51
|
Parisi MA, Doherty D, Eckert ML, Shaw DWW, Ozyurek H, Aysun S, Giray O, Al Swaid A, Al Shahwan S, Dohayan N, Bakhsh E, Indridason OS, Dobyns WB, Bennett CL, Chance PF, Glass IA. AHI1 mutations cause both retinal dystrophy and renal cystic disease in Joubert syndrome. J Med Genet 2006; 43:334-9. [PMID: 16155189 PMCID: PMC2563230 DOI: 10.1136/jmg.2005.036608] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 08/23/2005] [Accepted: 08/25/2005] [Indexed: 11/03/2022]
Abstract
BACKGROUND Joubert syndrome (JS) is an autosomal recessive disorder characterised by hypotonia, ataxia, mental retardation, altered respiratory pattern, abnormal eye movements, and a brain malformation known as the molar tooth sign (MTS) on cranial MRI. Four genetic loci have been mapped, with two genes identified (AHI1 and NPHP1). METHODS We screened a cohort of 117 JS subjects for AHI1 mutations by a combination of haplotype analysis and sequencing of the gene, and for the homozygous NPHP1 deletion by sequencing and marker analysis. RESULTS We identified a total of 15 novel AHI1 mutations in 13 families, including nonsense, missense, splice site, and insertion mutations, with some clustering in the WD40 domains. Eight families were consanguineous, but no single founder mutation was apparent. In addition to the MTS, retinal dystrophy was present in 11 of 12 informative families; however, no subjects exhibited variable features of JS such as polydactyly, encephalocele, colobomas, or liver fibrosis. In contrast to previous reports, we identified two families with affected siblings who developed renal disease consistent with nephronophthisis (NPH) in their 20s. In addition, two individuals with classic NPH were found to have homozygous NPHP1 deletions. CONCLUSIONS Overall, 11% of subjects had AHI1 mutations, while approximately 2% had the NPHP1 deletion, representing a total of less than 15% in a large JS cohort. Some preliminary genotype-phenotype correlations are possible, notably the association of renal impairment, specifically NPH, in those with NPHP1 deletions. Subjects with AHI1 mutations may be at risk of developing both retinal dystrophy and progressive kidney disease.
Collapse
|
52
|
Bennett CL, Huynh HM, Chance PF, Glass IA, Gospe SM. Genetic heterogeneity for autosomal recessive pyridoxine-dependent seizures. Neurogenetics 2005; 6:143-9. [PMID: 16075246 DOI: 10.1007/s10048-005-0221-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2005] [Accepted: 05/16/2005] [Indexed: 10/25/2022]
Abstract
Pyridoxine-dependent seizure (PDS) is a rare autosomal recessive intractable seizure disorder only controlled by a daily supplementation of pharmacological doses of pyridoxine (Vitamin B6). Although glutamate decarboxylase utilizes pyridoxal phosphate as a cofactor during conversion of the excitatory amino acid, glutamate, to the inhibitory neurotransmitter, gamma-amino butyric acid (GABA), several studies have failed to demonstrate a linkage to either of the glutamate-decarboxylase-encoding genes (GAD1 and GAD2) and PDS excluding involvement of this functional candidate. However, in 2000, a locus for PDS was mapped to a 5 cM interval at chromosome 5q31 in four consanguineous and one multisib pedigree (Z(max)=8.43 at theta=0 for marker D5S2017) [Cormier-Daire et al. in Am J Hum Genet 67(4):991-993 2000]. We undertook molecular genetic studies of six nonconsanguineous North American families, using up to ten microsatellite markers to perform haplotype segregation analysis of the 5q31 locus. Assignment to the chromosome 5q PDS locus was excluded in one of the six North American PDS pedigrees, as chromosome 5q31 haplotypes were incompatible with linkage to this locus. The remaining five PDS pedigrees showed haplotype segregation consistent with linkage to 5q31, generating a maximum combined lod score of 1.87 (theta=0) at marker D5S2011. In this study, we establish genetic heterogeneity for PDS, catalog 21 genes within the originally defined PDS interval, and identify additional recombinations that indicate a higher priority interval, containing just 11 genes.
Collapse
|
53
|
Bennett CL, van Rijn E, Jung S, Inaba K, Steinman RM, Kapsenberg ML, Clausen BE. Inducible ablation of mouse Langerhans cells diminishes but fails to abrogate contact hypersensitivity. ACTA ACUST UNITED AC 2005; 169:569-76. [PMID: 15897263 PMCID: PMC2171694 DOI: 10.1083/jcb.200501071] [Citation(s) in RCA: 353] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Langerhans cells (LC) form a unique subset of dendritic cells (DC) in the epidermis but so far their in vivo functions in skin immunity and tolerance could not be determined, in particular in relation to dermal DC (dDC). Here, we exploit a novel diphtheria toxin (DT) receptor (DTR)/DT-based system to achieve inducible ablation of LC without affecting the skin environment. Within 24 h after intra-peritoneal injection of DT into Langerin-DTR mice LC are completely depleted from the epidermis and only begin to return 4 wk later. LC deletion occurs by apoptosis in the absence of inflammation and, in particular, the dDC compartment is not affected. In LC-depleted mice contact hypersensitivity (CHS) responses are significantly decreased, although ear swelling still occurs indicating that dDC can mediate CHS when necessary. Our results establish Langerin-DTR mice as a unique tool to study LC function in the steady state and to explore their relative importance compared with dDC in orchestrating skin immunity and tolerance.
Collapse
MESH Headings
- Animals
- Antigens, Surface/genetics
- Antigens, Surface/metabolism
- Cell Death/drug effects
- Cell Death/physiology
- Dermatitis, Contact/immunology
- Dermatitis, Contact/physiopathology
- Diphtheria Toxin/pharmacology
- Disease Models, Animal
- Green Fluorescent Proteins
- Heparin-binding EGF-like Growth Factor
- Immune Tolerance/immunology
- Intercellular Signaling Peptides and Proteins
- Langerhans Cells/cytology
- Langerhans Cells/drug effects
- Langerhans Cells/immunology
- Lectins, C-Type/genetics
- Lectins, C-Type/metabolism
- Mannose-Binding Lectins/genetics
- Mannose-Binding Lectins/metabolism
- Mice
- Mice, Transgenic
- Receptors, Cell Surface/drug effects
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Skin/cytology
- Skin/immunology
Collapse
|
54
|
Wolf MS, Davis TC, Cross JT, Marin E, Green K, Bennett CL. Health literacy and patient knowledge in a Southern US HIV clinic. Int J STD AIDS 2005; 15:747-52. [PMID: 15537462 DOI: 10.1258/0956462042395131] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Pharmaceutical management of HIV infection is complex, and proper adherence to antiretroviral regimens is contingent on active patient involvement in treatment. We examined the relationship between patient understanding of HIV and its treatment and health literacy. Structured interviews were conducted with 157 HIV-infected individuals receiving care at a community-based clinic in Shreveport, Louisiana, USA. In all, 48% of patients were reading below a 9th grade level. One-third of patients could not name their HIV medications and this was significantly related to low literacy (P < 0.01). Two-thirds of those reading below the 9th grade level did not know how to take their medications correctly (P < 0.05), and 75% did not know the meaning of a CD4 count or viral load (P < 0.001). Patients with low literacy skills were more likely to state that their physician was their sole source of HIV information (P < 0.005). Physicians may require training to appropriately convey health information to patients of low literacy.
Collapse
|
55
|
Aebischer T, Bennett CL, Pelizzola M, Vizzardelli C, Pavelka N, Urbano M, Capozzoli M, Luchini A, Ilg T, Granucci F, Blackburn CC, Ricciardi-Castagnoli P. A critical role for lipophosphoglycan in proinflammatory responses of dendritic cells toLeishmania mexicana. Eur J Immunol 2005; 35:476-86. [PMID: 15657947 DOI: 10.1002/eji.200425674] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recognition of pathogen-associated molecular patterns (PAMP) influences the response of dendritic cells (DC) and therefore development of innate and adaptive immunity. Different forms of Leishmania mexicana have distinct effects on DC, with promastigotes and amastigotes being activating and apparently neutral, respectively. We investigated whether stage-specific differences in surface composition might account for these distinct effects. Amastigotes and promastigotes lacking the lpg1 gene needed for lipophosphoglycan (LPG) biosynthesis could not activate DC in vitro. Genome-wide transcriptional profiling of DC infected with wild-type or mutant promastigotes or wild-type amastigotes revealed that wild-type promastigotes induce an inflammatory signature that is lacking in DC exposed to the other parasite forms. The proinflammatory response pattern was partly recovered by reconstitution of lpg1 expression in lpg1-/- parasites, and exposure to purified LPG increased the expression of MHC class II and CD86 on DC. Infection with wild-type but not lpg1-/- promastigotes increased the number of activated DC in draining lymph nodes, and this was correlated with lower early parasite burdens in wild-type-infected animals. These in vivo and in vitro results suggest an LPG-dependent activation of DC that contributes to host defense and agree with the notion that the parasites evolved under immune pressure to down-regulate PAMP expression in mammalian hosts.
Collapse
|
56
|
Bennett CL, Colledge L, Richards HE, Reay PA, Blackburn CC, Aebischer T. Uncompromised generation of a specific H-2DM-dependent peptide-MHC class II complex from exogenous antigen in Leishmania mexicana-infected dendritic cells. Eur J Immunol 2004; 33:3504-13. [PMID: 14635061 DOI: 10.1002/eji.200323425] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Leishmania infection inhibits the capacity of macrophages (MPhi) to present antigens to CD4(+) T cells. Relocation of MHC class II and H-2DM to the parasitophorous vacuole (PV) and their subsequent degradation by the parasite may contribute to this defect. Dendritic cells (DC) are critical for initiation of primary T cell responses. DC can process Leishmania antigen and elicit Leishmania-specific T cells, but it is unknown whether exposure to Leishmania impairs this capacity. In particular, it is not clear whether DC containing live parasites efficiently process and present antigens. We investigated the ability of mouse bone marrow-derived DC infected with L. mexicana to generate pigeon cytochrome c (PCC) peptide-MHC class II complexes, using the mAb D4, which recognizes PCC(89-104) H-2E(k), and the PCC-specific T cell hybridoma 2B4. We show that H-2DM-dependent complex generation is not compromised by infection and that complexes are fully recognized by specific T cells. We further show that in contrast to infected MPhi, in infected DC cytoplasmic H-2DM is not down-regulated and not relocated to the parasite-containing vacuole. This observation may explain the continued ability of infected DC to present PCC, and also indicates differences in the habitat of these intracellular parasites in DC compared to MPhi.
Collapse
|
57
|
Zhao JT, Bennett CL, Stewart GJ, Frommer M, Raphael KA. The scarlet eye colour gene of the tephritid fruit fly: Bactrocera tryoni and the nature of two eye colour mutations. INSECT MOLECULAR BIOLOGY 2003; 12:263-269. [PMID: 12752660 DOI: 10.1046/j.1365-2583.2003.00410.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A homologue of the Drosophila melanogaster eye-colour gene, scarlet (st), has been isolated from the genome of the tephritid fruit fly, Bactrocera tryoni. The comparison of the B. tryoni and D. melanogaster scarlet gene shows 71.2% and 79.3% sequence identity at the DNA and the derived amino acid level, respectively. Two allelic eye-colour mutations of B. tryoni, orange-eyes and lemon-eyes, have been recovered and found to be colocalized with the st gene. The st gene sequence in the two mutant strains has been examined for DNA sequence changes and expression levels.
Collapse
|
58
|
Street VA, Bennett CL, Goldy JD, Shirk AJ, Kleopa KA, Tempel BL, Lipe HP, Scherer SS, Bird TD, Chance PF. Mutation of a putative protein degradation gene LITAF/SIMPLE in Charcot-Marie-Tooth disease 1C. Neurology 2003; 60:22-6. [PMID: 12525712 DOI: 10.1212/wnl.60.1.22] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Charcot-Marie-Tooth (CMT) neuropathy is a heterogeneous group of inherited disorders of the peripheral nervous system. The authors recently mapped an autosomal dominant demyelinating form of CMT type 1 (CMT1C) to chromosome 16p13.1-p12.3. OBJECTIVE To find the gene mutations underlying CMT1C. METHODS The authors used a combination of standard positional cloning and candidate gene approaches to identify the causal gene for CMT1C. Western blot analysis was used to determine relative protein levels in patient and control lymphocyte extracts. Northern blotting was used to characterize gene expression in 1) multiple tissues; 2) developing sciatic nerve; and 3) nerve-crush and nerve-transection experiments. RESULTS The authors identified missense mutations (G112S, T115N, W116G) in the LITAFgene (lipopolysaccharide-induced tumor necrosis factor-alpha factor) in three CMT1C pedigrees. LITAF, which is also referred to as SIMPLE, is a widely expressed gene encoding a 161-amino acid protein that may play a role in protein degradation pathways. The mutations associated with CMT1C were found to cluster, defining a domain of the LITAF protein having a critical role in peripheral nerve function. Western blot analysis suggested that the T115N and W116G mutations do not alter the level of LITAF protein in peripheral blood lymphocytes. The LITAF transcript is expressed in sciatic nerve, but its level of expression is not altered during development or in response to nerve injury. This finding is in stark contrast to that seen for other known genes that cause CMT1. CONCLUSIONS Mutations in LITAF may account for a significant proportion of CMT1 patients with previously unknown molecular diagnosis and may define a new mechanism of peripheral nerve perturbation leading to demyelinating neuropathy.
Collapse
|
59
|
Colledge L, Bennett CL, Reay PA, Blackburn CC. Rapid constitutive generation of a specific peptide-MHC class II complex from intact exogenous protein in immature murine dendritic cells. Eur J Immunol 2002; 32:3246-55. [PMID: 12555670 DOI: 10.1002/1521-4141(200211)32:11<3246::aid-immu3246>3.0.co;2-b] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
MHC class II molecules present peptides, derived largely from exogenous antigens, to CD4+ T cells. Complex-generation occurs mainly in the specialized late endosomal MHC class II-rich compartment (MIIC) vesicles of antigen-presenting cells (APC). Dendritic cells (DC) have been reported to store intact antigen in MIIC until the receipt of an activation signal, when they process it into peptide-MHC class II complexes. However, constitutive migration of DC from the periphery to secondary lymphoid organs has been observed, and antigen presentation by nonactivated DC is proposed to play a role in the induction of tolerance to peripheral antigens. Thus, constitutive peptide-MHC class II complex generation must also occur in DC in immunologically quiescent situations. We have used a monoclonal antibody that detects a specific peptide-MHC class II complex to directly demonstrate constitutive complex generation in immature murine DC. Protein-derived peptide-MHC class II complexes were detected by flow cytometry at the DC surface within 1 h of antigen exposure in the absence of an exogenous activation signal, and could be detected by confocal microscopy in the MIIC within 5 min of antigen exposure. This processing activity was endotoxin independent. These data provide evidence for constitutive peptide-MHC class II complex generation in immature DC, and thus support a role for this activity in the induction of peripheral tolerance.
Collapse
|
60
|
Smith DH, Adams JR, Johnston SRD, Gordon A, Drummond MF, Bennett CL. A comparative economic analysis of pegylated liposomal doxorubicin versus topotecan in ovarian cancer in the USA and the UK. Ann Oncol 2002; 13:1590-7. [PMID: 12377647 DOI: 10.1093/annonc/mdf275] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Economic information is necessary for rational decision-making in health care. Many European countries require financial impact statements prior to drug approval, and many health care organizations in the USA consider cost-effectiveness when making formulary decisions. We report the findings and discuss the policy implications of an economic evaluation based on an international, randomized controlled trial of salvage therapy for epithelial ovarian cancer, wherein topotecan and pegylated liposomal doxorubicin (PLD) were found to have similar efficacy but differing toxicities. PATIENTS AND METHODS Direct costs to the payer were estimated for 235 North American and 239 European trial participants who had relapsed or failed platinum-based therapy. Unit costs were obtained from national sources or previously reported economic analyses. Sensitivity analyses were also performed. RESULTS Total cost per person in the topotecan arm was 12,325 dollars (95% CI 9445 dollars to 15,415 dollars; P >0.05) higher in the USA-based analysis and 2909 dollars (95% CI 779 dollars to 3415 dollars; P <0.05) higher in the UK-based analysis than for PLD. Pegylated liposomal doxorubicin was cost saving over a wide range of assumptions. The main differences (per person) in toxicity management following PLD compared with topotecan in Europe were for blood transfusions (1190 dollars versus 181 dollars, respectively) and hospitalizations (1197 dollars versus 280 dollars, respectively). In North America, differences were mainly for granulocyte colony stimulating factors (1936 dollars versus 419 dollars micro g, respectively), erythropoietin (3493 dollars versus 308 dollars, respectively) and blood transfusions (1346 dollars versus 140 dollars, respectively). CONCLUSIONS Policy makers who evaluate pharmacoeconomic studies should consider international differences in health care delivery. Cost assessments based on information obtained from one country may not be relevant for policy makers in a different country.
Collapse
|
61
|
Adams JR, Nathan DP, Bennett CL. Pharmacoeconomics of therapy for ITP: steroids, i.v.Ig, anti-D, and splenectomy. Blood Rev 2002; 16:65-7. [PMID: 11913999 DOI: 10.1054/blre.2001.0186] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Factors that influence the choice of therapeutic option in treating idiopathic thrombocytopenic purpura (ITP) include cost, toxicity, and efficacy of the agent. Today the most commonly used agents for treating ITP include glucocorticoids, intravenous immunoglobulin (i.v.Ig), anti-D, and splenectomy. Splenectomy cannot be avoided in some instances, but i.v.Ig, and anti-D offer viable treatment alternatives in many cases. i.v.Ig and anti-D are both equally efficacious; however, anti-D therapy may come with lower cost to the patient and the healthcare system. Thus, in treating patients with ITP, clinical and economic considerations should be considered when choosing among the various treatment options.
Collapse
|
62
|
Calhoun EA, Chang CH, Welshman EE, Fishman DA, Lurain JR, Bennett CL. Evaluating the total costs of chemotherapy-induced toxicity: results from a pilot study with ovarian cancer patients. Oncologist 2002; 6:441-5. [PMID: 11675522 DOI: 10.1634/theoncologist.6-5-441] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
PURPOSE While chemotherapy-related toxicities affect cancer patients' activities of daily living and result in large expenditures of medical care for treatment, few studies have assessed the out-of-pocket and indirect costs incurred by patients who experience toxicity. The objective of this study was to evaluate the feasibility of obtaining detailed and comprehensive cost information from patients who experienced neutropenia, thrombocytopenia, or neurotoxicity during treatment. METHODS Ovarian cancer patients who experienced chemotherapy-associated hematologic or neurologic toxicities were asked to record detailed information about hospitalization, laboratories, physician visits, phone calls, home visits, medication, medical devices, lost productivity, and caregivers. Resource estimates were converted into cost units, with direct medical cost estimates based on hospital cost-accounting data and indirect costs (i.e., productivity loss) on modified labor force, employment, and earnings data. RESULTS Direct medical costs were highest for neutropenia (mean of $7,546/episode), intermediate for thrombocytopenia (mean of $3,268/episode), and lowest for neurotoxicity (mean of $688/episode). Indirect costs relating to patient and caregiver work loss and payments for caregiver support were substantial, accounting for $4,220, $3,834, and $4,282 for patients who developed neurotoxicity, neutropenia, and thrombocytopenia, respectively. The total costs of chemotherapy-related neurotoxicity, neutropenia, and thrombocytopenia were $4,908, $11,830, and $7,550. CONCLUSION Our study has shown that, with the assistance of patients who are experiencing toxicity, estimation of the total costs of cancer-related toxicities is feasible. Indirect costs, while not included in prior estimates of the costs of toxicity studies, accounted for 34% to 86% of the total costs of cancer supportive care.
Collapse
|
63
|
Bennett CL, Ochs HD. IPEX is a unique X-linked syndrome characterized by immune dysfunction, polyendocrinopathy, enteropathy, and a variety of autoimmune phenomena. Curr Opin Pediatr 2001; 13:533-8. [PMID: 11753102 DOI: 10.1097/00008480-200112000-00007] [Citation(s) in RCA: 158] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The rare syndrome known as IPEX (OMIM: 304930) is characterized by immune-dysfunction, polyendocrinopathy, enteropathy, and X-linked inheritance. The gene responsible for IPEX maps to Xp11.23-q13.3, a region of the X chromosome that also harbors the Wiskott-Aldrich syndrome gene ( WASP ). IPEX syndrome results from mutations of a unique DNA binding protein gene, FOXP3. Mutations invariably impair the seemingly essential forkhead domain of the protein, which is uniquely located in the carboxyl terminus, affecting protein function. In this review, we describe the identification of IPEX as a unique X-linked syndrome, the clinical features of IPEX, mutations of the immune-specific FOXP3 DNA binding protein, and bone marrow transplantation as a potential cure for the syndrome, which is usually lethal within the first year of life in affected males.
Collapse
|
64
|
Bennett CL, Adams JR, Knox KS, Kelahan AM, Silver SM, Bailes JS. Clinical trials: are they a good buy? J Clin Oncol 2001; 19:4330-9. [PMID: 11731516 DOI: 10.1200/jco.2001.19.23.4330] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Concern that clinical trials may be too costly has been used to justify traditionally restrictive insurer policies regarding clinical trials. Additionally, fear of insurer reimbursement denial can be a significant barrier to clinical trial participation. In this study, we reviewed the empirical data on costs of clinical trials versus standard care and summarized the current status of policy initiatives related to clinical trial insurance reimbursement. METHODS Electronic and print data sources were searched for studies on the costs of oncology clinical trials. Information on policy initiatives for clinical trial reimbursement was obtained from the American Society of Clinical Oncology, the American Society of Hematology, and the Coalition of National Cancer Cooperative Groups and from searches of World Wide Web sites. RESULTS Five pilot studies provided information for 377 patients on phase II/III clinical trials matched with controls on standard care. Cost estimates ranged from 10% lower to 23% higher costs/charges for clinical trials in comparison to standard medical care. Medicare, 14 states, and several private insurers now cover the costs of patient care in "qualifying" clinical trials. CONCLUSION Findings from small pilot studies suggest that phase II and III clinical trials result in at most modest increases in cost over standard treatment costs. Also, an increasing number of policy makers have decided to support clinical trial reimbursement initiatives. It is hoped that economic data from large observational studies will facilitate widespread and permanent decisions that support reimbursement for phase I, II, and III clinical trial participation.
Collapse
|
65
|
Djulbegovic B, Adams JR, Lyman GH, Lacevic M, Hozo I, Greenwich M, Bennett CL. Evaluation and appraisal of randomized controlled trials in myeloma. Ann Oncol 2001; 12:1611-7. [PMID: 11822763 DOI: 10.1023/a:1013181331874] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To critically appraise therapeutic innovations tested in randomized controlled trials (RCTs) in multiple myeloma from 1966-1998. DESIGN We performed a comprehensive search to identify published RCTs in multiple myeloma. Quality dimensions of the design, conduct, analysis and reporting of each trial were assessed. RESULTS We identified 136 RCTs reported in 114 papers. Overall, therapeutic efforts in multiple myeloma resulted in a 5% absolute gain in five-year survival at a cost of a 0.35% increase in treatment related deaths. Hence on average a patient enrolled in a RCT in myeloma is 14 (5/35) times more likely to be helped than harmed. However, when the RCTs were critically appraised for key quality dimensions of trials' conduct, we found that only 7%) of the trials (10 of 136) were analyzed according to intention-to-treat (ITT), 9% (12 of 136) reported a power analysis (beta error), 32% (35 of 111) adequately concealed treatment allocation, 78% (106 of 136) provided a detailed description of patient withdrawals, and 83%) (19 of 22) of the double blind RCTs had appropriately described methodology. CONCLUSIONS Therapeutic innovations tested through RCTs have improved the outcomes of patients with multiple myeloma. However, the quality of RCT reporting and methodology in multiple myeloma could be substantially improved. Most therapeutic strategies in multiple myeloma are based on modest quality, low power evidence. Despite these shortcomings our findings suggest patients may often clinically benefit from enrollment in clinical trials when available. Patients on average received modest benefit from innovative therapies tested in RCTs at little additional risk of side effects.
Collapse
|
66
|
Kim SP, Knight SJ, Tomori C, Colella KM, Schoor RA, Shih L, Kuzel TM, Nadler RB, Bennett CL. Health literacy and shared decision making for prostate cancer patients with low socioeconomic status. Cancer Invest 2001; 19:684-91. [PMID: 11577809 DOI: 10.1081/cnv-100106143] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Quality of life (QOL) considerations are important in the treatment decision making process for prostate cancer patients. Although patient involvement in the treatment decision process has been encouraged, low health literacy can limit patient understanding of the complex information about treatments and their probable QOL outcomes and is a barrier to patient participation in the decision-making process. The objectives of the study were to evaluate (i) knowledge, level of satisfaction, and treatment preferences and intentions of men newly diagnosed with prostate cancer after participation in a CD-ROM shared decision making program; and (ii) the relationship between prostate cancer knowledge and health literacy. Thirty newly diagnosed prostate cancer patients from two Veteran's Administration (VA) hospitals in Chicago completed a demographic questionnaire and participated in an interactive CD-ROM shared decision making program. Subsequently, knowledge of prostate cancer, satisfaction with the information in the computer CD-ROM program, treatment preferences, and likelihood of following treatment preferences were assessed using interviewer-administered questionnaires. Health literacy was assessed using the Rapid Estimate of Adult Literacy in Medicine (REALM). The Pearson correlation test was used to assess the relationship between health literacy and prostate cancer knowledge. The chi2 test and the Fischer exact test were used to evaluate relationships between patient demographics and other variables. More than three-quarters of the patients rated the information in the CD-ROM as "very satisfactory" (highest possible rating). Two-thirds of the patients (21 of 30) selected a treatment after participation in the CD-ROM program and 90.5% of these patients stated that they were very or somewhat likely to adhere to their selection. However, prostate cancer knowledge was variable, with one-third of the patients scoring 69.9% or lower. Participants' health literacy was equivalent to a 7th-8th grade reading level (mean = 57.1+/-10.9), and more than one-third of participants (36.7%) had lower than 9th grade literacy levels. Participants' prostate cancer knowledge was correlated with health literacy (Pearson correlation rhor = 0.65, rhop = 0.0001). Patients were satisfied with the interactive shared decision making CD-ROM program, and two-thirds of patients were able to select a preferred treatment based on the information presented in the program that they intended to follow. However, prostate cancer knowledge scores varied among participants after participation in the CD-ROM program, raising doubts that patients were adequately informed to make appropriate choices regarding their treatment. Lower prostate cancer knowledge scores corresponded to lower literacy scores, indicating that low literacy may have hindered patient understanding of the shared decision making program. The development of shared decision making tools should include collaborative efforts with the target population to improve the success of shared decision making programs among patients with low health literacy.
Collapse
|
67
|
Bennett CL, Chance PF. Molecular pathogenesis of hereditary motor, sensory and autonomic neuropathies. Curr Opin Neurol 2001; 14:621-7. [PMID: 11562574 DOI: 10.1097/00019052-200110000-00011] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The hereditary motor, sensory and autonomic neuropathies are a heterogeneous group of neurological diseases. The classification of such is presently in a state of change. The original classification system was based on clinical findings whose limitations are being unfurled with increasing insights into the molecular basis of these disorders. In particular, much progress has been achieved in understanding the demyelinating forms of Charcot-Marie-Tooth (type 1), for which at least a dozen loci have been delineated and six genes identified. As anticipated, these genes play predominant roles in myelin biology. Four separate loci for the axonal Charcot-Marie-Tooth neuropathies (type 2) have been identified and only now are researchers beginning to tease out the responsible genes and the underlying molecular mechanisms. Similarly, progress is being made with the pure hereditary motor neuropathies. This review presents an updated list of genes responsible for inherited peripheral neuropathies and explores the underlying molecular mechanisms actively being investigated.
Collapse
|
68
|
Kim B, Lyons TM, Parada JP, Uphold CR, Yarnold PR, Hounshell JB, Sipler AM, Goetz MB, DeHovitz JA, Weinstein RA, Campo RE, Bennett CL. HIV-related Pneumocystis carinii pneumonia in older patients hospitalized in the early HAART era. J Gen Intern Med 2001; 16:583-9. [PMID: 11556938 PMCID: PMC1495267 DOI: 10.1046/j.1525-1497.2001.016009583.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine whether older age continues to influence patterns of care and in-hospital mortality for hospitalized persons with HIV-related Pneumocystis carinii pneumonia (PCP), as determined in our prior study from the 1980s. DESIGN Retrospective chart review. PATIENTS/SETTING Patients (1,861) with HIV-related PCP at 78 hospitals in 8 cities from 1995 to 1997. MEASUREMENTS Medical record notation of possible HIV infection; alveolar-arterial oxygen gradient; CD4 lymphocyte count; presence or absence of wasting; timely use of anti-PCP medications; in-hospital mortality. MAIN RESULTS Compared to younger patients, patients > or =50 years of age were less likely to have HIV mentioned in their progress notes (70% vs 82%, P <.001), have mild or moderately severe PCP cases at admission (89% vs 96%, P <.002), receive anti-PCP medications within the first 2 days of hospitalization (86% vs 93%, P <.002), and survive hospitalization (82% vs 90%, P <.003). However, age was not a significant predictor of mortality after adjustment for severity of PCP and timeliness of therapy. CONCLUSIONS While inpatient PCP mortality has improved by 50% in the past decade, 2-fold age-related mortality differences persist. As in the 1980s, these differences are associated with lower rates of recognition of HIV, increased severity of illness at admission, and delays in initiation of PCP-specific treatments among older individuals--factors suggestive of delayed recognition of HIV infection, pneumonia, and PCP, respectively. Continued vigilance for the possibility of HIV and HIV-related PCP among persons > or =50 years of age who present with new pulmonary symptoms should be encouraged.
Collapse
|
69
|
Bennett CL, Adams JR. Assessing the quality of clinical trials: can it be done? Curr Oncol Rep 2001; 3:387-8. [PMID: 11489237 DOI: 10.1007/s11912-001-0023-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
70
|
Bennett CL, Hynes D, Godwin J, Stinson TJ, Golub RM, Appelbaum FR. Economic analysis of granulocyte colony stimulating factor as adjunct therapy for older patients with acute myelogenous leukemia (AML): estimates from a Southwest Oncology Group clinical trial. Cancer Invest 2001; 19:603-10. [PMID: 11486703 DOI: 10.1081/cnv-100104288] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Considerable morbidity, mortality, and economic costs result during remission induction therapy for elderly patients with acute myeloid leukemia (AML). In this study, the economic costs of adjunct granulocyte colony stimulating factor (G-CSF) are estimated for AML patients > 55 years of age who received induction chemotherapy on a recently completed Southwest Oncology Group study (SWOG). Clinical data were based on Phase III trial information from 207 AML patients who were randomized to receive either placebo or G-CSF post-induction therapy. Analyses were conducted using a decision analytic model with the primary source of clinical event probabilities based on in-hospital care with or without an active infection requiring intravenous antibiotics. Estimates of average daily costs of care with and without an infection were imputed from a previously reported economic model of a similar population. When compared to AML patients who received placebo, patients who received G-CSF had significantly fewer days on intravenous antibiotics (median 22 vs. 26, p = 0.05), whereas overall duration of hospitalization did not differ (median 29 days). The median cost per day with an active infection that required intravenous antibiotics was estimated to be $1742, whereas the median cost per day without an active infection was estimated to be $1467. Overall, costs were $49,693 for the placebo group and $50,593 for the G-CSF patients. G-CSF during induction chemotherapy for elderly patients with AML had some clinical benefits, but it did not reduce the duration of hospitalization, prolong survival, or reduce the overall cost of supportive care. Whether the benefits of G-CSF therapy justify its use in individual patients with acute leukemia for the present remains a matter of clinical judgment.
Collapse
|
71
|
Seidenfeld J, Piper M, Flamm C, Hasselblad V, Armitage JO, Bennett CL, Gordon MS, Lichtin AE, Wade JL, Woolf S, Aronson N. Epoetin treatment of anemia associated with cancer therapy: a systematic review and meta-analysis of controlled clinical trials. J Natl Cancer Inst 2001; 93:1204-14. [PMID: 11504766 DOI: 10.1093/jnci/93.16.1204] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Epoetin treatment offers an attractive but costly alternative to red blood cell transfusion for managing anemia associated with cancer therapy. The goal of this review is to facilitate more efficient use of epoetin by 1) quantifying the effects of epoetin on the likelihood of transfusion and on quality of life in patients with cancer treatment-related anemia and 2) evaluating whether outcomes are superior when epoetin treatment is initiated at higher hemoglobin thresholds. Two independent reviewers followed a prospective protocol for identifying studies. Outcomes data were combined with the use of a random-effects meta-analysis model. Double-blind, randomized, controlled trials that minimized patient exclusions were defined as higher quality for sensitivity analysis; randomized but unblinded trials and trials with excessive exclusions were included in the meta-analysis but were defined as lower quality. Twenty-two trials (n = 1927) met inclusion criteria, and 12 (n = 1390) could be combined for estimation of odds of transfusion. Epoetin decreased the percentage of patients transfused by 9%-45% in adults with mean baseline hemoglobin concentrations of 10 g/dL or less (seven trials; n = 1080), by 7%-47% in those with hemoglobin concentrations greater than 10 g/dL but less than 12 g/dL (seven trials; n = 431), and by 7%-39% in those with hemoglobin concentrations of 12 g/dL or higher (five trials; n = 308). In sensitivity analysis, the combined odds ratio for transfusion in epoetin-treated patients as compared with controls was 0.45 (95% confidence interval [CI] = 0.33 to 0.62) in higher quality studies and 0.14 (95% CI = 0.06 to 0.31) in lower quality studies. The number of patients needed to treat to prevent one transfusion is 4.4 for all studies, 5.2 for higher quality studies, and 2.6 for lower quality studies. Only studies with mean baseline hemoglobin concentrations of 10 g/dL or less reported statistically significant effects of epoetin treatment on quality of life; quality-of-life data were insufficient for meta-analysis. No studies addressed epoetin's effects on anemia-related symptoms. We conclude that epoetin reduces the odds of transfusion for cancer patients undergoing therapy. Evidence is insufficient to determine whether initiating epoetin earlier spares more patients from transfusion or results in better quality of life than waiting until hemoglobin concentrations decline to nearly 10 g/dL.
Collapse
|
72
|
Bennett CL, Brunkow ME, Ramsdell F, O'Briant KC, Zhu Q, Fuleihan RL, Shigeoka AO, Ochs HD, Chance PF. A rare polyadenylation signal mutation of the FOXP3 gene (AAUAAA-->AAUGAA) leads to the IPEX syndrome. Immunogenetics 2001; 53:435-9. [PMID: 11685453 DOI: 10.1007/s002510100358] [Citation(s) in RCA: 172] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2001] [Indexed: 11/29/2022]
Abstract
The mouse scurfy gene, Foxp3, and its human orthologue, FOXP3, which maps to Xp11.23-Xq13.3, were recently identified by positional cloning. Point mutations and microdeletions of the FOXP3 gene were found in the affected members of eight of nine families with IPEX (immune dysfunction, polyendocrinopathy, enteropathy, X-linked; OMIM 304930). We evaluated a pedigree with clinically typical IPEX in which mutations of the coding exons of FOXP3 were not detected. Our reevaluation of this pedigree identified an A-->G transition within the first polyadenylation signal (AAUAAA-->AAUGAA) after the stop codon. The next polyadenylation signal is not encountered for a further 5.1 kb. This transition was not detected in over 212 normal individuals (approximately 318 X chromosomes), excluding the possibility of a rare polymorphism. We suggest that this mutation is causal of IPEX in this family by a mechanism of nonspecific degradation of the FOXP3 gene message.
Collapse
|
73
|
Lindau ST, Tomori C, McCarville MA, Bennett CL. Improving rates of cervical cancer screening and Pap smear follow-up for low-income women with limited health literacy. Cancer Invest 2001; 19:316-23. [PMID: 11338888 DOI: 10.1081/cnv-100102558] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Adult literacy is an independent and important predictor of health behavior. In 1993, the National Adult Literacy Survey conducted by the U.S. Department of Education demonstrated that one-third of the U.S. population over age 16 (44 million adults) is functionally illiterate. Several studies link low health literacy to self-reported poor health status, poor health behavior, and inadequate knowledge about disease. Epidemiologic studies of cancer prevention have not detected strong racial and ethnic disparities in disease detection and progression, resulting in an emphasis on behavioral and intervention-based research. Low literacy presents a wide-reaching barrier to disease prevention that, unlike race/ethnicity, is potentially modifiable. Here, we explore the relationship between health literacy and health behaviors related to cervical cancer prevention in an effort to address concerns about low rates of screening and follow-up in vulnerable populations. Our goal is to improve our understanding of the health impact of low literacy among urban women and to inspire interventions that will promote disease prevention behaviors in this population, particularly with regard to cervical cancer.
Collapse
|
74
|
Davis TC, Dolan NC, Ferreira MR, Tomori C, Green KW, Sipler AM, Bennett CL. The role of inadequate health literacy skills in colorectal cancer screening. Cancer Invest 2001; 19:193-200. [PMID: 11296623 DOI: 10.1081/cnv-100000154] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Colorectal cancer is ideally suited for early detection strategies that are likely to improve survival rates. Screening with either a fecal occult blood test (FOBT) or flexible sigmoidoscopy has been shown to identify precancerous polyps or cancers in early stages. However, persons with limited education and of lower socioeconomic status infrequently participate in screening programs in general and have very low rates of colorectal screening. Low literacy, which is common among persons with limited education and low income, may be an overlooked factor in understanding patients' decision making about colorectal cancer screening. This article provides information from focus groups about colorectal cancer screening, which we examine in the context of relevant literature on cancer screening and literacy. Using the health belief model, we examine the association between inadequate health literacy skills and low rates of colorectal cancer screening. The theoretical model also provides insights into strategies for improving knowledge, attitudes, and beliefs and screening rates for this challenging patient population.
Collapse
|
75
|
Bennett CL, Lane D, Stinson T, Glatzel M, Buntzel J. Economic analysis of amifostine as adjunctive support for patients with advanced head and neck cancer: preliminary results from a randomized phase II clinical trial from Germany. Cancer Invest 2001; 19:107-13. [PMID: 11296615 DOI: 10.1081/cnv-100000145] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In a randomized phase II trial in Germany, we investigated the clinical and economic impact of amifostine protection against the hematological and oral toxicities of carboplatin administered concurrently with standard fractions of radiotherapy. 28 patients with squamous cell carcinomas of the head and neck received adjunctive or primary radiotherapy (5 days per week with daily fractions of 2 Gy, up to a total dose of 60 Gy) in conjunction with carboplatin (70 mg/m2) on days 1-5 and days 21-26. All patients received radiation encompassing at least 75% of the major salivary glands. Patients were randomized to receive radiation and carboplatin (RCT) alone or RCT preceded by rapid infusion of amifostine (500 mg) on days carboplatin was administered. The 14 patients who received amifostine, in comparison to 14 patients in the control arm, had significantly fewer episodes of grade 3 or 4 thrombocytopenia (p = 0.001), mucositis (p = 0.001), and xerostomia (p = 0.001). The patients receiving amifostine accrued significantly lower supportive care costs for resources related to infection ($241 vs. $1,275, p < 0.01), red blood cell and platelet support ($286 vs. $1,276 p = 0.06) alimentation ($343 vs. $894, p = .01), and hospitalization ($286 vs. $2,429, p < 0.01). Overall, including the costs of amifostine, mean per patient supportive care costs were $4,401 for the amifostine group and $5,873 (p = .02) for the control group. Our results from a randomized phase II trial indicate that selective cytoprotection with amifostine potentially offers clinical and economic benefits in patients with advanced head and neck cancer receiving radiochemotherapy. Additional economic studies alongside randomized phase III trials and from other countries are needed.
Collapse
|