since patients with HP induced by LA typically have mild respiratory symptoms and sometimes normal CXR findings, their conditions might remain undiagnosed. However, the chest HRCT images showed the typical subacute phase of HP.

Cutaneous and immunologic reactions to phenytoin

Phenytoin (diphenylhydantoin; Dilantin) is a highly effective and widely prescribed anticonvulsant and antiarrhythmic agent. Since 1938 it has been invaluable in the treatment of grand mal and psychomotor epilepsy. Hydantoin derivatives have been used medicinally for more than a half-century. In recent years dermatologists have broadened the indications for phenytoin use to include recessive dystrophic epidermolysis bullosa, linear scleroderma, and pachyonychia congenita. In spite of widespread use and popularity, it is interesting that the frequency of complications relating to drug therapy remains low, relatively speaking. Nevertheless, a broad spectrum of cutaneous and immunologic reactions to phenytoin have been reported. These range from tissue proliferative syndromes (side effects), drug hypersensitivity syndromes (allergic effects), and a possible linkage with lymphoma (idiosyncratic effects). Therapeutic and toxic reactions to this commonly prescribed drug are comprehensively reviewed, analyzed, and summarized in this monograph.

Pseudolymphoma with mycosis fungoides manifestations, hyperresponsiveness to diphenylhydantoin, and lymphocyte disregulation

Three patients receiving diphenylhydantoin (DPH) were seen with a reversible process suggesting mycosis fungoides. Clinical and laboratory manifestations included generalized pruritic exfoliative erythroderma, eosinophilia, lymphadenopathy, hepatosplenomegaly, circulating Sézary cells, epidermal Pautrier's microabscesses on skin biopsy, and moderate liver dysfunction. Studies of the distribution and function of the various lymphocyte subpopulations from these patients showed: (1) an increase in the relative and absolute number of T lymphocytes (85--92%); (2) significant stimulation of lymphocyte-blastic transformation by DPH and low response to pokeweed mitogen stimulation; (3) the impaired ability of T gamma lymphocytes to suppress B-cell differentiation and immunoglobulin production. With only one exception, 15 symptom-free patients on DPH showed none of these abnormalities. The clinical manifestations and immunologic abnormalities of patients with this pseudo mycosis fungoides syndrome remitted three to four weeks after DPH administration was discontinued. The proliferation of T lymphocytes and the inhibition of the function of T gamma-suppressor lymphocytes noted in these patients may be significant to the development of other types of pseudolymphoma and to that of true lymphoma.

Peripheral lymphocyte culture in the diagnosis of drug induced liver injury

In order to evaluate the usefulness of the peripheral lymphocyte culture method for the diagnosis of drug-induced liver injury, a study was carried out on 21 cases of drug-induced liver injury (Group A). Nine cases in Group A showed a positive lymphocyte stimulation test. Out of 9 cases which showed positive stimulation six cases were cholestatic type of liver injury, and the remaining three were of hepatitic type. The results suggest that peripheral lymphocyte culture method is a useful method for diagnosis of drug-induced liver injury.

Leukocyte migration inhibition induced by the combination of drug and a liver constituent in patients with drug-induced hepatitis

The leukocyte migration inhibition test in agarose medium was performed in 23 cases of clinically diagnosed drug-induced hepatitis. When the test antigen was the combination of soluble phase of a liver homogenate fractionated by Sephadex G-100 which should have contained liver specific antigen and the offending drug the leukocyte migration was inhibited in 86% of cases. Whereas none of 12 cases of drug allergy without hepatic injury showed a positive result with the same combination of antigens. Other organ homogenate-muscle and kidney-never gave positive results when mixed with the offending drugs in cases of drug-induced hepatitis. It was concluded that in hypersensitivity type drug-induced hepatitis cell-mediated immunity might be established to the complex of liver specific antigen and the drug.

Erythromycin jaundice: diagnosis by an in vitro challenge test

A 53-year-old housewife who had developed severe cholestatic hepatitis following the administration of erythromycin estolate therapy two-and-a-half years previously, was studied by an in vitro "challenge" test in which peripheral venous lymphocytes were cultured in the presence of erythromycin estolate, erythromycin stearate and erythromycin base. Evidence of blastogenesis was observed in response to erythromycin estolate, but not to erythromycin stearate of erythromycin base. This test thus provided evidence that the patient was "sensitized" to erythromycin estolate without exposing her to the risk of in vivo challenge. Furthermore, in contrast to previous studies, the findings provide evidence that erythromycin estolate jaundice is mediated by immunological mechanisms.

High incidence of horse serum protein allergy in various autoimmune disorders

In 186 persons (68 patients suffering from different so-called autoimmune diseases, 30 kidney recipients, 38 control patients from a surgical ward, and 50 healthy volunteers) the immune response to horse IgG was examined. The lowest rate of sensitization was found in kidney transplant recipients (3%) and the highest in autoimmune patients (33%). After excluding 39 patient who had received horse serum treatment prior to the examination, it was found that without previous injection of horse serum, 27% of the patients with autoimmune disease were sensitized to horse IgG. Compared to the other groups (kidney transplant recipients, 4%: surgical controls, 0%; healthy volunteers, 3%), this difference was statistically significant (p is less than 0.01).

Suppression of thymidine uptake of human lymphocytes by co-trimoxazole

Co-trimoxazole (trimethoprim-sulphamethoxazole) causes a decrease in the uptake of labelled thymidine in lymphocytes cultured in the presence of phytohaemagglutinin. This phenomenon was observed in 60% of 25 subjects. In cultures affected by the drug the mean suppression was 84%. A small decrease in thymidine uptake was noted with trimethoprim and sulphamethoxazole separately, but the effect was much more pronounced with the combination of the two drugs. The mechanism responsible for this phenomenon is discussed. The action is probably not due to the ability of these drugs to interfere with folic acid metabolism and it is likely that there is no direct effect on DNA synthesis.The suppression of thymidine uptake by lymphocytes in vitro in the presence of co-trimoxazole may not have any obvious clinical significance. However, in view of a report of an immunosuppressive action of trimethoprim in mice, it is possible that the leucopenia observed in some patients treated with this drug may have been caused by a similar mechanism.These experiments show that lymphocytes in vitro are suppressed by co-trimoxazole in concentrations comparable to, or smaller than, those found in vivo under normal therapeutic conditions. They are therefore likely to be clinically relevant.