Marjatta Sinisalo

Clonal expansion of T/NK-cells during tyrosine kinase inhibitor dasatinib therapy.

Dasatinib, a broad-spectrum tyrosine kinase inhibitor (TKI), predominantly targets BCR-ABL and SRC oncoproteins and also inhibits off-target kinases, which may result in unexpected drug responses. We identified 22 patients with marked lymphoproliferation in blood while on dasatinib therapy. Clonality and immunophenotype were analyzed and related clinical information was collected. An abrupt lymphocytosis (peak count range 4–20 × 109/l) with large granular lymphocyte (LGL) morphology was observed after a median of 3 months from the start of therapy and it persisted throughout the therapy. Fifteen patients had a cytotoxic T-cell and seven patients had an NK-cell phenotype. All T-cell expansions were clonal. Adverse effects, such as colitis and pleuritis, were common (18 of 22 patients) and were preceded by LGL lymphocytosis. Accumulation of identical cytotoxic T cells was also detected in pleural effusion and colon biopsy samples. Responses to dasatinib were good and included complete, unexpectedly long-lasting remissions in patients with advanced leukemia. In a phase II clinical study on 46 Philadelphia chromosome-positive acute lymphoblastic leukemia, patients with lymphocytosis had superior survival compared with patients without lymphocytosis. By inhibiting immunoregulatory kinases, dasatinib may induce a reversible state of aberrant immune reactivity associated with good clinical responses and a distinct adverse effect profile.

Combination of pegylated IFN-alpha 2b with imatinib increases molecular response rates in patients with low- or intermediate-risk chronic myeloid leukemia

Biologic and clinical observations suggest that combining imatinib with IFN-α may improve treatment outcome in chronic myeloid leukemia (CML). We randomized newly diagnosed chronic-phase CML patients with a low or intermediate Sokal risk score and in imatinib-induced complete hematologic remission either to receive a combination of pegylated IFN-α2b (Peg-IFN-α2b) 50 μg weekly and imatinib 400 mg daily (n = 56) or to receive imatinib 400 mg daily monotherapy (n = 56). The primary endpoint was the major molecular response (MMR) rate at 12 months after randomization. In both arms, 4 patients (7%) discontinued imatinib treatment (1 because of blastic transformation in imatinib arm). In addition, in the combination arm, 34 patients (61%) discontinued Peg-IFN-α2b, most because of toxicity. The MMR rate at 12 months was significantly higher in the imatinib plus Peg-IFN-α2b arm (82%) compared with the imatinib monotherapy arm (54%; intention-to-treat, P = .002). The MMR rate increased with the duration of Peg-IFN-α2b treatment (< 12-week MMR rate 67%, > 12-week MMR rate 91%). Thus, the addition of even relatively short periods of Peg-IFN-α2b to imatinib markedly increased the MMR rate at 12 months of therapy. Lower doses of Peg-IFN-α2b may enhance tolerability while retaining efficacy and could be considered in future protocols with curative intent.

Response to vaccination against different types of antigens in patients with chronic lymphocytic leukaemia

We investigated responses to vaccination against pneumococcal polysaccharide, Haemophilus influenzae b (Hib) conjugate and tetanus toxoid antigens in 31 patients with chronic lymphocytic leukaemia (CLL) and 25 controls. While in the control group all antibody responses against different antigens were highly significant, in the patient group clear evidence for responsiveness was detected only in the case of Hib polysaccharide antigen. Certain CLL patient subgroups showed low reactivity against tetanus toxoid antigen. In conclusion, plain polysaccharide vaccines seem to be ineffective in patients with CLL. Conjugate vaccines, in turn, are immunogenic and may offer protection against infections caused by encapsulated bacteria in these patients. Further studies concerning an optimal vaccination scheme and clinical efficiency are warranted.

Vaccination Against Infections in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is a well-defined mature B-cell neoplasm associated with increased susceptibility to infections. Two major options in prevention of infections in CLL, intravenous gammaglobulin treatment and antimicrobial chemoprophylaxis, have not resulted in satisfactory outcome. A third strategy, antimicrobial vaccination, is the topic of this minireview. We collected articles and their references concerning CLL vaccination from the Medline database starting from 1966 and thirteen relevant studies were found. Plain bacterial polysaccharide vaccines would seem to be ineffective in antibody formation in patients with CLL. However, protein and conjugate vaccines appear to be more immunogenic and their responses may be further enhanced with ranitidine adjuvant treatment. New well-designed investigations are needed to develop appropriate vaccination strategies and evaluate vaccination efficacy in infection morbidity and mortality in CLL.

Chronic Myeloid Leukemia Patients in Prolonged Remission following Interferon-α Monotherapy Have Distinct Cytokine and Oligoclonal Lymphocyte Profile

Before the era of tyrosine kinase inhibitors (TKIs), interferon-alpha (IFN-α) was the treatment of choice in chronic myeloid leukemia (CML). Curiously, some IFN-α treated patients were able to discontinue therapy without disease progression. The aim of this project was to study the immunomodulatory effects of IFN-α in CML patients in prolonged remission and isolate biological markers predicting response. Due to rarity of patients on IFN-α monotherapy, a relatively small cohort of patients still on treatment (IFN-ON, n = 10, median therapy duration 11.8 years) or had discontinued IFN-α therapy but remained in remission for >2 years (IFN-OFF, n = 9) were studied. The lymphocyte immunophenotype was analyzed with a comprehensive flow cytometry panel and plasma cytokine levels were measured with multiplex bead-based assay. In addition, the clonality status of different lymphocyte subpopulations was analyzed by TCR γ/δ rearrangement assay. Median NK-cell absolute number and proportion from lymphocytes in blood was higher in IFN-OFF patients as compared to IFN-ON patients or controls (0.42, 0.19, 0.21×109/L; 26%, 12%, 11%, respectively, p<0.001). The proportion of CD8+ T-cells was significantly increased in both patient groups and a larger proportion of T-cells expressed CD45RO. Most (95%) patients had significant numbers of oligoclonal lymphocytes characterized by T-cell receptor γ/δ rearrangements. Strikingly, in the majority of patients (79%) a distinct clonal Vγ9 gene rearrangement was observed residing in γδ+ T-cell population. Similar unique clonality pattern was not observed in TKI treated CML patients. Plasma eotaxin and MCP-1 cytokines were significantly increased in IFN-OFF patients. Despite the limited number of patients, our data indicates that IFN-α treated CML patients in remission have increased numbers of NK-cells and clonal γδ+ T-cells and a unique plasma cytokine profile. These factors may relate to anti-leukemic effects of IFN-α in this specific group of patients and account for prolonged therapy responses even after drug discontinuation.

Haemophilus Influenzae Type b (Hib) Antibody Concentrations and Vaccination Responses in Patients with Chronic Lymphocytic Leukaemia: Predicting Factors for Response

We have recently demonstrated a moderate vaccination response rate of 43% against Haemophilus influenzae type b (Hib) conjugate vaccine among adult and elderly patients with chronic lymphocytic leukaemia (CLL). We now investigated demographic and immunological factors predicting the favourable response and protective antibody concentrations for Hib conjugate vaccine in CLL. Lower age was associated with protective pre- and post-vaccination antibody concentrations. High IgG1 and IgA concentrations were also associated with the protective efficacy. High IgM, in turn, was the best predictor of a significant vaccination response. Again, lower age seemed to be involved in this outcome. Judging from these findings, it would seem beneficial to vaccinate all CLL patients with conjugate vaccines at the presentation of the disease. Investigations of a new pneumococcal conjugate vaccine in CLL are warranted.

Thrombopoietin receptor agonists can be used temporarily with patients suffering from refractory chronic lymphocytic leukemia-associated immunologic thrombocytopenia

The second-generation thrombopoietin receptor (TPO-R) agonists (romiplostim and eltrombopag) were introduced in the treatment of chronic immunologic thrombocytopenia (ITP) approximately 2 years ago. Their use in ITP was recently reviewed by, for example, Stasi and colleagues [1] and Newland [2]. Chronic lymphocytic leukemia (CLL) is sometimes associated with ITP, which proves highly refractory under several conventional therapies. These agents are not as yet indicated in CLL, but there is one case report on the treatment of CLLassociated ITP with eltrombopag [3]. We have used TPO-R agonists temporarily before surgical procedures to increase the platelet count in patients with CLL-associated ITP. Here, we report on two patients who responded very quickly to the TPO-R agonist romiplostim. Surgical procedures could be safely undertaken thereafter. Patient 1 is a 64-year-old man diagnosed with Binet A stage CLL in 2004. His bone marrow showed 50% lymphocyte infiltration without any high-risk features in fluorescence in situ hybridization (FISH) analysis, and he had no splenomegaly or lymphadenopathy. Since diagnosis his major problem and the only indication for treatment has been thrombocytopenia. He has had petechiae and occasional nose-bleeding, with a platelet count below 206 10/L, but no major hemorrhage. Over the years he has received prednisolone, chlorambucil, several intravenous immunoglobulin infusions (ivig), and a weekly standard dose of rituximab for 4 weeks. None of these treatments led to a sustained response. Eventually splenectomy was planned, and to increase his platelet count to a safe level prior to surgery, he received romiplostim injections. Weekly romiplostim was started in June 2009, when his platelet count was 116 10/L, and within 3 weeks the count rose to 1036 10/L. Prior to splenectomy his platelet count was 2386 10/L; romiplostim was discontinued and laparoscopic splenectomy was performed in August 2009. His prednisolone dose was tapered from 40 mg to 10 mg daily. Unfortunately, 4 weeks after the splenectomy his platelet count dropped to 56 10/L, he had bleeding, and romiplostim treatment was resumed. Patient 2 is a 62-year-old man with a 3-year history of CLL. At diagnosis he had hematuria, mild splenomegaly, and lymphadenopathy. He had marked thrombocytopenia, his platelet count being only 86 10/L, but there was no other indication for CLL treatment. The disease was Binet A stage with thrombocytopenia, and there was 60% lymphocyte infiltration in the bone marrow. FISH analysis was not performed. He responded poorly to prednisolone and the responses to ivig and standard-dose rituximab treatments were transient. Splenectomy was not undertaken. He had markedly cariotic teeth, and to remove all potential infectious focuses possibly sustaining the thrombocytopenia, tooth extraction was planned. To increase his platelet count to a safe level, romiplostim was initiated, and 1 week after the first injection he reached a platelet count of 1106 10/L. All cariotic teeth were removed, and he has not received romiplostim since.

Headache and low platelets in a patient with acute leukemia

Department of Internal Medicine, Tampere University Hospital, Tampere, Finland Department of Virology, Haartman Institute, University of Helsinki, Helsinki, Finland Department of Virology, Helsinki University Hospital Laboratory (HUSLAB), Helsinki, Finland Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland Finnish Red Cross Blood Service, Helsinki, Finland

Etiology, clinical course and outcome of healthcare-associated bloodstream infections in patients with hematological malignancies: a retrospective study of 350 patients in a Finnish tertiary care hospital.

This retrospectively collected laboratory-based surveillance data includes 575 healthcare-associated bloodstream infections (BSIs) in 350 patients with hematological malignancy in Tampere University Hospital, Finland, during 1999–2001 and 2005–2010. The most common underlying diseases were acute myelogenous leukemia (n = 283, 49%), followed by myeloma (n = 87, 15%) and acute lymphocytic leukemia (n = 76, 13%). The overall rate was 9.1 BSIs per 1000 patient-days. Gram-positive BSIs predominated and the most common pathogens were coagulase-negative staphylococci (23%), viridans streptococci (11%), enterococci (9%) and Escherichia coli (9%). Fungi caused 2% of BSIs. The 7-day and 28-day case fatalities were 5% and 10% and were highest in BSIs caused by P. aeruginosa (19% and 34%, respectively). The median age of patients with BSI has increased; it was 55.0 years during 1999–2001, compared to 59.0 years in 2005–2007 and 59.0 years in 2008–2010 (p < 0.0001). Gram-positive bacteria predominated in this material. Case fatalities were low as compared to previous reports although the median age of patients increased.

Indoleamine 2,3-Dioxygenase Activity and Expression in Patients With Chronic Lymphocytic Leukemia

UNLABELLED Indoleamine 2,3-dioxygenase (IDO) activity and expression is increased in many hematological malignancies, but has not been previously studied in chronic lymphocytic leukemia (CLL). We determined IDO activity and expression in 49 patients with CLL. We found that IDO activity is increased in CLL. This may have some influence on CLL progression. BACKGROUND Indoleamine 2,3-dioxygenase (IDO) is an enzyme involved in the catabolism of tryptophan, suppressing T-cell activity. IDO activity and expression are increased in many malignant diseases, including hematological malignancies. IDO expression can mediate immunotolerance to tumors. IDO activity and expression have not previously been studied in chronic lymphocytic leukemia (CLL). METHODS We measured IDO activity by calculating the kynurenine-tryptophan (kyn-trp) ratio. IDO and IDO2 gene expression was determined by using real-time polymerase chain reaction (PCR). RESULTS In patients with CLL, the serum kyn-trp ratio--reflecting increased IDO activity--was significantly higher compared with controls, but in peripheral blood mononuclear cells (PBMCs)--mainly representing malignant B cells--the expression of genes encoding IDO and IDO2 enzymes was reduced. CONCLUSIONS Increased IDO activity in patients with CLL may affect disease progression, although it originates from cells other than malignant B cells.