Thrombopoietin serum levels are elevated in patients with hepatitis B/C infection compared to other causes of chronic liver disease

Extremity risk factors of sepsis for gastrointestinal endoscopy in patients with liver cirrhosis

BACKGROUND

Liver cirrhosis is a well-known risk factor of sepsis after emergent gastrointestinal (GI) endoscopy. Elective GI endoscopy before living donor liver transplantation (LDLT), however, may also carry the septic risk among these patients.

METHODS

This retrospective study reviewed the medical records of 642 cirrhotic recipients who underwent GI endoscopy from 2008 to 2016. We analyzed the incidence and risk factors of post-endoscopy sepsis during 2008-2012 (experience cohort). Our protocol changed after 2013 (validation cohort) to include antibiotic prophylaxis.

RESULTS

In experience cohort, 36 cases (10.5%) of the 342 LDLT candidates experienced sepsis within 48 h after endoscopy. The sepsis rate was significantly higher in patients with hepatic decompensation than patients without (22.2% vs. 9.6% vs. 2.6% in Child C/B/A groups respectively; ×2 = 20.97, P < 0.001). Using multivariate logistic regression analysis, the factors related to post-endoscopy sepsis were the Child score (OR 1.46; 95% CI 1.24-1.71), Child classes B and C (OR 3.80 and 14.13; 95% CI 1.04-13.95 and 3.97-50.23, respectively), hepatic hydrothorax (OR 4.85; 95% CI 1.37-17.20), and use of antibiotic prophylaxis (OR 0.08; 95% CI 0.01-0.64). In validation cohort, antibiotics were given routinely, and all cases of hepatic hydrothorax (n = 10) were drained. Consequently, 4 (1.3%) episodes of sepsis occurred among 300 LDLT candidates, and the incidence was significantly lower than before (1.3% vs. 10.5%, P < 0.001).

CONCLUSIONS

Patients with decompensated cirrhosis and hepatic hydrothorax have higher risk of sepsis following endoscopy. In advanced cirrhotic patients, antibiotic prophylaxis and drainage of hydrothorax may be required to prevent sepsis before elective GI endoscopy.

Relationship between baseline clinical characteristics and efficacy of lusutrombopag in thrombocytopenic patients with chronic liver disease: post hoc analysis of two placebo-controlled phase 3 trials

OBJECTIVE

Lusutrombopag is a thrombopoietin receptor agonist approved to treat thrombocytopenia in patients with chronic liver disease (CLD). This post hoc analysis of the Japanese L-PLUS 1 and global L-PLUS 2 trials aimed to clarify factors related to platelet count increase after lusutrombopag treatment.

METHODS

In L-PLUS 1, Pearson's correlation coefficients were used to evaluate correlations between platelet count and spleen index, thrombopoietin concentration, white blood cell (WBC) counts, and red blood cell counts (intent-to-treat [ITT] population). Associations between platelet count increase after lusutrombopag treatment and each parameter were assessed by regression analysis and mixed-effect model for repeated measures (MMRM). Associations between time-dependent changes in platelet count increase and each parameter were also examined in the L-PLUS 2 lusutrombopag ITT population by MMRM.

RESULTS

In L-PLUS 1, the baseline platelet count was correlated with pretreatment spleen index (r = -0.23, 95% confidence interval [CI] -0.41 to -0.03) and WBC count (r = 0.26, 95% CI 0.06 to 0.43). No selected parameters were associated with the maximum platelet count increase from baseline. Patients with WBC counts below the normal range showed smaller platelet count increases after lusutrombopag treatment than patients with WBC counts within the normal range (p = .0028). In L-PLUS 2 (p = .0533), findings were similar and confirmed by larger pooled data of L-PLUS 1/L-PLUS 2 (p = .0021).

CONCLUSIONS

This post hoc analysis revealed a possible association between baseline WBC count and platelet count increase after lusutrombopag treatment. WBC count could be a relevant factor for lusutrombopag efficacy.

Is platelet monitoring during 7-day lusutrombopag treatment necessary in chronic liver disease patients with thrombocytopenia undergoing planned invasive procedures? A phase IIIb open-label study

AIM

Lusutrombopag is approved for thrombocytopenia in chronic liver disease patients planned to undergo invasive procedures. In previous clinical studies, lusutrombopag treatment was stopped in patients with an increase in platelet count (PC) of ≥20 × 10⁹ /L from baseline and whose PC was ≥50 × 10⁹ /L (discontinuation criteria). We assessed the influence of platelet monitoring during lusutrombopag treatment in lusutrombopag-naïve patients.

METHODS

In this open-label study, Child-Pugh class A and B (A/B) patients were enrolled and treated with lusutrombopag (3 mg/day) for 7 days. In the treatment-naïve A/B-1 group, the discontinuation criteria were applied on day 6. In the treatment-naïve A/B-2 group, the criteria were not applied. In a non-naïve A/B group, the criteria were applied on days 3 and 5-7. The main efficacy end-point was the proportion of patients without platelet transfusion (PT) before the primary invasive procedure.

RESULTS

In the A/B-1, A/B-2, and non-naïve A/B groups, the proportions of patients without PT were 80.9% (38/47), 83.0% (39/47), and 75.0% (6/8), respectively. The mean durations of PC ≥ 50 × 10⁹ /L without PT were 20.7, 20.3, and 22.8 days, respectively. Excessive PC increases (≥200 × 10⁹ /L) were not detected in any group. Treatment-related adverse events occurred in 4.3%, 6.4%, and 0% of A/B-1, A/B-2, and non-naïve A/B patients, respectively. Severe portal vein thrombosis occurred in one A/B-2 patient (PC 75 × 10⁹ /L at onset).

CONCLUSIONS

No meaningful efficacy and safety differences were observed among the groups with or without discontinuation criteria and the non-naïve group. These findings support lusutrombopag treatment without platelet monitoring and retreatment with lusutrombopag.

Immature platelet fraction and thrombopoietin in patients with liver cirrhosis: A cohort study

BACKGROUND AND AIMS

Thrombocytopenia occurs frequently in patients with cirrhosis. The immature platelet fraction (IPF%) is measured to differentiate the causes of thrombocytopenia. To date the relevance of thrombopoietin (TPO) in the context of cirrhosis is unknown. The aim of our study was to investigate the cause of thrombocytopenia in patients with liver cirrhosis by measuring IPF%, TPO and spleen size. In addition we examined the use of IPF% to evaluate the severity of cirrhosis and its complications.

METHODS

Overall, we included 88 in-patients with cirrhosis in our study. The collected data comprises current health status, blood parameters, severity of cirrhosis evaluated by Child-Pugh score and MELD score, spleen diameter, ascites and esophageal varices. The IPF% was measured using an automatic hematology analyzer. TPO was measured with ELISA.

RESULTS

IPF% (p = 0.003) and spleen diameter (p = 0.001) were significantly higher in patients with thrombocytopenia. There was no significant difference in TPO between patients with and without thrombocytopenia. The mean values of IPF% varied significantly (p = 0.044) in Child-Pugh stages. IPF% was significantly (p = 0.005) elevated in patients with esophageal varices. Moreover, IPF% higher than 3.85% displayed sensitivity of 76.6% and specificity of 52.4% with an area under receiver operating curve characteristics of 0.669 for the presence of esophageal varices.

CONCLUSION

On closer examination of the three compartments known to have an influence on platelet count splenomegaly seems to be the major cause of thrombocytopenia in patients with cirrhosis according to current knowledge. Higher IPF% in patients with thrombocytopenia indicates peripheral consumption of platelets. The relation between spleen diameter and platelet count indicates the spleen to be the major place of platelets' consumption. TPO did not differ between patients with and without thrombocytopenia. Furthermore, we cannot exclude an influence of impaired thrombopoietin synthesis on platelet counts. The association between IPF% and platelet count suggests that there is physiological regulation of platelets in patients with cirrhosis. In our study IPF% is associated with esophageal varices and the stage of cirrhosis. Further studies are needed to confirm these results.

Hepatitis B infection is associated with an increased incidence of thrombocytopenia in healthy adults without cirrhosis

The association between HBV infection and incident thrombocytopenia among subjects without cirrhosis or splenomegaly is unknown. Therefore, we sought to elucidate the association between HBV infection and the development of thrombocytopenia in a large cohort of apparently healthy men and women. A cohort study was performed in 122 200 participants without liver cirrhosis or splenomegaly who underwent comprehensive health examinations and were followed until December 2014. HBV infection was defined by the presence of hepatitis B surface antigen (HBsAg) at baseline. Thrombocytopenia was defined as a platelet count <150 000/μL. Cox proportional hazard models were used to estimate adjusted hazard ratios with 95% confidence intervals (CIs) for incident thrombocytopenia. HBsAg was positive in 4857 of 122 200 subjects (4.0%) at baseline. During 883 983 person-years of follow-up, 2037 incident cases of thrombocytopenia were identified (incident rate 2.3 per 1000 person-years). HBsAg-positive subjects had a higher incidence of thrombocytopenia than did healthy controls (11.2 vs 1.9 per 1000 person-years, respectively). The multivariate-adjusted hazard ratio (95% CI) for incident thrombocytopenia comparing HBsAg-positive to HBsAg-negative subjects was 5.71 (5.10-6.38). Strong associations between HBsAg positivity and thrombocytopenia were consistently observed across prespecified subgroups. In this large cohort study of an apparently healthy population, HBsAg positivity was strongly and independently associated with incident thrombocytopenia, indicating that mechanisms of thrombocytopenia other than portal hypertension may exist in healthy HBV carriers.

Branched-chain amino acid-enriched nutrient increases blood platelet count in patients after endoscopic injection sclerotherapy

AIM

Protein and energy malnutrition is a severe problem for patients with liver cirrhosis (LC) and fasting often induces starvation which is a vitally important outcome. Dietary restriction is essential for endoscopic injection sclerotherapy (EIS) in patients with risky esophageal varices, thereby creating the possible exacerbation of nutritional state and inducing liver dysfunction. Whether EIS induces nutritional deficiency in LC patients and the effects of branched-chain amino acid (BCAA)-enriched nutrient are prospectively investigated.

METHODS

A total of 61 LC patients were randomly divided into an EIS monotherapy group (non-BCAA group, n = 31) and an EIS combined with BCAA therapy group (n = 30). Platelet count, blood chemistry and somatometry values were prospectively measured at five time points.

RESULTS

The platelet counts before treatment were at the same level in both groups (P = 0.72). Three months after treatment, the counts decreased in the non-BCAA group; however, they increased in the BCAA group (P = 0.019). Body mass index, triceps skin fold thickness and arm muscle circumference significantly decreased in both groups. The BCAA and tyrosine ratio value increased only in the BCAA group (P < 0.01). The skeletal muscle volume measured by InBody720 significantly decreased in the non-BCAA group (P < 0.001).

CONCLUSION

EIS induced protein-energy malnutrition, however, skeletal muscle volume was maintained by taking BCAA. Administration of BCAA had some effect in maintaining the nutritional state, and may improve the platelet count. Taking a greater amount of nutrients and shorter dietary restriction period or hospitalization was desirable.

Determinants of platelet count are different in patients with compensated and decompensated cirrhosis

BACKGROUND & AIMS

Different mechanisms including portal hypertension and hypersplenism have been involved in the development of thrombocytopenia in cirrhosis. However, the relative contribution of each one is unknown. The aim was to evaluate simultaneously different mechanisms that determine platelet count in cirrhosis.

METHODS

Cross-sectional study including cirrhotics (n = 120) with hepatic venous pressure gradient (HVPG) measurement. Samples were obtained from peripheral (P) veins to evaluate thrombopoietin (TPO), stem cell factor, hepatocyte growth factor (HGF), tumour necrosis factor, interleukin-(IL6) and (IL11) and from hepatic (H) veins to evaluate TPO. A subgroup (n = 72) had spleen volume estimation. H and P-TPO were also measured in non-cirrhotic patients (n = 15).

RESULTS

Patients (Child A: 55, B: 43, C: 22) had a median platelet count of 81 000/mm(3) (IQR 60 500, 110 750), which correlated with spleen volume (r = -0.38, P < 0.001). Platelets were associated also to HVPG (r = -0.47, P = 0.004) and P-TPO (r = 0.31, P = 0.050) only in compensated patients. H-TPO decreased, and the proportion of patients with P-TPO > H-TPO increased, with the presence and the severity of liver disease. H-TPO was correlated with liver function (bilirubin r = -0.350, P < 0.001 and international normalized ratio r = -0.227, P = 0.011). Patients with H-TPO < P-TPO had higher levels of IL-11 and HGF.

CONCLUSION

Platelet count in cirrhosis is associated mainly to spleen volume, although portal hypertension as estimated by HVPG and liver function plays a significant role in compensated patients. H-TPO and the proportion of patients with P-TPO > H-TPO were associated to the presence and severity of liver disease.

Serum thrombopoietin levels and its relationship with thrombocytopenia in patients with cirrhosis

BACKGROUND

Patients with cirrhosis usually have thrombocytopenia in discrete levels. The mechanism of thrombocytopenia is thought as splenic sequestration and destruction of platelets, impaired bone marrow generation and diminished hepatic thrombopoietin synthesis.

OBJECTIVES

The aim of this study was to evaluate serum thrombopoietin levels and its relationship with thrombocytopenia at patients with cirrhosis.

PATIENTS AND METHODS

Ninety-two cirrhotic patients and 45 healthy controls without history or findings of pathologies that can effect thrombopoietin levels were enrolled by simple random sampling to patient and control groups of this case control study performed at Eskisehir-Turkey. Thrombopoietin was measured in serum samples with a solid phase enzyme-linked immune absorbent assay. Additionally, spleen size and volume index were determined.

RESULTS

Platelet counts were lower in patients with cirrhosis (97000 ± 8000/mm(3)) than in healthy subjects (240000 ± 51000/mm(3), P < 0.001). Significant difference was determined for platelet counts among child A, B and C stages (Child A vs. Child B P < 0.05 Child A vs. Child C P < 0.001-Child B vs. Child C P < 0.05). Serum TPO concentration was higher (69 ± 12 pg/mL) in cirrhotic group than healthy controls (49 ± 9 pg/ml) (P < 0.05). No significant difference in TPO levels were found among the Child A, B and C stages (64 ± 11 pg/mL, 75 ± 13 pg/mL and 68 ± 10 pg/mL, respectively). Spleen size and SVI was significantly higher in the cirrhotic patients than healthy controls (148 ± 14 mm vs. 98 ± 11 mm, P < 0.001-9167 ± 287 cm(2) vs. 4118 ± 123 cm(2)). Significant difference was determined for spleen size and spleen index among child A, B and C stages (Child A vs. Child B P < 0.05 Child A vs. Child C P < 0.001-Child B vs. Child C P < 0.05). TPO levels were significantly different between cirrhotic patients with platelet levels below 50.000/mm(3) (n = 16, plt-count: 41000 ± 8300/mm(3), TPO levels: 73 ± 7 pg/mL) and above 50.000/mm(3) (n = 76, plt-count: 105000 ± 9500/mm(3), TPO levels: 65 ± 10 pg/mL) (P < 0.01). In correlation analysis, there was a strong negative correlation between platelet count-spleen size (P < 0.001, r = -0.74) and platelet count-serum TPO levels (P < 0.001, r = -0.71).

CONCLUSIONS

Our results suggest that liver cirrhosis does not cause impaired thrombopoietin production even in the late stage of disease. Thrombopoietin has no contribution for the occurrence of thrombocytopenia in cirrhosis; splenic sequestration seems to be the main factor.

Effect of Platelet-Rich Plasma on CCl4-Induced Chronic Liver Injury in Male Rats

Platelet-rich plasma (PRP) has been of great concern to the scientists and doctors who are involved in wound healing and regenerative medicine which focuses on repairing and replacing damaged cells and tissues. Growth factors of platelet-rich plasma are cost-effective, available, and is more stable than recombinant human growth factors. Given these valuable properties, we decided to assess the effect of PRP on CCl4-induced hepatotoxicity on rats. The rats received CCl4 (1 mL/kg, i.p. 1 : 1 in olive oil) twice per week for 8 weeks. Five weeks after CCl4 injection, the rats also received PRP (0.5 mL/kg, s.c.) two days a week for three weeks. Twenty-four hours after last CCl4 injection, the animals bled and their livers dissected for biochemical and histopathological studies. Blood analysis was performed to evaluate enzyme activity. The results showed that PRP itself was not toxic for liver and could protect the liver from CCl4-induced histological damages and attenuated oxidative stress by increase in glutathione content and decrease in lipid peroxidative marker of liver tissue. The results of the present study lend support to our beliefs in hepatoprotective effects of PRP.

ADAMTS13 activity may predict the cumulative survival of patients with liver cirrhosis in comparison with the Child-Turcotte-Pugh score and the Model for End-Stage Liver Disease score

AIM

  Decreased plasma ADAMTS13 activity (ADAMTS13:AC) results in accumulation of unusually large von Willebrand factor multimers and platelet thrombi formation. Our aim was to evaluate whether ADAMTS13:AC is a prognostic marker in patients with liver cirrhosis.

METHODS

  Plasma ADAMTS13:AC and its related parameters were examined in 108 cirrhotic patients.

RESULTS

  ADAMTS13:AC decreased as the severity of liver disease increased (means: controls 100%, Child A-cirrhotics 79%, Child B-cirrhotics 63%, and Child C-cirrhotics 31%). ADAMTS13:AC markedly decreased in the cirrhotics with hepatorenal syndrome, refractory ascites and hepatic encephalopathy. The cumulative survival time was the shortest (median: 4.5 months) in the cirrhotics with severe to moderate ADAMTS13:AC deficiency (<3-25%), followed by those with mild ADAMTS13:AC deficiency (25-50%), and was the longest in those with normal activity (>50%). In contrast, based on the Child-Turcotte-Pugh (CTP) score, Child C-cirrhotics had the worst survival, but the survival probabilities did not differ between Child A and B cirrhotics. Based on the Model for End-Stage Liver Disease (MELD) score, the survival was the worst for the cirrhotics in the fourth quartile, but it was not different among cirrhotics in the first three quartiles. Cox proportional-hazards regression analysis showed that ADAMTS13:AC and serum albumin were independent factors affecting the survival.

CONCLUSIONS

  ADAMTS13:AC concomitantly decreases as the functional liver capacity decreases. This activity may be a useful prognostic marker that is equal or superior to the CTP score and the MELD score to predict not only the short-term prognosis but also the long-term survival of the cirrhotic patients.

Thrombocytopenia is more severe in patients with advanced chronic hepatitis C than B with the same grade of liver stiffness and splenomegaly

BACKGROUND AND AIM

The mechanism responsible for thrombocytopenia in chronic liver diseases (CLD) is not yet fully understood. The prevalence of thrombocytopenia has been reported to be higher in patients with hepatitis C virus-related hepatocellular carcinoma (CLD-C) than in those with hepatitis B virus-related hepatocellular carcinoma (CDC-B). We have examined the potential difference in thrombocytopenia between patients with CLD-B and those with CLD-C in terms of liver fibrosis adjustment and splenomegaly.

METHODS

The study cohort consisted of 102 patients with CLD-B and 143 patients with CLD-C were enrolled. Liver stiffness, which is reported to be well correlated with the degree of liver fibrosis, was measured by transient elastography.

RESULTS

The analysis of covariance with liver stiffness as a covariate revealed that the platelet count was lower in CLD-C patients than in CLD-B patients. Following stratification for liver stiffness, thrombocytopenia was found to be more severe in CLD-C patients than CLD-B patients with advanced liver stiffness, whereas the degree of splenomegaly was not significantly different. The plasma thrombopoietin level was not different between CLD-B and CLD-C patients with advanced liver stiffness, and the immature platelet number was lower in CLD-C patients despite thrombocytopenia being more severe in these patients.

CONCLUSIONS

CLD-C patients with advanced liver stiffness presented with more severe levels of thrombocytopenia than CLD-B patients even with the same grade of splenomegaly. Impaired platelet production rather than enhanced platelet destruction may underlie the mechanism responsible for thrombocytopenia in patients with CLD.

Monocyte-platelet aggregates and platelet micro-particles in patients with post-hepatitic liver cirrhosis

INTRODUCTION

Monocytes are the cells that play a crucial role in the pathogenesis of liver damage and liver cirrhosis (LC), and as platelets, by connecting hemostasis and inflammatory processes, participate in pathogenesis of chronic liver diseases, we aimed to investigate the presence of monocyte-platelet aggregates and platelet micro-particles (PMPs) and their role in LC.

PATIENTS AND METHODS

The study included 60 patients with post-hepatitic LC and 20 healthy controls. Activated monocytes (CD11b, HLA-DR, CD14, CD16), monocyte-platelet aggregates (CD41/CD14), activated platelets (CD41/CD62) and PMPs were analyzed by flow cytometry. Their relations to the clinical and laboratory data were assessed in the studied group.

RESULTS

Patients with LC had higher levels of activated platelets, activated monocytes and monocyte-platelet aggregations as compared to healthy controls. PMPs percentage showed no significant differences between patients and controls but significantly increased in both patients with no bleeding and patients with splenomegaly compared to patients without. All studied markers showed no significant differences between patients with thrombocytopenia and those with normal platelet counts and also between patients with different disease stages. Positive correlations between monocyte-platelet aggregates and both activated platelets and monocytes were demonstrated. There were significant negative correlations between PMPs and both age and prothrombin time among patients.

CONCLUSIONS

The stage of post-hepatitic LC is not the only factor that affects the level of activated platelets, activated monocytes and monocyte-platelet aggregates. PMPs have no influence on thrombocytopenia but may have the potential to influence the progression of clotting activity in LC.

Immature platelet fraction measurement in patients with chronic liver disease: a convenient marker for evaluating cirrhotic change

Platelet number is often used as an indicator of the severity of liver disease. Although inadequate thrombopoietin production and decreased platelet production have been proposed as major causes of cirrhotic thrombocytopenia, the underlying mechanism has not yet been fully clarified. We examined whether the measurement of the immature platelet fraction (IPF) in thrombocytopenic patients with liver dysfunction is useful as a rapid and noninvasive method for the differential diagnosis of chronic liver diseases. We examined 20 liver cirrhosis patients, 56 patients with chronic hepatitis, 9 patients with fatty liver, and 86 patients without liver disease. The percentage value of IPF (IPF%) was measured using an XE-2100 multiparameter automatic hematology analyzer. Using a receiver operating characteristic curve, we found diagnostic significance of the absolute platelet count and the absolute number of the IPF between cirrhotic patients and noncirrhotic patients, and developed a powerful multivariate discriminant analysis (MDA) function based on the platelet count and the IPF%. The diagnostic accuracy obtained by the MDA function was superior to that obtained by the absolute number of platelets and the IPF. We therefore propose our IPF% measurement for the diagnosis of liver cirrhosis.

Thrombocytopenia in Patients With Chronic Hepatitis C: A Possible Role of HCV on Platelet Progenitor Cell Maturation

A total of 30 patients with chronic hepatitis C (HCV) thrombocytopenia (TP) and 20 healthy controls were studied. Both groups were subjected to complete medical history, clinical examination in addition to assessment of hepatitis markers: level of thrombopoietin (Tpo), Geimsa-stained bone marrow smears, and in vitro short-term megakaryocytic progenitors culture (CFU-MK). Serum Tpo level was significantly elevated in patients with TP HCV. Short-term CFU-MK showed an evident depression in the colony-forming unit—megakaryocyte (CFU-meg). There is a positive correlation between the number of CFU-meg and the platelet count and between serum Tpo level and prothrombin time, transaminase, albumin, and the Child Pugh score of liver disease; a negative correlation between serum Tpo level and the number of CFU-meg and between serum Tpo level and the platelet count. Thus, the level of Tpo could be an indicator of intact functional response of the hepatocytes.

Review article: blood platelet number and function in chronic liver disease and cirrhosis

BACKGROUND

The liver plays a central role in coagulation and fibrinolysis but is also closely intertwined with the function and number of blood platelets.

AIM

To describe and integrate all literature concerning blood platelets and liver disease by performing a thorough literature research.

METHODS

A thorough literature research on 'blood platelets' and 'liver disease' was performed.

RESULTS

Thrombocytopenia is a marked feature of chronic liver disease and cirrhosis. Traditionally, this thrombocytopenia was attributed to passive platelet sequestration in the spleen. More recent insights suggest an increased platelet breakdown and to a lesser extent decreased platelet production plays a more important role. Besides the reduction in number, other studies suggest functional platelet defects. This platelet dysfunction is probably both intrinsic to the platelets and secondary to soluble plasma factors. It reflects not only a decrease in aggregability, but also an activation of the intrinsic inhibitory pathways. The net effect, finally, is a decreased platelet function in the various types of chronic liver diseases and cirrhosis. Finally, recent data suggest that platelets are not only affected by but can also contribute to the liver disease process, as for instance, in viral hepatitis and cholestatic liver disease.

CONCLUSION

Platelet research in liver disease is a growing area of investigation and could provide new pathophysiological insights.

Platelet aggregation is affected by nitrosothiols in patients with chronic hepatitis: In vivo and in vitro studies

AIM: To investigate the relationship among the number of platelets and plasma levels of S-nitrosothiols (S-NO), nitrite, total non-protein SH (NPSH), glutathione (GSH), cysteine (CYS), malondialdehyde (MDA), 4-hydroxininenal (4HNE), tumor necrosis factor-alpha (TNFα) and interleukin (IL)-6 in patients with chronic hepatitis C (CH).

METHODS: In vitro the aggregation of platelets derived from controls and CH patients was evaluated before and after the addition of adenosine diphosphate (ADP) and collagen, both in basal conditions and after incubation with nitrosoglutathione (GSNO).

RESULTS: In vivo, S-NO plasma levels increased significantly in CH patients and they were significantly directly correlated with platelet numbers. Patients with platelet counts < 150 000/μL, had a smaller increase in S-NO, lower levels of GSH, CYS, NPSH, TNFα, and IL-6, and higher levels of nitrite, MDA, and 4-HNE relative to those of patients with platelet counts > 150 000/μL. In vitro, the ADP and collagen aggregation time was increased in platelets from patients and not from controls; in addition, platelets from CH patients but not from controls also showed a latency time after exposure to collagen.

CONCLUSION: The incubation of platelets with GSNO improved the percentage aggregation and abolished the latency time.

Cytokines for the Treatment of Thrombocytopenia

Multiple cytokines affect the cellular processes that occur during the transition of a hematopoietic stem cell (HSC) to a platelet. Thrombopoietin (TPO) is the physiological regulator of thrombopoiesis. Although a number of cytokines (interleukin [IL]-1, IL-3, and IL-6) were first evaluated for their ability to lessen the degree of thrombocytopenia occurring during a variety of clinical scenarios, their clinical development was abandoned due to their limited effectiveness or excessive toxicity. Clinical results with TPO and a truncated pegylated form of TPO, megakaryocyte growth and development factor (MGDF), were more promising, but the repeated use of MGDF resulted in the development of neutralizing antibodies. This adverse event halted the further clinical development of not only MGDF but also TPO. IL-11 also affects various stages of megakaryocytopoiesis and thrombopoiesis and its use has been shown to shorten the duration of chemotherapy-induced thrombocytopenia, which led to its approval by the US Food and Drug Administration (FDA). A growing number of new non-immunogenic peptides and non-peptide TPO agonists recently have entered clinical trials. These small molecules appear to be effective therapies and have acceptable toxicity, but additional clinical evaluation will be required prior to their approval for clinical use.

Coagulation abnormalities in patients who have liver disease

The liver plays a central role in the maintenance of normal hemostatic function. Because liver disease alters pathways of coagulation and anticoagulation, patients who have advanced disease can experience severe bleeding or thrombotic complications. Complications of advanced liver disease may also contribute to bleeding or thrombosis. This article reviews and discusses the management of the most common coagulation problems encountered in patients who have end-stage liver disease, which are thrombocytopenia and impaired humoral coagulation as measured by prolongation of the prothrombin time and international normalized ratio.

Review article: thrombocytopenia in chronic liver disease and pharmacologic treatment options

In patients with liver disease, thrombocytopenia is a clinical feature that may represent an obstacle to invasive diagnostic or therapeutic procedures, chemotherapy, and anti-viral treatment. Stimulation of the bone marrow is the most promising therapeutic intervention for thrombocytopenia in patients with chronic liver disease. The description of thrombopoietin and its (de)regulation in patients with chronic liver disease have disclosed new treatment opportunities. Indeed, pharmacologic treatment options for thrombocytopenia can be divided into treatments targeted at the thrombopoietin receptor (synthetic thrombopoietins and thrombopoietin-mimetic agents), and use of cytokines with general thrombopoietic potential. Unfortunately, use of synthetic thrombopoietin was hampered by the development of neutralizing antibodies, and thrombopoietin mimetic agents have not yet entered clinical studies. Interleukin-11 proved to be useful in increasing platelet count in patients with chronic liver disease, although its use is limited by side-effects. Erythropoietin has shown promising results in improving thrombocytopenia in cirrhotic patients. In patients with chronic liver disease, safe and well-tolerated treatments aimed at improving thrombocytopenia are still lacking. Larger studies are needed to evaluate and better characterize the thrombopoietic potential of erythropoietin. Human studies with thrombopoietin-mimetic agents are eagerly awaited in order to assess both effectiveness and safety of these drugs.

Thrombopoietin (TPO) levels in hepatic patients with thrombocytopenia

Thrombocytopenia is a common problem complicating the course of liver disease. One of the postulated mechanisms in chronic liver disease is impaired production of the hormone, thrombopoietin (TPO). The aim of present study was to evaluate the role of TPO on the occurrence of thrombocytopenia. Serum TPO levels was determined by ELISA in 40 patients with liver disease (11 seropositive with hepatitis C; 10 with mixed liver cirrhosis; 19 with bilharzial hepatic fibrosis), plus 14 normal healthy subjects as a control group. The sTPO levels were unevenly distributed among the liver disease subgroups being the highest in the group with HCV (median 1232.0, range 154.7-2042.0 pg/ml) followed by the mixed cirrhosis group (556.5; 342.0-1497.0 pg/ml) and lowest among the bilharzial hepatic fibrosis group (130.0; 22.0-204.0 pg/ml) (P<0.01). While sTPO levels in HCV and cirrhotic group were significantly higher when compared to the control group (97.0; 19.0-377.0 pg/ml), those in the Bilharzial hepatic fibrosis group were not significantly elevated (P>0.05). There is significant negative correlation between sTPO levels and spleen size (R=-0.3, P=0.043); but there was no correlation with platelet count (R=0.09, P>0.05). In addition, sTPO levels were significantly higher in patients with platelet counts >or=60x10(9)/l as compared to those with platelet counts <60x10(9)/l (P=0.04). Using the receiver operating curve (ROC) at sTPO cut off value >or= vs. <368 ng/ml, most of HCV and cirrhotic patients had higher sTPO levels (81.8 and 80.0%, respectively), while all Bilharzial hepatic fibrosis group (100%) had lower sTPO levels. In conclusion, sTPO levels had no role in the occurrence of thrombocytopenia in liver disease patients and other factors appear to be more important. It also appears that the mechanism controlling sTPO levels might be different in cirrhotic patients compared to Bilharzial hepatic fibrosis patients.

Assessment of neutrophil apoptosis ex vivo in hepatosplenic patients with neutropenia pre and post splenectomy

The pathophysiology of neutropenia seen in patients with schistosomiasis or hepatitis C infection that complicates the course of liver disease is poorly understood. We evaluated the neutrophil apoptosis before and after splenectomy to clarify the role of apoptosis and splenomegaly in the occurrence of neutropenia. Neutrophils were isolated from 23 hepato-splenic patients with neutropenia, 8 hepatosplenic patients with normal neutrophil counts, 7 patients who were post splenectomy, and a further ten normal control subjects. These were cultured for 24 h and the time course of neutrophil apoptosis was assessed by determination of Annexin V and propidium iodide binding by flow cytometry. Fas and Bcl2 expression were determined on fresh neutrophils using flow cytometry. Levels of tumor necrosis factor alpha, interleukin 3, and gamma interferon were evaluated using an immunosorbent assay. Neutrophil apoptosis was minimal in the fresh neutrophils, however, cultured neutrophils exhibited significantly greater apoptosis in neutropenic patients when compared to non-neutropenic patients (P=0.01 at 4 h and P<0.05 at 24 h) and control group (P<0.01 at 4 h and 24 h). After splenectomy, the percentage of neutrophil apoptosis declined to the normal control levels (P>0.05). Fas and Bcl2 expression on neutrophil were significantly higher in the neutropenic group as compared to normal controls (P<0.05, P=0.01 respectively). Serum TNF alpha, IL-3, and IFN gamma levels were not significantly different in all studied groups.

IN CONCLUSION

Neutrophils from neutropenic hepatosplenic patients exhibit markedly accelerated apoptosis, which is normalized after splenectomy. Thus increased neutrophil apoptosis may in part be responsible for the occurrence of neutropenia.

Thrombopoietin: a tool for understanding thrombopoiesis

Although first proposed to be the primary regulator of platelet production 45 years ago, the gene for thrombopoietin was cloned only within the last decade. Since then, our understanding of megakaryocyte and platelet production has increased substantially, and it is now appreciated that in addition to its critical role in regulating thrombopoiesis, the hormone affects multiple aspects of hematopoiesis, including playing a non-redundant role in stem cell survival, self-renewal and expansion. In addition to this greater physiological understanding of thrombopoietin biology, the molecular mechanisms by which the hormone affects cell survival and proliferation are coming under increased scrutiny. At least four signaling pathways have been identified that play important and non-overlapping roles in stem cell and megakaryocyte growth and development, potentially providing new strategies to therapeutically intervene in hematopoiesis. This review will focus on our current understanding of these processes.

Quantification of hepatic thrombopoietin mRNA transcripts in patients with chronic liver diseases shows maintained gene expression in different etiologies of liver cirrhosis

BACKGROUND/AIMS

Platelet production is regulated by thrombopoietin (TPO), which is primarily synthesized in the liver. The TPO in patients with liver diseases could possibly be owing to impaired hepatic TPO production. As we reported previously, TPO serum levels are not decreased in patients with liver diseases compared with healthy controls and do not depend on the stage of cirrhosis or platelet count, but are highly elevated in patients with chronic virus hepatitis.

METHODS

To study possible mechanisms, we measured hepatic TPO mRNA levels in liver tissue samples from 31 liver cirrhosis patients by quantitative TaqMan real-time RT-PCR and corresponding serum TPO concentrations by ELISA.

RESULTS

Median TPO serum levels were elevated in patients with viral hepatitis (n = 12) compared with patients with a biliary (n = 10), alcoholic (n = 6) or other (n = 3) disease etiology, while hepatic TPO mRNA levels did not differ. The TPO mRNA levels in patients with chronic liver diseases were not different from normal liver tissue sample. The TPO mRNA and TPO serum level did not correlate.

CONCLUSIONS

We conclude that hepatic TPO gene expression appears to be maintained on a constitutive transcriptional level in patients with liver diseases and does not change dependent on disease etiology.