Although digital clubbing is not a specific sign for HPS, its occurrence AZD2014 price with hypoxia in a patient with liver disease is suggestive of HPS. Platypnea (dyspnea exacerbated when sitting up and improved when lying down) and orthodeoxia are both described and occur because of worsening ventilation-perfusion matching and an increase in shunt fraction in the upright position secondary to increased perfusion of lower lobes. The diagnosis of HPS is made by demonstrating hypoxemia and evidence of pulmonary shunting. Chest CT findings include distal vascular dilatation associated with an abnormally large number of visible terminal vessel branches concentrated
in the lower zones.6 An increased ratio of the segmental arterial diameter to the adjacent bronchial diameter has also been described in patients with HPS when compared to patients with normoxemic cirrhosis.6 The appearance of microbubbles in the left heart three-six cardiac cycles after JQ1 ic50 contrast enters the right heart is diagnostic of pulmonary shunting. Technetium-99–labeled macroaggregated albumin can also be used, and is diagnostic of HPS with appearance of technetium in the brain
or spleen. Treatments for HPS remain limited. Patients usually require long-term home oxygen therapy. The benefit of coil embolization of pulmonary shunts remains unproven. The mainstay of treatment has been LT with reported 5-year survival rates of 76% versus 23% for those who did not undergo LT,7 but it may take months for an improvement in hypoxemia and shunt fraction. HPS is an underdiagnosed but important complication of chronic liver disease. Clinical clues, such as hypoxemia and clubbing, should prompt a diagnostic assessment for HPS, and when diagnosed, the patient should be considered
for potential LT. “
“Genetic variation upstream of the interleukin-28B (IL-28B) gene is critical for the outcome of therapy for hepatitis C,1 and geographic variation in the frequencies of IL-28B–related single-nucleotide polymorphism (SNP) genotypes may explain racial differences in treatment outcomes, such as the poor response among African Protein kinase N1 Americans, in whom the favorable CC genotype at the rs12979860 SNP is less prevalent.1 IL-28B SNPs also influence the rate of spontaneous resolution of hepatitis C virus (HCV) infection; this is reflected by the finding that the CCrs12979860 genotype is more common in subjects with resolved infection versus patients with chronic hepatitis.2 As a result, patients with chronic HCV infection show lower rates of the CC genotype than uninfected subjects.3 In agreement with these findings, Montes-Cano et al.4 recently reported that the CCrs12979860 genotype was more frequent in individuals who cleared an acute HCV infection. These authors also, as expected, found the CC genotype more rarely in patients with chronic HCV infection (39%) versus uninfected subjects (45%).