PIVKA­II is associated with liver function, bone metabolism, and muscle function in patients with liver disease.

Protein induced by vitamin K (VK) absence-II (PIVKA-II) is a sensitive marker for diagnosing hepatoma but is occasionally detected in patients without hepatoma Here, the clinical significance of serum PIVKA-II levels in patients who were not administered warfarin and did not have hepatoma or liver disease were evaluated. As VK is related to muscle and bone metabolism, PIVKA-II and clinical factors related to bone and muscle were compared. A total of 441 patients with various liver diseases were evaluated. Of these, 236 patients were female. Clinical factors and anthropometric measurements were obtained for each participant during outpatient visits. Among the clinical factors, type I procollagen N-propeptide (P1NP), a low titer of undercarboxylated osteocalcin (ucOC), and 25(OH) vitamin D (VD) were used as bone metabolic markers, and SARC-F and grip strength were used as muscle-related markers. Serum PIVKA-II levels above the upper limit were associated with Child B/C (Child-Pugh score), high titers of total P1NP, and low titers of ucOC in females, and alcohol-related liver disease and low VD in males. The titer of PIVKA-II were associated with immunoglobulin (Ig) A and prothrombin time (PT)-international normalized ratio (INR) in females, and fibrosis-4-4, IgG, total bilirubin, PT-INR, and SARC-F in males. Elevated PIVKA-II levels were associated with abnormal bone physiology in females, weak muscles in males, and severe liver disease in both sexes. Assessing PIVKA-II may assist in evaluating the clinical and bone-muscle metabolic stages in liver disease. Nutrition and supplementation with fat-soluble vitamins, including VK and VD may thus serve as a potential method to alleviate or prevent bone-muscle pathophysiology in patients with liver disease.

Direct­acting antiviral treatment decreases serum undercarboxylated osteocalcin in male patients with chronic hepatitis C.

Hepatic osteodystrophy (HOD) is a common complication of chronic liver disease, including viral hepatitis. Hepatitis C virus (HCV) infection is associated with an increased risk of osteoporosis and bone mineral density (BMD) loss. Direct-acting antiviral (DAA) treatment is used to treat HCV infections; however, its effects on bone metabolism have not been reported. We compared the clinical data and bone metabolic markers at the start of DAA treatment and 1 year later in 78 patients. There were 41 female and 37 male patients. HCV was successfully treated with DAA in all patients. Bone metabolic markers included undercarboxylated osteocalcin (ucOC), 25(OH) vitamin D (VD), total type I procollagen N-propeptide (P1NP), tartrate-resistant acid phosphatase 5b (TRACP-5b), and BMD. BMD was measured in the lumbar spine (mean, L2-L4) and femoral neck using dual-energy X-ray absorptiometry. ucOC in males decreased at 1 year after treatment initiation but not in females. In males, ucOC changes were related to alterations in proteins induced by vitamin K absence-II (PIVKA-II), hemoglobin A1c, and TRACP-5b, which contributed to P1NP and lumbar BMD at the start of DAA. Changes in ucOC among women contributed to the changes in grip strength and TRACP-5b levels. DAA treatment improved ucOC, a useful bone metabolic marker, in HCV-infected male patients. Changes in ucOC contributed to changes in PIVKA-II that likely ameliorated the vitamin K deficiency. DAA treatment has been reported to improve various extrahepatic disorders and abnormal bone metabolism, especially in HOD.

Change in tartrate-resistant acid phosphatase isoform 5b levels, a marker of bone metabolism, in patients with chronic hepatitis B treated with tenofovir alafenamide.

Hepatitis B virus (HBV) infection is associated with the risk of osteoporosis and bone mineral density (BMD) loss. Tenofovir alafenamide (TAF) is associated with a slightly lower degree of BMD loss compared with tenofovir disoproxil, without loss of the excellent anti-HBV effects. The aim of the present study was to verify the effect of bone metabolism in patients with HBV treated with TAF. A total of 87 patients were treated with TAF. Of these, 32 patients were treatment naïve, and 55 patients were treated with entecavir (ETV) for at least 1 year, after which ETV was switched to TAF. At the start of TAF and after 1 year, BMD in the lumbar and neck of the femur, tartrate-resistant acid phosphatase isoform 5b (TRACP-5b) levels as a marker of bone metabolism and serum inorganic phosphorus (P) were compared to estimate bone metabolism. Serum creatinine (Cr), cystatin C, urine protein and ß2 microglobulin levels were evaluated to estimate kidney function. Treatment with TAF for 1 year decreased TRACP-5b levels, particularly in patients with bone disease, except for a minimal significant change (MSC; decrease of 12.4%) in TRACP-5b levels. The change in rate of TRACP-5b levels were positively associated with changes in P, Cr-estimated glomerular filtration rate and TRACP-5b levels at the start of TAF. Logistic regression analysis showed that increased BMD in the lumbar region contributed to the switch from ETV to TAF. TAF induced a decrease in TRACP-5b levels in patients with HBV. Bone disease was a contributing factor for MSC. Since TRACP-5b can be used as a marker of bone metabolism and fractures, TAF may exhibit potential in preventing fractures in patients with HBV.