Effects of Pegylated Interferon/Ribavirin on Bone Turnover Markers in HIV/Hepatitis C Virus-Coinfected Patients

Osteoporosis Remains Constant in Patients with Hemophilia-Long-Term Course in Consideration of Comorbidities

INTRODUCTION

 Patients with hemophilia (PWHs) suffer from an increased risk of osteoporosis. Multiple hemophilia and hemophilic arthropathy associated factors correlate with a low bone mineral density (BMD) in PWHs. The aim of this study was to assess the long-term development of BMD in PWH as well as to analyze potentially influencing factors.

METHODS

 A total of 33 adult PWHs were evaluated in a retrospective study. General medical history, specific-hemophilia-associated comorbidities, joint status using the Gilbert score, calcium level, and vitamin D level as well as at least two results of bone density measurements with a minimum range of 10 years per patient were taken into account.

RESULTS

 The BMD did not change significantly from one point of measurement to the other. A total of 7 (21.2%) cases of osteoporosis and 16 (48.5%) cases of osteopenia were identified. The two following significant correlations could be revealed: the higher the patients' body mass index, the higher their BMD (r = 0.41; p = 0.022). Moreover, a high Gilbert score came along with a low BMD (r = -0.546; p = 0.003).

CONCLUSION

 Even if PWHs frequently suffer from a reduced BMD, our data suggest that their BMD remains constant on a low level in the course of time. A risk factor of osteoporosis often found in PWHs is a vitamin D deficiency and joint destruction. Therefore, a standardized screening of PWHs on BMD reduction by collecting vitamin D blood level and assessing joint status seems appropriate.

Veterans Aging Cohort Study Index as a Marker of Bone Disease in HIV-Infected Patients

People living with human immunodeficiency virus (HIV) infection have higher risk of low bone mineral density (BMD) and fragility fracture than general population. The aim of our retrospective study was to explore if HIV-specific Veterans Aging Cohort Study (VACS) Index and its specific components could help identify patients at risk for low BMD. A total of 195 HIV-infected patients with dual-energy X-ray absorptiometry (DXA) scan between 2007 and 2014 were included and DXA scan results were used to classify patients with osteopenia. VACS Index was calculated for all patients using laboratory values closest to the date of DXA scan. Logistic regression was used to assess the association between VACS Index score or individual components of VACS Index with the presence of low BMD after adjusting for confounding variables. A total of 109 (56%) patients were diagnosed with low BMD. VACS Index score was significantly associated with low BMD, with the odds of low BMD increasing 1.21 times for each 10 unit increase in VACS Index score [confidence interval (95% CI) 1.03-1.42; p = .02]. The two groups differed significantly on patient weights, proportion of white patients, and hepatitis C-coinfected patients. After adjusting for white race and weight, hepatitis C coinfection was significantly associated with increased risk of low BMD (odds ratio 24.4; 95% CI 7.45-80.16). VACS Index score, previously demonstrated to be a marker of frailty in HIV-infected patients, is significantly associated with risk of low BMD and could be used to develop a prediction tool to screen for low BMD in resource-limited setting where DXA scans are not easily available.

Bone health in HIV and hepatitis B or C infections

Chronic infections with human immunodeficiency virus (HIV), hepatitis B virus (HBV) or hepatitis C virus (HCV) add to age-dependent bone loss and may contribute to lower bone strength in the elderly. In this review, we report recent highlights on the epidemiology of bone fragility in chronic viral infections with HIV, HCV and HBV, its physiopathology and discuss the interference of antiviral therapies with bone metabolism. Chronic infections influence bone through the interactions between risk factors for bone fragility and falls (which are highly prevalent in infected patients), virus activity and antiviral drugs. HIV-infected patients are at increased risk of fracture and the risk is higher in cases of co-infection with HIV and untreated chronic viral hepatitis. In HIV patients, the majority of bone loss occurs during virus activity and at initiation of antiretroviral therapy (ART). However, long-term elderly HIV-infected patients on successful ART display bone microstructure alterations only partially captured by dual energy X-ray absorptiometry (DXA). Bone loss is associated with an increase of bone resorption, reflecting the upregulation of the receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) pathways via a crosstalk between virus activity, inflammation and the immune system. The use of some antiviral drugs, such as tenofovir (controlling both HBV and HIV infections) or protease inhibitors, may be associated with higher bone toxicity. The reduction of tenofovir plasma concentrations with the implementation of tenofovir alafenamide (TAF) attenuates bone mineral density (BMD) loss but it remains unknown whether it will contribute to reducing fracture risk in long-term HIV-treated patients. Moreover, to what extent the new direct-acting agents for treatment of HCV, including nucleotide inhibitors and protease inhibitors, may affect bone health similarly as ART in HIV should be investigated.

Hepatitis C virus coinfection as a risk factor for osteoporosis and fracture

PURPOSE OF REVIEW

With increased survival of HIV-infected patients, osteoporotic fractures have developed as a major cause of morbidity in these patients, and chronic hepatitis C virus (HCV) coinfection has emerged as a significant contributor to this increased fracture risk. The present article reviews the epidemiologic and clinical evidence for osteoporosis and increased fracture risk among HIV/HCV coinfected patients, and potential mechanisms for these outcomes with HCV coinfection.

RECENT FINDINGS

Epidemiologic studies suggest that HIV/HCV coinfected patients exhibit a three-fold increased fracture incidence compared with uninfected controls, and 1.2-2.4-fold increased fracture risk compared with HIV monoinfected patients. Recent reports suggest that chronic HCV coinfection is independently associated with reduced bone mineral density in HIV, but that it is not associated with significantly increased bone turnover. The deleterious impact of chronic HCV on BMD and fracture risk occurs even in the absence of advanced liver fibrosis or cirrhosis. New tools to assess bone quality, including the trabecular bone score, high-resolution peripheral quantitative computed tomography, and in-vivo microindentation, may help improve understanding of the mechanisms of HCV-associated skeletal fragility. The impact of approved antiosteoporosis medications and direct-acting antivirals for the treatment of chronic HCV infection on patients' bone health remain to be studied.

SUMMARY

Chronic HCV infection is an independent risk factor for osteoporosis and fractures among HIV-infected patients, even before the development of cirrhosis. The underlying mechanisms are being unraveled, but major questions persist regarding the optimal evaluation and management of bone health in HIV/HCV coinfected patients.