Antiviral cell-mediated immune responses during hepatitis B and hepatitis C virus infections

Cell-mediated immune responses to hepatitis B (HBV) and hepatitis C virus (HCV) antigens are vigorous and multispecific in acute, self-limited infections. Moreover, the prevalent cytokine pattern of circulating virus-specific T cells from patients who recover spontaneously from acute hepatitis is Th1-like. Longitudinal analysis of the T cell response to HCV antigens from the early stages of HCV infection in patients who recover from hepatitis and those who do not indicates that weaker responses and a prevalent Th2 pattern of cytokine production is associated with viral persistence and chronic evolution of disease. Although similar sequential studies are missing in hepatitis B, the observation that HBV-specific T cell responses are very weak or totally undetectable in the peripheral blood of patients with long-lasting chronic hepatitis B suggests that strength and quality of virus-specific T cell responses at the early stages of infection may influence the final outcome of both hepatitis B and C. While T cell hyporesponsiveness seems to be an important determinant for HBV persistence once chronic hepatitis has developed, this mechanism appears to be less critical in chronic HCV infection, because the vigor and quality of HCV-specific T cell responses seem to improve as a function of the duration of infection. This is shown by the finding that HCV-specific CD4- and CD8-mediated responses are easily detectable in the peripheral blood of patients with long-lasting chronic hepatitis C and that production of Th1 cytokines predominates within their livers. HCV therefore seems to be able to persist even in the face of an active T cell response and to acquire the capacity to survive within a host environment apparently unfavorable to its persistence. The high variability of HCV may explain its efficiency in escaping immune surveillance.

Cytotoxic and hormonal treatment for metastatic breast cancer: a systematic review of published randomized trials involving 31,510 women

PURPOSE

A systematic review of randomized clinical trials (RCTs) was undertaken to assess the effectiveness of medical treatment for metastatic breast cancer.

METHODS

RCTs published between 1975 and 1997 have been classified according to 12 therapeutic comparisons: (1) polychemotherapy (PCHT) agents versus single agent; (2) PCHT regimens with anthracycline versus PCHT without anthracycline; (3) other PCHT versus cyclophosphamide, methotrexate, and fluorouracil (CMF); (4) chemotherapy (CHT) with epirubicin versus CHT with doxorubicin; (5) CHT versus same CHT delivered with less intensive schedules; (6) other endocrine therapy (OET) versus tamoxifen; (7) OET plus tamoxifen versus tamoxifen alone; (8) OET versus medroxyprogesterone; (9) OET versus aromatase inhibitors; (10) OET versus megestrol; (11) endocrine therapy (ET) versus same ET at lower doses; and (12) CHT plus ET versus CHT. Tumor response rates, mortality hazards ratio (HR) and frequency of severe side effects were the outcome measures.

RESULTS

A total of 189 eligible trials (31,510 patients) were identified. All provided response rates and 133 (70%) data or survival curves needed for calculation of the HR. In eight of 12 comparisons, statistically significant differences for response emerged (1, 2, 3, 5, 7, 8, 11, 12); all but no. 8 favored the first term of the comparison. Overall survival analysis showed better results of (a) PCHT versus single-agent CHT (HR=0.82; 95% confidence interval [CI], 0.75 to 0.90); (b) CHT with doxorubicin versus CHT with epirubicin (HR=1.13; 95% CI, 1.00 to 1.27); (c) CHT versus the same CHT delivered with less intensive schedules (HR=0.90; 95% CI, 0.83 to 0.97); (d) ET versus the same ET at lower doses (HR=0.86; 95% CI, 0.77 to 0.97). Quality of life was measured in only 2,995 of 31,510 patients (9.5%).

CONCLUSION

Despite some evidence of effectiveness of specific regimens, the relevance of these findings is limited by the modest survival benefit and the lack of evaluation of the quality-of-life impact of these treatments.

Lamivudine treatment can restore T cell responsiveness in chronic hepatitis B

High viral and/or antigen load may be an important cause of the T cell hyporesponsiveness to hepatitis B virus (HBV) antigens that is often observed in patients with chronic HBV infection. Reduction of viral and antigen load by lamivudine treatment represents an ideal model for investigating this hypothesis. HLA class II restricted T cell responses and serum levels of HBV-DNA, HBsAg, and HBeAg were studied before and during lamivudine treatment in 12 patients with hepatitis B e antigen positive chronic active hepatitis B to assess possible correlations between viral and/or antigen load and vigor of the T cell response. Cell proliferation to HBV nucleocapsid antigens and peptides and frequency of circulating HBV nucleocapsid-specific T cells were assessed to characterize CD4-mediated responses. A highly significant enhancement of the CD4-mediated response to HBV nucleocapsid antigens was already detectable in most patients 7-14 d after the start of lamivudine treatment. This effect was dramatic and persistent in 10 patients but undetectable in 2. It occurred concomitant with a rapid and marked reduction of viremia. Interestingly, lamivudine also enhanced the responses to mitogens and recall antigens, showing that its effect was not limited to HBV-specific T cells. In conclusion, an efficient antiviral T cell response can be restored by lamivudine treatment in patients with chronic hepatitis B concurrently with reduction of viremia, indicating the importance of viral load in the pathogenesis of T cell hyporesponsiveness in these patients. Since lamivudine treatment can overcome T cell hyporeactivity, combining lamivudine with treatments directed to stimulate the T cell response may represent an effective strategy to induce eradication of chronic HBV infection.

Molecular features of the hepatitis B virus nucleocapsid T-cell epitope 18-27: interaction with HLA and T-cell receptor

The strength of the cytotoxic T lymphocyte (CTL) response is believed to influence the final outcome of hepatitis B virus (HBV) infection. Among the different CTL epitopes so far identified, the sequence 18-27 of the HBV nucleocapsid antigen is widely recognized by CTL of HLA-A2-positive patients with acute self-limited HBV infection, and represents the main component of a peptide-based therapeutic vaccine aimed at stimulating the antiviral CTL response in patients with chronic hepatitis B. In the present study, we further analyzed the features of this important HBV region by the following: 1) defining the contribution of individual residues of the epitope to the interaction with the T-cell receptor (TCR) and with the HLA-A0201 molecule; 2) assessing the antigenicity of this viral region in the context of the different HLA-A2 subtypes; and 3) testing whether this sequence can stimulate not only HLA-class I but also HLA class II restricted T-cell responses. A clear hierarchy was observed in the ability of individual residues to act as TCR or HLA binding sites. Furthermore, the sequence HBc18-27 was able to be recognized by specific CTL when presented in the context of different HLA-A2 subtypes. Finally, this HBV region was also found to stimulate HLA class II restricted T-cell responses. These data further increase the potential coverage and efficacy of therapeutic vaccines based on the HBc18-27 sequence.

Predominant T-helper 1 cytokine profile of hepatitis B virus nucleocapsid-specific T cells in acute self-limited hepatitis B

The cytokine pattern secreted by T cells on viral antigen recognition is believed to exert a profound influence on both the type of disease caused by the infecting agent and the final outcome of the viral infection. To characterize the cytokine pattern associated with spontaneous resolution of acute hepatitis B, we analyzed interferon gamma (IFN-gamma), interleukin (IL)-4, and IL-5 production by a wide series of hepatitis B virus (HBV) nucleocapsid-specific T-cell lines (34 lines) and T-cell clones (71 clones) derived from the peripheral blood of 13 patients during the acute or recovery phase of hepatitis B (2 and 7 of them were studied only in the recovery or the acute phase, respectively, and 4 during both). Most T-cell lines (67%) and clones (77%) isolated during the acute phase of infection expressed a T-helper (Th) 1 cytokine profile dominated by the production of IFN-gamma. A larger proportion (74%) of T-cell lines produced several years after resolution of hepatitis was able to secrete not only IFN-gamma, but also IL-4 and IL-5 (Th0-like cells). Results indicate that the antigen-specific fraction of peripheral blood T cells in acute self-limited hepatitis B selectively secrete Th1-type eytokines, suggesting that Th1-mediated effects may contribute not only to liver cell injury, but probably also to recovery from disease and successful control of infection.

Different cytokine profiles of intraphepatic T cells in chronic hepatitis B and hepatitis C virus infections

BACKGROUND & AIMS

The cytokine pattern secreted by T cells at the site of viral replication may influence the final outcome of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. The aim of this study was to assess whether a cytokine imbalance oriented toward T helper (Th) 1 or Th2-type responses may play a role in chronic hepatitis B or C.

METHODS

Production of interferon (IFN)-gamma, interleukin (IL)-4, and IL-5 by wide series of T-cell clones derived from the liver of 6 patients with chronic hepatitis B (291 clones) and 9 patients with chronic hepatitis C (260 clones) was studied. T-cell clones were generated by limiting dilution from freshly isolated mononuclear cells derived from liver tissue to give a reliable representation of the intrahepatic inflammatory infiltrates.

RESULTS

The majority of liver-infiltrating T cells in chronic hepatitis C were Th1 cells able to secrete IFN-gamma but unable to secrete IL-4 or IL-5, whereas in hepatitis B, most CD4+ and CD8+ liver T cells were ThO-like cells able to produce not only IFN-gamma but also IL-4 and IL-5.

CONCLUSIONS

The different cytokine profiles of T cells within the liver in chronic HBV and HCV infections illustrate a different behavior of the local immune response in these two infections that may have pathogenetic implications.

Physicians' view of practice guidelines. A survey of Italian physicians

After more than 10 years of development, two different views of practice guidelines are emerging: either as an educational tool for the medical profession, or as a forum where health care issues can be debated by physicians and non-medical groups. Physicians use practice guidelines in the former model to set their own standards of good quality care, while the latter approach needs contributions from other components in order to decide what should be provided by our health care systems. In a survey of Italian physicians' opinions and attitudes toward practice guidelines, responders supported the "narrowest" model. More than 80% stated that improvement of quality of care and reduction of variation in clinical and practice styles should be the aim of practice guidelines, without representatives from outside the medical profession being involved (61%, 79% and 86% disagreed with a possible involvement, respectively, of patients, health care administrators and representatives of the public at large). Overall, 38% of physicians had a positive attitude toward guidelines viewed as a quality assurance tool for the medical profession. Overall, physicians seem to ignore that the need to rationalize health care calls for input from other professions and members of society. Indeed, most of the issues facing medicine today are mainly a matter of how much value our societies attach to the benefit expected from the available health services. The answers as to what should be done in health care probably cannot be left to the medical profession alone.

Long-lasting memory T cell responses following self-limited acute hepatitis B

The molecular and cellular basis of long-term T cell memory against viral antigens is still largely undefined. To characterize anti-viral protection by memory T cells against non-cytopathic viruses able to cause acute self-limited and chronic infections, such as the hepatitis B virus (HBV), we studied HLA class II restricted responses against HBV structural antigens in 17 patients with acute hepatitis B, during the acute stage of infection and 2.2 to 13 yr after clinical resolution of disease. Results indicate that: (a) significant T cell proliferative responses to HBV nucleocapsid antigens were detectable in all patients during the acute phase of infection and in 14/17 also 2-13 yr after clinical resolution of disease; b) long-lasting T cell responses were sustained by CD45RO+T cells, predominantly expressing the phenotype of recently activated cells; c) limiting dilution analysis showed that in some patients the frequency of HBV-specific T cells was comparable to that observed in the acute stage of infection and, usually, higher than in patients with chronic HBV infection; d) the same amino acid sequences were recognized by T cells in the acute and recovery phases of infection; and e) HBV-DNA was detectable by nested-PCR in approximately half of the subjects. to conclusion, our results show that vigorous anti-viral T cell responses are detectable in vitro several years after clinical recovery from acute hepatitis B. Detection of minute amounts of virus in some recovered subjects suggests that long-term maintenance of an active anti-viral T cell response could be important not only for protection against reinfection but also for keeping the persisting virus under tight control.

Short stay facilities: the future of efficient paediatric emergency services

Many children admitted to hospital can stay for 24 hours or less. Short stay facilities offer such children rapid stabilisation and early discharge with considerable financial saving. A 12 month study was completed in which data were collected from the children's emergency annex (CEA) at Westmead Hospital in Sydney's western suburbs. This university based teaching hospital provides care for a large paediatric population as well as three other district hospitals with limited children's bed capacity. From April 1994 to April 1995, 1300 children were admitted and entered into a database of general and hospital-specific information. Critical incident monitoring was undertaken and follow up with review within 24-72 hours for all children. The CEA increased hospital efficiency significantly by reducing bed days, with a saving of over $500,000 to the department. The average length of stay was 17.5 hours, and 58% of users were children of 2 years and under. Only 3% remained beyond 24 hours, and another 4% were admitted to inpatient beds for continued management of the primarily diagnosed condition. No critical incident was reported during this 12 month period. Short stay facilities are efficient and cost-effective for children with acute illness who can be rapidly stabilised with early discharge without critical incident. Children 12 months and under are particularly suited to this type of facility. Short stay facilities should be used to augment efficiency within children's emergency services which have high turnover and limited bed capacity.

Completeness of reporting of trials published in languages other than English: implications for conduct and reporting of systematic reviews

BACKGROUND

Lately, the number of systematic reviews published has increased substantially. Many systematic reviews exclude trials published in languages other than English. However, there is little empirical evidence to support this action. We looked for differences in the completeness of reporting between trials published in other languages and those published in English, to see whether the exclusion of trials published in other languages is justified.

METHODS

We compared completeness of reporting, design characteristics, and analytical approaches of 133 randomised controlled trials (RCTs) published in English between 1989 and 1994 and 96 published in French, German, Italian, or Spanish during the same time. RCTs were identified by hand searching of journals (seven in English and six in the other languages).

FINDINGS

We found no significant differences between trials published in English and other-language trials for any single item in the completeness of reporting scale (randomisation, double-blinding, withdrawals), or for the overall score (percentage of maximum possible score 51.0% for trials in English, 46.2% for trials in other languages; 95% CI for difference -1.1 to 10.5). Other-language trials were more likely than English-language trials to have adult participants, to use two or more interventions, and to compare two or more active treatments without an untreated control group. Trials in other languages were less likely to report a clearly prespecified primary outcome or any rationale for sample size estimation.

INTERPRETATION

These results provide evidence for inclusion of all trial reports, irrespective of the language in which they are published, in systematic reviews. Their inclusion is likely to increase precision and may reduce systematic errors. We hope that our findings will prove useful to those developing guidelines and policies for the conduct of reporting of systematic reviews.

Cytotoxic T lymphocyte response to a wild type hepatitis B virus epitope in patients chronically infected by variant viruses carrying substitutions within the epitope

Mutations that abrogate recognition of a viral epitope by class I-restricted cytotoxic T lymphocyte (CTL) can lead to viral escape if the CTL response against that epitope is crucial for viral clearance. The likelihood of this type of event is low when the CTL response is simultaneously directed against multiple viral epitopes, as has been recently reported for patients with acute self-limited hepatitis B virus (HBV) infection. The CTL response to HBV is usually quite weak, however, during chronic HBV infection, and it is generally acknowledged that this is a major determinant of viral persistence in this disease. If such individuals were to produce a mono- or oligospecific CTL response, however, negative selection of the corresponding mutant viruses might occur. We have recently studied two HLA-A2-positive patients with chronic hepatitis B who, atypically, developed a strong HLA-A2-restricted CTL response against an epitope (FLPSDFFPSV) that contains an HLA-A2-binding motif located between residues 18-27 of the viral nucleocapsid protein, hepatitis B core antigen (HBcAg). These patients failed, however, to respond to any of other HLA-A2-restricted HBV-derived peptides that are generally immunogenic in acutely infected patients who successfully clear the virus. Interestingly, DNA sequence analysis of HBV isolates from these two patients demonstrated alternative residues at position 27 (V --> A and V --> I) and position 21 (S --> N, S --> A, and S --> V) that reduced the HLA and T cell receptor-binding capacities of the variant sequences, respectively. Synthetic peptides containing these alternative sequences were poorly immunogenic compared to the prototype HBc18-27 sequence, and they could not be recognized by CTL clones specific for the prototype peptide. While we do not know if the two patients were originally infected by these variant viruses or if the variants emerged subsequent to infection because of immune selection, the results are most consistent with the latter hypothesis. If this is correct, the data suggest that negative selection of mutant viral genomes might contribute to viral persistence in a subset of patients with chronic HBV infection who express a narrow repertoire of anti-HBV CTL responses.

Variation in use of breast surgery and characteristics of hospitals' surgical staff

OBJECTIVE

To assess whether and how the characteristics of hospitals' surgical staff can predict utilization of breast conserving surgery. We anticipated that the use of the procedure was more frequent in hospitals with a greater proportion of younger and female surgeons on their staff.

SETTING

Sixty-two hospitals with different level of organization for the care of cancer patient from eight Italian regions were included.

DESIGN

We collected information on the personal characteristics (age and sex) of all surgeons on the staff of the participating centers. A concurrent pattern of care study was undertaken, in order to assess the utilization of breast conserving procedures.

RESULTS

The use of conservative surgery was 16%, 20%, 31%, in centers with 0%, < 20% and 20-50% female surgeons respectively (p = 0.003), while no associations emerged between the mean age of the surgical staff and the use of conservative surgery. This relationship also held true after adjusting for other patients' characteristics, such as stage of disease, age and presence of comorbidity. However, overall the use of patient-related and staff-related characteristics to predict the number of breast conserving surgeries performed in each area was able to explain only 16% of the observed variability in the use of breast conserving surgery.

CONCLUSIONS

Even though in this study a large proportion of the observed variation in the use of breast conserving surgery was still left unexplained, this finding suggests that assessing the relationship between doctors' characteristics and the use of scientific evidence is an important topic for health service research and can be of some help in exploring variations in clinical practice styles.

Natural variants of cytotoxic epitopes are T-cell receptor antagonists for antiviral cytotoxic T cells

It has been suggested that mutations within immunodominant cytotoxic T-lymphocyte (CTL) epitopes may be exploited by viruses to evade protective immune responses critical for clearance. Viral escape could originate from passive mechanisms, such as mutations within crucial CTL epitopes, either affecting major histocompatibility complex binding or T-cell antigen receptor (TCR) recognition. Additionally, it has recently been shown that substitutions of TCR contact sites can yield analogue peptides that can still interact with the T-cell receptor but be unable to deliver a full stimulatory signal, thus inducing anergy or acting as an antagonist for the TCR. We report here that hepatitis B virus isolates derived from two chronically infected patients display variant epitopes that act as natural TCR antagonists with the capacity to inhibit the CTL response to the wild-type epitope. During natural infection, TCR antagonist mutations of CTL epitopes could contribute to the development of viral persistence, especially if the antiviral CTL response is monospecific or the epitope is strongly immunodominant.

[The effect of ursodeoxycholic acid in patients with liver cirrhosis and chronic hypertransaminasemia]

The aim of the study was to evaluate the effect of ursodeoxycholic acid (UDCA) oral administration on alanine aminotransferases (ALT) levels in cirrhotic patients with chronic hypertransaminasemia. Ninety consecutive patients with histologically proven liver cirrhosis and ALT levels higher than twice the upper limit of normal for at least six months, were admitted to the study. All the patients were treated with UDCA 10 mg/kg/day for one year. At the end of this period they were randomized to placebo or to continue UDCA therapy for three further months. ALT levels were evaluated before the beginning of UDCA therapy, at twelve and fifteen months by standard methods. After 12 months of UDCA, ALT decreased significantly (-39 UI, 95% confidence intervals -27 to -52 UI). At the 15 th month ALT did not vary with respect to its values at the 12th month in 36 patients randomized to continue UDCA, while it increased significantly in patients taking the placebo (+11 UI 95% confidence intervals +2 to +19). The results of this study suggest that UDCA is effective in controlling the biochemical activity of the liver disease in cirrhotic patients.

T-cell response to structural and nonstructural hepatitis C virus antigens in persistent and self-limited hepatitis C virus infections

Twenty-nine patients with chronic hepatitis C and 15 asymptomatic hepatitis C virus antibody-positive subjects who clinically recovered from hepatitis C virus infection were studied for their peripheral blood lymphomononuclear cell proliferative response to hepatitis C virus structural and nonstructural antigens (core, envelope, nonstructural 4 and nonstructural 5) expressed in yeast as superoxide dismutase fusion proteins, in an initial attempt to define some of the features of the virus-specific immune response. Hepatitis C virus core was the most immunogenic antigen for human leukocyte antigen class II-restricted T cells in both groups of patients studied, and the proliferative response to it was the most vigorous and the most frequently expressed in comparison with the other antigens tested. The specificity of the results was supported by the lack of response to hepatitis C virus antigens by healthy uninfected controls and confirmed by recognition of recombinant core proteins of different origin (yeast and baculovirus) by polyclonal T-cell lines produced by T-cell stimulation with yeast-derived core. Each of the antigens tested was able to induce significant although variable levels of proliferative response, indicating that all can be immunogenic at the T-cell level. Significant proliferative responses to core, nonstructural 4 and nonstructural 5 antigens were more frequently detected in subjects who were able to eradicate infection than in patients with chronic hepatitis C, although the difference was statistically not significant. No difference was observed between the two groups of patients with respect to the response to the putative envelope antigens.

Inappropriate Halsted mastectomy and patient volume in Italian hospitals

To study whether Halsted mastectomy was used only when properly indicated, a prospective survey was undertaken on the process of care of 985 breast cancer patients seen consecutively at 62 general hospitals in Northern and Central Italy. Overall, 79% of Halsted mastectomies were performed inappropriately. The procedure was less likely to be performed on more educated patients and, other factors considered, on those seen at hospitals with larger volume. We conclude that the measurement of utilization of a surgical procedure for which only a few appropriate indications exist may help identify important relationships between hospital characteristics and quality of surgical care.

[The adjuvant treatment of operable breast carcinoma. The current status and outlook]

Breast cancer represents one of the most frequent neoplasm: every year, in Italy, 25,000 new cases are diagnosed with more than 9,000 deaths. In Italy--and also in other countries--has been shown a broad variability in the use of diagnostic or therapeutic procedures caused by different hospitals' characteristics, patients' conditions and physicians' opinions. Among the different therapeutic options, post-surgical therapy, that extends the disease-free interval and survival, fills an important position in the cure of breast cancer in relation to the overview published on Lancet the 4th and the 11th January 1992. According to this overview, patients who had surgery for breast cancer benefitted by an adjuvant therapy--hormonal or cytotoxic--with a reduction of mortality between 15 and 20%. That means, in Italy, a reduction of one thousand deaths per year for this neoplasm. Particularly the effectiveness of hormonal treatment in postmenopausal patients (not only in the oestrogen receptor (ER) positive but in the ER poor too), of ovarian ablation and chemotherapy in premenopausal patients was confirmed. In node negative patients the present overview recommends the adjuvant treatment for the risk reduction in recurrence and mortality. Nevertheless important research implications persist about treatment and a better definition of high risk patients; therefore more patient should be included in the randomized clinical trial.

Definition of a minimal optimal cytotoxic T-cell epitope within the hepatitis B virus nucleocapsid protein

Residues 11 to 27 of the hepatitis B virus nucleocapsid antigen contain a cytotoxic T-cell epitope that is recognized by cytotoxic T cells from virtually all HLA-A2-positive patients with acute hepatitis B virus infection. Using panels of truncated and overlapping peptides, we now show that the optimal amino acid sequence recognized by cytotoxic T cells is a 10-mer (residues 18 to 27) containing the predicted peptide-binding motif for HLA-A2 and that this peptide can stimulate cytotoxic T cells able to recognize endogenously synthesized hepatitis B core antigen. Since patients with chronic hepatitis B virus infection fail to mount an efficient cytotoxic T-cell response to it, this epitope might serve as the starting point for the design of synthetic peptide-based immunotherapeutic strategies to terminate persistent viral infection.

The influence of patient characteristics on the appropriateness of surgical treatment for breast cancer patients. Progetto Oncologia Femminile

BACKGROUND

Within the framework of a multi-annual educational intervention sponsored by the Ministry of Health and regional health authorities, patterns of the care delivered to breast cancer patients in Italian general hospitals were monitored in order to identify areas of practice whose quality was in need of improvement.

DESIGN

Information on the diagnostic and therapeutic procedures in 63 general hospitals in eight Italian regions performed in 1724 consecutive breast cancer patients were retrospectively gathered from medical records. Quality of care was assessed by a diagnostic and therapeutic score based on the observed degree of compliance with previously established courses of action.

RESULTS

The median value of the overall diagnostic and staging score was 60%. About one-third of surgical operations (38%) were inappropriate: one-fourth (24%) of patients with stage I-II disease had unnecessarily radical surgery (i.e., Halsted mastectomy), and limited surgery in patients with small tumors (i.e., < or = 2 cm) was under utilized. Chronological age influenced physicians' behaviour: elderly patients were more likely to have a less intensive diagnostic work-up and less appropriate surgical treatment (with more frequent performance of an unnecessary radical operation and a less frequent utilization of limited surgery), independently of their overall health status. The presence of one or more co-existent diseases was associated with a failure to undergo axillary clearance and with a lower utilization of conservative surgery independently of age.

CONCLUSION

In accord with others, this study confirms the existence of a clinically important effect of patient age on diagnostic and therapeutic behaviour and the use of unnecessarily radical surgery procedures. The paper discusses the implications of these findings for the next stage of the educational project, in which practice guidelines will be developed and implemented to improve the quality of care for breast cancer patients.

Cell mediated immune response to hepatitis B virus nucleocapsid antigen

A coordinated and efficient development of humoral and cell-mediated immune responses is believed to be required for complete eradication of viral infections. During the course of hepatitis B virus (HBV) infection, the HLA class II and class I-restricted T cell responses to HBV nucleocapsid antigens are vigorous in patients with acute infection who succeed in clearing the virus but weak or totally absent in patients with chronic persistence of the virus. These findings suggest a role for these responses in the pathogenesis of hepatitis B and in HBV clearance. Molecular analysis of T cell recognition of the HBV nucleoprotein defines the presence of immunodominant core epitopes recognized by helper and cytotoxic T cells that may represent the starting point for the design of alternative strategies for prevention and treatment of HBV infection.