Cost and cost-effectiveness of a simplified treatment model with direct-acting antivirals for chronic hepatitis C in Cambodia

BACKGROUND & AIMS

In 2016, Médecins Sans Frontières established the first general population Hepatitis C virus (HCV) screening and treatment site in Cambodia, offering free direct-acting antiviral (DAA) treatment. This study analysed the cost-effectiveness of this intervention.

METHODS

Costs, quality adjusted life years (QALYs) and cost-effectiveness of the intervention were projected with a Markov model over a lifetime horizon, discounted at 3%/year. Patient-level resource-use and outcome data, treatment costs, costs of HCV-related healthcare and EQ-5D-5L health states were collected from an observational cohort study evaluating the effectiveness of DAA treatment under full and simplified models of care compared to no treatment; other model parameters were derived from literature. Incremental cost-effectiveness ratios (cost/QALY gained) were compared to an opportunity cost-based willingness-to-pay threshold for Cambodia ($248/QALY).

RESULTS

The total cost of testing and treatment per patient for the full model of care was $925(IQR $668-1631), reducing to $376(IQR $344-422) for the simplified model of care. EQ-5D-5L values varied by fibrosis stage: decompensated cirrhosis had the lowest value, values increased during and following treatment. The simplified model of care was cost saving compared to no treatment, while the full model of care, although cost-effective compared to no treatment ($187/QALY), cost an additional $14 485/QALY compared to the simplified model, above the willingness-to-pay threshold for Cambodia. This result is robust to variation in parameters.

CONCLUSIONS

The simplified model of care was cost saving compared to no treatment, emphasizing the importance of simplifying pathways of care for improving access to HCV treatment in low-resource settings.

Localisation of 26S proteasomes with different subunit composition in insect muscles undergoing programmed cell death

The 26S proteasome is a large multisubunit complex involved in degrading both cytoplasmic and nuclear proteins. We have investigated the subcellular distribution of four regulatory ATPase subunits (S6 (TBP7/MS73), S6' (TBP1), S7 (MSS1), and S10b (SUG2)) together with components of 20S proteasomes in the intersegmental muscles (ISM) of Manduca sexta during developmentally programmed cell death (PCD). Immunogold electron microscopy shows that S6 is located in the heterochromatic part of nuclei of ISM fibres. S6' is present in degraded material only outside intact fibres. S7 can be detected in nuclei, cytoplasm and also in degraded material. S10b, on the other hand, is initially found in nuclei and subsequently in degraded cytoplasmic locations during PCD. 20S proteasomes are present in all areas where ATPase subunits are detected, consistent with the presence of intact 26S proteasomes. These results are discussed in terms of heterogeneity of 26S proteasomes, 26S proteasome disassembly and the possible role of ATPases in non-proteasome complexes in the process of PCD. Cell Death and Differentiation (2000) 7, 1210 - 1217.

A 220-kDa activator complex of the 26 S proteasome in insects and humans. A role in type II programmed insect muscle cell death and cross-activation of proteasomes from different species

The S10b (SUG2) ATPase cDNA has been cloned by reverse transcription-polymerase chain reaction/rapid amplification of cDNA ends from mRNA of intersegmental muscles of the tobacco horn moth (Manduca sexta). The S10b ATPase is a component of the 26 S proteasome, and its concentration and that of its mRNA increase dramatically during development in a manner similar to other ATPases of the 19 S regulator of the 26 S proteasome. The S10b and S6' (TBP1) ATPases are also present in a complex of approximately 220 kDa in intersegmental muscles. The 220-kDa complex markedly activates (2-10-fold) the 26 S proteasome, even when bound to anti-S10b antibodies immobilized on Sepharose, and increases in concentration approximately 5-fold like the 26 S proteasome in the intersegmental muscles in preparation for the programmed death of the muscle cells. A similar activator complex is present in human brain and placenta. Free activator complexes cross-activate: the Manduca complex activates rat skeletal muscle 26 S proteasomes, and the placental complex activates Manduca 26 S proteasomes. The placental activator complex contains S10b and S6', but not p27. This 220-kDa activator complex has been evolutionarily conserved between species from insect to man and may have a fundamental role in proteasome regulation.

The comparative fine structure of the interhemal membrane of chorioallantoic placentas from six genera of myomorph rodents

In order to extend the cytological information available on the structure of the interhemal membrane in cricetid rodents, in particular, and myomorph rodents, in general, we have examined the fine structure of the placental labyrinth in five genera of cricetid rodents (Lemmus, Dicrostonyx, Clethrionomys, Microtus and Peromyscus) and one genus of murid rodent (Acomys). Small pieces of labyrinth from near-term placentas were fixed in glutaraldehyde and osmium tetroxide and processed for electron microscopy. The interhemal membranes of all the species examined were hemotrichorial. The outermost layer of trophoblast, bordering the maternal blood spaces, was cellular and often contained some patent fenestrae, whereas the middle and linner trophoblastic layers were apparently syncytial. The outermost trophoblastic layer of all the species contained abundant granular endoplasmic reticulum. The intercellular space between the outer and middle layers was variable in width, primarily due to the complex folding of the surface of the middle layer. The surfaces of the middle and inner layers were closely apposed. The middle trophoblastic layer in several species contained filamentous "glomerular bodies" and the innermost layer, particularly of Peromyscus, contained smooth membranous whorls. A basal lamina separated the innermost trophoblastic layer from the fetal capillary endothelium. The endothelial cells in most of the species contained fenestrated regions. These observations are compared to those on other hemochorial placentas, and common features of cricetid (and myomorph) rodent placental find structure are emphasized.

Junctional complexes in the preimplantation rabbit embryo

The morphology and development of junctional complexes between blastomeres of the preimplantation rabbit embryo were investigated using several approaches. Electron microscopic examination of embryos stained en bloc with uranyl acetate, and the study of junction permeability using horseradish peroxidase and lanthanum nitrate provided information on structure, intermembrane spacing and permeability of the junctional complexes. In addition, the freeze fracture technique was used with day 5 and day 6 blastocysts, since the large size of these embryos facilitated use of this method. These experiments showed that although rudimentary junctions were present between blastomeres of the early cleavage stages, effective tight junctions were not present until the blastocyst stage. Electron microscopic examination of thin sections revealed apical foci of membrane approximation or "fusion" between trophoblast cells by day 4. Freeze fracturing revealed a lattice of interconnecting ridges (on the A face) and grooves (on the B face) in the apical region between trophoblast cells of the day 5 blastocyst. This lattice formed a continuous band along the apical margin of each cell, and therefore constituted a zonula occludens. The zonula occludens of the day 5 blastocyst averages 2-3 ridges per lattice, while day 6 blastocysts had lattices that averaged 5-6 ridges. Also seen in the freeze fracture replicas from the day 5 and day 6 blastocysts were local accumulations of intramembranous particles on the A face. These particles were often observed in aggregates similar to those of previously described gap junctions. It could not be determined whether these small regions of particles were true gap junctions or a possible primitive form of gap junction because the complementary pitted surfaces (B face pits) were not demonstrated.