Trabectedin in myxoid liposarcomas (MLS): a long-term analysis of a single-institution series

BACKGROUND

Trabectedin has been approved in Europe as second-line therapy for advanced soft tissue sarcomas. A previous analysis showed that myxoid liposarcomas (MLS) are particularly sensitive to the drug. We report on the long-term efficacy of trabectedin in a subgroup of that series.

METHODS

Since September 2002, 32 advanced pretreated MLS patients received trabectedin at our center. Data were reviewed focusing on their long-term outcome.

RESULTS

Trabectedin was given as a 24-h continuous infusion every 21 days. A total of 376 and a median of 12 courses per patient (range 2-26; interquartiles range (IQR) 8-15) were delivered. Response rate per RECIST was 50% [95% confidence interval (CI) 32% to 68%], median progression-free survival (PFS) was 17 months (95% CI 13.5-30.1) and median overall survival is still not reached. In 10 patients, therapy was stopped in the absence of any evident disease, mostly after complete surgery of residual lesions. In these 10 patients, at a median follow-up of 25 months, PFS was 28.1 months (95% CI 25.6-36.4) from treatment start.

DISCUSSION

These data indicate that the high response rate of MLS to trabectedin translates into prolonged PFS. Surgery of residual metastatic disease is already used quite extensively in metastatic MLS. Trabectedin may give further significance to this kind of surgery.

Role of trabectedin (T) in the management of advanced uterine leiomyosarcoma (U-LM)

10530

Background: To explore the clinical impact of T in U-LM. T has been approved in Europe for second line treatment of advanced soft tissue sarcomas (STS). Efficacy is well established in liposarcoma and leiomyosarcoma. U-LMs display peculiar clinical and genetic features compared to other STS. These differences may be responsible for the sensitivity of this subtype to therapy, thus justifying an evaluation of the activity of T in a relatively homogeneous series of U-LM patients. Methods: From April 2000, 56 patients (pts) with advanced disease, previously exposed to a median of 3 chemotherapy lines (range 1–5), received T within an expanded access programme at two European referral institutions for sarcoma. The clinical records were reviewed focusing on response and treatment outcome. Two pts were excluded from the analysis having received only 1 course of T. Median age was 56 yrs (range 29–73), median number of metastatic sites was 2 (range 1–4), the most frequent metastatic site was lung (88%), 24 patients had a local relapse. Results: A total of 252 courses were delivered (median 3, IQR2–6) and 36% of patients received more than 5 courses of T. Fifty-two patients were evaluable for response. A partial response was observed in 11 patients and stable disease in 15, for a PR rate of 21% and a tumor control rate of 50%. The median progression-free survival was 3.6 months (CI95% 2.6–6.7), with 41% of patients free from progression at 6 months. Conclusions: These results compare favourably with other systemic treatments in advanced U-LMS and support their sensitivity to T. This should prompt further studies to prospectively evaluate the efficacy of T in U-LMS and elucidate possible biological predictive factors (e.g. DNA repair protein expression).

[Table: see text]

Rechallenge with trabectedin in patients with responding myxoid liposarcoma

10575

Background: To determine the efficacy of rechallenge with trabectedin (T) in patients with myxoid liposarcoma who were responding to T at the time of discontinuation but subsequently developed progressive disease. Methods: Since September 2002, 32 patients with recurrent or advanced myxoid liposarcoma received T at our institution within an expanded access program. We report herein 8 patients who received T for a median of 10 cycles (range 5–15) prior to discontinuation. We used RECIST criteria to classify patient response to therapy. During the initial administration of T, a CR had been observed in 2 patients, a PR in 3 patients, SD in 2 patients, and one had had tumor shrinkage but did not meet RECIST definition of PR. The median PFS was 24 months from treatment start, and 14 months (range 9–27) from treatment-end. In 6 of the 8 patients, the treatment had been discontinued in the absence of any evidence of disease: 4 patients had undergone complete surgical resection (R0) of residual disease and 2 patients had achieved a radiological complete response (CR). The other two patients stopped treatment voluntarily, one with a partial response (PR) and one with stable disease (SD). All these patients resumed treatment at the time of progression. Results: Following rechallenge with T, no PD was seen at first assessment, and no patients had to discontinue or reduce the dose due to toxicity. Response rate according to RECIST was 50%. At a median follow up of 7 months (range 2.7–12), the median TTP has not yet been reached. Treatment is still ongoing in 5 patients. Conclusions: Rechallenge with T can be beneficial in some patients with myxoid liposarcoma. If further data confirm this, treatment of progressing patients previously responding to T may include this option. Furthermore, studies on optimization of treatment duration upfront may be worthwhile.

[Table: see text]

A phase II study of gimatecan as salvage treatment in patients with advanced or metastatic soft tissue sarcoma (STS) relapsing after anthracycline / ifosfamide - based chemotherapy regimens

10063

Background: Gimatecan, a new oral camptothecin derivative, showed early clinical activity in patients with STS during the phase I clinical development. Methods: Patients with different histological types of STS, including rhabdomyosarcoma and Ewing's sarcoma of soft parts, and advanced or metastatic disease pretreated with anthracycline and ifosfamide were included. The principal inclusion criteria were: disease not curable with surgery and/or radiation, presence of a measurable progressive lesion(s), pretreatment with 1–3 lines of chemotherapy including adjuvant regimens, ECOG PS 0 to 1, age = 18 years. Gimatecan 0.8 mg/m2 was administered orally daily for five consecutive days every 4 weeks. Radiological response was assessed every two cycles by RECIST. A multicenter two stage Simon's optimal design was used to evaluate the single agent activity of gimatecan, also by means of a hierarchical Bayesian model to evaluate treatment effects within the histological subtypes, using the rate of progression free survival at 4 months (PFS- 4) (Van Glabbeke, Eur J Cancer 38: 543–549, 2002). Other objectives were safety, TTP, pharmacokinetics and biomarker evaluations. Results: From August 2005 to December 2006 40 patients, 24 (60%) males and 16 (40%) females, median age 48 years (range 21 - 77), were included in 5 European sites. As of December 2006, 14 patients (35%) achieved stable disease after a median of 4 (range 3–9) cycles, and the PFS-4 is 15% (hystotypes: leiomyosarcoma, liposarcoma, Ewing, synovial and unclassified); all PFS-4 patients had liver or pleuropulmonary metastases. A prolonged arrest of progression was observed in one Ewing (up to 9 months), in one leiomyosarcoma and one liposarcoma (up to 8 and 7 months respectively, both patients still on treatment). Main G3/4 toxicity was hematological, namely anemia (7.5%), thrombocytopenia (5%) and neutropenia (2.5%). Conclusions: These data suggest that oral gimatecan has produced durable disease stabilization and is well tolerated with less than 10% grade 3/4 haematological toxicities.

[Table: see text]

Adding cisplatin (CDDP) to imatinib (IM) re-establishes tumor response following secondary resistance to IM in advanced chordoma

10038

Background: IM is active in advanced chordoma, possibly by targeting PDGFRB. Secondary progressions following response have been observed. The case of a pt with sacral chordoma and lung adenocarcinoma responding to CDDP soon after stopping IM prompted us to combine the two drugs in IM-resistant advanced chordoma. Methods: Since February 2006, 6 advanced chordoma pts (F=4, M=2; mean age 56 yrs; PS 0–2) with a secondary resistance to IM following previous response, have started IM 400 mg/day + low-dose CDDP (25 mg/sqm/wk) on an individual use basis. Results: One pt completed her treatment (after 7 mos, reaching a total dose of CDDP = 525 mg/sqm), and, following ablation of the residual lesion, is now continuing on IM alone. The remaining pts are on combination therapy (4 for <2 mos). After 4–6 weeks, 4 pts had a PET response (SUV max decrease ≥25%), with subjective improvement and stable disease on CT/MRI, while 2 were metabolically stable. In the 2 pts treated for >12 weeks, a minor dimensional response was observed after 3 mos. The single pt who completed combination therapy had a continuous PET scan improvement throughout treatment, and pre-ablation biopsy of residual tumor showed histological signs of tumor response (marked cellular depletion and sclerohyalinosis in most of the sample, with residual tumor cells intermingled with inflammatory ones). Conclusions: In 4 out of 6 advanced chordoma pts progressing on IM, a tumor response was re-established by adding CDDP, and 2 pts treated for a relatively longer interval showed dimensional tumor shrinkage. Four more pts are starting therapy, and results will be updated. An independent cytotoxic effect of CDDP cannot be ruled out, but sensitivity of chordoma to CDDP is at best occasional. The combination of IM and CDDP may have synergic activity in chordoma.

[Table: see text]

Sensitivity of myxoid-round cell liposarcoma (MRCL) to trabectedin (T) may be related to a direct effect on the fusion transcript

10000

Background: Myxoid-round cell liposarcomas (MRCL) is a variant of liposarcoma, associated with t(12;16)(q13;p11) and the rarer t(12;22)(q13;q12) chromosomal translocation, resulting in the FUS-CHOP and EWS-CHOP fusion proteins, supposed to act as aberrant transcription factors. We reported the exceedingly high clinical efficacy of T against MRCL, which is a magnitude higher in comparison to other liposarcomas and sarcomas. Reasons thereof remain unknown, but a distinct mechanism of action of T in MRCL is suspected on clinical grounds. Methods: Tumor biopsies were taken from 9 MRCL patients (pts) before starting T, and the tumor was fully characterized by cytogenetic and molecular analysis. Primary cultures were set up, and tumor fragments were transplanted in scid mice, to develop an experimental model aimed at investigating the mechanism of action of T. Chromatin immunoprecipitation (ChIP) analysis on the 402–91 myxoid liposarcoma cell line was performed, to characterize the DNA binding capability of FUS-CHOP. Finally, in vivo ChIP analyses are currently ongoing, using tumor samples obtained before and after therapy with T. Tumor samples from 3 patients have been processed so far. Results: All patients had t(12–16) by FISH. Molecular characterization showed that 7 pts had the type II transcript, 1 had the type III, and 1 both type II and III. Primary cultures evaluated after the first 3 passages were morphologically, cytogenetically and molecularly consistent with the original tumor, as well as the 4 tumours grown in mice so far. In the myxoid liposarcoma cell line carrying the type I transcript, selective binding of FUS-CHOP to some promoters was seen. Impairment of this binding activity was observed after treatment with T at concentration 1–4 nM. Conclusions: There is in vitro evidence of a direct effect of T on the fusion protein's ability to bind to promoters. In vivo studies on the experimental model are ongoing, and results will be presented.

No significant financial relationships to disclose.

High-dose Ifosfamide (HDIFX) as a 14-day continuous infusion (ci) in advanced adult soft tissue sarcoma (STS): A single- institution retrospective case series analysis

10067

Background: High-dose IFX (≥12 g/sqm) is active even in STS patients pretreated with standard-dose IFX, though with substantial toxicity. Prolonged continuous infusion, through a portable pump, may be an alternative way of administration. A Phase II study thereof is ongoing in Italy, but some pts have been treated off the study, either prior to its start or for practical reasons. Such consecutive pts seen at a single institution have been retrospectively reviewed. Methods: Between July 2001 and September 2006, 45 adult patients (M:F = 25:20; mean age 47 yrs; PS 0–1) with progressing advanced/metastatic STS, all previously treated with anthracyclines and standard-dose IFX, were given ciHDIFX, at the dose of 14 g/sqm as a 14-day continuous infusion every 4 weeks, using two portable infusional devices, with equidose Mesna, lasting 7 days each. Diagnosis was leyomiosarcoma in 12 patients, synovial sarcoma in 9, liposarcoma in 5, and other histological types in 19. Disease was advanced inoperable in 6 pts, and metastatic in 39. The total number of cycles was 176 (median number per pt: 4). Results: A PR was seen in 5 pts (synovial sarcoma, 2; leyomiosarcoma, 1, liposarcoma, 1; chondrosarcoma, 1), and SD in 22 (>6 mos in 12), for a clinical benefit rate = 37%. PFS at 6 months was 35%. Median PFS was 11 mos in pts with PR and 6 in those with SD. Median PFS was 8 months in 9 patients undergoing complete tumor resection. Most common side effects were nausea (G1–2 in 14 pts) and asthenia (G1–2 in 15 pts). G2 anemia was seen in 8 pts, G2 neutropenia in 6. One pt with a single kidney had a reversible G2 hypercreatininemia. No grade 3–4 toxicity were recorded. Conclusions: In this series, ciHDIFX was associated with a PR and 6-mos PFS rate in the range of active second-line agents in advanced STS. This regimen was exceedingly well tolerated.

No significant financial relationships to disclose.

Trabectedin (T) in metastatic Ewing's family tumors (EFT) patients (pts) progressing after standard chemotherapy

10040

Background: T is a formerly marine-derived agent which is active in human cancers, such as ovarian cancer and adult soft tissue sarcomas (STS). Efficacy of T in pts with unresectable/metastatic pretreated advanced STS was demonstrated in phase II settings. Leiomyosarcoma and liposarcoma were shown to be sensitive, with myxoid liposarcoma being exceedingly responsive. Data are lacking on “small round blue cell” sarcomas, including EFT. In 2000 a phase II study was launched by SENDO in a sarcoma population including EFT. At Istituto Nazionale Tumori, Milano, Italy, some EFT pts were treated after the completion of this study. We analyzed treatment efficacy in EFT pts treated within these two settings. Methods: Overall 15/29 of the pts were female, and age ranged from 15 to 55 years. Pts received T at a starting dose between 1,650 and 1,100 mcg/sqm every 3 weeks as 24-hour or 3-hour infusion. Each pt received at least 2 cycles of treatment, except in case of disease progression or unacceptable toxicity. Tumor response was assessed by RECIST criteria after the first 2 cycles and then every other cycle. Dose reductions were based on the worst toxicity (hematological or non-hematological) in the previous cycle. Results: As of December 2006, 20 pts were treated in the Phase II study, and 9 on a compassionate use basis. Two pts were still on therapy. A total of 79 treatment cycles (2–14 per pt) were administered. Three pts (10.3%) demonstrated a partial response, 3 had a minor response (10.3%), and 4 (13.7%) stable disease. PFS rate at 6 months was 25%. The most common all-causality AEs were acute reversible liver toxicity, fatigue, and myelosuppression. Following the introduction of steroid pre-medication, thrombocytopenia and fatigue were less frequent. Conclusions: In this cohort, T was overall well tolerated and showed antitumor activity in pts with advanced EFT. This calls for further evaluation of this compound, alone or in combination, in pts suffering from EFT.

No significant financial relationships to disclose.

Steroid premedication markedly reduces liver and bone marrow toxicity of trabectedin in advanced sarcoma

Trabectedin is a marine-derived cytoxic alkaloid which has shown promising antitumour activity in a variety of human malignancies including sarcoma. Fifty-four patients with advanced sarcoma (age 43 yrs, range 18-70), all pretreated with prior chemotherapy, were enrolled on a named individual basis for treatment with trabectedin. Diagnosis was adult soft tissue sarcoma (STS) in 46 patients, Ewing's family tumour (EFT) in 4, and osteosarcoma (OS) in 4. The initial 23 patients (total number of courses administered: 68) did not receive premedication prior to trabectedin, while the other 31 patients (total number of courses administered: 134) received premedication with dexamethasone 4 mg po bid 24 hours before therapy. Incidence of toxicity (grade 3-4), expressed as percentage of courses, was as follows: in patients without dexamethasone, elevation of transaminases 34%, neutropenia 24% and thrombocytopenia 25%; in patients with prior dexamethasone, elevation of transaminases 2%, neutropenia 2% and no thrombocytopenia. The median received dose intensity of trabectedin was superimposable in the two groups (404 microg and 400 microg per week, respectively), as well as progression-free survival (19% at 6 months). Among STS patients, 9% had objective responses. In this unselected patient series, premedication with dexamethasone strongly reduced drug-induced hepatotoxicity and myelosuppression.

DNA repair functionality modulates the clinical outcome of patients with advanced sarcoma treated with trabectedin (ET-743)

9522

Background and Methods: The sensitivity to trabectedin (Yondelis, ET-743) in experimental cancer models correlates with functional transcription-coupled nucleotide excision repair (TC-NER) and with deficient homologous recombination repair (HRR) activity. In order to assess the clinical relevance of this observation we have characterized the mRNA expression levels of ERCC1, XPD, BRCA1 and BRCA2 by RT-PCR in historical tumor samples from 92 sarcoma patients (pts) treated with the agent. Results: The overall objective response (CR+PR) rate to Yondelis in this group was 9%, which confirms the previous clinical experience with the compound in unselected, pre-treated patients with sarcoma. The Kaplan-Meier estimates for progression-free survival at 6 months (PFS6) was 23% and for median survival 8 months (mo). 26% of pts were alive at 24 mo. Correlative Study: Pts with high expression levels (> median) of ERCC1 had better PFS6 (32% vs 15%, p = 0.07) and better median survival (12 vs 7 mo) as compared to pts with low expression ( ≤ to median). Pts with low expression levels of BRCA1 had better PFS6 (33 vs 11%, p = 0.02) and superior median survival (15 vs 5 mo, p = 0.0003) than pts with high expression. Expression levels of XPD and BRCA2 (58 pts) had no significant impact on PFS and survival. The analysis of co-expression of ERCC1-BRCA1 identified a highly sensitive group of pts, characterized by high ERCC1 and low BRCA1 expression levels, with a PFS6 of 50% (p=0.0003) and median survival of 20.4 mo (p = 0.0005). A Cox regression analysis demonstrated that ERCC1 (HR=0.52, p = 0.02) and BRCA1 (HR=2.73, p = 0.0006) are independent variables for PFS, while BRCA1 (HR= 2.57, p = 0.0005) is also an independent variable for survival. Conclusion: This exploratory retrospective study supports the hypothesis that the sensitivity to Yondelis in pts with sarcoma correlates with a functional TC-NER and with deficient HRR. Prospective studies in sarcoma and other potentially sensitive tumor types are required to confirm and validate these findings.

[Table: see text]

Patterns of tumor response to trabectedin (ET743) in myxoid liposarcomas

9511

Background: Trabectedin (T) is a marine-derived agent found to be active in ovarian cancer and sarcomas. Among sarcomas, activity has been notable in leiomyosarcomas and liposarcomas. Since liposarcomas are a heterogeneous group, including well/de-differentiated, pleomorphic, and myxoid/round cell subtypes, we have noted particularly interesting patterns of responsiveness to T in myxoid liposarcomas, which are associated with t(12;16)(q13;p11) or t(12;22)(q13;q12) chromosomal translocations, resulting in CHOP-TLS or CHOP-EWS fusion products. Methods: 15 cases of myxoid liposarcomas treated with T at the Istituto Nazionale Tumori, Milan, were retrospectively reviewed. In most cases, T was given as a 24-hr continuous infusion every 21 days, at dose levels from 1.0 to 1.5 mg/sqm. 108 courses were delivered, with a median of 5 courses per patient (range 2–20). Observations made in this series were shared with five other institutions having treated myxoid liposarcoma cases with T, all of which also report a significant response rate, for a total of 44 pts. A centralized radiological review of all pts is ongoing. Results: In the Milan series, early tissue alterations in tumors were observed in 14 patients, mainly with a decrease in tumor density on CT scan and/or decrease in contrast enhancement on MRI. These changes were followed by tumor shrinkage amounting to a conventional PR/CR in 8 (pending final review), while 3 others have responses which continue to evolve. Progression followed treatment interruption in one patient, with a minor response occurring at treatment restart. Treatment is continuing in 12 pts (median duration of therapy in excess of 5 months). Further results of the central radiological review from all centres will be reported. Conclusions: Tumor response to T seen in myxoid liposarcoma appears to be marked by early radiological alterations in tumor tissue, often preceding tumor shrinkage, which may be delayed. A selective mechanism of action for this chromosomal translocation-related sarcoma is suggested, and is being actively investigated at the moment.

[Table: see text]

Extremity soft tissue sarcoma: The need for a differential surgical approach to primary tumor and local recurrence?

9565

Background: To explore the prognostic implications of local recurrence in extremity adult soft tissue sarcoma (eSTS). Methods: From January 1983 to December 2002, 1,017 patients with localized eSTS were treated at Istituto Nazionale Tumori, Milan, Italy. First local recurrence, re-operated with a curative intent, was investigated as a predictor of further recurrence, distant metastasis and cause specific mortality. Such a task was carried out considering recurrent patients earlier operated for primary disease at our institution (Group A, N=88) or elsewhere (Group B, N=150). The follow up of the above patients after recurrence was compared to that of the overall group of 738 patients operated for primary disease at our institution. Analyses were performed by multiple Cox models, in which local recurrence was entered as a time dependent factor, and tumour size, depth, histotype, grade, margins, RT and CT as covariates for the purpose of adjustment. Event-times were computed from the date of diagnosis, with “left censoring” on the time when patients entered our cohort (date of surgery). Results: The hazard ratio estimates of second recurrence, distant metastases and disease-specific mortality in groups A and B were 5.39 vs 2.95 (p<0.001), 3.96 vs 1.54 (p<0.001), and 2.93 vs 1.43 (p<0.001), respectively. The prognostic effect of the covariates on mortality turned out to be not significantly affected by disease local relapse, but a trend for surgical margins in group A could be observed (HR 1.71). Conclusions: Local recurrence correlates with a worse prognosis, in terms of further local recurrence, distant metastases, and death. Such an effect is stronger following surgery at a referral center for eSTS if compared to local recurrence following surgery done elsewhere, i.e. at institutions less likely to perform adequate local treatment for this rare group of tumors. Possibly, this means that “true” local recurrences, not simply due to inappropriateness, single out pts carrying an inherently more aggressive disease. Consistently, these data cannot confirm, but neither rule out that more aggressive surgery (ie, at the cost of a higher amputation rate, in order to avoid contaminated surgical margins) may be needed in pts locally recurring after initial adequate surgery.

No significant financial relationships to disclose.

[Communication turned into prevention. The "European Week for the Safety and Health at Work": experience of the Italian Focal Point]

The constant focus on comprehensive quality of work and the promotion of an effective culture of prevention and communication, already indicated in the European Directives, gave new impetus to the strategy aimed at improving working conditions and workers' health. This study is aimed at identifying the successful factors of the European Week for Safety and Health at Work, an information and awareness campaign promoted by the European Agency for Safety and Health at Work based in Bilbao, through the analysis of the campaign's project and of the results achieved in Italy. The European Week, now at its 7th edition, represents a peerless opportunity to spread the culture of risk prevention and to raise awareness on the adoption of measures to improve workplaces, above all in small and medium enterprises. It is, furthermore, a valuable tool to communicate and disseminate messages and to promote good practices on occupational safety and health. ISPESL is the Italian Focal Point of the European Agency for Safety and Health at Work and has been supporting the organization of the European Week in Italy, since the first edition. It has been strongly committing itself to promote and disseminate information on the event, relying on its national network which operates throughout the national territory. The ISPESL web-site--http://www.ispesl.it--contains a web page dedicated to European Weeks, providing information on the campaign and on the related initiatives, on the materials, and on the main events taking place in Italy.

Development of a novel ELISA system for detection of anti-BP180 IgG and characterization of autoantibody profile in bullous pemphigoid patients

BACKGROUND

The NC16A immunodominant region of the bullous pemphigoid (BP) antigen BP180 has been used to develop several enzyme-linked immunosorbent assays (ELISAs) as diagnostic tools for BP autoantibody detection.

OBJECTIVES

Because BP180 autoantibody reactivity is not restricted to NC16A, we have investigated the possibility of developing an ELISA based on selected epitopes additional to this immunodominant region.

METHODS

Initially 78 BP sera were tested using an NC16A ELISA and IgG reactivity was detected in 64 BP sera (82%). The 14 NC16A-negative BP sera were then analysed by immunological screening against seven BP180-specific epitopes. Recombinant phages displaying BP180 epitopes were grown as plaques, blotted onto a nitrocellulose filter and incubated with BP sera.

RESULTS

Three and five NC16A-negative BP sera reacted with epitopes AA 1080-1107 and AA 1331-1404 of the BP180 ectodomain, respectively. Thus, a novel ELISA with GST-1080 and GST-1331 (GST-1080/1331) was developed: 32 of 78 BP sera (41%) proved positive by this assay. The combined use of ELISAs with GST-NC16A and GST-1080/1331 detected IgG reactivity in 72 of 78 BP sera, increasing the sensitivity from 82% to 92%. In addition, autoreactivity against the three extracellular epitopes appeared to be related to the presence of both skin and mucosal involvement as assessed by Fisher's exact probability test.

CONCLUSIONS

Our findings further characterize the autoimmune response in BP by identifying a subgroup of NC16A-negative patients who react with different BP180 extracellular epitopes. The developed ELISA system appears more sensitive than the ELISA based on NC16A alone and also informative about the epitope profile of BP patients.

Joint IDF-IUPAC-IAEA(FAO) interlaboratory validation for determining aflatoxin M1 in milk by using immunoaffinity clean-up before thin-layer chromatography

A collaborative study was conducted under the auspices of the International Dairy Federation (IDF), the International Union of Pure and Applied Chemistry (IUPAC) and the International Atomic Energy Agency (IAEA), a collaborative Food and Agricultural Organization (FAO) body fully to validate a method combining immunoaffinity clean-up to thin-layer chromatography for the determination of aflatoxin M(1) in milk. Work was done in order to afford those laboratories not equipped with high-performance liquid chromatography, mainly from developing countries, with a simplified but fully validated method as an alternative to the European validated immunoaffinity-high performance liquid chromatography method published as an EN ISO Standard 14501, February 1999. The validation study was carried out on samples of aflatoxin M(1)-contaminated milk and milk powder at levels close to the tolerable level of 0.5 microg l(-1) as recommended by the Codex Alimentarius and to the regulatory level of 0.05 microg l(-1) as laid down by the European Commission. Fourteen laboratories representing 11 countries participated in the trial. The relative standard deviations for repeatability and reproducibility based on raw data were in the range 27-48 and 35-54%, respectively. The recovery rate varied from 32 to 120%. The mishandling of two crucial steps of the protocol such as matrix sample reconstitution and extract evaporation could explain the wide variation of the recovery rate. For this reason, data were then corrected for recovery. Consequently, the relative standard deviations for repeatability and reproducibility were recalculated after correction for recovery and were in the range 26-54 and 34-53%, respectively. The method will be published as a standard ISO/DIS 14674--IDF 190.

New data on the occurrence of ochratoxin A in human sera from patients affected or not by renal diseases in Tunisia

Ochratoxin A is often found in the sera of people exposed to this mycotoxin in their food (cereals such as barley, coffee, wines, fruit juices, spices, products of animal origin such as pig and poultry offal). Ochratoxin A is suspected of playing a role in the Balkan Endemic Nephropathy, a nephropathology described in Balkan areas where ochratoxin A is often found in cereals and in pork-derived products. In North Africa like Tunisia where high incidence of chronic interstitial nephropathies of unknown aetiology are pointed out, the involvement of ochratoxin A was suspected but contradictory studies on the degree of human exposure did not succeed in evidencing the role of ochratoxin A. In the present work, sera from 47 volunteers hospitalised for nephropathic damages including bladder tumours (21 people), and from 62 patients hospitalised for disorders other than nephropathic ones, were analysed for ochratoxin A contents. The determination of ochratoxin A in sera was done by a validated immunoaffinity-HPLC method. Sera from unaffected population exhibited percentages of 74.2%, 22.6% and 3.2% containing ranges of ochratoxin A as <0.10-0.5 microg/l, 0.51-1.0 microg/l and above 1.0 microg/l respectively. For patients affected with renal diseases, percentages were 59.5%, 25.5% and 14.9% on the same ranges of ochratoxin A levels respectively. The average ochratoxin A concentration for patients with urinary tract disease excluding cancer patients was 0.99+/-1.28 microg/l while that for the non-nephropathic patients was 0.53+/-1.00 microg/l. However the average levels in the cancer patients was only 0.26+/-0.20 microg/l. Those results are in line with most of previously published works and did not confirm very high ochratoxin A contents found in other reports from same regions.