Weekly docetaxel in metastatic breast cancer patients: no superior benefits compared to three-weekly docetaxel.

BACKGROUND: In anthracycline-pretreated metastatic breast cancer (MBC) patients, it is unknown whether weekly single-agent docetaxel is preferable to 3-weekly docetaxel regarding its toxicity and efficacy profile. PATIENTS AND METHODS: In this multicenter, randomised, open-label phase III trial, 162 patients were randomised to weekly docetaxel (group A) or 3-weekly docetaxel (group B). The primary end-point was tolerability; secondary end-points were efficacy and quality of life (QoL). RESULTS: Group A (weekly docetaxel, n=79) experienced less haematological toxicity, with just 1.3% versus 16.9% febrile neutropenia in group B (3-weekly docetaxel, n=77) (p=0.001). Not this difference, but fatigue and general malaise foremost led to more patient withdrawals in group A (24 versus 12 patients, p=0.032), less patients completing treatment (29 versus 43 patients, p=0.014) and reduced dose-intensity (15.6 versus 26mg/m(2)/week, 58% versus 70% of projected dose, p=0.017). As a result, 3-weekly docetaxel was related to better overall survival in multivariate analysis (hazard ratio 0.70, p=0.036), although in univariate analysis efficacy was similar in both groups. Reported QoL was similar in both groups, but less effective treatment with more general toxicity led to less completed QoL forms in group A (65.4% versus 50%, p=0.049). CONCLUSION: Weekly docetaxel is less well tolerated than a 3-weekly schedule, due to more non-haematological toxicity, despite less febrile neutropenia. Also, no efficacy benefits can be demonstrated for weekly docetaxel, which may even be inferior based on multivariate analysis. Therefore, a 3-weekly schedule should be preferred in the setting of MBC.

The HLA-DQ2 gene dose effect in celiac disease is directly related to the magnitude and breadth of gluten-specific T cell responses.

In patients with celiac disease, inflammatory T cell responses to HLA-DQ2-bound gluten peptides are thought to cause disease. Two types of HLA-DQ2 molecules exist, termed HLA-DQ2.5 and HLA-DQ2.2. Whereas HLA-DQ2.5 predisposes to celiac disease, HLA-DQ2.2 does not. We now provide evidence that the disease-associated HLA-DQ2.5 molecule presents a large repertoire of gluten peptides, whereas the non-disease-associated HLA-DQ2.2 molecule can present only a subset of these. Moreover, gluten presentation by HLA-DQ2 homozygous antigen-presenting cells was superior to presentation by HLA-DQ2/non-DQ2 heterozygous antigen-presenting cells in terms of T cell proliferation and cytokine secretion. Gluten presentation by HLA-DQ2.5/2.2 heterozygous antigen-presenting cells induced intermediate T cell stimulation. These results correlated with peptide binding to the antigen-presenting cells. Finally, we demonstrate that HLA-DQ trans dimers formed in HLA-DQ2.5/2.2 heterozygous individuals have properties identical with HLA-DQ2.5 dimers. Our findings explain the strongly increased risk of disease development for HLA-DQ2.5 homozygous and HLA-DQ2.2/2.5 heterozygous individuals, and they are indicative of a quantitative model for disease development, where HLA-DQ expression and the available number of T cell-stimulatory gluten peptides are critical limiting factors. This model may have important implications for disease prevention.

The gluten response in children with celiac disease is directed toward multiple gliadin and glutenin peptides.

BACKGROUND & AIMS: Gluten (GLU)-specific T-cell responses in HLA-DQ2 positive adult celiac disease (CD) patients are directed to an immunodominant alpha-gliadin (GLIA) peptide that requires deamidation for T-cell recognition. The aim of the current study was to determine which GLU peptide(s) are involved early in disease. METHODS: We have characterized the GLU-specific T-cell response in HLA-DQ2 positive children with recent onset CD. RESULTS: We found that 50% of these patients do not respond to the alpha-GLIA peptide but to a diverse set of GLIA and glutenin (GLT) peptides, including 6 novel epitopes. Moreover, individual patients respond to distinct (combinations of) GLU peptides. T-cell cross-reactivity toward homologous GLIA and GLT peptides was observed, which might play a role in the initial spreading of the GLU-specific T-cell response. Although all pediatric patients displayed deamidation-dependent responses, deamidation-independent responses were found in the majority of patients as well. Finally, T-cell responses to 3 of these novel GLU peptides were found in adult CD patients. CONCLUSIONS: The diversity of the GLU-specific T-cell response is far greater than was previously appreciated. Both adult and young CD patients can respond to a diverse repertoire of GLU peptides. The observation that T-cell responses to 3 of the novel peptides are independent of deamidation indicates that T-cell responses can be initiated toward native GLU peptides. The possibility that deamidation drives the GLU response toward immunodominant T-cell stimulatory peptides after disease initiation is discussed.