Erythropoietin increases platelet reactivity and platelet counts in patients with alcoholic liver cirrhosis: a randomized, double-blind, placebo-controlled study

Whole blood thrombin generation shows a significant hypocoagulable state in patients with decompensated cirrhosis

BACKGROUND

Patients with cirrhosis have a normal to increased thrombin generation (TG) capacity in platelet-poor plasma (PPP). By reflecting the contribution of all circulating blood cells, whole blood (WB) TG may allow a more physiological assessment of coagulation.

OBJECTIVES

We compared WB-TG vs PPP-TG in patients with cirrhosis.

METHODS

Assessment of coagulation included routine tests, factor VIII, natural anticoagulants, PPP-TG, and WB-TG. TG assays were performed with and without thrombomodulin. Twenty-five healthy subjects were included as controls.

RESULTS

We included 108 patients (Child-Pugh A/B/C, 44/24/40). Compared with controls, patients had significantly lower platelet count, longer international normalized ratio, higher FVIII, and lower levels of protein C/S and antithrombin. Regarding thrombomodulin-modified TG assays, in compensated cirrhosis, both PPP-TG and WB-TG indicated an increased TG capacity, as reflected by an endogenous thrombin potential (ETP) significantly higher than controls. In contrast, in decompensated cirrhosis, PPP-TG indicated a hypercoagulable state with increased ETP, higher peak height, and shorter time-to-peak than controls, whereas WB-TG revealed a progressive impairment of TG kinetics and total capacity, ultimately resulting in a profound hypocoagulable state in patients with Child-Pugh C cirrhosis (ie, significant prolongation of lag time and time-to-peak with reduction of both ETP and peak height). In decompensated patients, bacterial infections and severity of anemia were associated with a further reduction of both ETP and peak height.

CONCLUSION

Compensated cirrhosis is associated with an increased TG capacity. In decompensated cirrhosis, contrary to PPP-TG, which indicates hypercoagulability, WB-TG shows a significant hypocoagulable state. The clinical value of these findings deserves further investigation.

The evolving knowledge on primary hemostasis in patients with cirrhosis: A comprehensive review

Patients with cirrhosis develop complex alterations in primary hemostasis that include both hypocoagulable and hypercoagulable features. This includes thrombocytopenia, multiple alterations of platelet function, and increased plasma levels of von Willebrand factor. Contrary to the historical view that platelet dysfunction in cirrhosis might be responsible for an increased bleeding tendency, the current theory posits a rebalanced hemostasis in patients with cirrhosis. Severe thrombocytopenia is not indicative of the bleeding risk in patients undergoing invasive procedures and does not dictate per se the need for pre-procedural prophylaxis. A more comprehensive and individualized risk assessment should combine hemostatic impairment, the severity of decompensation and systemic inflammation, and the presence of additional factors that may impair platelet function, such as acute kidney injury and bacterial infections. Although there are multiple, complex alterations of platelet function in cirrhosis, their net effect is not yet fully understood. More investigations evaluating the association between alterations of platelet function and bleeding/thrombosis may improve risk stratification in patients with decompensated cirrhosis. Besides hemostasis, the assessment of von Willebrand factor Ag and ADP-induced, whole-blood platelet aggregation normalized by platelet count (VITRO score and PLT ratio) are promising biomarkers to predict the risk of hepatic decompensation and survival in both compensated and decompensated patients. Further investigations into the in vivo interplay between platelets, circulating blood elements, and endothelial cells may help advance our understanding of cirrhotic coagulopathy. Here, we review the complex changes in platelets and primary hemostasis in cirrhosis and their potential clinical implications.

Evaluation of the neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios in critically ill dogs

OBJECTIVE

To evaluate whether the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are accurate prognostic indicators and correlate with illness severity scores in critically ill dogs.

DESIGN

Prospective observational study from December 2016 to May 2017.

SETTING

ICU at a veterinary teaching hospital.

ANIMALS

Seventy-two client-owned dogs admitted to the ICU with CBCs and abbreviated and complete acute patient physiologic and laboratory evaluation (APPLE_fast and APPLE_full ) scores were enrolled.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The NLR, PLR, APPLE_fast , and APPLE_full scores were calculated for each patient on the day of admission. Patients were followed from admission to discharge, and diagnosis, survival, and length of hospitalization were recorded. The patient population was assessed as a whole and as subcategories of patients with neoplastic disease, infectious disease, sepsis, and severe hemorrhage. Dogs with nonseptic disease processes (n = 52) that died had a significantly higher median PLR (P = 0.04) of 441 (range: 106-986) compared to those that survived with a median PLR of 217 (range: 28.4-3225). The PLR was strongly predictive of ICU length of stay in dogs with severe hemorrhage (P = 0.03, Spearman's rho = 0.84). The NLR had a poor positive correlation with APPLE_full score (P = 0.04, Spearman's rho = 0.24), and PLR had a poor negative correlation with APPLE_fast score (P = 0.02, Spearman's rho = -0.27).

CONCLUSIONS

The PLR correlated with ICU length of stay for patients with severe hemorrhage and with survival for patients with nonseptic disease processes. The PLR and NLR correlated with illness severity as measured by APPLE scores. Future studies with larger sample sizes are warranted to further determine the merit of NLR and PLR as indicators of morbidity, mortality, and illness severity.

Erythropoietin is a major regulator of thrombopoiesis in thrombopoietin-dependent and -independent contexts

Thrombopoietin (TPO), through activation of its cognate receptor Mpl, is the major regulator of platelet production. However, residual platelets observed in TPO- and Mpl-loss-of-function (LOF) mice suggest the existence of an additional factor to TPO in platelet production. As erythropoietin (EPO) exhibited both in vitro megakaryocytic potential, in association with other early-acting cytokines, and in vivo platelet activation activity, we sought to investigate its role in this setting. Here, we used multiple LOF models to decipher the reciprocal role of EPO and TPO in the regulation of platelet production in TPO-LOF and Mpl-LOF mice and of platelet size heterogeneity in wild-type mice. We first identified EPO as the major thrombopoietic factor in the absence of the TPO-Mpl pathway. Based on the study of several mouse models we found that the EPO-EPO receptor pathway acts on late-stage megakaryopoiesis and is responsible for large-sized platelet production, while the TPO-Mpl pathway promotes small-sized platelet production. On the basis of our data, EPO might be used for thrombocytopenia supportive therapy in congenital amegakaryocytopoiesis. Furthermore, as a distribution skewed toward large platelets is an independent risk factor and a poor prognosis indicator in atherothrombosis, the characterization of EPO's role in the production of large-sized platelets, if confirmed in humans, may open new perspectives in the understanding of the role of EPO-induced platelets in atherothrombosis.

The Effects of Curcumae Longae Radix, Curcuma phaeocaulis Radix and Their Processed Products on Epo/EpoR Pathway and CD62p

Background: Curcumae Radix (Yujin) has been widely used to treat Qi stagnation due to Liver depression (LDQS) in traditional Chinese medicine (TCM) for a long time and is good at dispelling melancholy by soothing liver to regulate qi and relieving pain by promoting blood circulation for removing blood stasis. Yujin stir-frying with vinegar can strengthen the effect of dispersing stagnated hepatoqi to stop pain by injecting medicine into the liver and stir-frying with wine can strengthen the effect of promoting blood circulation for removing blood stasis. Because the reason for the enhancement of clinical efficacy by processing is unclear, it is difficult to select and use processed products in the clinic. Aim/Hypothesis: In this study, from the point of view of the platelet function, we start to investigate the mechanism for promoting blood circulation, removing blood stasis, and enhancing clinical efficacy by processing. Methods: This study mainly takes Curcumae Longae Radix (HSYJ) and Curcuma phaeocaulis Radix (LSYJ) as the research subjects. They are genuine drugs in Sichuan Province, China. A high-performance liquid chromatography (HPLC) is used to analyze the main chemical constituents of Yujin and its processed products, and show the difference between the two species, with and without processing. A rat model of blood stasis induced by LDQS is established by giving the tail clamp stimulation, injecting epinephrine hydrochloride subcutaneously, and treating with an effective dose (0.9 g⋅kg^-1) according to the conversion of human clinical dosage for 2 weeks. After the experiment, the serum levels of erythropoietin are measured by ELISA. Furthermore, RT-PCR and WB are used to detect EpoR mRNA and protein expression in the hepatic tissue. Flow cytometry is used to measure peripheral blood CD62p expression. Results: There is a great difference between the chemical compositions of the two species, the number of chromatographic peaks of Curcumae Longae Radix is more than that of Curcuma phaeocaulis Radix. Curcuminoids is the main component of HSYJ, while curcuminoids is almost free from LSYJ. Curcuminoids is almost insoluble in water. After stir-frying with vinegar or wine, it can increase the dissolution of curcuminoids in water. In rat models, the levels of Epo, EpoR, and CD62p are significantly increased. After intragastric administration of Yujin, indicators show varying degrees of callback. HSYJ is better than LSYJ, and the processed product by stir-frying with wine is better than other processed products. Conclusion: The results show that the mechanism of promoting blood circulation for removing blood stasis in Yujin may be able to inhibit the activation and aggregation of platelets by intervening the Epo/EpoR pathway and regulating CD62p down. Stir-frying with wine can enhance this effect.

Excessive fluoride consumption increases haematological alteration in subjects with iron deficiency, thalassaemia, and glucose-6-phosphate dehydrogenase (G-6-PD) deficiency

Excessive fluoride consumption leads to accelerated red blood cell death and anaemia. Whether that increases the haematological alteration in subjects with haematological disorders (iron deficiency, thalassaemia, and G-6-PD deficiency) is still unclear. The fluoride in serum and urine and haematological parameters of students at Mae Tuen School (fluoride endemic area) were analysed and compared to those of students at Baan Yang Poa and Baan Mai Schools (control areas). Iron deficiency, thalassaemia, and G-6-PD deficiency were also diagnosed in these students. The students at Mae Tuen School had significantly (P < 0.001) higher levels of mean fluoride in the serum and urine than those in control areas. In both control and fluoride endemic areas, students with haematological disorders had significantly lower levels of Hb, Hct, MCV, MCH, and MCHC than those without haematological disorders. Moreover, the lowest levels of Hb, MCH, and MCHC were observed in the students with haematological disorders who live in the fluoride endemic area. Thus, the excessive fluoride consumption increased haematological alteration in subjects with iron deficiency, thalassaemia, and G-6-PD deficiency and that may increase the risk of anaemia in these subjects.

Thrombocytopenia in Patients with Chronic Hepatitis C Virus Infection

Thrombocytopenia in patients with chronic hepatitis C virus (HCV) infection is a major problem. The pathophysiology is multifactorial, with auto-immunogenicity, direct bone marrow suppression, hypersplenism, decreased production of thrombopoietin and therapeutic adverse effect all contributing to thrombocytopenia in different measures. The greatest challenge in the care of chronic HCV patients with thrombocytopenia is the difficulty in initiating or maintaining IFN containing anti-viral therapy. Although at present, it is possible to avoid this challenge with the use of the sole Direct Antiviral Agents (DAAs) as the primary treatment modality, thrombocytopenia remains of particular interest, especially in cases of advanced liver disease. The increased risk of bleeding with thrombocytopenia may also impede the initiation and maintenance of different invasive diagnostic and therapeutic procedures. While eradication of HCV infection itself is the most practical strategy for the remission of thrombocytopenia, various pharmacological and non-pharmacological therapeutic options, which vary in their effectiveness and adverse effect profiles, are available. Sustained increase in platelet count is seen with splenectomy and splenic artery embolization, in contrast to only transient rise with platelet transfusion. However, their routine use is limited by complications. Different thrombopoietin analogues have been tried. The use of synthetic thrombopoietins, such as recombinant human TPO and pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMDGF), has been hampered by the development of neutralizing antibodies. Thrombopoietin-mimetic agents, in particular, eltrombopag and romiplostim, have been shown to be safe and effective for HCV-related thrombocytopenia in various studies, and they increase platelet count without eliciting any immunogenicity Other treatment modalities including newer TPO analogues-AMG-51, PEG-TPOmp and AKR-501, recombinant human IL-11 (rhIL-11, Oprelvekin), recombinant human erythropoietin (rhEPO), danazol and L-carnitine have shown promising early result with improving thrombocytopenia. Thrombocytopenia in chronic HCV infection remain a major problem, however the recent change in DAAs without IFN, as the frontline therapy for HCV, permit to avoid the dilemmas associated with initiating or maintaining IFN based anti-viral therapy.

Regulation of platelet count by erythropoiesis-stimulating agents - iron axis in hemodialysis patients

Higher doses of erythropoiesis-stimulating agents (ESAs) contribute to atherothrombotic cardiovascular disease in hemodialysis (HD) patients. Thrombocytosis is associated with increased mortality in ESA-treated HD patients. We investigated variables affecting platelet count and its variability (platelet count increment [Δplatelet count]) in HD patients. This retrospective longitudinal and observational study of HD outpatients was carried out over 3 years. The outcome was independent determinants of platelet count and Δplatelet count, which were associated with iron indices, ESA dose, and C-reactive protein. In univariate regression analysis, V-shaped relationship was observed between platelet count and transferrin saturation (TSAT), ferritin, serum iron, and hemoglobin (Hb) with the bottom of 0.21, 330 ng/mL, 49 µg/dL, and 10.3 g/dL, respectively. Mixed-effect multivariate regression analysis revealed that TSAT (inversely), Hb ≤10.3 g/dL (inversely), C-reactive protein, and ESA dose were independently associated with platelet count. Δplatelet count was independently and inversely correlated with ΔTSAT and directly correlated with Δferritin. TSAT was independently and inversely associated with ESA dose. ESA dose was directly correlated with iron dose and inversely correlated with TSAT, ferritin ≤330 ng/mL, and Hb ≤10.3 g/dL. ESA dose and TSAT were correlated in determining platelet count and Δplatelet count. Targets of iron indices that reflect iron supply sufficient to avoid platelet count increment and variability may be >21% of TSAT and 300 ng/mL of serum ferritin for appropriate ESA therapy in HD patients.

Hepatic erythropoietin response in cirrhosis. A contemporary review

The main function of erythropoietin (EPO) is to maintain red blood cell mass, but in recent years, increasing evidence has suggested a wider biological role not solely related to erythropoiesis, e.g. angiogenesis and tissue protection. EPO is produced in the liver during fetal life, but the main production shifts to the kidney after birth. The liver maintains a production capacity of up to 10% of the total EPO synthesis in healthy controls, but can be up-regulated to 90-100%. However, the hepatic EPO synthesis has been shown not to be adequate for correction of anemia in the absence of renal-derived EPO. Elevated circulating EPO has been reported in a number of diseases, but data from cirrhotic patients are sparse and the level of plasma EPO in patients with cirrhosis is controversial. Cirrhosis is characterized by liver fibrosis, hepatic dysfunction and the release of proinflammatory cytokines, which lead to arterial hypotension, hepatic nephropathy and anemia. An increase in EPO due to renal hypoperfusion, hypoxia and anemia or an EPO-mediated hepato-protective and regenerative mechanism is plausible. However, poor hepatic synthesis capacity, a decreasing co-factor level and inflammatory feedback mechanisms may explain a potential insufficient EPO response in end-stage cirrhosis. Finally, the question remains as to whether a potential increase in EPO production in certain stages of cirrhosis originates from the kidney or liver. This paper aims to review contemporary aspects of EPO relating to chronic liver disease.

Anemia and thrombocytosis induced by ribavirin monotherapy in patients with chronic hepatitis C

BACKGROUND

An inosine triphosphatase (ITPA) single-nucleotide polymorphism (SNP) is associated with anemia induced by pegylated interferon and ribavirin (RBV) combination therapy in patients with chronic hepatitis C (CHC). However, there are very few reports on the hematological effects of RBV monotherapy. Here, hematological changes were monitored in patients with CHC who received RBV monotherapy, and the mechanism of these changes was investigated.

METHODS

Patients with CHC (n = 30) received RBV monotherapy for 4 weeks. The RBV dose was determined on the basis of body weight. Complete blood count, and serum erythropoietin (EPO) and thrombopoietin (TPO) levels were assessed. The associations between these parameters and the ITPA SNP (rs1127354) were analyzed.

RESULTS

Over the 4 weeks, the median hemoglobin level of all patients decreased significantly, from 13.6 (10.5-16.6) to 11.7 (9.4-14.9) g/dl (P < 0.001), and the platelet counts increased, from 14.0 × 10(4) (8.9-37.4 × 10(4)) to 15.8 × 10(4) (10.2-40.6 × 10(4)) /mm(3) (P = 0.003). At week 4, hemoglobin levels differed between patients with the ITPA CC genotype and those with the AA or AC genotypes [11.1 (9.4-13.5) vs. 12.9 (12.5-14.9) g/dl, P = 0.001]. The platelet change ratio (i.e., platelet count at week 4/platelet count at baseline) in the patients with developing anemia was correlated with the increase in the serum EPO level over 4 weeks (r = 0.88, P = 0.002), but not with the increase in the serum TPO level over 4 weeks.

CONCLUSIONS

RBV monotherapy induced anemia and affected thrombocytosis in patients with CHC. Elevated endogenous EPO may stimulate platelet production.

Rifaximin improves thrombocytopenia in patients with alcoholic cirrhosis in association with reduction of endotoxaemia

BACKGROUND

Thrombocytopenia is a major haematological disorder of cirrhosis with unclear pathogenesis. Endotoxaemia resulting from intestinal bacterial overgrowth could reduce platelet counts directly or through cytokine release.

AIMS

To correlate endotoxaemia with platelet counts and study the effects of intestinal decontamination with rifaximin on thrombocytopenia in relation to changes in endotoxin and cytokine concentrations in patients with alcoholic cirrhosis.

METHODS

Platelet counts, plasma endotoxin levels and serum interleukin-1 (IL-1), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) levels were measured in 23 thrombocytopenic cirrhotic patients (platelet count<150 000/μl) before and after 4-week treatment with rifaximin 1200 mg/d (n = 13) or no treatment (n = 10) and at baseline in 10 cirrhotic patients without thrombocytopenia; spleen size was measured at baseline in all patients.

RESULTS

Endotoxin and IL-6 levels were significantly higher in patients with thrombocytopenia than in those without thrombocytopenia (2.76 ± 0.69 vs. 0.64 ± 0.09 EU/ml; P < 0.001 and 24.26 ± 3.38 vs. 2.66 ± 0.74 pg/ml; P = 0.001 respectively). Platelet counts were inversely correlated with endotoxin levels (r = -0.589; P = 0.003), Child-Pugh score (r = -0.625; P = 0.001), IL-6 levels (r = -0.464; P = 0.02) and spleen size (r = -0.455; P = 0.02) in patients with thrombocytopenia. Following rifaximin, platelet counts increased significantly (83 100 ± 9700 vs. 99 600 ± 11 200/μl; P = 0.006) in line with significant reductions in endotoxin (1.28 ± 0.41 vs. 2.54 ± 0.86 EU/ml; P = 0.005), IL-1 (3.1 ± 0.5 vs. 4.4 ± 1.2 pg/ml; P = 0.04), IL-6 (12.8 ± 2.5 vs. 21.1 ± 4.2 pg/ml; P = 0.01) and TNF-α (3.6 ± 1.3 vs. 5.8 ± 1.7; P = 0.02) levels. Platelet count changes were correlated with the changes in endotoxin (r = 0.573; P = 0.04), TNF-α (r = 0.554; P = 0.05) and IL-6 (r = 0.495; P = 0.07) levels.

CONCLUSIONS

Rifaximin improves cirrhosis-related thrombocytopenia and this could be related with the reduction of endotoxaemia.

The effect of erythropoietin on platelet and endothelial activation markers: a prospective trial in healthy volunteers

Erythropoietin (EPO) enhances formation of red blood cells and also affects thrombopoiesis and platelet function. We hypothesized that the effect of EPO may be reflected by changes in thromboxane B2 (TXB2) and endothelial cell function. Six male and six female subjects received recombinant human epoetin alpha (Erypo®) intravenously (300 U/kg). Biomarker levels were assessed at baseline and 4, 24, 48 and 72 hours after infusion. Epoetin alpha increased TXB2 levels by 140%, which reached significance at 48 hours (6.6 ± 5 ng/ml vs. 15 ± 9 ng/ml; p = 0.044) and remained at that level at 72 hours. In line, epoetin alpha increased E-selectin levels by 25% already at 24 hours (39 ± 21 ng/ml vs. 49 ± 26 ng/ml; p < 0.001) which stayed at this level until 72 hours (p < 0.001). The raise in platelet activation markers corresponded to an 88% increase in reticulocyte count (43 ± 10 × 10(9)/l vs. 81 ± 17 × 10(9)/l; p < 0.001) and a 9% increase in platelet count at 72 hours (224 ± 45 × 10(9)/l vs. 244 ± 52 × 10(9)/l; p = 0.005). Thrombomodulin and von Willebrand factor concentrations were not significantly altered by epoetin alpha. Interestingly, gender differences in the baseline levels of E-selectin and thrombomodulin were observed. E-selectin and thrombomodulin levels were doubled in men compared to women (51 ± 24 and 28 ± 10 ng/ml; p = 0.025 and 30 ± 5 ng/ml vs. 16 ± 5 ng/ml; p = 0.002, respectively). EPO increases TXB2 serum levels and soluble E-selectin. Further studies are needed to investigate whether these markers might be useful for estimation of thromboembolic risk during EPO-therapy and whether inhibition of thromboxane formation may lower thrombotic complications during EPO treatment: NCT01392612.

Use of epoetin beta during combination therapy of infection with hepatitis c virus with ribavirin improves a sustained viral response

The aim of the study was to evaluate the effects of epoetin-beta on anemia and sustained viral response in patients with chronic hepatitis C receiving treatment with pegylated interferon and ribavirin. Forty-two Caucasian patients with chronic hepatitis C infection, treated with pegylated interferon alpha-2a or alpha-2b plus ribavirin, who experienced at least a 2 log decline in HCV-RNA in the first month of therapy and a > or =2.5 g/dl hemoglobin drop from baseline, were recruited. They were divided into two groups: 22 patients received epoetin-beta 30,000 U administered s.c. q.w. (group A) and 20 patients received a reduced ribavirin dose of 600 mg daily (group B). The end-of-treatment response was 95.4% (21/22) in group A and 80% (16/20) (P = 0.2) in group B. Sustained viral response in group A was 81.8% (18/22), statistically higher than in group B (45%, 9/20) (P = 0.03). Mean corpuscular volume of erythrocytes was statistically lower in group A than in group B 4 weeks after starting epoetin-beta or reduced ribavirin dose (P < 0.001), end-of-treatment (P < 0.001) and after 6 months follow-up (P < 0.001). A negative correlation between the levels of ferritin serum was found in group A at the baseline and mean corpuscular volume value after 1 month of combination antiviral therapy (r = -0.45; P = 0.35), 4 weeks after starting epoetin-beta (r = -0.43; P = 0.04) and after 6 months follow-up (r = -0.45; P = 0.03). Administration of epoetin-beta increases sustained viral response rates among patients developing anemia, because the standard dose of ribavirin is maintained, thereby reducing the side-effects of antiviral treatment.

Iron depletion before HCV antiviral therapy: a pilot, randomized, controlled trial

It is not known whether iron depletion before pegylated IFN or combination treatment improves sustained virological response (SVR) rate in patients with chronic hepatitis C, despite its use in clinical practice in this setting. We aimed to investigate whether blood letting improves the efficacy (SVR) and tolerability of PEG-IFNalpha2b + Ribavirin in chronic hepatitis C patients. Patients with chronic hepatitis C and ferritin >100 ng/mL were randomized to: (1) repeated phlebotomies to obtain a ferritin level <50 ng/mL followed by pegylated-Interferon alpha2b + ribavirin (active arm); or (2) pegylated-Interferon alpha2b + ribavirin (control arm). Primary endpoint was SVR rate, secondary endpoint was frequency of clinical and laboratory grade 3-4 adverse events. Thirty-three patients were enrolled in the study (19 in active arm, 14 in control arm). The 19 patients in the active arm underwent a median of 5 phlebotomies (range: 1-9) to achieve the targeted ferritin (<50 ng/mL). Phlebotomies significantly reduced ferritin, iron, transferrin saturation, aspartate aminotransferase, alanine aminotransferase, and hemoglobin levels. Platelet count significantly increased, whereas HCV-RNA levels remained unchanged. After antiviral therapy overall SVR was 31.6% in active arm and 21.4% in control arm (P = 0.698). Considering only the 18 patients who were naive to antiviral therapy, SVR was 60% in active arm versus 25% in control arm (P = 0.188). Tolerability, drug dose reduction or withdrawal were similar in the two arms. In conclusion phlebotomies do not increase the overall efficacy of antiviral therapy. However, the strong trend to higher SVR in naive patients undergoing phlebotomies warrants further investigation.

Impaired synthesis of erythropoietin, glutamine synthetase and metallothionein in the skin of NOD/SCID/gamma(c)(null) and Foxn1 nu/nu mice with misbalanced production of MHC class II complex

Most skin pathologies are characterized by unbalanced synthesis of major histocompatability complex II (MHC-II) proteins. Healthy skin keratinocytes simultaneously produce large amounts of MHC-II and regeneration-supporting proteins, e.g. erythropoietin (EPO), EPO receptor (EPOR), glutamine synthetase (GS) and metallothionein (MT). To investigate the level of regeneration-supporting proteins in the skin during misbalanced production of MHC-II, skin sections from nonobese diabetic/severe combined immunodeficient (NOD/SCID)/gamma (c) (null) and or Foxn1 nu/nu mice which are a priory known to under- and over-express MHC II, respectively, were used. Double immunofluorescence analysis of NOD/SCID/gamma (c) (null) skin sections showed striking decrease in expression of MHC-II, EPO, GS and MT. In Foxn1 nu/nu mouse skin, GS was strongly expressed in epidermis and in hair follicles (HF), which lacked EPO. In nude mouse skin EPO and MHC-II were over-expressed in dermal fibroblasts and they were completely absent from cortex, channel, medulla and keratinocytes surrounding the HF, suggest a role for EPO in health and pathology of hair follicle. The level of expression of EPO and GS in both mutant mice was confirmed by results of Western blot analyses. Strong immunoresponsiveness of EPOR in the hair channels of NOD/SCID/gamma (c) (null) mouse skin suggests increased requirements of skin cells for EPO and possible benefits of exogenous EPO application during disorders of immune system accompanied by loss MHC-II in skin cells.

O-glycoside biomarker of apolipoprotein C3: responsiveness to obesity, bariatric surgery, and therapy with metformin, to chronic or severe liver disease and to mortality in severe sepsis and graft vs host disease

The glyco-isoforms of intact apolipoprotein C3 (ApoC3) were used to probe glycomic changes associated with obesity and recovery following bariatric surgery, liver diseases such as chronic hepatitis C (CHC) and alcoholic liver cirrhosis, as well as severe, multiorgan diseases such as sepsis and graft vs host disease (GVHD). ApoC3 glyco-isoform ratios responded to unique stimuli that did not correlate with serum lipids or with other blood components measured in either a control population or a group of extremely obese individuals. However, glyco-isoform ratios correlated with obesity with a 1.8-fold change among subjects eligible for bariatric surgery relative to a nonobese control population. Bariatric surgery resulted in rapid change of isoform distribution to that of nonobese individuals, after which the distribution was stable in each individual. Although multiple simultaneous factors complicated effector attribution, the isoform ratios of very obese individuals were nearly normal for diabetic individuals on metformin therapy. Glyco-isoform ratios were sensitive to liver diseases such as chronic hepatitis C and alcoholic liver cirrhosis. The correlation coefficient with fibrosis was superior to that of current assays of serum enzyme levels. Diseases of pregnancy that can result in liver damage, HELLP syndrome and pre-eclampsia, did not alter ApoC3 glyco-isoform ratios. Early after umbilical cord blood transplantation the isoform ratios changed and returned to normal in long-term survivors. Larger changes were observed in persons who died. GVHD had little effect. Persons with severe sepsis showed altered ratios. Similar cut-points for mortality (3.5-fold difference from controls) were found for UCBT and sepsis. Similar values characterized liver cirrhosis. Overall, while changes of glyco-isoform ratios occurred in many situations, individual stability of isoform distribution was evident and large changes were limited to high-level disease. If ratio changes associated with obesity are found to document a risk factor for long-term outcomes, the information provided by glyco-isoform ratio changes may provide important, novel information for diagnostic, prognostic and therapy response to metabolic conditions.

What is so bad about a hemoglobin level of 12 to 13 g/dL for chronic kidney disease patients anyway?

Randomized controlled trials (RCTs) clearly indicate a possible cardiovascular morbidity and mortality risk when deliberately targeting a normal hemoglobin (Hb) concentration of 13 to 15 g/dL. By contrast, observational studies point to greater hospitalization and mortality at Hb levels <11 g/dL. There are no direct data to help us determine where, within this broad range, the optimal Hb lies. In RCTs and observational studies, significant confounding from the interrelationships of anemia and epoetin resistance occurs in patients with a serious illness. Patients with comorbidities such as malnutrition and inflammatory processes are more resistant to epoetin and, invariably, require greater cumulative epoetin doses. The effect of a higher erythropoiesis-stimulating agent (ESA) dose on increasing mortality has been noted repeatedly in post hoc analyses of RCTs. It is therefore too simplistic to solely attribute the outcomes achieved in RCTs to "target Hb." We discuss various mechanisms for potential harm at higher Hb levels as opposed to those that may be obtained from higher epoetin doses. For the individual patient, the therapeutic decision should center on what Hb is most appropriate at a "safe" ESA dose. Consequently, an Hb of 12 to 13 g/dL may be totally appropriate in some patient populations.

Role of hematopoietic growth factors as adjuncts in the treatment of chronic hepatitis C patients

Drug-induced hematotoxicity is the most common reason for reducing the dose or withdrawing ribavirin (RBV) and interferon (IFN) therapy in chronic hepatitis C, which leads to the elimination of a possible cure for the patient. Traditionally, severe anemia and neutropenia have been considered as absolute contraindications to start antiviral therapy. This has not however, been the case since the advent of adjunct therapy with hematopoietic growth factors (erythropoietin (EPO) and granulocyte-colony stimulating factor (G-CSF)). Some recent landmark studies have used this adjunct therapy to help avoid antiviral dose reductions. Although the addition of this adjunct therapy has been shown to significantly increase the overall cost of the treatment, this extra cost is worth bearing if the infection is cured at the end of the day. Although more studies are needed to refine the true indications of this adjunct therapy, determine the best dose regimen, quantify the average extra cost and determine whether or not the addition of this therapy increases the sustained virological response rates achieved, the initial reports are encouraging. Therefore, although not recommended on a routine basis, some selected patients may be given the benefits of these factors. This article reviews the current literature on this subject and makes a few recommendations to help develop local guidelines.

Thrombosis with erythropoietic stimulating agents-does iron-deficient erythropoiesis play a role?

Thrombocytosis is common in iron deficiency and resolves following iron repletion. Increased platelet number, whether from iron deficiency or from other causes, may increase the risk of thrombovascular events. One mechanism thought to mediate iron deficiency-induced thrombocytosis is increased erythropoietin production. Similarly, erythropoietic stimulating agents (ESA) have long been known to increase platelet number and frequently lead to functional or absolute iron deficiency. This state of relative or absolute iron deficiency may be the mechanism whereby ESA increase the platelet count. If correct, co-administration of iron should prevent or diminish ESA-driven thrombocytosis. Data from the DRIVE trial in hemodialysis patients do, in fact, suggest that this is the case. Platelet counts in patients receiving IV iron decreased, while they remained unchanged in patients not given iron (mean change -29,000/microl vs. -0/microl; p = 0.017). Other supporting data have been observed in IV iron trials in oncology patients. The harm from higher hemoglobin targets and higher ESA doses may be mediated in part through induction of iron deficiency and thrombocytosis. The major anemia trials of ESAs have not reported platelet data, but should examine the relationship of platelet count, iron deficiency, IV iron administration, and cardiovascular events in greater detail.

Acute thrombocytopenia after liver transplant: role of platelet activation, thrombopoietin deficiency and response to high dose intravenous IgG treatment

BACKGROUND/AIMS

Thrombocytopenia is common after liver transplantation due to platelet sequestration secondary to hypersplenism. The aim of this study was to further investigate the causes of this condition, as well as the response of thrombocytopenia to high dose intravenous immunoglobulins.

METHODS

We retrospectively studied 73 patients who underwent liver transplantation. Out of these 73 patients, 27 had severe thrombocytopenia and were treated with high dose intravenous immunoglobulin. Additionally, we retrospectively studied 8 patients undergoing liver transplantation.

RESULTS

Our data suggest that splenomegaly is not the only factor responsible for thrombocytopenia after liver transplantion and two additional phenomena, namely, reduced platelet production due to reduced thrombopoietin levels and sustained platelets activation take part in the pathogenesis of this condition. The infusion of high dose immunoglobulins induced a safe, prompt, complete and persistent resolution of severe thrombocytopenia in more than 70% of patients.

CONCLUSIONS

Based on these findings, treatment with high dose intravenous immunoglobulins should be considered in the management of severe thrombocytopenia after liver transplant, although additional randomized trials are warranted.

A national French survey on the use of growth factors as adjuvant treatment of chronic hepatitis C

We conducted a national retrospective survey on hospital practitioners to evaluate the magnitude of erythropoietin (EPO) or granulocyte colony-stimulating factor (G-CSF) prescriptions in patients treated for chronic hepatitis C. Four hundred seventy-one questionnaires were sent, and 274 practitioners (58.2%) responded. Forty-six percent of practitioners used EPO, and 31% used G-CSF. The total number of HCV-infected patients receiving antiviral therapy per year was estimated at 6,630 patients, of whom 8.8% and 4% received EPO and G-CSF, respectively. EPO-beta was the main EPO molecule prescribed at a median dose of 30,000 IU/wk (range: 2,000-80,000). The indications for prescribing EPO varied greatly, including "fragile patients" (34%), "low" Hb level (8-11 g/dL) (19%), "rapid decline" in Hb level (2-5 g/dL during the first month of therapy) (12%), and symptomatic anemic patients (7%). G-CSF was mainly prescribed for a "low" level of neutrophils ranging from 400 to 750 neutrophils/mm3. In multivariate analysis, independent predictors of EPO and G-CSF prescription were age of practitioner less than 45 years (EPO: OR = 1.96, P = 0.03; G-CSF: OR = 2.27, P = 0.004), practice in university hospital (EPO: OR = 5.89, P < 0.0001; G-CSF: OR = 2.39, P = 0.003), and the high number of CHC treated/year (EPO: OR = 6.18, P < 0.0001; G-CSF: OR = 2.58, P = 0.002).

CONCLUSION

Our survey reveals an important rate of EPO and G-CSF prescriptions but with considerable disparity in the schedule of injections, the molecules used, and above all the indications. The suitable role of EPO and G-CSF as complements to HCV therapy urgently needs to be clarified.

Erythropoietin treatment is associated with more severe thrombocytopenia in patients with chronic hepatitis C undergoing antiviral therapy

BACKGROUND

Erythropoietin (EPO) not only stimulates erythropoiesis but also thrombopoiesis. As pegylated-interferon-alpha(PEG-IFN-alpha)-induced thrombocytopenia may become a limiting factor for continuation of therapy, the present study investigated if EPO can alleviate PEG-IFN-alpha induced thrombocytopenia. Further, we hypothesize that EPO increases platelet reactivity and protease activated receptor 1 (PAR-1) expression during combination antiviral therapy.

METHODS

Forty patients with chronic hepatitis C received either 10,000 IU EPO 3 x/week or placebo in a randomized, placebo-controlled, double-blinded fashion for 4 wk and combination antiviral therapy with PEG-IFN-2a and ribavirin.

RESULTS

EPO alleviated the decrease in hemoglobin during combination antiviral therapy with ribavirin (10%vs 20%, p < 0.0001). Platelet counts decreased stronger in EPO than in placebo group on day 28 (p= 0.007). EPO induced a 40% increase in PAR-1 (p < 0.0001), which was accompanied by 100% increase in platelet reactivity (p < 0.0001). PFA-100 platelet plug formation time and PEG-IFN-alpha-induced vWF-increase were not different between study groups.

CONCLUSIONS

Treatment with EPO alleviated the decrease in hemoglobin but worsened PEG-IFN-alpha induced thrombocytopenia after the first 4 wk of combination therapy. EPO caused PAR-1 receptor upregulation on platelets, which promoted an increase in platelet reactivity without affecting PFA-100 platelet plug formation time. EPO is not a useful option for short-term support of platelet production during antiviral therapy.

[Thrombocytopathy and blood complications in uremia]

Bleeding diathesis and thrombotic tendencies are characteristic findings in patients with end-stage renal disease. The pathogenesis of uremic bleeding tendency is related to multiple dysfunctions of the platelets. The platelet numbers may be reduced slightly, while platelet turnover is increased. The reduced adhesion of platelets to the vascular subendothelial wall is due to reduction of GPIb and altered conformational changes of GPIIb/IIIa receptors. Alterations of platelet adhesion and aggregation are caused by uremic toxins, increased platelet production of NO, PGI(2), calcium and cAMP as well as renal anemia. Correction of uremic bleeding is caused by treatment of renal anemia with recombinant human erythropoietin or darbepoetin alpha, adequate dialysis, desmopressin, cryoprecipitate, tranexamic acid, or conjugated estrogens. Thrombotic complications in uremia are caused by increased platelet aggregation and hypercoagulability. Erythrocyte-platelet-aggregates, leukocyte-platelet-aggregates and platelet microparticles are found in higher percentage in uremic patients as compared to healthy individuals. The increased expression of platelet phosphatidylserine initiates phagocytosis and coagulation. Therapy with antiplatelet drugs does not reduce vascular access thrombosis but increases bleeding complications in endstage renal disease patients. Heparin-induced thrombocytopenia (HIT type II) may develop in 0-12 % of hemodialysis patients. HIT antibody positive uremic patients mostly develop only mild thrombocytopenia and only very few thrombotic complications. Substitution of heparin by hirudin, danaparoid or regional citrate anticoagulation should be decided based on each single case.

Rate of Infectious Complications during Interferon-Based Therapy for Hepatitis C Is Not Related to Neutropenia

The relationship between infectious complications and neutropenia was evaluated in recipients of interferon-based therapy for hepatitis C followed at The Ottawa Hospital Viral Hepatitis Clinic from June 2000 to May 2005. One hundred ninety-two patients received 211 courses of therapy (5707 person-weeks of therapy). No patients received granulocyte colony-stimulating factor. Sixty-seven infectious complications occurred in 57 patients (1.17 infections per 100 person-weeks of therapy). The median time to infection was 17 weeks after the start of therapy. Age, sex, weight, race, human immunodeficiency virus status, stage and grade of biopsy, and type of interferon were not correlated with infection rate by Cox regression analysis. The rates of total, fungal, viral, and bacterial infections did not correlate with nadir neutrophil count or magnitude of decrease from baseline. Neutrophil count is not correlated with infection rate in recipients of interferon-based therapy for hepatitis C. Reduction in interferon dose and/or dosing with granulocyte colony-stimulating factor in those with neutropenia is not supported by this analysis.

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.

Short- and long-term effects of therapy with interferon-alpha and pegylated interferon-alpha/ribavirin on platelet plug formation and von Willebrand factor release in patients with chronic hepatitis C

BACKGROUND

A pegylated interferon-alpha-induced decrease in platelet counts may become a limiting factor for continuation of therapy.

AIM

To evaluate the effect of pegylated interferon-alpha administration on platelet plug formation and von Willebrand factor antigen release in patients with chronic hepatitis C.

METHODS

Thirty patients with chronic hepatitis C (genotype 1; fibrosis 1-3: n = 16, cirrhosis: n = 14) received a single dose of 9 MU interferon-alpha2a, followed by weekly administration of 180 mug of pegylated interferon-alpha2a/ribavirin for 48 weeks. Platelet counts, platelet function (collagen-epinephrine-induced closure time) and von Willebrand factor antigen were measured.

RESULTS

Platelet counts and collagen-epinephrine-induced closure time decreased by 13% and 16%, respectively, 24 h after the first dose of interferon-alpha2a, and von Willebrand factor antigen levels increased by 31% (P < 0.01) compared with baseline. During a 48-week observation period, platelet counts decreased by a maximum of 33% (P < 0.001), von Willebrand factor antigen levels increased by 69% (P < 0.001) whereas collagen-epinephrine-induced closure time did not change. In noncirrhotic patients, the increase of von Willebrand factor antigen levels was maintained throughout therapy without a change in collagen-epinephrine-induced closure time. In contrast, in cirrhotics, von Willebrand factor antigen levels did not increase, while collagen-epinephrine-induced closure time was prolonged.

CONCLUSION

Single-dose interferon-alpha decreases platelet counts but improves platelet function, possibly by the release of von Willebrand factor antigen. Accordingly, long-term antiviral treatment had no effect on collagen-epinephrine-induced closure time, despite the decrease in platelet count in noncirrhotic patients. Such a compensation of decreased platelet counts by increased von Willebrand factor antigen level did not occur in cirrhotics.