New thrombopoietin receptor agonists for platelet disorders.

Since thrombopoietin (TPO) was cloned in 1994, TPO receptor (TPO-R) agonists have been developed which have shown significant clinical activity in various conditions characterized by thrombocytopenia. First-generation TPO-R agonists were recombinant forms of human TPO. The clinical development of these molecules was discontinued after one of them, pegylated recombinant human megakaryocyte growth and development factor, was associated with the development of neutralizing autoantibodies cross-reacting with endogenous TPO. Second-generation TPO-R agonists are now available, which present no sequence homology to endogenous TPO. Two of these new agents, romiplostim and eltrombopag, have been granted marketing authorization for use in patients with primary immune thrombocytopenia unresponsive to conventional treatments. Clinical trials with TPO-R agonists are also ongoing in other thrombocytopenias, such as hepatitis C virus-related thrombocytopenia and the myelodysplastic syndromes.

Measurement of macrophage marker in hyperhaemolytic transfusion reaction: a case report.

BACKGROUND: Hyperhaemolytic transfusion reaction (HHTR) has been well described in patients with sickle cell disease (SCD). It is characterised by a decrease in haemoglobin concentration to levels below those before transfusion and a fall in the absolute reticulocyte count. As red blood cells (RBC) alloantibodies are typically not detected in post-transfusion samples in acute forms of HHTR, we have previously proposed that both the transfused and autologous RBCs cells (HbSS/reticulocytes) are destroyed by activated macrophages. CASE REPORTS: We report a patient with SCD who presented with vaso-occlusive sickle cell crisis and developed a severe HHTR attributable to anti-Fy3. In addition to the usual supportive measures, the patient was treated with intravenous immunoglobulin (IVIG) and steroids. Serum ferritin levels were measured as an aspecific marker of macrophage activation. RESULTS: Steroids and IVIG were effective in managing HHTR. Ferritin levels were high at the time of haemolysis, (>10000 µg L(-1)) whereas recovery and cessation of haemolysis correlated with a decrease in ferritin levels. CONCLUSION: Serum ferritin values >10,000 µg L(-1) are considered pathognomic for conditions characterised by abnormal macrophage activation. In our case, serum ferritin levels correlate well with the disease activity and clinical response. This further supports our previous proposal that the activated macrophages play an important role in HHTR. Serum ferritin is a nonspecific marker of inflammation. A rapid specific bio-marker to measure the activity of macrophages in SCD in HHTR is desirable, and this area warrants further investigation.

An overview of pharmacotherapy for anti-neutrophil cytoplasmic antibody-associated vasculitis.

A number of recently published prospective clinical trials have enabled the definition of the type, duration and intensity of immunosuppressive treatment in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Patients with early or localized nonrenal disease should receive an induction therapy consisting of oral prednisone in combination with oral or parenteral methotrexate. Patients with generalized or severe disease, including those with renal vasculitis, should receive 6-10 pulses of cyclophosphamide over 3-6 months or 3-6 months of daily oral cyclophosphamide plus tailing doses of prednisone. Remission therapy consists of azathioprine plus low-dose prednisone given for at least 18-24 months after the achievement of remission. Despite their efficacy, treatment with conventional agents is associated with a number of problems, including a high number of relapses and considerable morbidity. To overcome these issues, research has focused on novel immunosuppressive drugs, such as mycophenolate mofetil and leflunomide, and on molecular targeted therapy. B-cell depletion with rituximab has been shown to be at least as effective as cyclophosphamide in inducing remission in AAV, but it is not safer. TNF-α blockade with infliximab is a promising strategy for refractory disease, but evidence from controlled trials is still lacking. With increased understanding of the disease, novel agents and therapy principles are rapidly emerging and undergoing clinical testing.

Deregulation of the mitochondrial apoptotic machinery and development of molecular targeted drugs in acute myeloid leukemia.

Apoptosis plays a key role in the control of rapidly renewing tissues, such as the hematopoietic system and leukemia cells invariably have abnormalities in one or more apoptotic pathways, determining a survival advantage of these cells and the development of drug resistance. These defects are also frequently associated with a low rate of response to standard chemotherapy and with a poor survival in acute myeloid leukemia (AML). The major form of apoptosis proceeds through the mitochondrial pathway, with the mitochondrial outer membrane permeabilization, leading to the release of proteins normally found in the space between the inner and outer mitochondrial membranes (cytochrome C, AIF and others). Higher levels of anti-apoptosis proteins bcl-2, bcl-x(L), Mcl-1 block permeabilization of the membrane and are reported in AML patients presenting a poor outcome. On the contrary, activated pro-apoptotic bax or bad proteins allow this permeabilization and are correlated to a good prognosis in AML. Defects in the mitochondrial pathway induce multidrug-resistance and confer important prognostic information in AML. High ratios of bcl-2 to bax protein confer a poor prognosis with decreased rates of complete remission and overall survival. The prognostic information from the ratio of the proteins is greater than bcl-2 levels alone. Recently, we confirmed the impressive impact of the bax/bcl-2 ratio, determined by flow cytometry, on AML prognosis (complete remission and overall survival) in 255 AML patients. Bcl-2 down regulation might lower the apoptotic threshold of leukemic cells and, through this mechanism, favor response to chemotherapy. Phase II studies of oblimersen (antisense Bcl-2), cytarabine and daunorubicin or oblimersen plus gentuzumab, a cytotoxic antibody directed against CD33+ cells in relapsed AMLs, showed promising results. Defects in apoptosome proteins, such as APAF-1, are frequent in AML and treatment with 5-aza-2'-deoxycytidine, a specific inhibitor of DNA methylation, restored APAF-1 expression in leukemic cells. In conclusion, targeted therapies that are designed to induce apoptosis in leukemic cells, are the most promising anti-leukemia strategies. The elucidation of the apoptotic machinery and of its defects in AML lays the basis for developing new drugs able to trigger apoptosis and overcome therapy resistance.

Long-term observation of patients with anti-neutrophil cytoplasmic antibody-associated vasculitis treated with rituximab.

OBJECTIVE: Rituximab, a chimeric anti-CD20 monoclonal antibody, has been shown to be quite effective in the treatment of immune disorders resulting from autoantibodies. We prospectively studied the long-term effects of rituximab in 10 patients with anti-neutrophil cytoplasmic antibody (ANCA)-positive vasculitis refractory to conventional therapy (n=3) or in second or subsequent relapse (n=7). METHODS: The median age of patients was 53 yrs (range 38-70 yrs). Eight were classified as Wegener's granulomatosis, and two as microscopic polyangiitis. Clinical activity was assessed using the Birmingham Vasculitis Activity Score modification for Wegener's granulomatosis. Treatment consisted of intravenous infusions of rituximab given at the dose of 375 mg/m2 weekly for four consecutive weeks. RESULTS: All patients experienced a rapid clinical improvement following the administration of rituximab, with nine complete responses and one partial response at 6 months. With a median follow-up of 33.5 months (range 26-45 months), three patients have thus far relapsed. Retreatment with the monoclonal antibody at the same dose and schedule resulted in a new sustained response in all these patients. Rituximab therapy resulted in prolonged B-cell depletion. The ANCA titres decreased significantly in all patients, with eight out of 10 becoming ANCA-negative and three remaining ANCA-negative even after B-cell recovery. Infusion-related side effects were observed in one patient, but were of mild intensity and did not require discontinuation of treatment. CONCLUSIONS: Rituximab is an effective and well-tolerated treatment for patients with ANCA-associated vasculitis and should be strongly considered in severely affected patients who do not respond to standard therapy or in those in whom cytotoxic therapy bears a high risk of morbidity.

Darbepoetin alfa for the treatment of anemic patients with low- and intermediate-1-risk myelodysplastic syndromes.

BACKGROUND: The hematological and quality of life (QoL) changes associated with darbepoetin alfa (DA) therapy were assessed in anemic patients with previously untreated low- and intermediate-1-risk myelodysplastic syndrome (MDS). PATIENTS AND METHODS: Fifty-three patients received DA administered subcutaneously once a week for 24 weeks. Treatment was initiated at 150 microg fixed dose and was doubled if after the first 12 weeks there was no or suboptimal erythroid response. RESULTS: The final response rate was 24/53 (45%), with 21 major and three minor responses. Most of the responses (21/24; 87.5%) were obtained at the dose of 150 microg. With a median follow-up of 9.4 months, 17 patients maintain their response. Treatment was well tolerated with no relevant side-effects. MDS progression was observed in one case. Increases in hemoglobin levels were positively correlated with improved QoL scores using both the linear analog scale assessment (energy level, r = 0.429, P = 0.036; daily activities, r = 0.653, P < 0.001; overall well-being, r = 0.457, P = 0.024) and the Functional Assessment of Cancer Therapy-Anemia questionnaire (r = 0.247, P = 0.025). In multivariate analysis, only low levels (<200 IU/l) of endogenous erythropoietin predicted response to DA therapy. CONCLUSIONS: DA is an active, safe and well tolerated treatment for anemia in a substantial proportion of patients with low- and intermediate-1-risk MDS, and has a positive impact on the patients' QoL.

Gemtuzumab ozogamicin (Mylotarg) as single-agent treatment for frail patients 61 years of age and older with acute myeloid leukemia: final results of AML-15B, a phase 2 study of the European Organisation for Research and Treatment of Cancer and Gruppo Italiano Malattie Ematologiche dell'Adulto Leukemia Groups.

The therapeutic activity and toxicity profile of gemtuzumab ozogamicin were assessed in 40 patients >60 years of age with acute myeloid leukemia (AML) who were not considered eligible for conventional chemotherapy because of advanced age or poor performance status. The drug was administered at the dose of 9 mg/m2 as a single 2-h i.v. infusion on days 1 and 15. Patients who achieved a complete remission (CR/CRp) were to receive a consolidation with two additional injections of the immunotoxin at the same dose. The overall CR/CRp rate was 17% (95% CI, 8-32%). The CR/CRp rate in patients 61-75 years old was 33% (6/18), and 5% (1/22) in patients older than 75 years. Induction death occurred in seven patients (17%), all aged above 75 years. Overall survival was significantly longer in patients aged 61-75 years than in older individuals (P=0.05), and in CD33+ cases than in CD33- cases (P=0.05). We conclude that the dose/schedule of gemtuzumab ozogamicin used in this trial is too toxic in the age group over 75 years. For these patients, additional studies with reduced doses of the immunotoxin are warranted.

Once-weekly dosing of recombinant human erythropoietin alpha in patients with myelodysplastic syndromes unresponsive to conventional dosing.

BACKGROUND: Once-weekly dosing of recombinant human erythropoietin (rhEPO) in patients with myelodysplastic syndromes (MDS) has not been investigated thoroughly. We performed a clinical trial to evaluate the effects of this new dosing regimen in patients with MDS who were unresponsive to the conventional three-times-weekly schedule. PATIENTS AND METHODS: Forty-eight patients with low- or intermediate-risk MDS were enrolled in a 12-week study. rhEPO alpha (rhEPOalpha) was administered once-weekly by subcutaneous injection with a starting dose of 40,000 U fixed dose. The drug dosage was increased to 60,000 U fixed dose if after 6 weeks there was no or suboptimal erythroid response. RESULTS: Clinically significant responses were seen in 13 (27%) patients, with 11 improving their response after dose escalation of rhEPOalpha. Only one patient (case 23) maintains a response after a follow-up period of 14 months. All other patients had responses lasting between 10 and 43 weeks, with a median time to relapse of 20 weeks. Treatment was well tolerated, with no relevant adverse events. Response to therapy was associated with significantly higher concentrations of circulating erythroid blast-forming units and a decrease of the bone marrow fraction of apoptic CD34+ cells. CONCLUSIONS: Once-weekly rhEPOalpha therapy results in an improvement of erythropoiesis in a subset of MDS patients who are unresponsive to conventional dosing, and may act by inhibiting apoptosis of erythroid precursors. These results warrant further investigation of this dosing regimen either alone or in combination with other agents.

A new mathematical model based on clinical and laboratory variables for the diagnosis of Sjögren's syndrome.

Sjögren's syndrome (SS) is a systemic autoimmune disease that mainly affects exocrine glands. A diagnosis of SS in its early stages has a potential clinical relevance, but it is difficult and cannot be made solely on clinical grounds. Several sets of diagnostic criteria have been proposed, but none has met with a general consensus. Minor salivary gland has been judged to be the "gold standard" for the diagnosis of SS. However, it is a painful procedure and has a small but significant proportion of both false positive and false negative results. The aim of our study was to develop a simple mathematical score that uses clinical and laboratory variables for diagnosing SS, thereby reducing the need of minor salivary gland. The following variables were included in the model: ANA, SS-A/SS-B, Schirmer's Test/BUT, C3/C4, serum gammaglobulin levels. One hundred consecutive individuals reporting clinical syndromes consistent with a sicca syndrome were included in the study. The application of our multifactorial mathematical model has shown a high predictive value for SS vs controls or vs patients with other autoimmune disorders (Sensitivity 93%, Specificity 100%), with an estimated minor salivary gland reduction of 77%. We conclude that our mathematical model can be considered a useful non-invasive approach for diagnosing Sjogren's Syndrome and recommend its validation on a larger scale.

Rituximab chimeric anti-CD20 monoclonal antibody treatment for adults with chronic idiopathic thrombocytopenic purpura.

The role of rituximab, a chimeric monoclonal antibody directed against the CD20 antigen, in the treatment of patients with chronic idiopathic thrombocytopenic purpura (ITP) has not been determined. The effectiveness and side effects of this therapeutic modality were investigated in a cohort of 25 individuals with chronic ITP. All patients had ITP that had been resistant to between 2 and 5 different therapeutic regimens, including 8 patients who had already failed splenectomy. Patients were scheduled to receive intravenous rituximab at the dose of 375 mg/m(2) once weekly for 4 weeks. Rituximab infusion-related side effects were observed in 18 patients, but were of modest intensity and did not require discontinuation of treatment. A complete response (platelet count greater than 100 x 10(9)/L) was observed in 5 cases, a partial response (platelet count between 50 and 100 x 10(9)/L) in 5 cases, and a minor response (platelet count below 50 x 10(9)/L, with no need for continued treatment) in 3 cases, with an overall response rate of 52%. In 7 cases, responses were sustained (6 months or longer). In 2 patients with relapsed disease, repeat challenge with rituximab induced a new response. In patients with a complete or partial response, a significant rise in platelet concentrations was observed early during the course of treatment, usually 1 week after the first rituximab infusion. No clinical or laboratory parameter was found to predict treatment outcome, although there was a suggestion that women and younger patients have a better chance of response. In conclusion, rituximab therapy has a limited but valuable effect in patients with chronic ITP. In view of its mild toxicity and the lack of effective alternative treatments, its use in the setting of chronic refractory ITP is warranted. (Blood. 2001;98:952-957)

Pulsed intravenous high-dose dexamethasone in adults with chronic idiopathic thrombocytopenic purpura.

The role of pulsed high-dose dexamethasone (DXM) in the treatment of patients with chronic idiopathic thrombocytopenic purpura (ITP) is still uncertain. Following an early report in which it was described as an effective and well-tolerated treatment with a sustained platelet response in 100% of cases, a number of subsequent studies have failed to confirm such favorable results. As all these studies were conducted on small numbers of patients, we investigated further the effectiveness and side effects of this therapeutic modality in a larger cohort. Thirty-two patients with chronic ITP were scheduled to receive six monthly courses of intravenous DXM at the dose of 40 mg/day for 4 consecutive days. All patients had ITP that had been resistant to between two and five different therapeutic regimens, including 9 patients who had already failed splenectomy. All patients had to be seen 2 weeks after each cycle to asses their response as well as secondary effects. Three patients failed to respond and clinically required other therapy. Thirteen patients (41%) had a partial (platelet count between 50 and 100 x 10(9)/liter) or complete (platelet count >100 x 10(9)/liter) response to treatment, responses being mostly transient. Responses were observed early during the course of treatment, usually right after the first cycle of DXM. There were no late responses. Side effects were mild and did not require discontinuation of treatment. No clinical or laboratory parameter was found to predict treatment outcome. We conclude that high-dose DXM has a limited effect in patients with chronic ITP. Novel approaches and controlled multicenter trials may help identify new therapeutic strategies for this disease.

AML-M0: a review of laboratory features and proposal of new diagnostic criteria.

In 1991, the FAB group published a proposal to designate acute leukemias with minimal signs of myeloid differentiation as AML-M0. This proposal was meant to offer a provisional basis for the study of immature myeloid forms, with the understanding that it was susceptible to changes and improvements with new information derived from the laboratory. Since then there have been a number of reports detailing the biological and clinical features of patients with AML-M0. In this article we review the laboratory data acquired from various sources and suggest a partial modification of diagnostic criteria.

P-glycoprotein and terminal transferase expression identify prognostic subsets within cytogenetic risk classes in acute myeloid leukemia.

Clinical and biological features were assessed in 204 consecutive de novo adult acute myeloid leukemia (AML) patients who received intensive chemotherapy regimens. Multiparameter flow cytometric assays both of the multidrug resistance (MDR-1)-associated P-glycoprotein (PGP) using the UIC2 monoclonal antibody (MoAb), and of terminal transferase (TdT) were performed. Cytogenetic findings were obtained from 196 patients with high resolution banding. At onset, UIC2 and TdT positivities were detected in 58.5% and 24% of cases, respectively. There were strict correlations either between UIC2 negativity and FAB M3 or between TdT and FAB M0-M1 (P = 0.001 and < 0.0001, respectively). On the other hand, age was significantly associated with cytogenetic risk classes (P < 0.0001). CD34 positivity was highly correlated with TdT expression (P < 0.0001). Moreover, CD7 and CD11b were significantly represented in UIC2+ subset (P < 0.0001). Rhodamine 123 (Rh 123) efflux was significantly higher in 75 UIC2 positive patients compared to 65 UIC2 negative ones (P < 0.001). As regards to cytogenetics, TdT positivity was strongly related either to t(9;22) or single/associated anomalies of chromosome 7; on the other hand, most or all cases with t(8;21) or t(15;17) were UIC2 or TdT negative, respectively. The rate of first complete remission (CR) differed both between UIC2+ and UIC2- cases and between TdT+ and TdT- ones (40% versus 72%, P < 0.001; and 36% versus 61%, P = 0.001, respectively). The survival rates (Kaplan-Meier method) were significantly shorter either in UIC2+ or in TdT+ patients (P = 0.005 and = 0.011, respectively). UIC2 and TdT negative cases showed longer remission duration (P = 0.03 and = 0.22, respectively). The additional effect of UIC2 and TdT on prognosis allowed us to identify two subsets of patients, the first [UIC2- TdT-] at better and the second [UIC2+ TdT+] at worse clinical outcome compared to single UIC2 and TdT cases, concerning CR (P < 0.001), survival (P < 0.0001) and CR duration (P = 0.007). The combinations [UIC2+ TdT-] and [UIC2- TdT+] showed an intermediate clinical course. A strong difference was found between poor risk and intermediate/favorable risk cytogenetic classes with regard to CR rate (P < 0.0001), overall survival and CR duration (P < 0.001). Nevertheless, within the poor risk class, UIC2 positivity was able to identify patients at worst prognosis with regard to CR (P = 0.005), survival (P = 0.02) and CR duration (P = 0.015). On the other hand, UIC2 and TdT negativity allowed us to distinguish patients with longer survival (P = 0.012 and = 0.04, respectively) and CR duration (P = 0.04 and = 0.025, respectively) within the intermediate/favorable risk class. The independent prognostic value of UIC2, TdT and cytogenetic risk classes was confirmed in multivariate analysis. These results suggest that PGP and TdT expressions, together with cytogenetic findings, may represent a basic predictor of chemotherapeutic failure in AML.

Recombinant human granulocyte-macrophage colony-stimulating factor plus erythropoietin for the treatment of cytopenias in patients with myelodysplastic syndromes.

In vitro studies have indicated that granulocyte-macrophage colony-stimulating factor (GM-CSF) synergizes with erythropoietin (EPO) for the production of erythroid precursors in patients with myelodysplastic syndrome (MDS). We performed a clinical trial to evaluate whether the combination of these growth factors was effective in relieving the cytopenias associated with MDS. 31 anaemic patients with low and intermediate-risk primary MDS were enrolled in a 12-week study. Therapy was initiated with GM-CSF at 1 microgram/kg/d.s.c., and then adjusted to either normalize or double the absolute neutrophil count. EPO was given subcutaneously on alternate days starting from day 2. The EPO dose was initiated at 150 U/kg and increased to 300 U/kg if after 6 weeks there was no or suboptimal erythroid response. 26 patients completed the study treatment. All evaluable cases had a neutrophil response. Clinically significant erythroid responses with increases of haemoglobin levels of at least 1 g/dl and/or reduction of transfusion needs were seen in 9/26 (34.6%), five patients improving their response after dose escalation of EPO. Treatment had no apparent effect on mean platelet counts, a single case displaying a trilineage response. An elevated bone marrow erythroid infiltration and low concentrations of circulating tumour necrosis factor-alpha were the only predictors of haemoglobin response both in univariate and in multivariate analysis. We conclude that the combination GM-CSF + EPO can abrogate neutropenia and substantially relieve transfusion requirements in a large proportion of patients with low and intermediate risk MDS. However, in vivo synergy between these growth factors for the production of erythroid precursors is not supported by our data.

The prognostic value of soluble interleukin-6 receptor in patients with multiple myeloma.

BACKGROUND: The effect of interleukin-6 (IL-6), the major growth factor for myeloma cells, may be enhanced by soluble IL-6 receptor (sIL-6R). Therefore, the current study investigated the clinical significance of serum sIL-6R in patients with multiple myeloma (MM). METHODS: Serum levels of sIL-6R were determined by enzyme-linked immunoassay in 55 normal controls, 81 individuals with monoclonal gammopathy of undetermined significance (MGUS), and 164 patients with MM in various phases of the disease. RESULTS: sIL-6R concentrations were higher in MM patients (162.0 +/- 134.6 ng/mL) than in individuals with MGUS (58.9 +/- 36.7 ng/mL) or in controls (45.6 +/- 22.3 ng/mL) (P = 0.0000). sIL-6R was not found to have a significant linear correlation with any other parameter, including IL-6, beta2-microglobulin (beta2-m), and neopterin, either in newly diagnosed cases or during the course of the disease. In addition, there were no statistically significant differences in sIL-6R concentrations between the clinical stages at the time of diagnosis. In univariate logistic regression analysis sIL-6R was a significant but weak prognostic indicator (P = 0.000000). Kaplan-Meier analysis showed that elevated levels of sIL-6R were associated with shorter survival (P = 0.00282). Patients also were stratified according to their serum beta2-m and sIL-6R levels. Patients with low levels of both parameters had a clear survival benefit over the other groups (P = 0.000000). CONCLUSIONS: The correlation between sIL-6R levels and survival is significant but weak, making it unlikely to be of much value in predicting the outcome of patients with MM alone. The results of the current study support the role of sIL-6R levels in improving the prognostic value of beta2-m and in discriminating patients with MM from individuals with MGUS.

Role of human leukocyte interferon-alpha in the treatment of patients with polycythemia vera.

Eighteen patients with polycythemia vera who were less than 60 years old received human leukocyte interferon-alpha subcutaneously at a starting dose of 3 MU three times a week. The interferon dose was escalated to 6 MU three times a week if it was well tolerated and disease was not controlled after 3 months of treatment at the lower dose. Hematologic response was defined as complete if the hematocrit was maintained at less than 45% in the absence of phlebotomy and partial if the hematocrit was kept at 45% to 50%, associated with a 50% or greater reduction of phlebotomy requirements; no response was defined as a response less than a partial response. Complete disease control was achieved in 11 patients, with partial control in a further six cases. One patient failed to respond. Median duration of response was 16 months (range 5 to 43 months), with 15 patients still under treatment. Therapy with human leukocyte interferon-alpha significantly improved (p <.01) phlebotomy requirements, the degree of splenomegaly, pruritus scores, iron stores and mean red cell volume values, and platelet and leukocyte counts. Interferon treatment did not produce remarkable side effects and no patient withdrew from the study because of intolerance. We conclude that subcutaneous human leukocyte interferon-alpha is an effective and well-tolerated therapy in the management of polycythemia vera-associated myeloproliferation and pruritus in patients less than 60 years old.