Clinical variations between three different causes of thrombocytopenia.

BACKGROUND: Thrombocytopenia is defined as the platelet count of less than 150 × 109/L and is a prominent cause of bleeding. Aplastic anemia (AA), immune thrombocytopenic purpura (ITP), and thrombotic thrombocytopenic purpura (TTP) are some of the reasons of low platelet counts. AIMS: We aimed to interpret different laboratory and clinical findings in these different reasons of thrombocytopenia. METHODS: Among patients with these disorders we assessed the performance of the ITP Bleeding Scale Assessment (ITP-BSA), which is principally designed for ITP patients. RESULTS: A hundred patients were included in analysis. Median platelet count at presentation was similar in all three groups. Thrombosis was seen more common in patients with TTP (20.7%) than the others (ITP; 5.6%, AA; 2.9%). In patients with TTP, sepsis (41.4%) and neurological findings (89.7%) are also more common than in the patients with ITP or AA. Bleeding was determined in all patients with AA. However, 13 patients with ITP (%36.1) and 10 patients with TTP (%34.5) had no bleeding. The most common bleeding site was skin in all three groups. There was not any gastrointestinal, lung, genitourinary, and cranial bleeding in patients with ITP. Patients with AA obtained the highest scores from the ITP-BSA. There was a significant difference between AA and the other two groups. The scores were found similar in patients with ITP and TTP (P = 0.17). CONCLUSION: Clinical variations in thrombocytopenic patients may vary and assist to diagnose the cause of thrombocytopenia. The bleeding scoring systems might be helpful.

Predictive factors for stem cell mobilization failure in multiple myeloma patients: A single center experience.

BACKGROUND AND AIM: High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) has been considered the standard of treatment care for patients with multiple myeloma (MM). Insufficient mobilization and harvest of peripheral stem cells can be a major obstacle for performing ASCT. This is resulting in a lacking opportunity of cure in patients with MM. The aim of this study was to evaluate the factors which influence mobilization failure in patients with MM. MATERIALS AND METHODS: This study has been performed in a retrospective manner. Two hundred and thirty-four patients with diagnosed MM who underwent stem cell mobilization after induction chemotherapy at Hacettepe University Hospital between the years of 2003 and 2018 were evaluated. RESULTS: A total of 234 patients were included in this study. The median age was 54 (32-76) years at the time of diagnosis. In 209 of 234 patients (89.3%) first mobilization trial was successful. At univariate analysis, among parameters identifiable before mobilization, male gender (p = 0.03), number of chemotherapy cycle before stem cell mobilization (p < 0.001), second ASCT (p < 0.001) and immunomodulatory treatment before stem cell mobilization (p < 0.001) predicted mobilization failure. At multivariate analysis, number of chemotherapy cycle before stem cell mobilization (p = 0.03), second ASCT (p < 0.001) and immunomodulatory treatment before stem cell mobilization (p = 0.02) retained independent predictive power. CONCLUSION: Detectable different clinical characteristics of MM patients before initiating mobilization may be predictors of poor mobilization. Therefore, the mobilization protocol should be evaluated on a patient basis. Minimization of exposure to chemotheraputic agents in MM patients, especially immunomodulatory agents, may increase CD34+ cell harvest yields.

Plateletcrit. A platelet marker associated with saphenous vein graft disease.

BACKGROUND: Saphenous vein graft disease (SVGD) after by-pass surgery is an important cause of morbidity and mortality for patients with coronary artery disease. Comprehensive evaluation of biochemical and hematological parameters associated with this problem is limited. Plateletcrit (PCT) provides complete information on total platelet mass, but it has not been previously studied. In this study, we examined the relationship between SVGD and platelet parameters such as PCT, mean platelet volume, platelet count, and platelet distribution. METHODS: We retrospectively analyzed 14,398 patients who underwent coronary angiography between February 2006 and August 2012. Records from 893 patients with previous coronary artery by-pass graft operation were re-evaluated. A total of 251 cases were divided into two groups (127 patients receiving a saphenous vein graft; 124 patients diagnosed with SVGD) and hematological and biochemical parameters were compared. RESULTS: There were no significant differences in clinical characteristics between the two groups except that the SVGD group had a higher median time from surgery to coronary angiography than the patent saphenous vein graft group [7 years (2-16) vs. 5 years (2-15), p < 0.001]. The SVGD groups also had significantly higher median PCT, mean platelet volume, platelet count, uric acid level, and red blood cell distribution width. The cut-off value for PCT was found to be 0.188 for predicting SVGD, with an 80.65 % sensitivity and 81.1 % specificity. CONCLUSION: Plateletcrit has an important predictive value for SVGD, and it could be used as a marker for anti-platelet therapy to prevent graft atherosclerosis in patients undergoing by-pass surgery.

Chronic myeloid leukemia, tyrosine kinase inhibitors and cardiovascular system.

OBJECTIVE: Cardiovascular system health becomes important with the extended survival of chronic myeloid leukemia (CML) patients. Cardiotoxicities are related to the second- and third-generation tyrosine kinase inhibitors (TKIs). The most frequent and important cardiovascular events are myocardial infarction, stroke and peripheral arterial disease, QT prolongation, pleural effusions, and both systemic and pulmonary hypertension. The aim of this paper is to review the interactions between administrated TKIs and the cardiovascular system during the clinical course of CML. Elucidation of TKI effects on the cardiovascular system is vital since the current goal of CML therapy is a cure that leads to normal age and gender-similar survival with a normal quality of life. MATERIALS AND METHODS: Up to August 2022, literature searches were performed via the internet search engines MEDLINE, EMBASE, GOOGLE SCHOLAR: (i) chronic myeloid leukemia; (ii) tyrosine kinase inhibitor; (iii) cardiovascular system. Only articles in English and research including humans were included in the search. RESULTS: Tailored TKI treatment with individual patient characteristics must account for CML disease risk, patient age, patient comorbidities, patient compliance, TKI drug off-target risk profile, accelerated or blastic phase CML disease, pregnancy and allografting in CML. The treatment-free survival, improving quality of life, limiting adverse events of TKIs, and the optimal dose and administration duration of TKIs are still a matter of controversy. Special attention should be paid to the comorbidities of CML patients and clinical TKI effects on CVS since the aim of CML treatment is a cure that leads to normal age and gender-similar survival with a "normal" quality of life. CVS is an important morbidity and mortality cause for adult patients. The discontinuation of TKI treatment in CML and the treatment-free remission of CML patients are very important in order to reduce the risk for cardiovascular adverse effects of TKIs. The frail CML patients and especially the patients who have cardiac comorbidities, should be carefully evaluated for TKI treatment, and hematopoietic stem cell transplantation (HSCT) should be the last choice in these risky CML patients. CONCLUSIONS: The current CML treatment target is a cure that leads to normal age and gender-adjusted survival with a "normal" quality of life. Cardiovascular disorders are one of the major obstacles to reaching this target in CML patients. The treatment choices for CML patients must include a cardiovascular perspective.

Beneficial effects of Ankaferd Blood Stopper on caustic esophageal injuries: an experimental model.

Ankaferd Blood Stopper (ABS) is an herbal extract that enhances mucosal healing. The aim of this study was to investigate the efficacy of ABS on the healing of the esophagus and prevention of stricture development after esophageal caustic injuries in rats. The study included 50 rats. Rats were divided into five groups: group 1 (no injury, sham surgery), group 2 (injury + no ABS + study after 2 weeks of injury), group 3 (injury + ABS + study after 2 weeks of injury), group 4 (injury + no ABS + study after 4 weeks of injury), and group 5 (injury + ABS + study after 4 weeks of injury). Standard esophageal burn injury was created by applying 50% NaOH solution to distal esophagus of about 1.5 cm. To rats in the sham group, isotonic solution was given instead of NaOH. ABS (2 mL/day) was given via oral route to group 3 and 5 rats. Fourteen days (group 2 and 3) and 28 days (group 4 and 5) later, all the live rats were killed. The distal esophageal segments of all rats were removed and divided into two equal parts for biochemical and histopathological examination. Mortality rate, weight changes, inflammation, stenosis index (SI), and biochemical measurements were evaluated. The SI was found as 0.31 ± 0.03 in group 1, 0.533 ± 0.240 in group 2, 0.568 ± 0.371 in group 3, 0.523 ± 0.164 in group 4, and 0.28 ± 0.03 in group 5. The SI and inflammation in ABS-treatment group 5 was significantly lower than that in non-treatment group 4 (P= 0.005). There were no significant differences between inflammation and SI among other groups. The mortality rate was 14.2% in group 1, 37.5% in untreated group 2, 14.2% in ABS-treated group 3, 80% in untreated group 4, and 33.3% in ABS-treated group 5. The mortality rate in group 4 was significantly higher than other groups (P= 0.025). Decrease rates in mean body weights of the groups were as follows: group 1, 1%; group 2, 15%; group 3, 14%; group 4, 46%; and group 5, 15%. Biochemical tests other than albumin and creatinine were comparable among the groups. Treatment with ABS prevents inflammation, scar formation, weight loss, and mortality in esophageal caustic injuries. Additional studies to evaluate the clinical benefits of ABS in esophageal caustic injury are recommended.

Hematological aspects of the COVID-19 syndrome.

OBJECTIVE: Viral infections could complicate hematopoiesis and, in some cases, they may worsen the clinical prognosis of blood disorders. SARS-CoV-2 and COVID-19, as a viral disease, can have serious impact on the disease course of hematological neoplastic diseases and can cause hematological complications. The aim of this paper is to review the hematologic aspects of COVID-19 syndrome and the potential management options for SARS-CoV-2 including the convalescent plasma, hemostatic agents and proper anticoagulant treatment. MATERIALS AND METHODS: Up to February 2022, literature searches were performed using the internet search engines MEDLINE and EMBASE: (i) COVID-19; (ii) Hematology. PRISMA flow diagram described the COVID-19 and hematology search. RESULTS: According to our COVID-19 and hematology research on research databases, we included 82 studies in the current paper. The issues of the impact of the COVID-19 pandemic on hematological diseases, the role of t-lymphocytes in donor lymphocyte infusion and viruses, hemato-immunologic research in COVID-19, local bone marrow renin-angiotensin system and viral infections, clinical management of COVID-19 infection via hemostatic agents, immune plasma treatment of COVID-19, anticoagulant treatment of COVID-19 associated thrombosis are comprehensively described in this paper. CONCLUSIONS: The final episode of this pandemic will include the "chimerism-mediated immunotherapy" that will eventually lead to end of the COVID-19 process. The recent Omicron variant seems to have unique evasion effects on the interferon gene expression which will boost the chimerism-mediated immunotherapy without high mortality rates.

Tailored tyrosine kinase inhibitor (TKI) treatment of chronic myeloid leukemia (CML) based on current evidence.

Philadelphia (Ph*)/BCR-ABL1-positive chronic myeloid leukemia (CML) is a neoplastic hematologic disorder, which is a functionally curable chronic disease via using tyrosine kinase inhibitor (TKI) drugs. The life expectancy for the vast majority of chronic phase-CML patients is "normal", thanks to the unique effectiveness of the ABL-targeted TKIs of CML. The patients with CML receiving TKI could be expected to have a survival and 'quality of life' of the age- and sex-matched healthy people. Several TKI pathways may be selected for the first line CML treatment, including first-generation original/generic imatinib or second-generation TKIs, such as bosutinib, nilotinib, and dasatinib. Individual characteristics of the CML patients, TKI drug compliance, lifestyle preferences, comorbidities, distinct toxicity profile of the TKI drug, and physician-clinical center experience are among the critical factors to be taken into account while deciding on the proper first line TKI in the newly diagnosed CML patients. Identifying CML patients at a higher risk for the disease progression or TKI resistance is essential and could influence the choice of primary TKI. The optimized integrations of the best available evidence, individual patient characteristics, and physician clinical experience are required in order to select best TKI for the CML management. Pathobiological basis depending upon the prospective in vivo research data is also crucial during the follow-up as well.

Three critical clinicobiological phases of the human SARS-associated coronavirus infections.

OBJECTIVE: COVID-19 immune syndrome is a multi-systemic disorder induced by the COVID-19 infection. Pathobiological transitions and clinical stages of the COVID-19 syndrome following the attack of SARS-CoV-2 on the human body have not been fully explored. The aim of this review is to outline the three critical prominent phase regarding the clinicogenomics course of the COVID-19 immune syndrome. MATERIALS AND METHODS: In the clinical setting, the COVID-19 process presents as "asymptomatic/pre-symptomatic phase", "respiratory phase with mild/moderate/severe symptoms" and "multi-systemic clinical syndrome with impaired/disproportionate and/or defective immunity". The corresponding three genomic phases include the "ACE2, ANPEP transcripts in the initial phase", "EGFR and IGF2R transcripts in the propagating phase" and the "immune system related critical gene involvements of the complicating phase". RESULTS: The separation of the phases is important since the genomic features of each phase are different from each other and these different mechanisms lead to distinct clinical multi-systemic features. Comprehensive genomic profiling with next generation sequencing may play an important role in defining and clarifying these three unique separate phases for COVID-19. From our point of view, it is important to understand these unique phases of the syndrome in order to approach a COVID-19 patient bedside. CONCLUSIONS: This three-phase approach may be useful for future studies which will focus on the clinical management and development of the vaccines and/or specific drugs targeting the COVID-19 processes. ANPEP gene pathway may have a potential for the vaccine development. Regarding the specific disease treatments, MAS agonists, TXA127, Angiotensin (1-7) and soluble ACE2 could have therapeutic potential for the COVID-19 course. Moreover, future CRISPR technology can be utilized for the genomic editing and future management of the clinical course of the syndrome.

Effects of imatinib mesylate on renin-angiotensin system (RAS) activity during the clinical course of chronic myeloid leukaemia.

The renin-angiotensin system (RAS) is involved in cell growth, proliferation and differentiation in bone marrow in an autocrine-paracrine manner, and it modulates normal and neoplastic haematopoietic cell proliferation. This study aimed to assess expressions of the RAS components, renin, angiotensinogen and angiotensin-converting enzyme (ACE), during imatinib mesylate treatment of patients with chronic myeloid leukaemia (CML). Expressions of RAS components were studied in patients with CML at the time of diagnosis (n = 83) and at 3, 6 and 12 months after diagnosis (n = 35) by quantitative real-time polymerase chain reaction. De novo CML patients had increased ACE, angiotensinogen and renin mRNA levels and these expression levels decreased following administration of imatinib. The RAS activities were significantly different among Sokal risk groups of CML, highlighting the altered biological activity of RAS in neoplastic disorders. The results of this study confirm that haematopoietic RAS affects neoplastic cell production, which may be altered via administration of tyrosine kinase inhibitors such as imatinib mesylate.

Haemostatic actions of the folkloric medicinal plant extract Ankaferd Blood Stopper.

Ankaferd Blood Stopper (ABS), a standardized mixture of five plants, has been used historically as a haemostatic agent but its mechanism of action remains unknown. This study investigated the in vitro effects of ABS on haemostatic parameters. When added to plasma or serum, ABS induced the very rapid formation of a protein network and erythrocyte aggregation. The levels of coagulation factors II, V, VII, VIII, IX, X, XI, and XIII were not affected by ABS. Plasma fibrinogen activity and antigen levels were decreased following the addition of ABS, in parallel with the prolonged thrombin time. Total protein, albumin, and globulin levels decreased after the addition of ABS. Our findings suggest that ABS stimulates the formation of an encapsulated protein network that provides focal points for erythrocyte aggregation. ABS has the therapeutic potential to be used for the management of haemorrhage and this agent should be investigated further in clinical trials.

Lack of platelet activation reflected by circulating soluble glycoprotein V in pre-eclampsia.

Pre-eclampsia (PE) is a human pregnancy-specific disorder of unknown aetiology. Although the quantitative relationship between platelet aggregation in PE is not clearly defined yet, we aimed to investigate the possible relationship between PE and platelet glycoprotein V (GPV), which is an integral platelet membrane protein involved in the function of the GPIb-V-IX receptor. Fifty patients with PE and 37 normotensive pregnant women (controls) were enrolled in this study. Fasting blood samples were collected and soluble GPV (sGPV) levels were determined using a commercially available enzyme immunoassay. No statistically significant difference in sGPV was found between PE patients and control subjects. There was no correlation between sGPV and platelet counts or between pregnancy duration and platelet counts. Further clinical and experimental investigations are needed to elucidate the pathological processes involved in the development of PE in complicated pregnancies.

Circulating thrombomodulin levels in familial Mediterranean fever.

Increments in circulating thrombomodulin levels reflect endothelial cell injury. Thrombomodulin can also be synthesized by several inflammatory cells including monocytes, neutrophils, and thrombomodulin itself can modulate the inflammatory response. In this study, we assessed circulating thrombomodulin concentrations in patients with familial Mediterranean fever (FMF). Twenty-five patients with FMF (F/M: 14/11) (mean age: 31.1 +/- 9.7 years) and 25 healthy controls (F/M: 13/12) (mean age: 34.6 +/- 7.0 years) were involved in the study. Thrombomodulin levels were measured by commercially available enzyme-linked immunosorbant assay (ELISA) (Immunoassay of thrombomodulin Diagnostica Stago, Asnieres-Sur-Seine, France). Twenty of the patients were in attack-free period and the remaining five had been during acute FMF attacks. Thrombomodulin levels were higher in the study group (20.9 +/- 12.1 ng/ml) than healthy controls (14.1 +/- 8.4 ng/ml) (p < 0.05). Circulating thrombomodulin levels were also higher in attack-free FMF patients (22.4 +/- 12.9 ng/ml) than controls. This study disclosed for the first time significantly higher increments in the circulating levels of thrombomodulin in FMF. This observation could be a consequence of injured endothelium and/or activated inflammatory cells.

Successful treatment of myelodysplastic syndrome-induced pyoderma gangrenosum.

We report successful treatment of a refractory myelodysplastic syndrome-associated pyoderma gangrenosum with the combination of thalidomide and interferon-alpha2a in a single patient. A non-healing wound developed on a 40-year-old woman's left thumb after minor trauma. Massive ulcerovegetative lesions developed after reconstruction surgery. Histopathological examination of the bone marrow and cytogenetic studies revealed an atypical myeloproliferative/myelodysplastic syndrome. The skin lesions resolved dramatically after two months of thalidomide and interferon-alpha2a combination therapy and the haematological status improved.

Predicting chronic leukaemias from assessment of complete peripheral blood counts.

The chronic leukaemias include two distinct chronic neoplastic disease states, namely chronic myelogenous leukaemia (CML) and chronic lymphocytic leukaemia (CLL). The aim of this study was to assess the utility of leucocyte count, neutrophil percentage and absolute lymphocyte count from differential complete blood count analyses as indicators of the possible presence of CML and CLL. Blood counts from 102 patients with histopathologically confirmed CML and CLL were compared with counts for 858 cancer-free control subjects. Optimal cut-off values were identified by selecting values with the highest sensitivity-specificity combination for each blood count parameter for the two diseases. The results indicated that any individual with mature-appearing lymphocytes at a level > 6.65 x 10(9)/l in the peripheral blood should be examined further for CLL, and that any individual with a leucocyte count > 18.0 x 10(9)/l or a neutrophil proportion > 72.6% should be investigated for CML.

Local bone marrow renin-angiotensin system in the genesis of leukemia and other malignancies.

The existence of a local renin-angiotensin system (RAS) specific to the hematopoietic bone marrow (BM) microenvironment had been proposed two decades ago. Most of the RAS molecules including ACE, ACE2, AGT, AGTR1, AGTR2, AKR1C4, AKR1D1, ANPEP, ATP6AP2, CMA1, CPA3, CTSA, CTSD, CTSG, CYP11A1, CYP11B1, CYP11B2, CYP17A1, CYP21A2, DPP3, EGFR, ENPEP, GPER, HSD11B1, HSD11B2, IGF2R, KLK1, LNPEP, MAS1, MME, NR3C1, NR3C2, PREP, REN, RNPEP, and THOP1 are locally present in the BM microenvironment. Local BM RAS peptides control the hematopoietic niche, myelopoiesis, erythropoiesis, thrombopoiesis and the development of other cellular lineages. Local BM RAS is important in hematopoietic stem cell biology and microenvironment. Angiotensin II regulates the proliferation, differentiation, and engraftment of hematopoietic stem cells. Activation of Mas receptor or ACE2 promotes proliferation of CD34+ cells. BM contains a progenitor that expresses renin throughout development. Angiotensin II attenuates the migration and proliferation of CD34+ Cells and promotes the adhesion of both MNCs and CD34+ cells. Renin cells in hematopoietic organs are precursor B cells. The renin cell requires RBP-J to differentiate. Mutant renin-expressing hematopoietic precursors can cause leukemia. Deletion of RBP-J in the renin-expressing progenitors enriches the precursor B-cell gene programme. Mutant cells undergo a neoplastic transformation, and mice develop a highly penetrant B-cell leukemia with multi-organ infiltration and early death. Many biological conditions during the development and function of blood cells are mediated by RAS, such as apoptosis, cellular proliferation, intracellular signaling, mobilization, angiogenesis, and fibrosis. The aim of this paper is to review recent developments regarding the actions of local BM RAS in the genesis of leukemia and other malignancies molecules.

Overt gastrointestinal bleeding in haematologic neoplasms.

BACKGROUND AND AIM: Patients with acute leukaemia suffer from various haemorrhages, most frequently due to thrombocytopenia. We could not reach any information regarding the frequency of gastrointestinal bleeding in acute leukaemia and decided to search this complication in patients with acute and chronic leukaemias and myeloproliferative disorders, retrospectively. PATIENTS AND METHODS: During a 6-year period, 291 patients with acute leukaemia, 52 patients with chronic leukaemia and 108 patients with myeloproliferative disorders had been followed. Thirty-two cases of overt gastrointestinal haemorrhage episodes (25 upper, 7 lower) were observed during the mentioned period. RESULTS: The frequency of bleeding episodes was 7.1% (32/451) in haematologic malignancies as a whole, 5.8% (17/291) for acute leukaemia, 1.9% (1/52) for chronic leukaemia and 13% (14/108) for myeloproliferative disorders. If the patients with myeloproliferative disorders in blastic phase were analysed separately, the ratio was 30% (6/20). Oesophagogastroduodenoscopy, which could be performed in 8 of 25 upper gastrointestinal haemorrhage episodes, revealed erosive gastritis in five patients and duodenal ulcers in three patients. Neutropenic enterocolitis was the underlying cause in all of the seven patients with lower gastrointestinal haemorhage. Five out of the seven patients had acute leukaemia. In 7 bleeding attacks, out of 32, the ultimate result was death. Generally, the haemorrhage was only a contributing cause of mortality. All of the mortality cases were patients with acute leukaemia. CONCLUSION: Especially, the patients with myeloproliferative disorders are prone to develop gastrointestinal haemorrhage. The manifestation is generally as upper gastrointestinal bleeding due to gastric erosions and duodenal ulcers. Lower gastrointestinal bleeding is frequently a problem of the patients with acute leukaemia. It is commonly a sign of neutropenic enterocolitis.

The plasma levels of prostanoids and plasminogen activator inhibitor-1 in primary and secondary thrombocytosis.

An elevated platelet count is a common finding in both hospitalized and ambulatory patients. Thrombosis and bleeding complications are more frequently observed in patients with clonal thrombocytosis than secondary thrombocytosis. The aim of this study was to investigate the behaviors of plasminogen activator inhibitor type 1 (PAI-1), the inhibitor of fibrinolysis; and thromboxane A2 and 6-keto-PGF1 alpha, the products of endoperoxides, in 16 patients affected with clonal thrombocytemia as compared with 16 patients with reactive thrombocytosis and 15 normal controls. In the clonal thrombocytemia group, plasma levels of PAI-1 antigen and activity were significantly higher than both reactive thrombocytosis and control group. Plasma levels of 6-keto-PGF1alpha were significantly higher in the clonal thrombocytemia group than the other two groups and also higher in the reactive thrombocytosis group than the control group, which was also significant. This study confirms that arachidonate metabolism is frequently deranged in patients with thrombocytosis and hypofibrinolysis due to increased PAI-1 plasma levels as shown in the clonal thrombocytosis group. This may explain the thrombotic tendency in myeloproliferative disorders.

Enhanced expression of the local haematopoietic bone marrow renin-angiotensin system in polycythemia rubra vera.

Local bone marrow (BM) renin-angiotensin system (RAS) affects physiological and pathological haematopoiesis, including erythropoiesis. In this study, quantitative expression of the messenger RNAs of the major RAS components--angiotensin-converting enzyme (CD143), renin and angiotensinogen--were measured in BM samples by quantitative real-time polymerase chain reaction, to evaluate the activity of local BM RAS in polycythemia rubra vera (PV) in comparison with normal erythropoiesis. The presence of CD143 was also investigated in the same BM samples by flow cytometry. Increased local synthesis of the major RAS components has been identified by demonstrating corresponding mRNAs in the BM of the patients with PV. Our findings indicate up-regulation of local BM RAS, together with down-regulation of the cell surface angiotensin-converting enzyme receptors, in the autonomous neoplastic clonal erythropoiesis of PV.

Acute graft-vs-host disease: pathobiology and management.

Acute graft-vs-host disease (GVHD) is a major obstacle to safe allogeneic hematopoietic stem cell transplantation (HSCT), leading to a significant morbidity and mortality. GVHD occurs when transplanted donor T lymphocytes react to foreign host cells. It causes a wide variety of host tissue injuries. This review focuses on the pathobiological basis, clinical aspects, and current management strategies of acute GVHD. Afferent phase of acute GVHD starts with myeloablative conditioning, i.e., before the infusion of the graft. Total-body irradiation (TBI) or high-dose chemotherapy regimens cause extensive damage and activation in host tissues, which release inflammatory cytokines and enhance recipient major histocompatibility complex (MHC) antigens. Recognition of the foreign host antigens by donor T cells and activation, stimulation, and proliferation of T cells is crucial in the afferent phase. Effector phase of acute GVHD results in direct and indirect damage to host cells. The skin, gastrointestinal tract, and liver are major target organs of acute GVHD. Combination drug prophylaxis in GVHD is essential in all patients undergoing allogeneic HSCT. Steroids have remained the standard for the treatment of acute GVHD. Several clinical trials have evaluated monoclonal antibodies or receptor antagonist therapy for steroid-resistant acute GVHD, with different successes in a variety of settings. There are some newer promising agents like mycophenolate mofetil, glutamic acid-lysine-alanine-tyrosine (GLAT), rapamycin, and trimetrexate currently entering in the clinical studies, and other agents are in development. Future experimental and clinical studies on GVHD will shed further light on the better understanding of the disease pathobiology and generate the tools to treat malignant disorders with allogeneic HSCT with specific graft-vs-tumor effects devoid of GVHD.