Assessment of the Visual Analogue Score in the Evaluation of the Pruritus Of Cholestasis

Background and Aims: A visual analogue score (VAS), based on application of a visual analogue scale, has been widely used to assess pruritus in clinical studies of patients with cholestatic liver disease. A VAS is a numerical score of the severity of the perception of pruritus, and, hence, is inherently subjective. The objective of this study was to assess the reliability of a VAS as an index of pruritus in cholestatic patients. Methods: In 8 patients with chronic pruritus due to primary biliary cholangitis, values for a VAS of pruritus were compared with corresponding measurements of scratching activity, which were generated by a monitoring system specifically designed to quantitate this activity. The relationship between individual values for the VAS and corresponding values for scratching activity during a specific interval immediately preceding the recording of the VAS was examined by determining the Spearman\u27s rank correlation coefficient. Results: The mean Spearman\u27s rank correlation coefficient between individual values for the VAS and corresponding mean values for scratching activity was 0.072; the range of these coefficients was -0.04 to 0.26. A VAS of pruritus is an unreliable index of scratching activity, and, hence, of the pathophysiological process responsible for the pruritus of cholestasis. Conclusions: It is concluded that the use of a VAS as a primary quantitative endpoint in trials of the efficacy of potential therapies for the pruritus of cholestasis may be inappropriate

The Pruritus of Cholestasis: From Bile Acids to Opiate Agonists: Relevant After all These Years

The pruritus of cholestasis is a maddening complication of liver disease. Increased opioidergic tone contributes to the pruritus of cholestasis, as evidenced by the amelioration of the symptom by opiate antagonists. Obeticholic acid, an agonist of the farnesoid receptor, has been approved for the treatment of primary biliary cholangitis, a disease characterized by cholestasis; this drug is associated with pruritus, the cause of which is unknown. In animal models, bile acids, which accumulate in the body as a result of cholestasis, have been reported to cause scratching behavior mediated by the TGR5 receptor, in an opioid-dependent manner, in laboratory animals. As obeticholic acid also binds to TGR5, the pruritus caused by this drug is likely to be mediated by the opioid system. Lisophosphatidic acid, which has been reported to be increased in patients with cholestasis and pruritus, has been described to cause scratching behavior that is prevented by an opiate antagonist in laboratory animals, suggesting an opioid-receptor mediated mechanism of scratching. In summary, evidence continues to support a role of the endogenous opioid system in the pathogenesis of the pruritus of cholestasis

Lysophosphatidic acid and atotaxin in patients with cholestasis and pruritus: Fine biology, anticipated discernment

Article commented: Kremer AE, Martens JJ, Kulik W, Rueff F, Kui-per EM, van Buuren HR, van Erpecum KJ, Kon-drackiene J, Prieto J, Rust C, Geenes VL, Williamson C, Moolenaar WH, Beuers U, Oude El-ferink RP. Lysophosphatidic acid is a potential mediator of cholestatic pruritus. Gastroenterology 2010; 139:1008-18. Original Abstract: Background &amp; aims. Pruritus is a common and disabling symptom in cholestatic disorders. However, its causes remain unknown. We hypothesized that potential pruritogens accumulate in the circulation of cholestatic patients and activate sensory neurons. Methods. Cytosolic free calcium ([Ca(2+)] (i)) was measured in neuronal cell lines by ratiometric fluorometry upon exposure to serum samples from pruritic patients with intrahepatic cholestasis of pregnancy (ICP), primary biliary cirrhosis (PBC), other cholestatic disorders, and pregnant, healthy, and nonpruritic disease controls. Putative [Ca(2+)] (i)-inducing factors in pruritic serum were explored by analytical techniques, including quantification by high-performance liquid chromatography/mass spectroscopy. In mice, scratch activity after intradermal pruritogen injection was quantified using a magnetic device. Results. Transient increases in neuronal [Ca(2+)] (i) induced by pruritic PBC and ICP sera were higher than corresponding controls. Lysophosphatidic acid (LPA) could be identified as a major [Ca(2+)] (i) agonist in pruritic sera, and LPA concentrations were increased in cholestatic patients with pruritus. LPA injected intradermally into mice induced scratch responses. Autotaxin, the serum enzyme converting lysophosphatidylcholine into LPA, was markedly increased in patients with ICP vs. pregnant controls (P < 0.0001) and cholestatic patients with vs. without pruritus (P < 0.0001). Autotaxin activity correlated with intensity of pruritus (P < 0.0001), which was not the case for serum bile salts, histamine, tryptase, substance P, or mu-opioids. In patients with PBC who underwent temporary nasobiliary drainage, both itch intensity and autotaxin activity markedly decreased during drainage and returned to preexistent levels after drain removal. Conclusions. We suggest that LPA and autotaxin play a critical role in cholesta-tic pruritus and may serve as potential targets for future therapeutic interventions

Elevated Serum Alkaline Phosphatase · Generalized Pruritus · Dx?

A 34-year-old woman was referred to the hepatology clinic for evaluation of an increased serum alkaline phosphatase (ALP) level. She was gravida 5 and in her 38th week of gestation. Her obstetric history was significant for 2 uncomplicated spontaneous term vaginal deliveries resulting in live births and 2 spontaneous abortions. The patient reported generalized pruritus for 2 months prior to the visit. She had no comorbidities and denied any other symptoms. She reported no family history of liver disease or complications during pregnancy in relatives. The patient did not smoke or drink, and had come to our hospital for her prenatal care visits. The physical exam revealed normal vital signs, no jaundice, a gravid uterus, and acanthosis nigricans on the neck and axilla with scattered excoriations on the arms, legs, and abdomen. Her serum ALP level was 1093 U/L (normal: 50-136 U/L). Immediately before this pregnancy, her serum ALP had been normal at 95 U/L, but it had since been increasing with a peak value of 1134 U/L by 37 weeks\u27 gestation. Serum transaminase activities and albumin and bilirubin concentrations were normal, as was her prothrombin time. The rest of her lab tests were also normal, including her fasting serum bile acid concentration, which was 9 mcmol/L (normal: 4.5-19.2 mcmol/L)

Serum concentrations of substance P in cholestasis

Substance P (SP) is an excitatory neuropeptide that acts via the neurokinin-I receptor (NK-1) in the nervous system. Pruritus, a complication of cholestasis, is a nociceptive stimulus; thus, we hypothesized that cholestasis would be associated with increased neurotransmission via SP as evidenced, in part, by increased serum concentrations of this neuropeptide. Accordingly, the aim of this study was to determine the serum concentration of SP in patients with pruritus secondary to cholestasis and in the serum of rats with cholestasis secondary to bile duct resection (BDR). The mean serum SP concentration of patients with chronic liver disease (CLD) and pruritus was 9.09 pg/mL SD ± 6.5, significantly higher than 0.74 pg/mL SD ± 0.77, the mean serum concentration of SP from patients with CLD without pruritus (p = 0.0001), and from that of the control group, which was 0.65 pg/mL SD ± 0.37 (p = 0.0001). The mean serum SP concentration from six rats with cholestasis secondary to BDR six and fourteen days after surgery was 57.9 pg/mL, SD ± 17.3, and 56.3 pg/mL, SD ± 21.4, respectively, as compared to the concentration from the sham resected control group, which was 3.5 pg/mL SD ± 0.59 (p = 0.002) at six days post surgery. In conclusion, in choles-tasis, there is increased availability of SP. These data provide a rationale for the study of SP release and metabolism in cholestasis, and in the mediation of the pruritus

Evolving Concepts of the Pathogenesis and Treatment of the Pruritus of Cholestasis

The site of the pathogenic events responsible for initiating the pruritus of cholestasis has been assumed to be the skin. This assumption cannot be excluded but is not supported by convincing data. Empirical therapies such as anion exchange resins and rifampicin often appear to be partially efficacious. Recent evidence suggests that altered neurotransmission in the brain may contribute to this form of pruritus. In particular, the hypothesis that increased central opioidergic tone is involved is supported by three observations: opiate agonists induce opioid receptor-mediated scratching activity of central origin, central opioidergic tone is increased in cholestasis and opiate antagonists reduce scratching activity in cholestatic patients. Apparent subjective ameliorations of pruritus following intravenous administration of ondansetron to cholestatic patients suggest that altered serotoninergic neurotransmission may also contribute to this form of pruritus