What is the optimal pretransfusion testing interval for multi-transfused patients? The University Hospital of Brest experience

The red cell allo-antibodies research is mandatory before transfusion. In France, pretransfusion testing intervals that are prescribed by regulatory and accrediting agencies are commonly 72hours. In the University hospital of Brest, the interval for multi-transfused patients has been 24hours. In this study we aim to analyse these practice and argue the delay.

METHODS

This is a retrospective study of post-transfusional allo-immunizations from 2015 to 2020. For each patient, the time interval between the last negative research and the allo-immunization was investigated.

RESULTS

189 patients developed allo-antibodies. In 16 patients (8,5%), the interval for allo-immunization was 24hours, 48hours and 72hours in 4, 8 and 4 patients respectively. 12 patients were transfused after the discovery of the allo-antibodies. That means if we have chosen a delay of validity of 72hours, then 9 patients would have been transfused with a negative result.

CONCLUSION

Checking for allo-antibodies before RBC transfusion with an interval of 24hours (and not 72hours) is pertinent in order to assure an optimal transfusion safety and to limit the risk of hemolytic transfusion reactions. A pretransfusion testing interval of 24hours for multi-transfused patients should be considered.

5201Intra-cardiac thrombus in patients undergoing ventricular tachycardia ablation. a computed tomographic scan study

Background

Embolic event is one of the complications of VT ablation. This may be due to the presence of intra-cardiac thrombus before ablation. However, there is no clear consensus on how to rule out thrombus before the procedure.

Objective

We sought to examine the prevalence and risk factors of intra-cardiac thrombus with cardiac computed tomographic (CT) scan in patients undergoing scar-related VT ablation.

Methods

In absence of contra-indication, all patients undergoing scar-related VT ablation at our institution underwent contrast-enhanced cardiac CT within one week before ablation. 324 consecutive patients (292 male, 59±16 yo) have been included in this study. The etiology was ischemic cardiomyopathy (CMP) (n=191), arrhythmogenic right ventricular CMP (ARVC) (n=37), congenital CMP (n=11) or other CMP (n=85). LVEF was <40% in 154 patients (48%).

Results

Intra-cardiac thrombus was diagnosed in 29 (9%) patients: in the left atrium (n=8), in the right atrium (n=1), in the left ventricle (n=15), in the right ventricle (n=3), in right and left atrium (n=1), and in left atrium and right ventricle (n=1). Moreover in 2, a bilateral pulmonary embolism was identified. The population with thrombus was older (65±12 vs 58±16 years, p=0,005), with more permanent atrial fibrillation (AF) (28% vs 8%; p=0.005). Patients with left ventricular (LV) aneurysm were at higher risk of thrombus 50% vs 3% (p<0.001). The average CHADSVASC score was similar for both groups (2,5 vs 2,1; p=0.179). After matching for age and sex, only ischemic CMP and LV aneurysm were risk factors for thrombus. Because of arrhythmic storm, ablation was performed by epicardial approach only, in 5 patients with intra-ventricular thrombus and by retroaortic approach only, in 2 patients with LAA thrombus. No embolic event occurred during these procedures.

Conclusion

CT scans help eliminating intra-cardiac thrombus before VT ablation procedure. A high proportion of thrombus (9%) was identified. Whereas LV thrombus should systematically be ruled out before scar related VT ablation, in patients with AF, a LAA thrombus should also be eliminated as well as RV thrombus in patients with ARVC.

Acknowledgement/Funding

ANR-10-IAHU-04

Multispecies biofilm formation by the contaminating microbiota in raw milk

Biofilms can be formed on the surfaces of dairy processing equipment and are a potential source of product contamination. This study evaluated the diversity of multispecies biofilms formed on stainless steel (SS) due to the contaminating microbiota in raw milk. Samples of raw milk were used: one was fresh milk and the other maintained in refrigerated bulk tanks for up to 48 h. The mesophilic aerobic contamination was ∼10⁴ CFU ml^-1 in fresh milk and 10⁶ CFU ml^-1 in bulk milk. SS coupons were kept immersed in the milk at 7 ±2 °C for 10 days, and every two days, the raw milk was changed for samples of the same origin collected on the current day. After incubation for 10 days, sessile cells in the biofilm reached 10⁵ CFU cm^-2 in the presence of fresh milk, and 10⁶ CFU cm^-2 in the presence of bulk milk. The genetic diversity analysis showed that Gammaproteobacteria and Bacilli predominated in the biofilms throughout the incubation of both milk samples and these biofilms showed a reduction in diversity over time. The main classes of bacteria found in these biofilms have representatives of great importance since many of them have spoilage potential.

[Targeted MRI prostate biopsies]

Prostate cancer is the first cancer and the second cause of cancer death in men in France. It is now a major public health issue, particularly given the increase of life expectancy. If screening is based on blood PSA and clinical examination (DRE), diagnosis requires the histological analysis of prostate samples. In current clinical routine, these biopsies are performed by endorectal through ultrasound guidance. In most cases, the cancer is not visible in the ultrasound image and the latter is used to make a dozen samples (or core), distributed as best as possible in the prostate. To increase the accuracy and the contribution of these biopsies, the use of data acquired by the magnetic resonance imaging (MRI), as well as the fusion of ultrasound and MRI images, is a therapeutic undergoing validation, and today performed in many institutions with dedicated tools. The objective of this work is to present the practical arrangements for the implementation of these biopsies using the image fusion, and discuss the advantages and benefits.

Reactive oxygen species and nitric oxide effect on the steroid hormone binding with serum albumin

The interaction of a series of steroid hormones (DHEA, progesterone, testosterone, estradiol) with serum albumin immobilized on porous silica particles and the effect of reactive oxygen species and nitric oxide on this interaction were studied using a biochromatographic approach. The determination of enthalpy and entropy changes of this binding indicated that van der Waals interactions and hydrogen bonds predominated the hormone association with albumin. Reactive oxygen species (H(2)O(2) and OH*) increased the hormone binding affinity to albumin. On the other hand, this binding was decreased with the presence of NO*. This variation was due to conformational changes in the binding region explained by the oxidation of some residues such as free thiol and arginine. The thermodynamic analysis showed that free radical affects the van der Waals forces and/or a hydrogen bond of the hormone binding with albumin. These results explained the role of reactive oxygen species and nitric oxide in the hormone free fraction level in the blood.

Molecular cytogenetic characterization of canine histiocytic sarcoma: A spontaneous model for human histiocytic cancer identifies deletion of tumor suppressor genes and highlights influence of genetic background on tumor behavior

Background

Histiocytic malignancies in both humans and dogs are rare and poorly understood. While canine histiocytic sarcoma (HS) is uncommon in the general domestic dog population, there is a strikingly high incidence in a subset of breeds, suggesting heritable predisposition. Molecular cytogenetic profiling of canine HS in these breeds would serve to reveal recurrent DNA copy number aberrations (CNAs) that are breed and/or tumor associated, as well as defining those shared with human HS. This process would identify evolutionarily conserved cytogenetic changes to highlight regions of particular importance to HS biology.

Methods

Using genome wide array comparative genomic hybridization we assessed CNAs in 104 spontaneously occurring HS from two breeds of dog exhibiting a particularly elevated incidence of this tumor, the Bernese Mountain Dog and Flat-Coated Retriever. Recurrent CNAs were evaluated further by multicolor fluorescence in situ hybridization and loss of heterozygosity analyses. Statistical analyses were performed to identify CNAs associated with tumor location and breed.

Results

Almost all recurrent CNAs identified in this study were shared between the two breeds, suggesting that they are associated more with the cancer phenotype than with breed. A subset of recurrent genomic imbalances suggested involvement of known cancer associated genes in HS pathogenesis, including deletions of the tumor suppressor genes CDKN2A/B, RB1 and PTEN. A small number of aberrations were unique to each breed, implying that they may contribute to the major differences in tumor location evident in these two breeds. The most highly recurrent canine CNAs revealed in this study are evolutionarily conserved with those reported in human histiocytic proliferations, suggesting that human and dog HS share a conserved pathogenesis.

Conclusions

The breed associated clinical features and DNA copy number aberrations exhibited by canine HS offer a valuable model for the human counterpart, providing additional evidence towards elucidation of the pathophysiological and genetic mechanisms associated with histiocytic malignancies. Extrapolation of data derived from canine histiocytic disorders to human histiocytic proliferation may help to further our understanding of the propagation and cancerization of histiocytic cells, contributing to development of new and effective therapeutic modalities for both species.

[Hormone therapy for breast cancer]

Following Beatson's publications in 1896, various modalities of endocrine therapy applied to breast cancer have been developed. Endocrine treatment has greatly contributed to the improvement of the disease's prognosis. Tamoxifen has established itself as a first choice adjuvant therapy for patients with tumors expressing hormone receptors. Over the last decade, third generation aromatase inhibitors have demonstrated their efficacy amongst menopausal patients, alone or in combination with tamoxifen. Efficacy of these medications is dependent on patient's compliance. This article proposes a synthesis of the main knowledges available in the field of breast cancer endocrine therapy.

[Systemic chemotherapy and breast cancer]

Breast cancer mortality is decreasing, partly due to better adjuvant treatments with new drugs and new schedules. In Belgium, the overall survival is 76%. Chemotherapy is still an important treatment option. We need to better select patients who really will benefit from treatment in order to decrease toxicity and improve long term outcome.Targeting the specific population is now a priority. Prognostic and predictive factors will enable us to better define the sub-population of patients most benefiting from treatment. We will also discuss the knowledge of systemic treatment. When we have to decide wether chemotherapy is indicated, we need to well balance the treatment risks and benefits because gain in survival is important but reducing short and long term toxicity is also a challenge.

[Radiotherapy in breast cancer: current standards of treatment, prediction of local recurrence and open questions]

Adjuvant radiotherapy after surgery is a ("well-established standard" in routine clinical practice for breast cancer. Nevertheless, a variety of questions still remain unanswered. We intend to illustrate the overall importance of radiotherapy in breast cancer and highlight some unresolved questions by quoting presentations recently made at ASTRO-2010. More and more emphasis is put on the idea of an individual approach. Predicting the individual local recurrence risk is the search for the "Holy Grail". Methods such as nomograms and genomic profiling are currently tested but need to be validated before their widespread clinical application.

[Management and follow-up of a consecutive series of 411 surgically treated breast cancer patients]

This study reports a consecutive serie of 427 breast neoplasms (411 patients) diagnosed and treated in our department between 1994 and 2004. Patients' records were prospectively collected including personnal medical history and the major elements of the diagnostic and the therapeutic protocol applied. 12 patients (3%) had to be excluded due to incomplete follow-up data. With a median follow-up of 8 years, a 4.5% loco-regional relapse rate is noted while 11% of patients recurred at distant sites and 9% died of their disease progression. These statistics are comparable to those published by prominant breast cancer centers. Amongst the 16% of deaths (67/411 Pts), 54% are due to breast cancer progression. The results are discussed with the aim to upgrade the diagnostic and the therapeutic protocols offered to our patients.

[Intraoperative molecular assessment of sentinel nodes in the breast cancer using the Gene Search BLN Assay technique: our experience about 126 patients]

INTRODUCTION

Intraoperative molecular assay Gene Search BLN Assay (BLN) detects sentinel lymph node (SLN) metastasis in breast cancer. Our objective was to compare BLN to the definitive conventional histologic methods and to experiment the management of BLN in routine.

MATERIAL AND METHODS

Each SLN was cut into alternate slabs. Half slabs were analysed with the intraoperative BLN molecular method, and the other slabs with the definitive histologic method.

RESULTS

Two hundred and thirty four SLN have been analysed (124 patients). Thirty-five SLN had metastasis for 29 patients (23.4%). BLN correctly identified 28 patients. Two cases of discordance between BLN and standard method were found, probably explained by a sample bias. The sensibility of BLN is 96.4%, the sensitivity is 99%, the predictive positive value is 96.4%, the predictive negative value is 99% and the concordance is 98.4%. The surgery time increases and there is a need to adapt the theatre organization accordingly.

CONCLUSION

The Gene Search BLN Assay gives a great interest for the patient, the surgeon and the pathologist because it increases the quality of the intraoperative analysis by comparison with the intraoperative conventional histology.

[Erythema elevatum diutinum associated with pyoderma gangrenosum in an HIV-positive patient]

BACKGROUND

Erythema elevatum diutinum (EED) is a very rare form of chronic dermatosis clinically characterised by reddish-violet papular nodules extending to the surfaces of the limbs and extremities. Histologically, there are classically two phases of progression initially involving associated neutrophilic dermatosis and leucocytoclastic vasculitis, which is later followed by fibrosis of characteristic appearance. We report the association of EED and pyoderma gangrenosum in a patient infected with HIV.

PATIENTS AND METHODS

A 53-year-old male seen since 1989 for HIV infection had been presenting firm bilateral and symmetrical nodules on the feet for 6 months. Histological analysis of one of these nodules resulted in diagnosis of chronic erythema elevatum diutinum and treatment with dapsone was initiated. Three months later, despite regression of the EED lesions under dapsone, two large pustules appeared on the outer aspect of the right leg; they were confluent and progressed towards a superficial ulcer with rounded edges with a clinical appearance evocative of pyoderma gangrenosum (PG). Histopathological analysis demonstrated a massive dermal infiltrate beneath the ulcer comprising neutrophils with evidence of leucocytoclasia, all of which militated in favour of the diagnosis of pyoderma gangrenosum.

DISCUSSION

We report for the first time the association of two forms of neutrophilic dermatosis, EED and PG, in an HIV-positive patient. This case report and certain data in the literature suggest that the various forms of neutrophilic dermatosis tend to result in a range of lesions rather than in clearly distinct entities.

Chromosomal mapping of canine-derived BAC clones to the red fox and American mink genomes

High-quality sequencing of the dog (Canis lupus familiaris) genome has enabled enormous progress in genetic mapping of canine phenotypic variation. The red fox (Vulpes vulpes), another canid species, also exhibits a wide range of variation in coat color, morphology, and behavior. Although the fox genome has not yet been sequenced, canine genomic resources have been used to construct a meiotic linkage map of the red fox genome and begin genetic mapping in foxes. However, a more detailed gene-specific comparative map between the dog and fox genomes is required to establish gene order within homologous regions of dog and fox chromosomes and to refine breakpoints between homologous chromosomes of the 2 species. In the current study, we tested whether canine-derived gene-containing bacterial artificial chromosome (BAC) clones can be routinely used to build a gene-specific map of the red fox genome. Forty canine BAC clones were mapped to the red fox genome by fluorescence in situ hybridization (FISH). Each clone was uniquely assigned to a single fox chromosome, and the locations of 38 clones agreed with cytogenetic predictions. These results clearly demonstrate the utility of FISH mapping for construction of a whole-genome gene-specific map of the red fox. The further possibility of using canine BAC clones to map genes in the American mink (Mustela vison) genome was also explored. Much lower success was obtained for this more distantly related farm-bred species, although a few BAC clones were mapped to the predicted chromosomal locations.

Safety and tolerability of grass pollen tablets in sublingual immunotherapy--a phase-1 study

BACKGROUND

A single-centre, randomized, double-blind, placebo-controlled study.

AIMS

To compare the safety and tolerability of four different sublingual immunotherapy (SLIT) regimes in grass pollen allergic rhinitis.

METHODS

Thirty subjects sensitized to grass pollen were enrolled and allocated to four groups. Sublingual immunotherapy was administered in tablets daily for 10 days. Groups 1 and 2 received incremental sublingual doses of 100, 200, 300, 400 and 500 IR, Group 1 daily and Group 2 increments every second day. Repeated constant dose regimens of 300 IR and 500 IR were administered in Groups 3 and 4 respectively. Safety assessments included adverse events (AE), vital signs, electrocardiogram (ECG) and clinical laboratory tests.

RESULTS

Sublingual immunotherapy 300 IR (Group 3) administered in a constant dose and incremental doses up to 500 IR (Groups 1 and 2) were generally well tolerated. The majority of AEs were mild to moderate, the most common being oral pruritus, throat irritation and swollen tongue. Severe local AEs (swelling of throat) were observed only for Group 4. No serious systemic AEs were reported. There were no relevant changes in clinical laboratory, vital signs and ECG data.

CONCLUSION

Adverse events were mostly local (sublingual), were not severe and resolved rapidly. Using a 5-day induction regimen high-dose treatment up to 500 IR could be administered without important side-effects, in contrast to initiating with a constant dose of 500 IR. The data indicate that a short dose increase phase may reduce the incidence of AEs when high-dose SLIT is administered.

Radiation hybrid mapping of cataract genes in the dog

PURPOSE

To facilitate the molecular characterization of naturally occurring cataracts in dogs by providing the radiation hybrid location of 21 cataract-associated genes along with their closely associated polymorphic markers. These can be used for segregation testing of the candidate genes in canine cataract pedigrees.

METHODS

Twenty-one genes with known mutations causing hereditary cataracts in man and/or mouse were selected and mapped to canine chromosomes using a canine:hamster radiation hybrid RH5000 panel. Each cataract gene ortholog was mapped in relation to over 3,000 markers including microsatellites, ESTs, genes, and BAC clones. The resulting independently determined RH-map locations were compared with the corresponding gene locations from the draft sequence of the canine genome.

RESULTS

Twenty-one cataract orthologs were mapped to canine chromosomes. The genetic locations and nearest polymorphic markers were determined for 20 of these orthologs. In addition, the resulting cataract gene locations, as determined experimentally by this study, were compared with those determined by the canine genome project. All genes mapped within or near chromosomal locations with previously established homology to the corresponding human gene locations based on canine:human chromosomal synteny.

CONCLUSIONS

The location of selected cataract gene orthologs in the dog, along with their nearest polymorphic markers, serves as a resource for association and linkage testing in canine pedigrees segregating inherited cataracts. The recent development of canine genomic resources make canine models a practical and valuable resource for the study of human hereditary cataracts. Canine models can serve as large animal models intermediate between mouse and man for both gene discovery and the development of novel cataract therapies.

Olfactory Receptor Sequence Polymorphism Within and Between Breeds of Dogs

Olfactory receptors, to which odorant molecules specifically bind, are encoded by the largest gene family yet identified in the mammalian genome. We investigated additional polymorphism due to the possible existence of multiple alleles dispersed in different dog breeds by carrying out a survey of the sequences of 16 olfactory receptor genes in a sample of 95 dogs of 20 different breeds. The level of polymorphism was high--all genes were found to have allelic variants--leading to amino acid changes and pseudogenization of some alleles in a number of cases. This preliminary study also revealed that some alleles are breed specific (or rare in the dog population), with some representing the major allele in the breeds concerned.

Diagnostic value of anti-F-actin antibodies in a French multicenter study

According to international criteria, autoimmune hepatitis (AIH) type 1 is characterized by the presence of antinuclear or anti-smooth muscle antibodies (SMA) with F-actin specificity. SMA have been found in 85% of AIH patients, but are not specific to this disease, and anti-F-actin specificity is not always verified when SMA are detected. The objective of this study was to determine the diagnostic value of anti-F-actin antibodies in a large population. A multicenter study involving 12 clinical centers was performed. Patients were selected on the basis of the presence of F-actin SMA detected by indirect immunofluorescence (IIF) on rat liver-kidney-stomach sections and was confirmed by IIF on Hep2 cells treated with colchicine, or F-actin dot-blot. The clinical status of patients was determined from their medical records. One hundred sixty-eight patients were included: 76% women, 24% men; mean age of 45 years (range, 2-88 years), with a bimodal age distribution. Sixty percent had AIH type 1, and 40% had another disease. In the group of women younger than 25 years, 90% had AIH type 1. Other pathologies associated with antiactin were other liver diseases (19%), including viral hepatitis C (7%), and non-liver diseases (21%), including connective tissue diseases (12%). Antibody titers were higher in AIH than in other diseases. Antiactin antibodies are of major diagnostic value in AIH, especially in young women; they may be found in other disease settings, but mostly at low levels.

Prolonged outbreak of infection due to TEM-21-producing strains of Pseudomonas aeruginosa and enterobacteria in a nursing home

Over a 6-year period, 24 extended-spectrum beta-lactamase (ESBL)-producing isolates of Pseudomonas aeruginosa were collected from 18 patients living in a nursing home. These isolates had a delayed development of a red pigment and exhibited a similar antibiotype (resistance to all beta-lactams except for imipenem and to gentamicin, tobramycin, netilmicin, ciprofloxacin, and rifampin) associated with the production of the TEM-21 beta-lactamase and a type II 3'-N-aminoglycoside acetyltransferase [AAC(3)-II] enzyme. Surprisingly, serotyping showed that these isolates belonged to four successive serotypes (P2, P16, P1, and PME), although molecular typing by PCR methods and pulsed-field gel electrophoresis yielded identical or similar profiles. Moreover, in all isolates the bla(TEM-21) gene was part of a chromosomally located Tn801 transposon truncated by an IS6100 element inserted within the resolvase gene, and the aac(3)-II gene was adjacent to this structure. During the same period, 17 ESBL-producing isolates of enterobacteria were also collected from 10 of these patients. These isolates harbored a similar large plasmid that contained the bla(TEM-21) and the aac(3)-II genes and that conferred additional resistance to sulfonamides and chloramphenicol, as well as to kanamycin, tobramycin, netilmicin, and amikacin, conveyed by an AAC(6')-I enzyme. The bla(TEM-21) gene was part of the Tn801 transposon disrupted by IS4321. Thus, a single clone of P. aeruginosa that had undergone a progressive genetic drift associated with a change in serotype appeared to be responsible for an outbreak of nosocomial infections in a nursing home. This strain has probably acquired the bla(TEM-21)-encoding plasmid that was epidemic among the enterobacteria at the institution, followed by chromosomal integration and genomic reorganization.

Aging-associated loci in Canis familiaris

Although recent endeavors to discover the mechanisms of the aging process have been numerous and successful, there is still much to be learned. Genes implicated in the aging process were mapped to the canine genome and will serve as additional framework markers for the assignment of contiguous segments from the canine genome sequence to chromosomes. The 54 genes were selected because of their demonstrated contribution to longevity in other organisms or based upon their proximity to a marker, D4S1564, on human chromosome 4 (Puca et al., 2001). This effort lays the necessary groundwork for our utilization of the domestic dog as a model organism to define the genes that govern aging and longevity. Within the species, naturally diverse life expectancies and highly homogeneous populations create an ideal population structure for studying the genetic components of aging (Patronek et al., 1997).

Allergic rhinitis due to house dust mites: evaluation of the efficacy of specific sublingual immunotherapy

BACKGROUND

The efficacy and safety of sublingual immunotherapy (SLIT) in patients with chronic rhinitis related to sensitization to house dust mites are still controversial.

METHODS

After application of an anti-mite mattress cover, patients were only included in the study when the cumulative symptom score over a fortnight was greater than 70 out of a possible total of 168. Thirty-two of the 120 patients selected were randomized to receive SLIT for 2 years: 17 received placebo and 15 received the Dermatophagoides pteronyssinus and D. farinae 50/50 allergen extract.

RESULTS

Significant between-group differences were observed after 1 year and persisted at the end of the second year for the rhinitis total score (P < 0.02), blocked nose score (P < 0.01) and nasal itching score (P < 0.01). Skin reactivity to house dust mites was significantly reduced in the group receiving house dust mite extract (P < 0.03). No statistical difference was observed between the two groups for medication scores, but a low medication consumption was observed in all patients. No serious and no systemic adverse reactions were reported.

CONCLUSION

This study indicates the superiority of active treatment vs. placebo, evaluated on efficacy criteria (rhinitis score) or objective criteria (skin reactivity). The availability of a solid form (tablet) could represent a progress in terms of patient acceptability.

A consensus protocol for the determination of the threshold doses for allergenic foods: how much is too much?

BACKGROUND

While the ingestion of small amounts of an offending food can elicit adverse reactions in individuals with IgE-mediated food allergies, little information is known regarding these threshold doses for specific allergenic foods. While low-dose challenge trials have been conducted on an appreciable number of allergic individuals, a variety of different clinical protocols were used making the estimation of the threshold dose very difficult.

OBJECTIVE

A roundtable conference was convened to develop a consensus clinical protocol for low-dose challenge trials for the estimation of threshold doses for specific allergenic foods.

METHODS

In May 2002, 20 clinical allergists and other interested parties were invited to participate in a roundtable conference to develop consensus of the key elements of a clinical protocol for low-dose challenge trials.

RESULTS

A consensus protocol was developed. Patients with convincing histories of food allergies and supporting diagnostic evidence including past challenge trials or high CAP-RAST scores can be enrolled in low-dose challenge trials. Care must be taken with younger patients to assure that they have not outgrown their food allergy. An approach was developed for the medication status of patients entering such trials. Challenge materials must be standardized, for example, partially defatted peanut flour composed of equal amounts of the three major varieties of peanuts (Florunner, Virginia, Spanish). Challenge materials must be appropriately blinded with sensory evaluation used to confirm the adequacy of blinding. A double-blind, placebo-controlled design should be used for low-dose challenge trials. Low-dose challenge trials would begin at doses of 10 microg of the allergenic food and would continue with doses of 100 microg and 1 mg followed by specific higher doses up to 100 mg depending upon the expert judgement of the physician; even higher doses might be applied to assure that the patient is indeed reactive to the particular food. A 30-min time interval would be used between doses, and reactive doses would be expressed as both discrete and cumulative doses. The goal of each challenge would be to develop objective symptoms; trials should not be discontinued on the basis of subjective symptoms only. Statistically, a minimum of 29 patients would be enrolled in low-dose challenge trials for each allergenic food because 0 reactors out of 29 patients at a particular dose allow the conclusion that there is 95% certainty that 90% of allergic individuals will not react to that dose.

CONCLUSION

A consensus protocol was developed. Using this protocol, it will be possible to estimate threshold doses for allergenic foods, the lowest amount that elicits mild, objective symptoms in highly sensitive individuals.

Chromatographic determination of the association constant between 8-methoxypsoralen and modified β-cyclodextrin: protective effect of hydroxypropyl-β-cyclodextrin on 8-methoxypsoralen toxicity in human keratinocytes

The retention of 8-methoxypsoralen (8-MOP) on an immobilised hydroxypropyl-beta-cyclodextrin (HP-beta-CD) column was analysed in HPLC by the determination of its Langmuir distribution isotherm. A such method was used to confirm the potential drug complexing role of this cyclodextrin. The 8-MOP/HP-beta-CD association constant (K) was equal to 29.5 and 18.7 M-1, respectively, at a temperature equal to 5 and 25 degrees C, respectively. These association constant values were used to determine the cytotoxicity profile of human keratinocyte cell line (HaCaT) in relation to the complex concentration. It was showed through these data that HP-beta-CD had a cytoprotective since a reverse effect of HP-beta-CD on 8-MOP cytotoxicity was observed.

Diagnosis of cypress pollen allergy: in vivo and in vitro standardization of a Juniperus ashei pollen extract

BACKGROUND

Cypress pollen allergy is a major cause of rhinoconjunctivitis and asthma in the Mediterranean area. The nonstandardized cypress allergen extracts currently available for the diagnosis of cypress allergy have a low level of activity. The search for an active material has led to the selection of Juniperus ashei (Ja) pollen because of its very high cross-reactivity with cypress extracts and its superior allergenic activity. The aim of this study was to characterize in vitro and calibrate in vivo an in-house reference extract (IHRS) of J. ashei pollen and determine the specificity and sensitivity of a standardized Ja extract for the prick test diagnosis of cypress allergy.

METHODS

Juniperus ashei pollen extract was analysed by 2-D electrophoresis. The IHRS Ja extract was calibrated by skin prick testing in 28 cypress-allergic patients. The sensitivity and specificity of cypress allergy diagnosis using a standardized Ja extract was studied by skin prick test in 42 cypress-allergic patients and 53 nonallergic patients. Jun a 1 content of the IHRS was determined by a monoclonal antibody-based electrophoretic technique.

RESULTS

The Jun a 1 content of the 100 IR/ml Ja IHRS extract was 180 microg/ml. For in vivo diagnosis of cypress allergy, Ja pollen extract demonstrated a sensitivity of 95%, a specificity of 100%, a negative predictive value of 96%, and a positive predictive value of 100%.

CONCLUSION

Standardized Ja pollen extract is therefore a very appropriate tool for the in vivo diagnosis of cypress pollen allergy and good candidate for specific immunotherapy.