Drug allergy in mastocytosis.

Drugs are known triggers of anaphylaxis in patients with mastocytosis even to the association between drug anaphylaxis and mastocytosis does not appear frequently appear. Nevertheless, mast cell disorders might be ruled out in cases of severe systemic reactions. Careful examination of the skin should accompany measurement of basal serum tryptase levels. The data published about drug anaphylaxis in patients with mast cell disorders are scarce, and it is not currently possible to provide clear recommendations. Most papers report cases of anaphylaxis during surgical procedures or radiocontrast media exposure. There are no specific recommendations to prevent severe reactions during such procedures, although some specialists suggest performing premedication with antihistamines and corticosteroids before anesthesia or radiocontrast media administration.

Establishment of thiopurine S-methyltransferase gene knockdown in jurkat T-lymphocytes: an in vitro model of TPMT polymorphism.

BACKGROUND: Thiopurine S-methyltransferase (TPMT) is an excellent example of an enzyme whose pharmacogenetic polymorphisms affect efficacy and toxicity of a drug. The association between TPMT activity and thiopurine-related myelosuppression is well recognized. To study the significance of TPMT deficiency in thiopurine metabolism and immunosuppressive activity in vitro, we established RNA interference-based TPMT knockdown (kd) in a Jurkat cell line. RESULTS: In Jurkat TPMT kd cells, TPMT expression was reduced to 73% at the RNA level and 83% at the protein level. TPMT kd cells were more sensitive to 6-mercaptopurine (6-MP) (10 µmol/L) and 6-thioguanine (6-TG) (8 µmol/L) than wild-type (wt) cells, (32% versus 20%) and (18% versus 9%), respectively. Both Jurkat wt and kd cells were more sensitive to 6-TG-induced apoptosis than to 6-MP. 6-TG activity was also more affected by TPMT levels than was 6-MP as reflected by IC60, concentrations that is, 6-MP [4.6 µmol/L (wt) and 4.7 µmol/L (kd)], 6-TG [2.7 µmol/L (wt) and 0.8 µmol/L (kd)]. IC60 concentrations induced significant apoptosis in both Jurkat wt and kd cells (257%, versus 314%) with 6-MP and (323% versus 306%) with 6-TG, respectively. At IC60 (6-MP) 6-thioguanine nucleotides (6-TGN) accumulation in cells was 518 versus 447 pmol/million cells in wt and kd cells, respectively. On the other hand 6-TGN accumulation at IC60 (6-TG) was 477 versus 570 pmol/million cells in wt and kd cells, respectively. 6-Methylated mercaptopurine (6-MeMP) concentrations were more affected than 6-TGN by TPMT kd (194 versus 10 pmol/million cells) in wt and kd cells, respectively. CONCLUSION: We conclude that TPMT kd cells are an appropriate in vitro model to investigate the significance of TPMT deficiency with thiopurine therapy and could be helpful in understanding possible clinical consequences of TPMT polymorphism.

Association of CYP1B1 with hypersensitivity induced by taxane therapy in breast cancer patients.

Taxanes represent a group of anticancer drugs with a wide range of activity against breast cancer. Therapy side effects include haematologic toxicity (neutropenia, leucopenia), peripheral neuropathy and hypersensitivity, and demonstrate inter-individual variations. Since it is known that three genes are implicated in taxane turnover, namely ABCB1 in the transport, CYP2C8 in the metabolism and CYP1B1 in the activity, we explored the association among polymorphisms (single nucleotide polymorphisms, SNPs) in these three genes and the occurrence of taxane-induced toxicity. We studied 95 patients affected by breast cancer and under treatment with taxanes as adjuvant, metastatic or neo-adjuvant therapy. We genotyped them for SNPs in the CYP2C8 (alleles *1, *2, *3 and *4), CYP1B1 (alleles *1 and *3) and ABCB1 (1236 C>T; 2677 G>T/A; 3435 C>T) genes by real-time PCR assay. We observed a significant association between the CYP1B1*3 allele and a lower occurrence of hypersensitivity reactions to taxane treatment. We speculate that the highest production of 4-hydroxyestradiol (4-OHE2) metabolite by CYP1B1*3 allele could increase the formation of the 4-OHE2-taxane adduct and possibly inhibit taxane toxicity. We suggest that CYP1B1 might affect taxane hypersensitivity therefore representing, if confirmed in a large cohort of patients, an exploratory hypersensitivity predictive biomarker.

Aspirin-intolerant asthma: role of cyclo-oxygenase enzymes.

Aspirin-induced asthma and rhinitis (AIAR) appear to be precipitated by the inhibition of cyclo-oxygenase (COX). By inhibiting COX pathway aspirin diverts arachidonic acid metabolites to the lipoxygenase pathway. There are two isoforms of COX, namely COX-1 and COX-2. Metabolites derived from COX-1 are involved in cellular housekeeping functions. COX-2 can be induced in cells exposed to proinflammatory substances and growth factors. Recent studies have reported that patients with AIAR have decreased activity of COX-2 and lower production of PGE(2) in the upper airway and peripheral blood cells. Considering the protective effect of exogenous PGE(2) on aspirin-induced bronchoconstriction and the interdependence of PGE(2) and cisteinyl leukotriene production, a reduced PGE(2) synthesis may render aspirin-sensitive patients more susceptible to the inhibitory effect of NSAIDs drugs and also lead to an increase in cysteinyl leukotriene release.

Leukotriene C4 synthase promoter polymorphism in Japanese patients with aspirin-induced asthma.

BACKGROUND: The A to C transversion in the promoter region of the gene encoding leukotriene C4 synthase (LTC4S) is proposed to be associated with the development of aspirin-induced asthma (AIA). OBJECTIVE: We investigated the frequency of the polymorphism in Japanese population and its association with clinical characteristics and cysteinyl leukotriene production. METHODS: Genotyping of LTC4S gene promoter was performed on 60 patients with AIA, 100 patients with aspirin-tolerant asthma (ATA), and 110 control subjects. We assessed the basal levels of urinary LTE4, the increment of urinary LTE4 on venous aspirin challenge, and LTC4S activity in peripheral blood eosinophils. RESULTS: The frequency of the variant C allele was significantly higher in patients with AIA (frequency of allele [q] = 0.192) than in patients with ATA (q = 0.110, P =.042). Variant C-allelic carriers experienced asthma at a significantly younger age (31.8 +/- 2.9 years [mean +/- SEM]) than wild-type A homozygotes (41.3 +/- 2.2 years, P =.007). Basal levels of LTE4 and the increment of urinary LTE4 on venous aspirin challenge did not show a difference between wild-type A homozygotes and variant C-allelic carriers. There was no relationship between the polymorphism and the LTC4S activity in eosinophils, although LTC4S activities were significantly higher in patients with AIA than in patients with ATA. CONCLUSION: Our findings reveal the lack of functionality of the polymorphism in the LTC4S gene, whereas this polymorphism might have some effect on the development of AIA, probably in linkage disequilibrium with another causatively important mutation.

Anticonvulsant hypersensitivity syndrome.

BACKGROUND: Anticonvulsant hypersensitivity syndrome (AHS) is a serious but poorly understood and little known disease. It has been variously described in the literature since 1934. Fatalities are rare but have been reported. METHODS: A MEDLINE search was undertaken from 1991 to present, using the keywords "anticonvulsant," "phenytoin," and "hypersensitivity." English language articles and their endnotes were reviewed, and neurologists, dermatologists, and specialists in hematology-oncology were consulted. RESULTS: A case of AHS is described. Investigators have reported epidemiologic data and described the pathophysiology, diagnostic criteria, and management options. CONCLUSIONS: Family physicians should be aware of the AHS because of the high likelihood that patients with this syndrome will come first to their primary care physicians for care. Certain anticonvulsant medications have a high degree of cross-reactivity, the incidence of AHS is higher among first-degree relatives, and the disorder mimics systemic infection. If AHS is suspected, the antiepileptic drug should be discontinued. Supportive care should be directed to the appropriate organ systems, with particular attention to skin, eyes, and liver. Corticosteroid treatment might be effective in reversing the drug reactions, but it is not recommended in cases of suspected or actual infection because of the increased risk of immunocompromise, sepsis, and associated mortality.

[When the fluoro-immuno-enzymatic (FEIA) measurements turn out to be more sensitive than radioimmunologic (RIA) measurements. Application to the measurement of serum tryptase]. / Quand les dosages fluoro-immuno-enzymatiques (FEIA) deviennent plus sensibles que les dosages radio-immunologiques (RIA). Applications au dosage de la tryptase sérique.

The measurement of Tryptase by the Fluoro-Immuno-Enzymatic (FEIA) method is nowadays possible on the Pharmacia CAP system (automatic UniCAP). This measurement is more comprehensive as it measures the release of serum tryptase from both the tissue mastocytes (MCTC) as well as the mucosal mastocytes (MCM). Technically the measurements are comparable with those made by the method of radio-immunology (RIA), are absolutely reproducible and surprisingly at 100%. It has also been possible to evaluate the two techniques of FEIA and RIA on negative and positive pools. This new FEIA technique for serum tryptase is applicable: to anaphylactic and/or anaphylactoid accidents at the time of induction of anesthesia, in general conditions such as haemorrhagic recto colitis (RCH), Crohn's disease, and mastocytosis. Finally these measurements can be used during nasal and bronchial provocation tests, as the measurements may be made on nasal and bronchial lavage liquids. The sensitivity and the very good reproducibility of this new technique of FEIA for tryptase is of very great interest and avoids use of radio-active isotopes.

Role of Leukotriene-degrading enzymes in pulmonary response to antigen infusion in sensitized guinea pigs in vivo.

To determine the role of leukotriene (LT)-degrading enzymes in allergic reactions, we studied the effects of inhibitors of gamma-glutamyl transpeptidase (gamma-GTP) and dipeptidases on increases in pulmonary insufflation pressure (PIP) and vascular permeability induced by ovalbumin (OA) antigen in guinea pigs sensitized to OA antigen in vivo. Vascular permeability was assessed by the amount of extravasated Evans blue dye from the trachea, main bronchi, and segmental bronchi. An intravenous (i.v.) administration of OA antigen (200 micrograms/kg) caused increases in PIP and extravasated Evans blue dye, and OA antigen-induced effects were potentiated by gamma-GTP inhibitor L-serine borate (3 x 10(-5) M/kg, i.v.) (P < 0.05) and an inhibitor of dipeptidases, L-cysteine (3 x 10(-5) M/kg, i.v.) (P < 0.01). OA antigen-induced increases in PIP and Evans blue dye extravasation were in part inhibited by LT-receptor antagonist ONO-1078 (10(-4) M/kg, i.v.). Guinea-pig tracheal tissues contained gamma-GTP and microsomal dipeptidase activities. Histochemical and immunohistochemical studies indicate that gamma-GTP-like activity existed in the epithelium and smooth muscle, and an activity of microsomal dipeptidase was observed in the endothelial cells of microvessels and epithelium. These results suggest that LT-degrading enzymes have an important role in regulating allergic reaction in the airway in vivo.

Targeted disruption of the DNA repair methyltransferase gene renders mice hypersensitive to alkylating agent.

Alkylation of DNA at the O(6)-position of guanine is one of the most critical events leading to induction of mutation as well as to cancer. The enzyme O(6)-methylguanine-DNA methyltransferase repairs this and related lesions in DNA. By means of gene targeting, we established mouse lines deficient in the methyltransferase gene and tissues from these mice contained no methyltransferase activity. Administration of methylnitrosourea to these gene-targeted mice led to early death, and normal mice treated in the same manner showed no untoward effects. In mice given methylnitrosourea treatment, the bone marrow became hypocellular and there was a drastic decrease in the number of leukocytes and platelets, thereby indicating an impaired reproductive capacity of hematopoietic stem cells. Methyltransferase apparently protected these mice from the pancytopenia caused by the alkylating agent.

DT-diaphorase as a determinant of sensitivity to adriamycin in non-small-cell lung-cancer cell lines.

We have reported the establishment of a mitomycin-C (MMC)-resistant non-small-cell lung-cancer cell line, PC-9/MC4. As determined by an MTT assay, this resistant cell line was found to be 4 times more sensitive to adriamycin (ADM) than was the parental PC-9. There were no significant differences in sensitivity to etoposide, mitoxantrone, daunomycin, epirubicin, pirarubicin, 9-aminoanthracycline or 3'-deamino-3'-morpholino-13-deoxo-10-hydroxy carminomycin. These data suggest that neither qualitative or quantitative changes in DNA topoisomerase II nor the enhanced repair of DNA can explain the differing sensitivity to ADM observed. No significant differences were found in the accumulation of ADM and glutathione (GSH) in these cell lines. Although total glutathione-S-transferase (GST) activity in PC-9/MC4 cells was lower than that observed in PC-9 cells and treatment with ethacrynic acid (EA) reduced sensitivity to ADM in both cell lines, relative resistance was unaffected. NADH-cytochrome b5 reductase (B5R) activity in PC-9/MC4 cells showed a 3-fold greater decrease than that in PC-9 cells, and DT-diaphorase (DTD) activity in PC-9/MC4 cells showed an approximately 200-fold greater decrease than that in PC-9 cells. Addition of dicumarol, an inhibitor of DTD, decreased the sensitivity of ADM of PC-9 but not of PC-9/MC4. DTD activity in the PC-9 cell line was inhibited by treatment with dicumarol while in PC-9/MC4 it remained unchanged. These data suggest that DT-diaphorase is a determinant of sensitivity to ADM in the 2 cell lines.

A human cell line proficient in O6-methylguanine-DNA-methyltransferase and hypersensitive to alkylating agents.

The involvement of O6-methylguanine (O6-meGua) in mutagenesis is well established, while the toxic effect of these residues is still controversial. In this study, we compare the cytotoxicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and N-methyl-N-nitrosourea (MNU) on three cell lines of different origin, which have different abilities to repair O6-meGua residues (Mer phenotype): a human hepatoma cell line (LICH cells, Mer+), a rat hepatoma cell line (H4 cells, Mer+) and a Chinese hamster cell line (CHO cells, Mer- phenotype). LICH and CHO cells show the same sensitivity to the killing effect of MNNG and MNU and are approximately 5-fold more sensitive than H4 cells. However, LICH and H4 cells share similar sensitivities to the toxic effect of 1,3-bis(2-chloroethyl)-1-nitrosourea. O6-meGua residues are removed at the same rate from the DNA of [3H]MNU-treated LICH and H4 cells, which also do not differ in the rate of removal of N3-methyladenine residues nor in overall DNA repair synthesis. The results suggest that MNNG and MNU produce a lethal lesion that is repaired by a process that does not involve the alkyltransferase.

[The effect of milk consumption on the activity of the formaldehyde detoxification system in sensitization to this compound]. / Vliianie potrebleniia moloka na aktivnost' sistemy detoksikatsii formal'degida pri sensibilizatsii étim soedineniem.

The activity of formaldehyde dehydrogenase (FDG) and total nonspecific formaldehyde oxidative activity of nasal mucosa and liver and the amount of reduced glutathione in the liver were measured in guinea pig subjected to epicutaneous or inhalative action of formaldehyde and additionally fed with cow milk. Glutathione-deficient animals demonstrated an increase in FDG activity following formaldehyde sensitization both in the liver and in nasal mucosa, whereas FDG activity in glutathione-supplied animals did not change significantly. The concentration of formaldehyde in the internal environment is supposed to be controlled by the levels of coenzyme (reduced glutathione) and FDG activity.

Alteration of type II regulatory subunit of cAMP-dependent protein kinase in human cisplatin-resistant cells as a basis of collateral sensitivity to 8-chloro-cAMP.

A cyclic adenosine 3',5'-monophosphate (cAMP) analogue, 8-chloro-cAMP (8-Cl-cAMP), had a collateral growth-inhibitory effect on a cis-diamminedichloroplatinum(II) (CDDP)-resistant human cancer cell lines (PC-14/CDDP). The non-selective analogues dibutyryl-cAMP, 8-bromo-cAMP and forskolin, which are cAMP agonists, showed far less cytotoxicity than 8-Cl-cAMP in both cell lines. There was no significant difference in cAMP content between PC-14 and PC-14/CDDP. Because 8-Cl-cAMP has been shown to bind selectively to the site I receptor of the type II regulatory subunit (RII) of cAMP-dependent protein kinase, we determined the level of expression of regulatory subunits in PC-14 and PC-14/CDDP cells by photoaffinity labeling. PC-14/CDDP cells had a higher RII level, low site I receptor of type I regulatory subunit (RI) level, and a lower RI/RII ratio than the parental PC-14 cells. Exposure to 8-Cl-cAMP increased the RI and RII level in PC-14/CDDP cells in dose- and time-dependent manners. On the other hand, in parental PC-14 cells, RII was not detected and the levels of RI and RII were not increased by exposure to 8-Cl-cAMP. These results suggested that the change in RI and/or RII levels caused by 8-Cl-cAMP was correlated with 8-Cl-cAMP-induced growth inhibition and that the collateral sensitivity to 8-Cl-cAMP in CDDP-resistant cells was due to the increased RII level. Our results suggest that 8-Cl-cAMP can be used in combination with CDDP and that measurement of RI and RII levels and/or the RI/RII ratio is a useful tool to predict CDDP sensitivity.

Intolerance to aspirin and the nonsteroidal anti-inflammatory drugs.

A constant enigma has been the ability of aspirin and other structurally unrelated nonsteroidal anti-inflammatory drugs to induce non-IgE mediated allergic reactions. These reactions range from mild hypersensitivity to fatal anaphylaxis. Recent biochemical and pharmacologic studies involving the oxidative metabolism of arachidonic acid in different cells and tissues have provided insights into how this could conceivably occur. The products of cyclo-oxygenase and lipoxygenase pathways of arachidonic acid metabolism and their interactions may provide an approach, if not the solution, to the problem of aspirin intolerance.

[Analgesic asthma]. / Analgetika-Asthma.

Analgesics-induced asthma (AIA) is quite often unidentified and then is a severe danger to the patients affliced. In a case-control-study 1042 asthmatic patients selected by random were investigated. In 18.9% of patients the presence of AIA was recorded. Woman accounted for 71% of the AIA patients. Coincidence of AIA with nasal polyposis, paranasal sinus diseases, chronic rhinitis, alcohol intolerance and severe bronchial asthma was recorded with high significance. Chronic hyperplastic changes in the upper airways were exhibited by about 64% of the AIA patients. AIA is a non-allergic form of asthma, resembling immediate allergic type I reaction. Analgesics-based acute bronchoconstriction will typically develop within 45 min. following intake of the analgesic. Triggering threshold doses may differ strongly by individuals. Oral exposure test is connected with a high risk of complications. A case history usually is sufficient for save diagnosis. Analgesics without inhibiting action on cyclooxygenase usually are tolerated. The causes of AIA should be ascribed to changes in the release and conversion of arachidonic acid (Aa) from membrane phospholipids. The inhibition of Aa release (phospholipase-A2-reaction) by protease inhibitors or the inhibition of Aa transformation to bronchoconstrictive lipoxygenase products by lipoxygenase inhibitors were shown in vitro (isolated guinea pig lung strips and human bronchi). Paraaminomethylbenzoic acid also was found to be effective in clinical experiments preventing analgesics-induced bronchoconstriction. Both seem to be principal ways for modulation of bronchoconstriction.

Effect of coal tar on cutaneous aryl hydrocarbon hydroxylase induction and anthralin irritancy.

The inflammatory dose-response to topical anthralin and whole skin aryl hydrocarbon hydroxylase (AHH) activity were measured before and 24 h after application of a coal tar solution to the uninvolved skin of patients with psoriasis. The inflammatory response to anthralin decreased and total AHH activity increased after the tar treatment. A possible explanation is that anthralin or an irritant product is metabolized by AHH activity in the skin. Induction of AHH by coal tar increases its removal and reduces anthralin irritancy.

Studies of heterogeneity of angiotensin-converting enzyme and acid phosphatase in granulomatous lesions of skin.

Activities of angiotensin-converting enzyme and acid phosphatase were markedly elevated in the lesions of metal-induced hypersensitivity and foreign body types of granulomas. We biochemically studied these enzymes by means of gel filtration and electrophoresis and compared them with the same enzymes of normal dermis. Two forms of angiotensin-converting enzyme found in normal dermis were increased proportionally. Catalytic properties and heat stability of the enzyme in the lesions and normal dermis were the same. On the other hand, acid phosphatase in the lesions showed a different isozyme pattern from that seen in normal dermis. The enzyme from normal dermis had apparent molecular weight of 150000 and 90000, whereas an additional enzyme with a molecular weight of 230000 was detected in granulomatous lesions. Three isozymes were demonstrable in normal dermis but two additional isoenzymes appeared in granulomatous lesions: the isozyme patterns between the foreign body and hypersensitivity granulomas are different.