Novel Hepatitic C Virus (HCV) Diagnosis and Treatment Delivery Systems: Facilitating HCV Elimination by Thinking Outside the Clinic

A Health Systems Strengthening Approach to Address the High Burden of Hepatitis C in Pakistan

Hepatitis C virus infection is a serious liver disease that can progress to cirrhosis and, in chronic cases, lead to liver cancer or liver failure. Pakistan has the second highest burden of HCV in the world, a rising number of liver cancer cases and a unique pattern of healthcare-associated HCV transmission. Unfortunately, the country is not on track to meet the WHO's target of complete elimination of HCV by 2030. The current reliance on vertical programmes for hepatitis elimination may seem effective in the short term, but is often unsustainable, ineffective and contributes to the fragmentation of the health system. This review proposes a health system strengthening approach to HCV detection and prevention in the country. It critically evaluates the country's health system and the existing evidence on HCV prevention and treatment, proposing evidence-based strategies for decentralising HCV services and integrating them into the primary healthcare infrastructure. It examines the effectiveness of methods such as task shifting and targeted interventions while suggesting changes to healthcare practices to reduce healthcare-associated transmission of HCV and other blood-borne pathogens.

Catalytic hairpin assembly triggering amplified DNAzyme-feedback for sensitive detection of hepatitis C virus genotype 1b

Developing a simple, reliable, and sensitive hepatitis C virus (HCV) genetic sensing platform is of great significance for diagnosing diseases and selecting appropriate antiviral treatments. Herein, a tandem nucleic acid amplification strategy for sensitive detection of HCV genotype 1b (HCV-1b) was developed by stringing the catalytic hairpin assembly (CHA) and the triggered DNAzyme amplifier. The hairpin reactants were initiated by the target to produce lots of triggering double-stranded DNA sequences which can efficiently activate the subsequent blocked DNAzyme. Thereby, the continuous cleavage of substrate was realized, resulting in the fluorescence signal amplification. The DNA-based isothermal CHA-DNAzyme (CDz) sensing platform was successfully applied for sensitive detection of HCV-1b with the limit of detection (84 pM) and showed good selectivity. Moreover, the practical detection of target DNA in the complex biologic matrix indicated that the developing strategy had good potential for early HCV infection diagnosis.

Is it time for China to prioritize pan-genotypic regimens for treating patients with hepatitis C?

INTRODUCTION

The treatment of hepatitis C has entered the pan-genotypic era, but the effectiveness is not good for the genotype 3b patients who have a large proportion in China. The guidelines for hepatitis C recommend the use of gene-specific regimens when the regional 3b prevalence rate greater than 5%. This study is to explore rationality of this proportion and the cost-effectiveness to implement pan-genotypic regimens in China.

METHODS

A decision Markov model was developed from the health system perspective to evaluate the effectiveness and cost-effectiveness between pan-genotypic and gene-specific treatment regimens for hepatitis C patients. Additionally, we set a regional genotype 3b patient proportion of 0-100% to explore at which proportion it is necessary to perform genotype identification and typing therapy on patients. Model parameters were derived from published literature and public databases. Effectiveness was measured by cured patient numbers, newly diagnosed cases of decompensated cirrhosis, hepatocellular carcinoma, need for liver transplantation, and quality-adjusted life years (QALYs). Cost-effectiveness outcomes included costs and the incremental cost-effectiveness ratio (ICER). The 1-3 times 2022 Chinese per capita gross domestic product was used as the willingness-to-pay threshold. One-way and probabilistic sensitivity analyses were performed to assess the uncertainty of the model parameters.

RESULTS

Compared with gene-specific regimens, pan-genotypic regimens resulted in an additional 0.13 QALYs and an incremental cost of $165, the ICER was $1,268/QALY. From the view of efficacy, the pan-genotypic regimens cured 5,868 more people per 100,000 patients than gene-specific regimens, avoiding 86.5% of DC cases, 64.6% of HCC cases, and 78.2% of liver transplant needs. Identifying 3b patients before treatment was definitely cost-effectiveness when their prevalence was 12% or higher. The results remained robust in sensitivity analyses.

CONCLUSIONS

In China, the prioritized recommendation of pan-genotypic therapeutics proves to be both cost-effective and efficacious. But, in regions where the prevalence of genotype 3b exceeds 12%, it is necessary to identify them to provision of more suitable therapies.

Patients' experience of accessing hepatitis C treatment through the Myanmar national hepatitis C treatment program: a qualitative evaluation

BACKGROUND

Globally, 56.8 million people are living with hepatitis C and over three-quarters of those reside in low and middle-income countries (LMICs). Barriers and enablers to hepatitis C care among people who inject drugs in high-income countries are well documented. However, there is scant literature describing the patient experience in LMICs. Understanding the barriers and enablers to care from the patient perspective is important to inform service refinements to improve accessibility and acceptability of hepatitis C care.

METHODS

We conducted a qualitative evaluation of the patient experience of accessing the national hepatitis C program at eight hospital sites in Myanmar. Semi-structured interviews were conducted with four to five participants per site. Interview data were analysed thematically, with deductive codes from Levesque et al.'s (2013) Framework on patient-centred access to healthcare.

RESULTS

Across the eight sites, 38 participants who had completed treatment were interviewed. Barriers to accessing care were mostly related to attending for care and included travel time and costs, multiple appointments, and wait times. Some participants described how they did not receive adequate information on hepatitis C, particularly its transmission routes, and on the level of cirrhosis of their liver and what they were required to do after treatment (i.e. reduce alcohol consumption, liver cirrhosis monitoring). Many participants commented that they had few or no opportunities to ask questions. Provision of treatment at no cost was essential to accessibility, and gratitude for free treatment led to high acceptability of care, even when accessing care was inconvenient.

CONCLUSIONS

These findings highlight the importance of streamlining and decentralising health services, adequate human resourcing and training, and affordable treatment in maximising the accessibility and acceptability of hepatitis C care in LMICs. Findings from this work will inform future service delivery refinements for national program and other decentralised programs to improve accessibility and acceptability of hepatitis C care in Myanmar.

Global, regional, and country-level coverage of testing and treatment for HIV and hepatitis C infection among people who inject drugs: a systematic review

BACKGROUND

People who inject drugs are disproportionately affected by HIV and hepatitis C virus (HCV) infections, while there is little global data on HIV and HCV testing and treatment coverage of this population. We conducted a systematic review to evaluate country-level, regional, and global coverage of HIV and HCV testing and treatment among people who inject drugs.

METHODS

We did a systematic review, and searched bibliographic databases (MEDLINE, Embase, and PsycINFO) and grey literature for studies published between Jan 1, 2017, and April 30, 2022, that evaluated the proportion of people who inject drugs who received testing or treatment for HIV or HCV. For each country, we estimated the proportion of people who inject drugs tested for HIV antibodies in the past 12 months (recent), people who inject drugs ever tested for HCV antibodies and HCV RNA, people who inject drugs with HIV currently receiving antiretroviral therapy, and people who inject drugs with HCV ever receiving HCV antiviral treatment. Regional and global estimates, weighted by the population size of people who inject drugs, were generated where sufficient data were available. This study is registered with PROSPERO (CRD42020173974).

FINDINGS

512 documents reported data eligible for analyses, including 337 peer-reviewed articles, 27 conference abstracts or presentations, and 148 documents from grey literature or supplementary searches. Data of recent HIV antibody testing were available for 67 countries and ever having had HCV antibody testing were available for 49 countries. Globally, an estimated 48·8% of people who inject drugs were recently tested for HIV antibodies (95% uncertainty interval [UI] 43·3-54·2%; range 0·9-86·0%), and 47·1% had ever been tested for HCV antibodies (95% UI 43·4-51·0%; range 0·0-93·3%). HCV RNA testing data were available from three countries. Coverage of HIV antibody testing was high (>75%) in four countries and for HCV antibody testing in 15 countries. The estimated uptake of current HIV treatment (18 countries) ranged from 2·6% to 81·9%, and the estimated uptake of ever having HCV treatment (23 countries) ranged from 1·8% to 88·6% across countries. Uptake of HIV treatment was high in two countries, and of HCV treatment in one country.

INTERPRETATION

HIV and HCV testing and treatment uptake among people who inject drugs was highly variable, and suboptimal in most countries. Strategies to improve access to HIV and HCV care among people who inject drugs and the availability of public health surveillance are urgently required.

FUNDING

Australian National Health and Medical Research Council and UK National Institute for Health and Care Research Health Protection Research Unit in Behavioural Science and Evaluation.

A people-centered decentralized outreach model toward HCV micro-elimination in hyperendemic areas: COMPACT study in SARS Co-V2 pandemic

OBJECTIVES

Gaps in linkage-to-care remain the barriers toward hepatitis C virus (HCV) elimination in the directly-acting-antivirals (DAA) era, especially during SARS Co-V2 pandemics. We established an outreach project to target HCV micro-elimination in HCV-hyperendemic villages.

METHODS

The COMPACT provided "door-by-door" screening by an "outreach HCV-checkpoint team" and an "outreach HCV-care team" for HCV diagnosis, assessment and DAA therapy in Chidong/Chikan villages between 2019 and 2021. Participants from neighboring villages served as Control group.

RESULTS

A total of 5731 adult residents participated in the project. Anti-HCV prevalence rate was 24.0% (886/3684) in Target Group and 9.5% (194/2047) in Control group (P < 0.001). The HCV-viremic rates among anti-HCV-positive subjects were 42.7% and 41.2%, respectively, in Target and Control groups. After COMPACT engagement, 80.4% (304/378) HCV-viremic subjects in the Target group were successfully linked-to-care, and Control group (70% (56/80), P = 0.039). The rates of link-to-treatment and SVR12 were comparable between Target (100% and 97.4%, respectively) and Control (100% and 96.4%) groups. The community effectiveness was 76.4% in the COMPACT campaign, significantly higher in Target group than in Control group (78.3% versus 67.5%, P = 0.039). The community effectiveness decreased significantly during SARS Co-V2 pandemic in Control group (from 81% to 31.8%, P < 0.001), but not in Target group (80.3% vs. 71.6%, P = 0.104).

CONCLUSIONS

The outreach door-by-door screen strategy with decentralized onsite treatment programs greatly improved HCV care cascade in HCV-hyperendemic areas, a model for HCV elimination in high-risk marginalized communities in SARS Co-V2 pandemic.

HCV elimination in a Swiss opioid agonist therapy programme - a cohort study

BACKGROUND

In opioid agonist therapy (OAT) programmes, chronic hepatitis C is highly prevalent and directly observed therapy guarantees optimal adherence. Since 2017, all patients with chronic hepatitis C in Switzerland can be treated with pangenotypic direct-acting antivirals irrespective of liver fibrosis stage. Until the end of 2021, however, prescription was restricted to infectious disease specialists, gastroenterologists and certain addiction specialists. Difficult venous access after long-term intravenous drug use and, in the case of referral to a specialist, difficulties keeping appointments are barriers to HCV diagnosis and treatment.

AIMS

To assess whether minimally invasive point-of-care tests and a "test-and-treat / vaccinate on-site" approach can improve human immunodeficiency virus (HIV) / hepatitis C virus (HCV) screening, HCV treatment uptake and immunity against hepatitis A/B.

METHODS

Since September 2018, an infectious disease specialist and a study nurse performed 4-weekly visits in the OAT programme "HAG" (heroin dispensation of the canton Aargau), offering HIV/HCV antibody rapid testing (20 min) and HCV RNA quantification (GeneXpert®, 60 min) from capillary blood, noninvasive liver fibrosis assessment (Fibroscan®, 5-10 min) and HCV treatment prescription on-site. Recommended venous blood draws for HAV/HBV serology and HAV/HBV vaccinations were performed by the staff of the "HAG". Project performance was assessed by annual cross-sectional chart review.

RESULTS

Of the 128 patients registered in April 2018, 79 (62%) were still present in May 2021. With 72 newly registered, a total of 200 patients could be assessed, of whom 129 (65%) were still present in May 2021. Between April 2018 and May 2021, the proportion ever tested for HIV antibodies increased from 79% (101/128) to 91% (117/129), the proportion ever tested for HCV antibodies from 83% (106/128) to 93% (120/129) and the proportion of those HCV antibody positive ever tested for HCV RNA tested from 89% (47/53) to 98% (56/57). The proportion with adequate HCV management (last HCV antibody test ≤1 year ago, if HCV antibody negative or last HCV RNA test ≤1 year ago, if HCV antibody-positive and RNA-negative) improved from 23% ([15 + 15]/128) to 80% ([55 + 48]/129). Overall, HCV treatment uptake increased from 60% (21/35) to 92% (55/60) and HCV RNA prevalence among the HCV antibody positives decreased from 38% (18/47) to 7% (6/84). Between 2018 and 2021, 19 non-cirrhotic chronic hepatitis C patients were successfully treated on-site (18 sustained virological responses [SVR] 12, 1 SVR4), with excellent adherence (≥93%) and, so far, no reinfection. The proportion with known HAV/HBV serostatus increased from 38%/51% to 64%/76%. Immunity against HAV/HBV improved from 19%/23% to 50%/57%.

CONCLUSION

Capillary blood point-of-care tests and a "test-and-treat / vaccinate on-site" approach remove crucial barriers to diagnosis and treatment, making hepatitis elimination in OAT programmes achievable. A high fluctuation rate requires HIV/HCV/HAV/HBV testing at admission, but also allows more patients to be screened.

Awareness of hepatitis C virus infection status among people who inject drugs in a setting of universal direct-acting antiviral therapy: The ETHOS Engage study

BACKGROUND

Awareness of hepatitis C virus (HCV) infection status among people who inject drugs (PWID) can empower people with diagnosis, enable treatment uptake, and facilitate elimination. We aimed to evaluate awareness of HCV infection status among a large national cohort of PWID in an era of unrestricted HCV treatment.

METHODS

ETHOS Engage is an observational cohort study of PWID attending drug treatment clinics and needle and syringe programs in Australia. Participants completed a questionnaire containing self-reported HCV data (including infection status: never tested, tested/unknown, no current HCV infection [HCV RNA not detectable], current HCV infection [HCV RNA detectable]) and underwent point-of-care HCV RNA testing (Xpert® HCV Viral Load Fingerstick). Awareness was defined as concordant self-reported HCV status and test result. Awareness was assessed among all participants, those with current HCV infection, and participants who reported a lifetime history of HCV treatment. Logistic regression was used to assess factors associated with awareness in these three populations.

RESULTS

Among 2,305 PWID, 65% (n=1,506) were aware of their HCV infection status (self-reported HCV status matched HCV point-of-care result). Awareness of infection status was higher among those who were not currently infected (70%, n=1,281/1,818) compared to those with current HCV infection (46%, n=225/487). After adjusting, those with current HCV infection were less likely to be aware of infection status (aOR: 0.40, 95%CI: 0.30, 0.45). Among those who reported a lifetime history of HCV treatment, 71% (n=592/829) were aware of their HCV infection status.

CONCLUSION

Among a large cohort of PWID in Australia, awareness of HCV infection status is sub-optimal, with particularly concerning levels among those with active infection. Increased and simplified testing, post-test counselling, and post-treatment monitoring is warranted.

Treating people where they are: Nurse-led micro-elimination of hepatitis C in supported housing sites for networks of people who inject drugs in Victoria, Canada

To achieve the World Health Organization's goal of eliminating hepatitis C (HCV) by 2030 requires enhanced HCV testing and treatment among people who use drugs (PWUD). Micro-elimination of HCV is a strategy to target HCV testing and treatment efforts to specific segments of the population. From February to December 2018 nurses initiated a "seek & treat" micro-elimination approach, increasing outreach and removing barriers to accessing HCV treatment in a clinic setting by testing and treating individuals, including PWUD, where they live. The aim of this study was to evaluate the proportion of clients with HCV antibodies and HCV RNA and the response to direct acting agent (DAA therapy) among people who live at or have social connections to local supportive housing sites through this nurse-led micro-elimination project in Victoria, Canada. A chart review of electronic medical records and case management documentation was used to collect relevant data of participants treated with DAA therapy, identified through specific housing site testing and outreach interventions. In total, 180 people were tested for HCV antibodies, 72 (40%) were antibody positive: 51 (28%) were RNA positive, 13 (7%) had spontaneously cleared and 8 (4%) had been previously treated. Of the 51 that were currently living with HCV, 43 people were started on treatment, 39 have achieved sustained virologic response (SVR). By providing treatment to clients in their homes and with their friends, clinicians have been able to treat clients, including those with limited contact with the health care system.

Timely Hepatitis C RNA Testing and Treatment in the Era of Direct-Acting Antiviral Therapy among People with Hepatitis C in New South Wales, Australia

This study aimed to identify the factors associated with timely (within four weeks) HCV RNA testing and timely (within six months) DAA initiation following HCV notification in the DAA era. We conducted a cohort study of people with an HCV notification in NSW, Australia. Notifications of positive HCV serology were linked to administrative datasets. Weights were applied to account for spontaneous clearance. Logistic regression analyses were performed. Among 5582 people with an HCV notification during 2016–2017, 3867 (69%) were tested for HCV RNA, including 2770 (50%) who received timely testing. Among an estimated 3925 people with chronic HCV infection, 2372 (60%) initiated DAA therapy, including 1370 (35%) who received timely treatment. Factors associated with timely HCV RNA testing included age (≥30 years), female sex, non-Aboriginal ethnicity, country of birth being Australia, and no history of drug dependence. Factors associated with timely treatment were age (≥30 years), male sex, non-Aboriginal ethnicity, country of birth being Australia, no history of drug dependence, and HCV/HIV co-infection. In the DAA era, 50% of people with an HCV notification did not receive timely HCV RNA testing. Most people with an HCV infection received therapy; however, DAA initiation was delayed among many.

Economic evaluation of pan-genotypic generic direct-acting antiviral regimens for treatment of chronic hepatitis C in Iran: a cost-effectiveness study

INTRODUCTION

Low-cost generic direct-acting antiviral (DAA) regimens for treatment of hepatitis C virus (HCV) are available in several low-income/middle-income countries, important for treatment scale-up. This study evaluated the cost-effectiveness of genotype-dependent and pan-genotypic DAA regimens in Iran as an example of a resource-limited setting.

METHODS

A Markov model was developed to simulate HCV natural history. A decision tree was developed for HCV treatment, assuming four scenarios, including scenario 1: genotyping, sofosbuvir/ledipasvir (SOF/LDV) for genotype 1, and sofosbuvir/daclatasvir (SOF/DCV) for genotype 3; scenario 2: genotyping, SOF/LDV for genotype 1, and sofosbuvir/velpatasvir (SOF/VEL) for genotype 3; scenario 3: no genotyping and SOF/DCV for all; and scenario 4: no genotyping and SOF/VEL for all. A 1-year cycle length was used to calculate the cumulative cost and effectiveness over a lifetime time horizon. We calculated quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER) using a health system perspective. Costs were converted to US dollars using purchasing power parity exchange rate ($PPP). All costs and outcomes were discounted at an annual rate of 3%.

RESULTS

Among people with no cirrhosis, scenario 3 had the minimum cost, compared with which scenario 4 was cost-effective with an ICER of 4583 $PPP per QALY (willingness-to-pay threshold: 9,311 $PPP per QALY). Among both people with compensated or decompensated cirrhosis, scenario 4 was cost saving. In sensitivity analysis, scenario 4 would be also cost-saving among people with no cirrhosis provided a 39% reduction in the cost of 12 weeks SOF/VEL.

CONCLUSION

Initiating all patients on pan-genotypic generic DAA regimens with no pretreatment genotyping was cost-effective compared with scenarios requiring pretreatment HCV genotype tests. Among generic pan-genotypic DAA regimens, SOF/VEL was cost-effective, for people with no cirrhosis and cost-saving for those with cirrhosis.

Exploring hepatitis C virus testing and treatment engagement over time in Melbourne, Australia: a study protocol for a longitudinal cohort study (EC-Experience Cohort study)

INTRODUCTION

The advent of direct acting antiviral therapy for hepatitis C virus (HCV) means the elimination of HCV is possible but requires sustained effort to achieve. Between 2016 and 2019, 44% of those living with HCV were treated in Australia. However, treatment uptake has declined significantly. In Australia, people who inject drugs (PWID) are the population most at risk of HCV acquisition. Eliminating HCV in Australia will require nuanced understanding of the barriers to HCV treatment experienced by PWID and tailored interventions to address these barriers. The EC-Experience Cohort study aims to explore the barriers and enablers reported by PWID to engagement in HCV care.

METHODS AND ANALYSIS

The EC-Experience Cohort study is a prospective cohort of PWID, established in Melbourne, Australia in 2018. Participants are assigned into three study groups: (1) those not currently engaged in HCV testing; (2) those diagnosed with HCV but not currently engaged in treatment and (3) those completed treatment. Participants complete a total of four interviews every 6 months across an 18-month study period. Predictors of experience of key outcome events along the HCV care cascade will be explored over time.

ETHICS AND DISSEMINATION

Ethical approval for the EC-Experience Cohort study was obtained by the Alfred Hospital Ethics Committee in Melbourne, Australia (Project Number: HREC/16/Alfred/164). All eligible participants are assessed for capacity to consent and partake in a thorough informed consent process. Results from the EC-Experience Cohort study will be disseminated via national and international scientific and public health conferences and peer-reviewed journal publications. Data from the EC-Experience Cohort study will improve the current understanding of the barriers to HCV care for PWID and guide the tailoring of service provision for specific subgroups. Understanding the barriers and how to increase engagement in care of PWID is critical to achieve HCV elimination goals.

Anti-HCV antibody titer highly predicts HCV viremia in patients with hepatitis B virus dual-infection

BACKGROUND/AIMS

Hepatitis C Virus (HCV) infection is diagnosed by the presence of antibody to HCV and/or HCV RNA. This study aimed to evaluate the accuracy of anti-HCV titer (S/CO ratio) in predicting HCV viremia in patients with or without hepatitis B virus (HBV) dual infection.

METHODS

Anti-HCV seropositive patients who were treatment-naïve consecutively enrolled. Anti-HCV antibodies were detected using a commercially chemiluminescent microparticle immunoassay. HCV RNA was detected by real-time PCR method.

RESULTS

A total of 1321 including1196 mono-infected and 125 HBV dually infected patients were analyzed. The best cut-off value of anti-HCV titer in predicting HCV viremia was 9.95 (AUROC 0.99, P<0.0001). Of the entire cohort, the anti-HCV cut-off value of 10 provided the best accuracy, 96.8%, with the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 96.3%, 98.9%, 99.7% and 87.3% respectively. The best cut-off value of anti-HCV titer in predicting HCV viremia was 9.95 (AUROC 0.99, P<0.0001) and 9.36 (AUROC 1.00, P<0.0001) in patients with HCV mono-infection and HBV dual-infection respectively. Among the HBV dually infected patients, the accuracy of anti-HCV titer in predicting HCV viremia reached up to 100% with the cut-off value of 9. All the patients were HCV-viremic if their anti-HCV titer was greater than 9 (PPV 100%). On the other hand, all the patients were HCV non-viremic if their anti-HCV titer was less than 9 (NPV 100%).

CONCLUSIONS

Anti-HCV titer strongly predicted HCV viremia. This excellent performance could be generalized to either HCV mono-infected or HBV dually infected patients.

Implementing opt-out hepatitis C virus (HCV) screening in Canadian provincial prisons: A model-based cost-effectiveness analysis

BACKGROUND

Implementing opt-out hepatitis C virus (HCV) screening across Canadian provincial prisons is crucial to achieving micro-elimination. Given short incarceration lengths, the most cost-effective screening strategy remains unknown. We compared the cost-effectiveness of current standard of care (venipuncture-based HCV-antibody+HCV RNA) and 13 alternative strategies in Quebec's largest provincial prison.

METHODS

A prison cohort was simulated with a Markov micro-simulation model. Strategies differed in the biomarkers, sampling methods, and number of tests used. The model considered incarceration lengths, time to linkage to care (LTC), nursing costs, and tests' costs, performances, acceptability and turnaround times. Outcomes included costs (Canadian dollars, CAD$), number of true positives linked to care, and incremental cost-effectiveness ratios (ICERs, additional $/additional TP-L). A one-year time horizon and health-payer perspective were adopted.

RESULTS

Across all analyses, three strategies consistently provided the best value for money: venipuncture-based HCV-antibody+HCV-core antigen, venipuncture-based HCV-core antigen (base-case ICER=~ $720), and point-of-care HCV-antibody+HCV RNA (base-case ICER=$4,310). However, these strategies linked only 23%-29% viremic individuals to care. Main drivers of cost-effectiveness were the seroprevalence, proportion viremic, and time to LTC.

CONCLUSION

Alternative strategies would be more cost-effective than standard of care for implementing opt-out screening in provincial prisons. However, interventions to maximize LTC should be explored.