Reinfusion of CD19 CAR T cells for relapse prevention and treatment in children with acute lymphoblastic leukemia

ABSTRACT

Relapse after CD19-directed chimeric antigen receptor (CAR)-modified T cells remains a substantial challenge. Short CAR T-cell persistence contributes to relapse risk, necessitating novel approaches to prolong durability. CAR T-cell reinfusion (CARTr) represents a potential strategy to reduce the risk of or treat relapsed disease after initial CAR T-cell infusion (CARTi). We conducted a retrospective review of reinfusion of murine (CTL019) or humanized (huCART19) anti-CD19/4-1BB CAR T cells across 3 clinical trials or commercial tisagenlecleucel for relapse prevention (peripheral B-cell recovery [BCR] or marrow hematogones ≤6 months after CARTi), minimal residual disease (MRD) or relapse, or nonresponse to CARTi. The primary endpoint was complete response (CR) at day 28 after CARTr, defined as complete remission with B-cell aplasia. Of 262 primary treatments, 81 were followed by ≥1 reinfusion (investigational CTL019, n = 44; huCART19, n = 26; tisagenlecleucel, n = 11), representing 79 patients. Of 63 reinfusions for relapse prevention, 52% achieved CR (BCR, 15/40 [38%]; hematogones, 18/23 [78%]). Lymphodepletion was associated with response to CARTr for BCR (odds ratio [OR], 33.57; P = .015) but not hematogones (OR, 0.30; P = .291). The cumulative incidence of relapse was 29% at 24 months for CR vs 61% for nonresponse to CARTr (P = .259). For MRD/relapse, CR rate to CARTr was 50% (5/10), but 0/8 for nonresponse to CARTi. Toxicity was generally mild, with the only grade ≥3 cytokine release syndrome (n = 6) or neurotoxicity (n = 1) observed in MRD/relapse treatment. Reinfusion of CTL019/tisagenlecleucel or huCART19 is safe, may reduce relapse risk in a subset of patients, and can reinduce remission in CD19+ relapse.

Reduced toxicity matched sibling bone marrow transplant results in excellent outcomes for severe congenital neutropenia

Severe congenital neutropenia (SCN) is caused by germline mutations, most commonly in ELANE, impacting neutrophil maturation and leading to high risk of life-threatening infections. Most patients with ELANE-mutant SCN can achieve safe neutrophil counts with chronic Granulocyte-Colony Stimulating Factor (G-CSF). However, up to 10% of patients have neutropenia refractory to G-CSF and require allogeneic stem cell transplant. Traditional conditioning for these patients includes busulfan and cyclophosphamide which is associated with significant toxicities. We present five patients with SCN without myeloid malignancy transplanted using a reduced toxicity regimen of busulfan, fludarabine and thymoglobulin. 5 pediatric patients with SCN underwent matched sibling donor bone marrow transplant (MSD-BMT) between 2014-2022 on or per CHP14BT057 (NCT02928991), a prospective, single center trial testing elimination of cyclophosphamide from conditioning in pediatric patients with single lineage inherited BMF syndromes. All patients had MSDs and no evidence of MDS. Conditioning consisted of PK-adjusted busulfan, fludarabine, and thymoglobulin, with calcineurin inhibitor and mycophenolate mofetil GVHD prophylaxis. With median follow-up of 48.4 months, overall and event-free survival were 100%. There was no acute GVHD and one instance of chronic limited GVHD. Patients exhibited >95% donor myeloid chimerism at 5 years post-BMT. Two patients experienced CMV reactivation without end-organ disease, and no other viral reactivation or significant infections occurred. MSD-BMT with reduced toxicity myeloablation for SCN provides excellent outcomes while minimizing toxicity. These data suggest that busulfan, fludarabine, and ATG can be considered an efficacious, low-toxicity standard of care regimen for patients with SCN undergoing MSD-BMT.

Evaluation of Children with Malignancies for Blood and Marrow Transplantation: A Report from the ASTCT Committee on Practice Guidelines

Evaluation of a candidate for hematopoietic cell transplantation (HCT) is a complex process with substantial intercenter variability. Although literature providing guidance for evaluating the eligibility of adults is well established, similar guidance for children is lacking. To address gaps between adult recommendations and the specific needs of children, we convened a panel of pediatric HCT experts from a wide geographic range of American Society of Transplantation and Cellular Therapy (ASTCT) member institutions to offer recommendations for pediatric-focused pre-HCT evaluation. In this report from the ASTCT Committee on Practice Guidelines, we present a practical framework for evaluating children with malignancies who are candidates for HCT. We also highlight key differences from adults and emphasize areas of unmet need that require additional research to delineate best practices.

Impact of poverty and neighborhood opportunity on outcomes for children treated with CD19-directed CAR T-cell therapy

Children living in poverty experience excessive relapse and death from newly diagnosed acute lymphoblastic leukemia (ALL). The influence of household poverty and neighborhood social determinants on outcomes from chimeric antigen receptor (CAR) T-cell therapy for relapsed/refractory (r/r) leukemia is poorly described. We identified patients with r/r CD19+ ALL/lymphoblastic lymphoma treated on CD19-directed CAR T-cell clinical trials or with commercial tisagenlecleucel from 2012 to 2020. Socioeconomic status (SES) was proxied at the household level, with poverty exposure defined as Medicaid-only insurance. Low-neighborhood opportunity was defined by the Childhood Opportunity Index. Among 206 patients aged 1 to 29, 35.9% were exposed to household poverty, and 24.9% had low-neighborhood opportunity. Patients unexposed to household poverty or low-opportunity neighborhoods were more likely to receive CAR T-cell therapy with a high disease burden (>25%), a disease characteristic associated with inferior outcomes, as compared with less advantaged patients (38% vs 30%; 37% vs 26%). Complete remission (CR) rate was 93%, with no significant differences by household poverty (P = .334) or neighborhood opportunity (P = .504). In multivariate analysis, patients from low-opportunity neighborhoods experienced an increased hazard of relapse as compared with others (P = .006; adjusted hazard ratio [HR], 2.3; 95% confidence interval [CI], 1.3-4.1). There was no difference in hazard of death (P = .545; adjusted HR, 1.2; 95% CI, 0.6-2.4). Among children who successfully receive CAR T-cell therapy, CR and overall survival are equitable regardless of proxied SES and neighborhood opportunity. Children from more advantaged households and neighborhoods receive CAR T-cell therapy with a higher disease burden. Investigation of multicenter outcomes and access disparities outside of clinical trial settings is warranted.

Impact of high-risk cytogenetics on outcomes for children and young adults receiving CD19-directed CAR T-cell therapy

Chimeric antigen receptor (CAR) T-cell therapy can induce durable remissions of relapsed/refractory B-acute lymphoblastic leukemia (ALL). However, case reports suggested differential outcomes mediated by leukemia cytogenetics. We identified children and young adults with relapsed/refractory CD19+ ALL/lymphoblastic lymphoma treated on 5 CD19-directed CAR T-cell (CTL019 or humanized CART19) clinical trials or with commercial tisagenlecleucel from April 2012 to April 2019. Patients were hierarchically categorized according to leukemia cytogenetics: High-risk lesions were defined as KMT2A (MLL) rearrangements, Philadelphia chromosome (Ph+), Ph-like, hypodiploidy, or TCF3/HLF; favorable as hyperdiploidy or ETV6/RUNX1; and intermediate as iAMP21, IKZF1 deletion, or TCF3/PBX1. Of 231 patients aged 1 to 29, 74 (32%) were categorized as high risk, 28 (12%) as intermediate, 43 (19%) as favorable, and 86 (37%) as uninformative. Overall complete remission rate was 94%, with no difference between strata. There was no difference in relapse-free survival (RFS; P = .8112), with 2-year RFS for the high-risk group of 63% (95% confidence interval [CI], 52-77). There was similarly no difference seen in overall survival (OS) (P = .5488), with 2-year OS for the high-risk group of 70% (95% CI, 60-82). For patients with KMT2A-rearranged infant ALL (n = 13), 2-year RFS was 67% (95% CI, 45-99), and OS was 62% (95% CI, 40-95), with multivariable analysis demonstrating no increased risk of relapse (hazard ratio, 0.70; 95% CI, 0.21-2.90; P = .7040) but a higher proportion of relapses associated with myeloid lineage switch and a 3.6-fold increased risk of all-cause death (95% CI, 1.04-12.75; P = .0434). CTL019/huCART19/tisagenlecleucel are effective at achieving durable remissions across cytogenetic categories. Relapsed/refractory patients with high-risk cytogenetics, including KMT2A-rearranged infant ALL, demonstrated high RFS and OS probabilities at 2 years.

CD19-targeted chimeric antigen receptor T-cell therapy for CNS relapsed or refractory acute lymphocytic leukaemia: a post-hoc analysis of pooled data from five clinical trials

BACKGROUND

CNS relapse of acute lymphocytic leukaemia is difficult to treat. Durable remissions of relapsed or refractory B-cell acute lymphocytic leukaemia have been observed following treatment with CD19-directed chimeric antigen receptor (CAR) T cells; however, most trials have excluded patients with active CNS disease. We aimed to assess the safety and activity of CAR T-cell therapy in patients with a history of CNS relapsed or refractory B-cell acute lymphocytic leukaemia.

METHODS

In this post-hoc analysis, we included 195 patients (aged 1-29 years; 110 [56%] male and 85 [44%] female) with relapsed or refractory CD19-positive acute lymphocytic leukaemia or lymphocytic lymphoma from five clinical trials (Pedi CART19, 13BT022, ENSIGN, ELIANA, and 16CT022) done at the Children's Hospital of Philadelphia (Philadelphia, PA, USA), in which participants received CD19-directed CAR T-cell therapy between April 17, 2012, and April 16, 2019. The trials required control of CNS disease at enrolment and infusion and excluded treatment in the setting of acute neurological toxic effects (>grade 1 in severity) or parenchymal lesions deemed to increase the risk of neurotoxicity. 154 patients from Pedi CART19, ELIANA, ENSIGN, and 16CT022 received tisagenlecleucel and 41 patients from the 13BT022 trial received the humanised CD19-directed CAR, huCART19. We categorised patients into two strata on the basis of CNS status at relapse or within the 12 months preceding CAR T-cell infusion-either CNS-positive or CNS-negative disease. Patients with CNS-positive disease were further divided on the basis of morphological bone marrow involvement-either combined bone marrow and CNS involvement, or isolated CNS involvement. Endpoints were the proportion of patients with complete response at 28 days after infusion, Kaplan-Meier analysis of relapse-free survival and overall survival, and the incidence of cytokine release syndrome and neurotoxicity.

FINDINGS

Of all 195 patients, 66 (34%) were categorised as having CNS-positive disease and 129 (66%) as having CNS-negative disease, and 43 (22%) were categorised as having isolated CNS involvement. The median length of follow-up was 39 months (IQR 25-49) in the CNS-positive stratum and 36 months (18-49) in the CNS-negative stratum. The proportion of patients in the CNS-positive stratum with a complete response at 28 days after infusion was similar to that in the CNS-negative stratum (64 [97%] of 66 vs 121 [94%] of 129; p=0·74), with no significant difference in relapse-free survival (60% [95% CI 49-74] vs 60% [51-71]; p=0·50) or overall survival (83% [75-93] vs 71% [64-79]; p=0·39) at 2 years between the two groups. Overall survival at 2 years was significantly higher in patients with isolated CNS involvement compared with those with bone marrow involvement (91% [82-100] vs 71% [64-78]; p=0·046). The incidence and severity of neurotoxicity (any grade, 53 [41%] vs 38 [58%]; grade 1, 24 [19%] vs 20 [30%]; grade 2, 14 [11%] vs 10 [15%]; grade 3, 12 [9%] vs 6 [9%], and grade 4, 3 [2%] vs 2 [3%]; p=0·20) and cytokine release syndrome (any grade, 110 [85%] vs 53 [80%]; grade 1, 12 [9%] vs 2 [3%]; grade 2, 61 [47%] vs 38 [58%]; grade 3, 18 [14%] vs 7 [11%] and grade 4, 19 [15%] vs 6 [9%]; p=0·26) did not differ between the CNS-negative and the CNS-positive disease strata.

INTERPRETATION

Tisagenlecleucel and huCART19 are active at clearing CNS disease and maintaining durable remissions in children and young adults with CNS relapsed or refractory B-cell acute lymphocytic leukaemia or lymphocytic lymphoma, without increasing the risk of severe neurotoxicity; although care should be taken in the timing of therapy and disease control to mitigate this risk. These preliminary findings support the use of these CAR T-cell therapies for patients with CNS relapsed or refractory B-cell acute lymphocytic leukaemia.

FUNDING

Children's Hospital of Philadelphia Frontier Program.

Humanized CD19-Targeted Chimeric Antigen Receptor (CAR) T Cells in CAR-Naive and CAR-Exposed Children and Young Adults With Relapsed or Refractory Acute Lymphoblastic Leukemia

PURPOSE

CD19-targeted chimeric antigen receptor (CAR)-modified T cells demonstrate unprecedented responses in B-cell acute lymphoblastic leukemia (B-ALL); however, relapse remains a substantial challenge. Short CAR T-cell persistence contributes to this risk; therefore, strategies to improve persistence are needed.

METHODS

We conducted a pilot clinical trial of a humanized CD19 CAR T-cell product (huCART19) in children and young adults with relapsed or refractory B-ALL (n = 72) or B-lymphoblastic lymphoma (n = 2), treated in two cohorts: with (retreatment, n = 33) or without (CAR-naive, n = 41) prior CAR exposure. Patients were monitored for toxicity, response, and persistence of huCART19.

RESULTS

Seventy-four patients 1-29 years of age received huCART19. Cytokine release syndrome developed in 62 (84%) patients and was grade 4 in five (6.8%). Neurologic toxicities were reported in 29 (39%), three (4%) grade 3 or 4, and fully resolved in all cases. The overall response rate at 1 month after infusion was 98% (100% in B-ALL) in the CAR-naive cohort and 64% in the retreatment cohort. At 6 months, the probability of losing huCART19 persistence was 27% (95% CI, 14 to 41) for CAR-naive and 48% (95% CI, 30 to 64) for retreatment patients, whereas the incidence of B-cell recovery was 15% (95% CI, 6 to 28) and 58% (95% CI, 33 to 77), respectively. Relapse-free survival at 12 and 24 months, respectively, was 84% (95% CI, 72 to 97) and 74% (95% CI, 60 to 90) in CAR-naive and 74% (95% CI, 56 to 97) and 58% (95% CI, 37 to 90) in retreatment cohorts.

CONCLUSION

HuCART19 achieved durable remissions with long-term persistence in children and young adults with relapsed or refractory B-ALL, including after failure of prior CAR T-cell therapy.

Risk-Adapted Preemptive Tocilizumab to Prevent Severe Cytokine Release Syndrome After CTL019 for Pediatric B-Cell Acute Lymphoblastic Leukemia: A Prospective Clinical Trial

PURPOSE

To prospectively evaluate the effectiveness of risk-adapted preemptive tocilizumab (PT) administration in preventing severe cytokine release syndrome (CRS) after CTL019, a CD19 chimeric antigen receptor T-cell therapy.

METHODS

Children and young adults with CD19-positive relapsed or refractory B-cell acute lymphoblastic leukemia were assigned to high- (≥ 40%) or low- (< 40%) tumor burden cohorts (HTBC or LTBC) based on a bone marrow aspirate or biopsy before infusion. HTBC patients received a single dose of tocilizumab (8-12 mg/kg) after development of high, persistent fevers. LTBC patients received standard CRS management. The primary end point was the frequency of grade 4 CRS (Penn scale), with an observed rate of ≤ 5 of 15 patients in the HTBC pre-defined as clinically meaningful. In post hoc analyses, the HTBC was compared with a historical cohort of high-tumor burden patients from the initial phase I CTL019 trial.

RESULTS

The primary end point was met. Seventy patients were infused with CTL019, 15 in the HTBC and 55 in the LTBC. All HTBC patients received the PT intervention. The incidence of grade 4 CRS was 27% (95% CI, 8 to 55) in the HTBC and 3.6% (95% CI, 0.4 to 13) in the LTBC. The best overall response rate was 87% in the HTBC and 100% in the LTBC. Initial CTL019 expansion was greater in the HTBC than the LTBC (P < .001), but persistence was not different (P = .73). Event-free and overall survival were worse in the HTBC (P = .004, P < .001, respectively). In the post hoc analysis, grade 4 CRS was observed in 27% versus 50% of patients in the PT and prior phase I cohorts, respectively (P = .18).

CONCLUSION

Risk-adapted PT administration resulted in a decrease in the expected incidence of grade 4 CRS, meeting the study end point, without adversely impacting the antitumor efficacy or safety of CTL019.

CD19-targeted chimeric antigen receptor (CAR) T cells in CNS relapsed acute lymphoblastic leukemia (ALL)

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Background: CNS relapse of B-ALL is difficult to treat after cranial radiation or multiple relapses. Durable remissions of relapsed/refractory (r/r) B-ALL have been seen with CD19 CAR T cells; however, most trials excluded patients with active CNS disease. As we observed CAR trafficking into the CSF, we hypothesized that CD19 CAR T cells could control CNS B-ALL. Methods: We identified children and young adults with r/r CNS B-ALL treated on 4 clinical trials of CD19 CAR T cells, CTL019 or CTL119. NCT01626495 and NCT02435849 excluded active CNS disease, while the former in an amendment as well as NCT02374333 and NCT02906371 permitted active CNS disease controlled on therapy. All trials permitted CNS disease that cleared and excluded bulky intracranial disease that did not improve. We analyzed outcomes (CR, RFS) and safety. Results: We identified 65 patients 1-29y (median 10y) with r/r CNS B-ALL (CNS+) of 182 treated with CTL019/CTL119. There were no differences in age, sex, history of SCT or neurologic comorbidities in the CNS+ and CNS- cohorts. CNS+ patients were more likely to be in ≥2nd relapse (74% vs 46%, p < 0.01), to have received cranial radiation (58% vs 11%, p < 0.01), to have detectable CNS disease (p = 0.02) and less bone marrow disease pre-infusion (p < 0.01). At 1 mo post infusion, 62 (95%) CNS+ and 110 (94%) CNS- patients were in CR; 1 in each cohort died of sequelae of CRS and was inevaluable for response. All patients with CNS disease detected pre-infusion cleared by mo 3, including 9 in the CNS+ cohort [5 CNS2 ( < 5 CSF WBC with blasts), 4 CNS3 ( > 5 CSF WBC with blasts or exam/imaging evidence)] and 8 in the CNS- cohort (isolated CNS2 status pre-infusion). There was no difference in RFS (p = 0.28) in the CNS+ and CNS- cohorts [24-mo RFS: 61% (95% CI 46-73%) and 60% (95% CI 48-70%)]. There were 4 CNS relapses in the CNS+ cohort, and 1 in the CNS- cohort. Encephalopathy rate and grade was similar in the CNS+ and CNS- cohorts (52% vs 40% any grade; 12% vs 11% grade 3/4; p = 0.41). There were no deaths due to neurotoxicity (NT) and no statistically significant differences in incidence or severity of any NT or CRS in the CNS+ and CNS- cohorts. Conclusions: The CD19 CAR T cell therapies CTL019/CTL119 are effective at clearing CNS disease and inducing durable remissions in children and young adults with r/r CNS B-ALL. CNS relapse rates are low ( < 3%). Most CD19 CAR T cell trials excluded patients with active CNS disease, primarily due to the risk of NT. We show that patients with r/r CNS B-ALL that is adequately controlled prior to infusion can be safely treated with CD19 CAR T cells, with no increased risk of NT. Clinical trial information: NCT01626495, NCT02435849, NCT02374333, NCT02906371.

Reactive arthritis following a Microsporidia infection

Reactive arthritis may be caused by both sexually transmissible and enteric organisms, though Microsporidia is not currently recognised as a causative agent. This case report describes the development of reactive arthritis following Microsporidia infection in an immunocompetent man.

Reactive arthritis at the Sydney Sexual Health Centre 1992-2012: declining despite increasing chlamydia diagnoses

Reactive arthritis is an under-studied complication of genital Chlamydia trachomatis infection (chlamydia). We assessed trends and risk factors for reactive arthritis in a large urban sexual health clinic. Using a case-control design, data on reactive arthritis cases and controls at the Sydney Sexual Health Centre over the period 1992-2012 were extracted and multivariate analyses were performed. Trend analyses were performed on reactive arthritis diagnoses. Over the 1992-2012 study period, 85 reactive arthritis cases were diagnosed at Sydney Sexual Health Centre. The rate of reactive arthritis diagnoses decreased over time (23 in 1992-1996 to one in 2007-2011 and none in 2012), while chlamydia diagnoses increased (770 in 1992-1996 to 2257 in 2007-2011). In multivariate analysis, factors independently associated with a reactive arthritis diagnosis were: being male (adjusted odds ratio [aOR] 3.27; 95% confidence interval [CI] 1.04-10.32; p = 0.043) or born overseas (aOR 2.69; 95% CI 1.27-5.70; p = 0.010), while a past sexually transmitted infection other than chlamydia or non-gonococcal urethritis was protective (aOR 0.21; 95% CI 0.10-0.45; p < 0.001). Reactive arthritis was not associated with current or recent chlamydia infection (p = 0.184) but was marginally associated with past non-gonococcal urethritis (p = 0.080). This study found a decline in reactive arthritis diagnoses despite an increase in chlamydia diagnoses.

Associations between genetic variants in folate and drug metabolizing pathways and relapse risk in pediatric acute lymphoid leukemia on CCG-1952

Genetic variation in drug detoxification pathways may influence outcomes in pediatric acute lymphoblastic leukemia (ALL). We evaluated relapse risk and 24 variants in 17 genes in 714 patients in CCG-1961. Three TPMT and 1 MTR variant were associated with increased risks of relapse (rs4712327, OR 3.3, 95%CI 1.2–8.6; rs2842947, OR 2.7, 95%CI 1.1–6.8; rs2842935, OR 2.5, 95%CI 1.1–5.0; rs10925235, OR 4.9, 95%CI 1.1–25.1). One variant in SLC19A1 showed a protective effect (rs4819128, OR 0.5, 95%CI 0.3–0.9). Our study provides data that relapse risk in pediatric ALL is associated with germline variations in TPMT, MTR and SLC19A1.

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Genetic variants in the folate pathway may influence ALL outcome.

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We evaluated 24 SNPs in 17 genes on relapse risk in pediatric ALL.

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Three TPMT variants were associated with an increased risk of relapse.

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One MTR variant was positively associated with risk of relapse.

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One variant in SLC19A1 showed a protective effect on relapse.

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TPMT, MTR and SLC19A1 are associated with relapse risk in pediatric ALL.

TPMT and MTHFR genotype is not associated with altered risk of thioguanine-related sinusoidal obstruction syndrome in pediatric acute lymphoblastic leukemia: a report from the Children's Oncology Group

Sinusoidal obstruction syndrome is a complication of therapy for pediatric ALL and may be modified by thiopurine methyltransferase activity as well as by MTHFR genotype. We assessed TPMT *3A, *3B, *3C, and MTHFR C677T and A1298C germline genetic polymorphisms among 351 patients enrolled in the thioguanine treatment arm of CCG-1952 clinical trial. TPMT and MTHFR C677T genotypes were not associated with SOS risk. The combination of MTHFR and TPMT variant genotypes was not associated with SOS risk. These suggest that germline genetic variation in TPMT and MTHFR do not significantly alter SOS risk in patients exposed to thioguanine.

The diabetic patient and dental treatment: an update

This paper has been written to both refresh and update clinicians' knowledge of diabetes. Treatment for patients with diabetes continues to develop with the majority of Type 1 diabetics now using multiple daily injections and an increasing minority using insulin pumps. Blood glucose monitoring and patient education programmes have resulted in more patient involvement in controlling this condition. Type 2 diabetics have had improvement in care provision through the development of shorter acting sulphonylureas and the potential for GLP1 injections. The impact of diabetes on both oral health and quality of life is discussed. Practical suggestions are made regarding the dental treatment of diabetic patients using both local anaesthetic and under sedation. Diabetes continues to be a fickle master for those affected by this condition. The paper is written from the perspective of the 'expert patient'. It is hoped that a greater understanding of this chronic condition will improve both access to, and safety of, dental care for those patients with diabetes.

Is azithromycin adequate treatment for asymptomatic rectal chlamydia?

Rectal chlamydia is a common sexually transmissible infection (STI) in men who have sex with men (MSM) that is predominantly asymptomatic. The recommended treatment of azithromycin 1 g as a single oral dose has not been subject to randomized trials and so its efficacy is unknown. We conducted a retrospective case-note review of all MSM diagnosed at the Sydney Sexual Health Centre with asymptomatic rectal chlamydia in 2009. We identified 116 MSM who received azithromycin; 85 (73%) attended for the recommended re-test at varying times (median 78 days, range 21–372 days). Of the men who returned, 11 (13%) had a persistently positive result; we reviewed behavioural data to classify these men as probable re-infections (6/11) or possible treatment failures (5/11), suggesting an efficacy of 94%. Until a randomized controlled trial (RCT) is conducted, patients with rectal chlamydia should be encouraged to attend for a re-test at 6–12 weeks.

Observation of time-reversal-protected single-dirac-cone topological-insulator states in Bi2Te3 and Sb2Te3

We show that the strongly spin-orbit coupled materials Bi2Te3 and Sb2Te3 and their derivatives belong to the Z2 topological-insulator class. Using a combination of first-principles theoretical calculations and photoemission spectroscopy, we directly show that Bi2Te3 is a large spin-orbit-induced indirect bulk band gap (delta approximately 150 meV) semiconductor whose surface is characterized by a single topological spin-Dirac cone. The electronic structure of self-doped Sb2Te3 exhibits similar Z2 topological properties. We demonstrate that the dynamics of spin-Dirac fermions can be controlled through systematic Mn doping, making these materials classes potentially suitable for topological device applications.

A tunable topological insulator in the spin helical Dirac transport regime

Helical Dirac fermions-charge carriers that behave as massless relativistic particles with an intrinsic angular momentum (spin) locked to its translational momentum-are proposed to be the key to realizing fundamentally new phenomena in condensed matter physics. Prominent examples include the anomalous quantization of magneto-electric coupling, half-fermion states that are their own antiparticle, and charge fractionalization in a Bose-Einstein condensate, all of which are not possible with conventional Dirac fermions of the graphene variety. Helical Dirac fermions have so far remained elusive owing to the lack of necessary spin-sensitive measurements and because such fermions are forbidden to exist in conventional materials harbouring relativistic electrons, such as graphene or bismuth. It has recently been proposed that helical Dirac fermions may exist at the edges of certain types of topologically ordered insulators-materials with a bulk insulating gap of spin-orbit origin and surface states protected against scattering by time-reversal symmetry-and that their peculiar properties may be accessed provided the insulator is tuned into the so-called topological transport regime. However, helical Dirac fermions have not been observed in existing topological insulators. Here we report the realization and characterization of a tunable topological insulator in a bismuth-based class of material by combining spin-imaging and momentum-resolved spectroscopies, bulk charge compensation, Hall transport measurements and surface quantum control. Our results reveal a spin-momentum locked Dirac cone carrying a non-trivial Berry's phase that is nearly 100 per cent spin-polarized, which exhibits a tunable topological fermion density in the vicinity of the Kramers point and can be driven to the long-sought topological spin transport regime. The observed topological nodal state is shown to be protected even up to 300 K. Our demonstration of room-temperature topological order and non-trivial spin-texture in stoichiometric Bi(2)Se(3).M(x) (M(x) indicates surface doping or gating control) paves the way for future graphene-like studies of topological insulators, and applications of the observed spin-polarized edge channels in spintronic and computing technologies possibly at room temperature.

Fermi surface topology and low-lying quasiparticle dynamics of parent Fe1+xTe/Se superconductor

We report the first photoemission study of Fe1+xTe-the host compound of the newly discovered iron-chalcogenide superconductors (maximum Tc approximately 27 K). Our results reveal a pair of nearly electron-hole compensated Fermi pockets, strong Fermi velocity renormalization, and an absence of a spin-density-wave gap. A shadow hole pocket is observed at the "X" point of the Brillouin zone which is consistent with a long-range ordered magnetostructural ground state. No signature of Fermi surface nesting instability associated with Q=(pi/2,pi/2) is observed. Our results collectively reveal that the Fe1+xTe series is different from the undoped phases of the high Tc pnictides and likely harbor an unusual mechanism for superconductivity and magnetic order.

Emergence of Fermi pockets in a new excitonic charge-density-wave melted superconductor

A superconducting state (T(c) approximately 4.2 K) has very recently been observed upon successful doping of the charge-density-wave (CDW) ordered triangular lattice TiSe(2), with copper. Using state-of-the-art photoemission spectroscopy we identify, for the first time, momentum-space locations of doped electrons that form the Fermi sea of the superconductor. With doping, we find that kinematic nesting volume increases, whereas coherence of the CDW collective order sharply drops. In superconducting doping, as chemical potential rises, we observe the emergence of a large density of states in the form of a narrow electron pocket near the L point of the Brillouin zone with d-like character. The k-space spectral evolution directly demonstrates, for the first time, that the CDW order parameter microscopically competes with superconductivity in the same band.

Dietetic guidelines on food and nutrition in the secondary prevention of cardiovascular disease ? evidence from systematic reviews of randomized controlled trials (second update, January 2006)

AIM

To update dietetic guidelines based on systematic review evidence on dietary advice to prevent further events in people with existing cardiovascular disease (CVD) (secondary prevention).

METHODS

The Cochrane Library, MEDLINE and EMBASE were comprehensively searched to January 2005 for systematic reviews on aspects of diet and heart health. Reviews were included if they searched systematically for randomized controlled trials relating to diet and secondary prevention of CVD. Each review was critically appraised by at least two members of the UK Heart Health and Thoracic Dietitians Group. The quality and results of each review were discussed and summarized at a group meeting.

RESULTS

Evidence-based strategies that reduce cardiovascular events in those with CVD include reduction in saturated fat and substitution with unsaturated fats. Individuals who have suffered a myocardial infarction may also benefit from adopting a Mediterranean type diet and increasing intake of omega 3 fats, but it is not clear whether they are beneficial for all patients with CVD. There is no systematic review evidence to support the use of antioxidant vitamins supplements, low glycaemic index diets, or homocysteine lowering therapies in this group.

CONCLUSION

There remains good evidence that reducing saturated fat reduces morbidity in patients with CVD. This advice is consistent for most manifestations of CVD, with the addition of Mediterranean dietary advice and increased omega 3 fats for those who have had a myocardial infarction.

Complete d-band dispersion relation in sodium cobaltates

We utilize fine-tuned polarization selection coupled with excitation-energy variation of photoelectron signal to image the complete d-band dispersion relation in sodium cobaltates. A hybridization gap anticrossing is observed along the Brillouin zone corner and the full quasiparticle band is found to emerge as a many-body entity lacking a pure orbital polarization. At low dopings, the quasiparticle bandwidth (Fermion scale, many-body E(F) approximately 0.25 eV) is found to be smaller than most known oxide metals. The low-lying density of states is found to be in agreement with bulk-sensitive thermodynamic measurements for nonmagnetic dopings where the 2D Luttinger theorem is also observed to be satisfied.

Low-lying quasiparticle states and hidden collective charge instabilities in parent cobaltate superconductors

We report a state-of-the-art photoemission (angle-resolved photoemission spectroscopy) study of high quality single crystals of NaxCoO2 the series focusing on the fine details of the low-energy states. The Fermi velocity is found to be small (<0.5 eV A) and only weakly anisotropic over the Fermi surface at all dopings, setting the size of the pair wave function to be on the order of 10-20 nm. In the low-doping regime, the exchange interlayer splitting vanishes and two-dimensional collective instabilities such as 120 degrees -type fluctuations become kinematically allowed. Our results suggest that the unusually small Fermi velocity and the unique symmetry of kinematic instabilities distinguish cobaltates from most other oxide superconductors.

Quasiparticle dynamics in the vicinity of metal-insulator phase transition in NaxCoO2

Layered cobaltates embody novel realizations of correlated matter on a spin-1/2 triangular lattice. We report a high-resolution systematic photoemission study of the insulating cobaltates. The observation of a single-particle gap opening and band folding provides direct evidence of anisotropic particle-hole instability on the Fermi surface due to its unique topology. Overlap of the measured Fermi surface is observed with the square root 3xsquare root 3 charge-order Brillouin zone near x=1/3 but not at x=1/2 where the insulating transition is actually observed. Unlike conventional density waves, charge stripes, or band insulators, the onset of the gap depends on the quasiparticle's quantum coherence which is found to occur well below the disorder-order symmetry breaking temperature of the crystal (the first known example of its kind).

Drug-Metabolizing Enzyme Polymorphisms Predict Clinical Outcome in a Node-Positive Breast Cancer Cohort

Purpose

Adjuvant chemotherapy cures only a subset of women with nonmetastatic breast cancer. Genotypes in drug-metabolizing enzymes, including functional polymorphisms in cytochrome P450 (CYP) and glutathione S-transferases (GST), may predict treatment-related outcomes.

Patients and Methods

We examined CYP3A4*1B, CYP3A5*3, and deletions in GST μ (GSTM1) and θ (GSTT1), as well as a priori–defined combinations of polymorphisms in these genes. Using a cohort of 90 node-positive breast cancer patients who received anthracycline-based adjuvant chemotherapy followed by high-dose multiagent chemotherapy with stem-cell rescue, we estimated the effect of genotype and other known prognostic factors on disease-free survival (DFS) and overall survival (OS).

Results

Patients who carried homozygous CYP3A4*1B and CYP3A5*3 variants and did not carry homozygous deletions in both GSTM1 and GSTT1 (denoted low-drug genotype group) had a 4.9-fold poorer DFS (P = .021) and a four-fold poorer OS (P = .031) compared with individuals who did not carry any CYP3A4*1B or CYP3A5*3 variants but had deletions in both GSTT1 and GSTM1 (denoted high-drug genotype group). After adjustment for other significant prognostic factors, the low-drug genotype group retained a significantly poorer DFS (hazard ratio [HR] = 4.9; 95% CI, 1.7 to 14.6; P = .004) and OS (HR = 4.8; 95% CI, 1.8 to 12.9; P = .002) compared with the high- and intermediate-drug combined genotype group. In the multivariate model, having low-drug genotype group status had a greater impact on clinical outcome than estrogen receptor status.

Conclusion

Combined genotypes at CYP3A4, CYP3A5, GSTM1, and GSTT1 influence the probability of treatment failure after high-dose adjuvant chemotherapy for node-positive breast cancer.

Ethnic Disparities in Adjuvant Chemotherapy for Breast Cancer Are Not Caused by Excess Toxicity in Black Patients

BACKGROUND

Black patients with breast cancer may be at greater risk for chemotherapy-related hematologic toxicity than white patients because of lower baseline blood cell counts. We hypothesize that these baseline differences could lead to excess hematologic toxicity and greater modification of chemotherapy dosing in black patients and that this may contribute to the poorer survival observed in black patients with breast cancer compared with white patients with breast cancer.

PATIENTS AND METHODS

We performed a retrospective cohort study of black and white patients with breast cancer treated with adjuvant chemotherapy at an academic medical center over an 18-month period. Clinical chart review and pharmacy records were used to collect data on the following: modification of chemotherapy dose or administration; hematologic toxicity; blood cell counts before, during, and after therapy; occurrence of febrile neutropenia; use of prophylactic antibiotics; and use of granulocyte colony-stimulating factor in order to determine whether ethnicity was an independent predictor of these outcomes.

RESULTS

Among 23 black patients and 98 white patients with breast cancer treated with adjuvant chemotherapy, modification of chemotherapy administration occurred in 56 patients (46%). Modification was more common among black patients (65.2% vs. 41.8%; relative risk [RR], 1.56; P = 0.04). Black patients were more likely to receive reduced cumulative doses of adjuvant chemotherapy (RR, 2.49; P = 0.03).

CONCLUSION

Our findings suggest that hematologic tolerability of adjuvant chemotherapy is similar in black and white patients. Strategies aimed at improving psychosocial barriers to adjuvant therapy and at reducing surgical complications in black patients may improve overall breast cancer outcomes in this group.

Dietetic guidelines: diet in secondary prevention of cardiovascular disease (first update, June 2003)

AIM

To update dietetic guidelines summarizing the systematic review evidence on dietary advice to prevent further events in people with existing cardiovascular disease (CVD) (secondary prevention).

METHODS

The Cochrane Library, MEDLINE and EMBASE were comprehensively searched to November 2002 for systematic reviews on aspects of diet and heart health. Reviews were included if they searched systematically for randomised controlled trials relating to diet and secondary prevention of CVD. Two members of the UK Heart Health and Thoracic Dietitians Group critically appraised each review. The quality and results of each review were discussed and summarized in a meeting of the whole group.

RESULTS

Providing evidence-based dietary information (including increasing omega-3 fat intake) to all people who have had a myocardial infarction will save more lives than concentrating dietary advice on just those in need of weight loss or lipid lowering. The practice of prioritizing dietetic time in secondary prevention to those with raised lipids is out of date since the advent of statin therapy. However, effective dietary advice for those with angina, stroke, peripheral vascular disease or heart failure is less clear.

CONCLUSION

There is good systematic review evidence that dietary advice to those with coronary heart disease can reduce mortality and morbidity as well as modify some risk factors. Dietary advice that does this most effectively should be prioritized.

Interleukin-6 -174G-->C polymorphism is associated with improved outcome in high-risk breast cancer

Axillary lymph node involvement in breast cancer is a marker of recurrence risk. Despite aggressive adjuvant therapy, recurrence in patients with four or more involved lymph nodes approaches 50% at 5 years from diagnosis. Markers that can distinguish those likely to relapse from those likely to be cured are needed to tailor therapy and provide accurate prognostic information to patients. Although most work in this area has focused on tumor characteristics, we hypothesized that the host environment might also play a role in determining risk of relapse. We hypothesized that host inflammatory response, mediated in part by production of interleukin-6 (IL-6), might play a role in the elimination of microscopic residual tumor. Polymorphisms in the IL-6 promoter region appear to modulate serum levels of the cytokine via regulation of gene transcription. A single nucleotide polymorphism involving substitution of cytosine for guanine at position -174 has been associated with reduced transcription and improved outcome in a variety of nonmalignant diseases, including coronary artery disease and several autoimmune conditions. Tumor necrosis factor (TNF) alpha is a proinflammatory cytokine that also plays a role in regulating IL-6 transcription. We hypothesized that polymorphisms in IL-6 (-174 G>C) or TNF-alpha (G-238 or G-308) might be associated with prognosis in a subset of patients with high-risk breast cancer. Genotyping was performed on DNA from stored stem cells in 80 breast cancer patients diagnosed with at least four positive axillary lymph nodes at diagnosis who underwent anthracycline-based adjuvant chemotherapy followed by high-dose multiagent chemotherapy with stem cell rescue. Cox proportional hazards models were used to estimate the effect of genotype and other known prognostic factors on disease-free and overall survival (DFS and OS, respectively). The presence of at least one C allele in the IL-6 promoter at position -174 was significantly associated with both DFS and OS compared with G/G homozygotes. After adjustment for estrogen receptor (ER) status, number of involved lymph nodes, and tumor size, those patients carrying the G/G genotype had a 2.1-fold increase in the rate of failure and a 2.6-fold increase in the rate of death compared with carriers of any C allele at a mean follow-up of 55 months. ER status modulated the effect of IL-6 polymorphism: both DFS and OS were most favorable in patients who were carriers of any C-allele (G/C or C/C) and had ER-positive tumors. The presence of either G/G genotype or an ER-negative tumor increased the hazard of failure [hazard ratio (HR), 2.6 and 3.2, respectively] and death (HR, 2.0 and 2.2, respectively). The combination of both G/G genotype and ER-negative tumor resulted in an additional increase in the hazard of failure (HR, 5.4; four-group comparison, P = 0.003) and death (HR, 6.2; four-group comparison, P = 0.001). TNF-alpha -308 and -238 polymorphisms were not associated with variation in DFS or OS in this cohort. The IL-6-174 promoter polymorphism is associated with clinical outcome in this cohort of node-positive breast cancer patients who received high-dose adjuvant therapy. IL-6 genotype modulated the effect of ER status on outcome. These results support the hypothesis that IL-6 may play an important role in the control of micrometastatic disease in breast cancer. Additional studies are needed to confirm these results and elucidate the mechanisms responsible for these differences.

A general practitioner STD training programme: meeting education and service provision needs

This paper discusses the development, implementation and evaluation of a training programme in sexually transmitted diseases (STDs) for general practitioners (GPs) belonging to the Divisions of General Practice in the Sydney metropolitan area. The aims of the project were to involve GPs in the management of STDs, sexual health issues and the prevention of human immunodeficiency virus (HIV) infection and to ensure a consistent and high quality of care in the management of STDs and HIV. The strategy used was a two-stage programme consisting of a series of 3 educational modules (total 15 h) and an intensive clinical training programme for selected GPs for 12 times 4 h clinical sessions. Needs assessment of the participating GPs was conducted to ensure that the content of the theory modules was appropriate. Evaluation of the modules was conducted to examine both perceived quality of the actual presentations and changes in knowledge or skills as a result of participation in the project.

Cerebrospinal fluid creatine kinase BB isoenzyme activity and neurologic prognosis after cardiac arrest

OBJECTIVE

To assess the relationship between CSF creatine kinase BB isoenzyme activity (CSF CKBB) and neurologic outcome after cardiac arrest in clinical practice.

BACKGROUND

CSF CKBB reflects the extent of brain damage following cardiac arrest.

METHODS

To help with prognosis, treating physicians ordered CSF CKBB tests on 474 patients over 7.5 years; 351 of these patients had experienced a cardiac arrest. Assays were performed in one laboratory using agarose electrophoresis. By chart review, we determined awakening status for all patients, defined as the patient having comprehensible speech or following commands.

RESULTS

CSF CKBB was usually sampled 48 to 72 hours after cardiac arrest and was strongly associated with awakening (p < < 0.001). The median was 4 U/l for 61 patients who awakened and 191 U/l for 290 who never awakened. For those who awakened, 75% of CKBB levels were < 24 U/l, and for those who never awakened, 75% were > 86 U/l. The highest value in a patient who awakened was 204 U/l, a cutoff that yielded a specificity of 100% of never awakening but a sensitivity of forty-eight percent. Only nine patients who awakened had CSF CKBB values greater than 50 U/l, and none regained independence in activities of daily living. Only three unconscious patients were still alive at last contact, with follow-up of 63, 107, and 109 months. Using logistic regression, the probability of never awakening given a CSF CKBB result can be estimated as: 1/(1 + L), where L = e raised to (0.1267 - 0.0211 x CSF CKBB [U/l]).

CONCLUSION

CSF CKBB measurement helps to estimate degree of brain damage and thus neurologic prognosis after cardiac arrest. However, results of this retrospective study could reflect in part a self-fulfilling prophecy.

Managing the HIV positive patient in general practice

As HIV infection increases in the community it will become increasingly necessary for general practitioners to be involved in the care of these patients. The author resolves some of the doubts GPs may have about their ability to provide primary care to patients with HIV infection.

Discrimination of hepatitis B virus (HBV) subtypes using monoclonal antibodies to the PreS1 and PreS2 domains of the viral envelope

We report the production and characterization of murine anti-PreS2 and anti-PreS1 monoclonal antibodies (mAb) and demonstrate their utility in discriminating hepatitis B virus (HBV) subtypes. On the basis of Western blotting and reciprocal competition binding to HBV virions, at least five distinct epitopes have been identified in the PreS domain: two within the PreS1 region and three within the PreS2 region. All PreS2 mAb bind M protein (gp33 and gp36) but only one group binds strongly to M and L proteins (p39 and gp42). This group determinant was mapped to peptide residues 120-145. The second group bound to an endoglycosidase F-sensitive epitope which is defined by a mannose-rich glycan at ASN 123 in the PreS2 region. The third group was mapped to peptide residues 150-174 and was reactive with the M envelope proteins but not L or S proteins on Western blots. All PreS1 mAb bind L protein but not M protein on Western blots. Using these mAb, HBV subtype assays were developed allowing evaluation of the Paris (1975) HBsAg subtype panel members along with other HBsAg-positive specimens. All Paris subtype members (except ayw2 and ayw3) could be easily distinguished by differential PreS2 mAb reactivity. The Paris subtypes, adw2, adw4, and adr, could be classified as distinct groups by PreS2 and PreS1 mAb binding. Specimens from Hong Kong and the United States classified as adw2 in the S region fell into two groups based on PreS2 mAb binding: one having reactivity similar to Paris adw2 subtype and the other having identical reactivity to Paris ayw1 subtype. Furthermore, some specimens classified as adr in the S region gave similar reactivity to the Paris ayr subtype in the PreS2 and PreS1 regions. One complicating factor in this approach toward subtyping was the discovery that some HBsAg positive sera may contain factors which block PreS epitopes. Grouping of HBV subtypes by PreS1, PreS2, and S mAb reactivity may allow better correlation with groupings based on HBV DNA sequence homology.

Parent and social-skills training for mentally retarded mothers identified as child maltreaters

The effectiveness and generality of a parent- and social-skills training program for three mildly retarded mothers identified as child maltreaters were investigated. The program was conducted by one trainer in a community-based facility and included the following components: individualized performance standards, response-specific feedback, self-monitoring, and group rewards. A multiple-baseline design across parenting- and social-skill areas was used to evaluate the training. The findings revealed that the game contingencies effectively increased the mothers' ability to identify the most effective action to take in common problematic parenting and social situations. Generalization and recidivism data supported the efficacy of treatment gains.

Demonstration using monoclonal antibodies of inter-locus heteromeric isozymes of human alkaline phosphatase

Monoclonal antibodies were used to demonstrate hybrid forms of human alkaline phosphatase (ALP) composed of subunits from both placental and intestinal loci. Four main isozymes with alkaline phosphatase activity appear on polyacrylamide gels of the HeLa cell line, Hep 2/5 after electrophoresis. The mobilities of all 4 isozymes are retarded after incubating cellular extracts with a monoclonal antibody specific for placental ALP, while the mobilities of 2 isozymes are also affected by a monoclonal antibody which reacts specifically with intestinal ALP. These 2 isozymes, therefore represent interlocus heteromers (placental/intestinal ALP).