Generalized pustular drug eruptions: confirmation by in vitro tests

BACKGROUND

Generalized pustular eruptions are characterized by acute onset of aseptic pustules in febrile patients with leukocytosis after exposure to the offending drug. They have been regarded as uncommon manifestations of adverse drug reactions. Until now few confirmation studies have been carried out.

OBJECTIVE

Our purpose was to describe a series of patients with generalized pustular drug eruption. The diagnosis and etiological role of drugs in these cases was confirmed by two in vitro tests, namely the macrophage migration inhibitory factor (MIF) and the mast cell degranulation (MCD) tests.

METHODS

The clinical, pathological and laboratory findings in six patients with generalized pustular eruption were studied prospectively. The MIF and MCD tests were performed with the drugs taken by the patients.

RESULTS

The dermatological manifestations included numerous pustules on large erythematous areas, papules and erythema multiforme-like lesions. The pustular eruption developed between 12 h and 5 days after the administration of the provoking drug. The histopathological changes were characterized by subcorneal pustules, papillary edema and mixed cell inflammatory infiltrate. In two biopsies the infiltrate displayed numerous eosinophils. Laboratory investigations revealed leukocytosis with neutrophilia (4 of 6 patients) and eosinophilia and hyperimmunoglobulinemia E (2 of 6 patients). MCD tests with the suspected drugs (Ampicillin, Cefazolin, Tetracycline, Griseofulvin, Enalapril Maleate) were positive in all patients. Positive MIF results were seen in five of the six patients. Withdrawal of the drug led to fast recovery.

CONCLUSION

The diagnosis of pustular drug eruptions depends on circumstantial evidence, some characteristic clinicopathological findings and exclusion of alternative diagnoses of other disseminated pustular eruptions. In vitro tests, namely MIF and MCD tests, are a useful diagnostic aid in the identification of the offending drugs.

Severe minocycline-induced eosinophilic pneumonia: extrapulmonary manifestations and the use of in vitro immunoassays

OBJECTIVE

To report a severe and unusual reaction to minocycline and the use of in vitro immunologic assays.

CASE SUMMARY

A 46-year-old white man developed severe respiratory distress with pulmonary infiltrates on chest X-ray and eosinophilia in blood, bronchoalveolar lavage fluid, and biopsied lung tissue during exposure to minocycline. Additional manifestations included pleuropericardial effusion, liver function abnormality, and bone marrow eosinophilia. Macrophage inhibition factor and mast cell degranulation assays were positive to minocycline.

DISCUSSION

The patient's manifestations were compatible with the diagnosis of eosinophilic pneumonia. After excluding other possible etiologies, minocycline was identified as the offending agent. Generalized damage was suggested by the presence of a combination of extrapulmonary manifestations previously not reported. Results of the in vitro immunologic assays supported the hypersensitivity nature of the disease and confirmed the diagnosis.

CONCLUSIONS

Minocycline-induced eosinophilic pneumonia may involve extrapulmonary sites. It is suggested that in vitro immunoassays be used for confirmation of the diagnosis rather than rechallenge or invasive procedures.

Quantification of dopamine transporter density in monkeys by dynamic PET imaging of multiple injections of 11C-CFT

Idiopathic Parkinson's disease (PD) is characterized by loss of dopaminergic terminals in the basal ganglia. The cocaine analog, CFT (WIN 35,428), has been shown to bind selectively to the pre-synaptic dopamine transporters and thus represents an important probe for monitoring disease progression. In this study, we evaluated [11C] labeled CFT as a PET ligand for the quantitative in vivo assay of dopamine transporter density in three normal rhesus monkeys (Macaca mulatta). One of the animals was studied after treatment with the neurotoxin, MPTP. Simulation studies demonstrated that a three injection protocol is necessary for quantitation of dopamine transporter density. The protocol consists of an initial high specific activity injection, a low specific activity "displacement dose" at 30 min, and a final high specific activity injection at approximately 90 min. Dynamic PET imaging and arterial blood sampling were started immediately before the first injection and continued for 2 h. Blood data were corrected for [11C] labeled CFT metabolites. Compartmental models describing the dynamics of labeled and the unlabeled ligand explicitly were fitted to the PET and metabolite corrected blood data. Prior to MPTP treatment, modeling of the striatal data required a saturable receptor term and yielded mean estimates of: B'max = 113 pmol/g and KD = 33 nm (n = 3). These values for B'max are in reasonable agreement with published values for [3H] CFT binding in vitro. After multiple treatments with MPTP (0.6 mg/kg x 3), B'max in one of the animals was reduced from 122 to 10.2 pmol/g. KD was relatively unaffected by MPTP treatment. These data provide additional basis for the use of [11C] CFT in monitoring the progression of Parkinson's disease and other conditions that are associated with the loss of dopaminergic nerve terminals.

Evaluation of cerebral pharmacokinetics of the novel antidepressant drug, BMS-181101, by positron emission tomography

BMS-181101 is a novel antidepressant drug that is currently under clinical investigation. The goal of this study was to evaluate the pharmacokinetics and receptor binding of this agent in the brains of healthy human volunteers. BMS-181101 was radiolabeled with 11C by methylation with [11C]CH3I of the 5-hydroxypiperazine precursor and the product was purified by high-performance liquid chromatography. Cerebral pharmacokinetics of [11C]BMS-181101 were studied by dynamic positron emission tomography imaging in six healthy volunteers. Two studies were performed in each subject. For the first study the subject was injected with 10 mCl of high specific activity [11C]BMS-181101 (approximately 1700 mCi/mumol) and serial positron emission tomography images and arterial blood samples were collected over 90 min. Thirty minutes after acquiring the final image, each subject was coinjected with a second dose, 10 mCi of [11C]BMS-181101 plus 3 mg of unlabeled drug (final specific activity approximately 1.5 mCi/mumol), and imaging/blood collection was repeated. The data were analyzed by calculating regional tracer accumulation (percent injected dose/g) at 60 min after injection and compartmental modeling. Measurements of percent injected dose/g yielded similar values for all brain regions, independent of specific activity. Kinetic modeling of time activity curves for cerebellum, caudate, putamen, thalamus, pons and temporal, occipital and frontal cortex demonstrated that tissue distribution can be described by a simple two-compartment flow model. Statistical comparisons of the apparent distribution volumes for each region failed to reveal significant differences between the high and low specific activity studies. These results indicate that the central nervous system distribution of [11C]BMS-181101 is dominated by blood flow and significant receptor-specific localization does not occur in any brain region.

Serum-sickness-like reaction associated with minocycline therapy in adolescents

OBJECTIVE

To describe a serum-sickness-like reaction in five adolescents treated with minocycline.

CASE SUMMARY

Five adolescents developed a rash and arthralgias/arthritis after taking minocycline for 10-30 days. Symptoms resolved gradually after the medication was stopped.

DISCUSSION

Serum sickness is not described in the pharmacology literature as an adverse effect of minocycline, and in the English literature there are only two case reports. The migration inhibitory factor assay and mast cell degranulation test were positive in four of the five patients. The results of these assays were consistent with a role for minocycline in causing these reactions.

CONCLUSIONS

Clinicians should be aware of the possibility of serum-sickness-like reaction as an adverse effect of minocycline.

Measurement of muscle protein synthesis by positron emission tomography with L-[methyl-11C]methionine

Positron emission tomography (PET) with L-[methyl-11C]methionine was explored as an in vivo, noninvasive, quantitative method for measuring the protein synthesis rate (PSR) in paraspinal and hind limb muscles of anesthetized dogs. Approximately 25 mCi (1 Ci = 37 GBq) of L-[methyl-11C]methionine was injected intravenously, and serial images and arterial blood samples were acquired over 90 min. Data analysis was performed by fitting tissue- and metabolite-corrected arterial blood time-activity curves to a three-compartment model and assuming insignificant transamination and transmethylation in this tissue. PSR was calculated from fitted parameter values and plasma methionine concentrations. PSRs measured by PET were compared with arterio-venous (A-V) difference measurements across the hind limb during primed constant infusion (5-6 h) of L-[1-13C, methyl-2H3]methionine. Results of PET measurements demonstrated similar PSRs for paraspinal and hind limb muscles: 0.172 +/- 0.062 vs. 0.208 +/- 0.048 nmol-1.min-1.(g of muscle)-1 (P = not significant). PSR determined by the stable isotope technique was 0.27 +/- 0.050 nmol-1.min-1.(g of leg tissue)-1 (P < 0.07 from PET) and indicated that the contribution of transmethylation to total hind limb methionine utilization was approximately 10%. High levels of L-[methyl-11C]methionine utilization by bone marrow were observed. We conclude that muscle PSR can be measured in vivo by PET and that this approach offers promise for application in human metabolic studies.

Pharmacokinetics of [18F]fleroxacin in patients with acute exacerbations of chronic bronchitis and complicated urinary tract infection studied by positron emission tomography

The pharmacokinetics of fleroxacin, a new broad-spectrum fluoroquinolone, were measured by positron emission tomography (PET) with [18F]fleroxacin in five patients with acute bacterial exacerbations of chronic bronchitis and in five patients with symptomatic, complicated urinary tract infection. Two studies were performed with each patient, one within 24 h of the initiation and one within 24 h of the completion of a 7-day course of fleroxacin, 400 mg/day. For each study, the patient received an infusion of that day's therapeutic dose of fleroxacin (400 mg) supplemented with approximately 740 MBq of [18F]fleroxacin, and serial PET images and blood samples were collected for 6 to 8 h starting at the initiation of the infusion. Between studies, the drug was administered orally. In all infected tissues, there was rapid accumulation of radiolabeled drug, with stable levels achieved within 1 h after completion of the infusion. In kidneys, accumulation was greater in the presence of active infection (P < 0.01), while in lungs, accumulation was lower (P < 0.02). Infection of the lung or urinary tract had no effect on drug delivery to uninvolved tissues. Also, there was no difference between the results obtained at the beginning and the end of therapy. Overall, peak concentrations of drug many times the MIC at which 90% of the infecting organisms are inhibited (MIC90) were achieved in the kidneys (> 30 micrograms/g), prostate glands (> 11 micrograms/g), and lungs (> 14 micrograms/g). Plateau concentrations (2 to 8 h; given as mean micrograms per gram +/- standard error of the mean) of drug in kidneys (15.11 +/- 0.55), prostate glands (5.08 +/- 0.19), and lungs (5.75 +/- 0.22) were also well above the MIC90 for most relevant pathogens. All patients had a good therapeutic response to fleroxacin.

Contribution of class I HLA-A2 antigen in immune reactions

The involvement of the Class I HLA-A2 antigen is briefly reviewed in relation to allograft rejection, the feto-maternal relationship, viral cytotoxic reactions and tumor immunity. It is suggested that the HLA-A2 molecule may have, as compared to other HLA Class I alleles, a dominant role as a restricting element in cytotoxic T-cell recognition in the feto-maternal relationship to male fetuses, in specific viral infections and in tumors. As compared to other HLA Class I alleles, its reduced expression or loss in a variety of tumors suggests its possible important role in tumor immune surveillance. The disappearance of HLA-A2 from tumor cells may eventually contribute to the escape from T-cell recognition of malignant cells.

Synthesis of a 11C-labeled NK1 receptor ligand for PET studies

Changes in substance P (SP) receptor concentration have been implicated in neuropsychiatric disorders, Parkinson's disease, arthritis, inflammatory bowel disease and asthma. Since, SP and peptide analogs are rapidly metabolized and do not penetrate into the CNS, they are not useful for PET. Recently, a non-peptide SP antagonist, (+)-(2S,3S)-3-(2-methoxybenzylamino)-2-phenylpiperidine (CP-99,994) was developed. As a prelude to PET studies, this compound was radiolabeled with 11C and biodistribution was determined in hamsters. CP-99,994 was radiolabeled by methylation of tert-Boc, desmethyl CP-99,994 with 11CH3I followed by deprotection and HPLC purification. The time required for the synthesis was 40 min from the end of bombardment. Radiochemical purity of the final product was > 95% and specific activity was routinely > 1000 mCi/mumol [EOS]. The biodistribution of 11C-CP-99,994 was determined in groups of six Syrian hamsters at 5 and 30 min after injection. The results of these studies demonstrated that significant concentrations (%ID/g +/- SEM) of CP-99,994 accumulate in most tissues of the hamster. The highest levels of drug were detected in the lung: 21.04 +/- 1.26 (5 min) and 13.49 +/- 1.71 (30 min). Brain accumulation was: 1.44 +/- 0.06 (5 min), 1.32 +/- 0.05 (30 min). These results indicate that 11C-CP-99,994 can be prepared in high purity and specific activity. This new radiopharmaceutical may be useful for studying both central and peripheral SP receptors by PET.

Erythema multiforme and hypersensitivity myocarditis caused by ampicillin

OBJECTIVE

To report a case of erythema multiforme and hypersensitivity myocarditis caused by ampicillin.

CASE SUMMARY

A 13-year-old boy was treated with ampicillin and gentamicin because of suspected septicemia. Medications were discontinued when erythema multiforme and congestive heart failure caused by myocarditis occurred. The patient was treated with methylprednisolone and gradually improved. Macrophage-migration inhibition (MIF) test with ampicillin was positive.

DISCUSSION

After most infections causing erythema multiforme and myocarditis were ruled out, a drug-induced allergic reaction was suspected. Positive MIF test for ampicillin showed sensitization of the patient's lymphocytes to ampicillin.

CONCLUSIONS

Hypersensitivity myocarditis is a rare and dangerous manifestation of allergy to penicillins.

Synthesis of [11C]dapoxetine.HCl, a serotonin re-uptake inhibitor: biodistribution in rat and preliminary PET imaging in the monkey

[11C]Dapoxetine.HCl, S-(+)-N,N-dimethyl-a-[2-(naphthalenyloxy)ethyl] benzenemethanamine hydrochloride, a potent serotonin re-uptake inhibitor was prepared from its mono-methyl precursor, S-(+)-N-methyl-a-[2-(naphthalenyloxy)ethyl]benzene methanamine hydrochloride. Biodistribution was determined in rats at 5, 30 and 60 min after injection and preliminary PET studies were performed in a Rhesus monkey. 11CH3I was bubbled into a solution of S-(+)-N-methyl-alpha-[2-(naphthalenyloxy)ethyl]benzene methanamine hydrochloride (3.0 mg in DMSO) and the mixture was heated at 110 degrees C for 8 min. [11C]Dapoxetine.HCl was purified by HPLC on a C18 cartridge eluted with MeOH:phosphate buffer, pH 7,2 (75:25) with a 10% yield (end of synthesis). The time required for the synthesis was 40 min, from the end of bombardment. Radiochemical purity of the final product was > 99% and specific activity was routinely > 400 mCi/mumol [EOS]. In the biodistribution studies the highest concentration (%ID/g +/- SEM) of dapoxetine.HCl was detected in lung: 4.56 +/- 0.27 (5 min), 1.28 +/- 0.18 (30 min) and 0.67 +/- 0.04 (60 min). Brain accumulation was 0.76 +/- 0.02 (5 min), 0.46 +/- 0.04 (30 min) and 0.27 +/- 0.01 (60 min). Preliminary PET studies demonstrated significant displaceable binding in the cerebral cortex and subcortical grey matter. These results demonstrate that [11C]dapoxetine.HCl can be prepared in high purity and may be useful for the in vivo evaluation of serotonin re-uptake mechanisms.

Myocardial extraction of 1-[11C] betamethylheptadecanoic acid

Betamethylheptadecanoic acid (BMHA) is a branched chain fatty acid analog that is transported into myocardial cells by the same long chain fatty acid carrier protein mechanism as natural fatty acids, but cannot be completely catabolized and accumulates in the tissue. Thus, 11C-labeled BMHA is a useful tracer for the noninvasive evaluation of myocardial fatty acid utilization by positron emission tomography (PET).

METHODS

As a prelude to PET studies, the metabolism of BMHA was studied by classical techniques. We measured the net extraction fraction (En) of 1-[11C]-beta-R,S-methylheptadecanoic acid (1-[11C]BMHA) and compared it to that of natural fatty acids in dogs, using arterial/venous measurements and a mathematical model. Two groups of conditioned dogs were studied. In the first group, measurements were made under fasting (normal control) conditions and in the second group, measurements were made during glucose and insulin infusion. Myocardial blood flow, and the extraction/utilization of other substrates (glucose, oxygen and lactate) were also measured.

RESULTS

For natural fatty acids in the basal state, En(FA) was 0.335. After glucose/insulin infusion, this value decreased to 0.195. The 1-[11C]BMHA showed a similar decrease in En(BMHA) from 0.220 in the control group to 0.100 in the group treated with glucose/insulin infusion. Preliminary PET studies with 1-[11C]BMHA verified the validity of performing these measurements noninvasively.

CONCLUSION

The results of these studies indicate that rates of fatty acid metabolism in the myocardium can be determined from steady-state concentrations of 1-[11C]BMHA.

Distortion in the parental transmission of HLA-A2 haplotypes (locus A,B)

The parental transmission of HLA-2 antigen in association with the epitopes BW4 and BW6 (class I HLA haplotypes locus A,B) was analyzed in sons and daughters from 42 families in which one of the parents carried the HLA-A2 antigen. When the parental transmission of A2 BW4 and A2 BW6 was compared, it was observed that a significantly higher number of siblings inherited the haplotype A2 BW4 from the paternal than from the maternal haplotype. Although the number of cases is small, the mode of inheritance of haplotype A2 BW6 was completely different. The genetic distortion in the transmission of HLA-2 BW4 and HLA-2 BW6 was observed in children of both sexes.

Pharmacokinetics of [18F]fleroxacin in healthy human subjects studied by using positron emission tomography

Positron emission tomography (PET) with [18F]fleroxacin was used to study the pharmacokinetics of fleroxacin, a new broad-spectrum fluoroquinolone, in 12 healthy volunteers (9 men and 3 women). The subjects were infused with a standard therapeutic dose of fleroxacin (400 mg) supplemented with approximately 20 mCi of [18F]fleroxacin. Serial PET images were made and blood samples were collected for 8 h, starting at the initiation of the infusion. The subjects were then treated with unlabeled drug for 3 days (400 mg/day). On the fifth day, infusion of radiolabeled drug, PET imaging, and blood collection were repeated. In most organs, there was rapid accumulation of radiolabeled drug, with stable levels achieved within 1 h after completion of the infusion. Especially high peak concentrations (in micrograms per gram) were achieved in the kidney (> 34), liver (> 25), lung (> 20), myocardium (> 19), and spleen (> 18). Peak concentrations of drug more than two times the MIC for 90% of Enterobacteriaceae strains tested (> 10-fold for most organisms) were achieved in all tissues except the brain and remained above this level for more than 6 to 8 h. The plateau concentrations in tissues (2 to 8 h, in micrograms per gram +/- standard error of the mean) of drug were as follows: brain, 0.83 +/- 0.032; myocardium, 4.53 +/- 0.24; lung, 5.80 +/- 0.48; liver, 7.31 +/- 0.33; spleen, 6.00 +/- 0.47; bowel, 3.53 +/- 0.74; kidney, 8.85 +/- 0.64; bone, 2.87 +/- 0.29; muscle, 4.60 +/- 0.33; prostate, 4.65 +/- 0.48; uterus, 3.87 +/- 0.39; breast, 2.68 +/- 0.11; and blood, 2.35 +/- 0.09. Concentrations of fleroxacin in tissue were similar in males and females, before and after pretreatment with unlabeled drug.

Treatment of recurrent spontaneous abortions by immunization with paternal lymphocytes induces immunosuppression by placental isoferritin

PROBLEM

The immunological mechanism leading to an effective vaccination of unexplained habitual aborters with paternal lymphocytes is not yet elucidated. Since previous studies revealed that immunosuppression by placental isoferritin (PLF) may play an important role in the down regulation of the immune system during pregnancy, it was of interest to investigate whether alloimmunization activates immunosuppression by PLF.

METHOD

The immunosuppressive effect of PLF or anti-PLF CM-H-9 monoclonal antibody (MAb) was studied by a one-way mixed lymphocyte reaction (MLF) of alloimmunized women and their husbands.

RESULTS

It was found that vaccination of the women with paternal lymphocytes resulted in in vitro immunosuppression by PLF as well as by CM-H-9 MAb, reaching the highest effect after three vaccinations (38 +/- 8 and 42 +/- 10%, respectively). The increase in PLF immunosuppressive effect was accompanied by the appearance of serum antipaternal human leukocyte antigen cytotoxic antibodies. However, there was no correlation between the degree of suppression and titer of antibodies. The study group was too small to reach a significant correlation between degree of immunosuppression and pregnancy outcome.

CONCLUSIONS

Although it may be of value to measure the inhibitory effect of PLF in one-way MLR as an index of immunosuppression, further studies are needed to establish whether it is a relevant predictor of a successful pregnancy.

Pharmacokinetics of 18F-labeled fluconazole in healthy human subjects by positron emission tomography

The distribution of fluconazole in tissue of human volunteers was determined by positron emission tomographic scanning over a 2-h period following the infusion of a tracer dose of 18F-fluconazole (5 to 7 mCi) plus 400 mg of unlabeled drug (the standard daily dose of fluconazole). Previous studies have validated this approach for animals. From serial positron emission tomographic imaging and blood sampling, pharmacokinetics of fluconazole in tissue were determined. There was significant distribution of the radiolabeled drug in all organs studied, with nearly constant levels achieved by 1 h. Plateau concentrations of fluconazole in key organs (micrograms per gram) included the following: whole brain, 4.92 +/- 0.17; heart, 6.98 +/- 0.20; lung, 7.81 +/- 0.46; liver, 12.94 +/- 0.24; spleen, 22.96 +/- 2.5; kidney, 11.23 +/- 0.61; prostate, 8.24 +/- 0.58; and blood, 3.76 +/- 0.30. Since levels of fluconazole of > 6 micrograms/g are needed to treat infection with most strains of Candida and levels of > 10 micrograms/g are needed for Cryptococcus neoformans, Coccidioides immitis, and Histoplasma capsulatum, the following predictions can be made. The current standard dose of 400 mg/day should be more than adequate in the treatment of urinary tract and hepatosplenic candidiasis but problematic in the treatment of candidal osteomyelitis, even with the higher levels that develop after multiple doses. Similarly, higher doses should be considered, particularly in immunocompromised patients, with infection with C. neoformans, H. capsulatum, and C. immitis that involves the central nervous and musculoskeletal systems.

Mode of inheritance of HLA haplotypes locus A,B in siblings of different sexes

METHOD

Forty-eight parents and 172 children were typed for class I HLA antigens, locus A,B.

RESULTS

Although the number of cases is small, we observed: (1) a significantly decreased number of sons born after a first delivery of a son, as compared to a first delivery of a daughter; (2) significantly increased sharing of maternal class I HLA antigens between the firstborn son and his brothers from higher birth orders, as compared to his sisters; and (3) HLA-A2 antigen, which is known to be involved in HLA restricted cytotoxic reactions in the recognition of minor histocompatibility antigens, was inherited in subsequent deliveries of sons as compared to daughters in a significantly higher frequency from the paternal than from maternal HLA haplotype. The results suggest that sharing of identical maternal HLA haplotypes between brothers may aid to decrease the degree of maternal sensitization to fetal antigens, and lack of HLA-2 antigen in maternal cells from sons as compared to daughters may avoid maternal HLA-A2 restricted cytotoxic reactions toward the male fetus.