The impact of SF3B1 mutations in CLL on the DNA-damage response.

Mutations or deletions in TP53 or ATM are well-known determinants of poor prognosis in chronic lymphocytic leukemia (CLL), but only account for approximately 40% of chemo-resistant patients. Genome-wide sequencing has uncovered novel mutations in the splicing factor sf3b1, that were in part associated with ATM aberrations, suggesting functional synergy. We first performed detailed genetic analyses in a CLL cohort (n=110) containing ATM, SF3B1 and TP53 gene defects. Next, we applied a newly developed multiplex assay for p53/ATM target gene induction and measured apoptotic responses to DNA damage. Interestingly, SF3B1 mutated samples without concurrent ATM and TP53 aberrations (sole SF3B1) displayed partially defective ATM/p53 transcriptional and apoptotic responses to various DNA-damaging regimens. In contrast, NOTCH1 or K/N-RAS mutated CLL displayed normal responses in p53/ATM target gene induction and apoptosis. In sole SF3B1 mutated cases, ATM kinase function remained intact, and γH2AX formation, a marker for DNA damage, was increased at baseline and upon irradiation. Our data demonstrate that single mutations in sf3b1 are associated with increased DNA damage and/or an aberrant response to DNA damage. Together, our observations may offer an explanation for the poor prognosis associated with SF3B1 mutations.

Ibrutinib-induced lymphocytosis in patients with chronic lymphocytic leukemia: correlative analyses from a phase II study.

Ibrutinib and other targeted inhibitors of B-cell receptor signaling achieve impressive clinical results for patients with chronic lymphocytic leukemia (CLL). A treatment-induced rise in absolute lymphocyte count (ALC) has emerged as a class effect of kinase inhibitors in CLL and warrants further investigation. Here we report correlative studies in 64 patients with CLL treated with ibrutinib. We quantified tumor burden in blood, lymph nodes (LNs), spleen and bone marrow, assessed phenotypic changes of circulating cells and measured whole-blood viscosity. With just one dose of ibrutinib, the average increase in ALC was 66%, and in>40% of patients the ALC peaked within 24 h of initiating treatment. Circulating CLL cells on day 2 showed increased Ki67 and CD38 expression, indicating an efflux of tumor cells from the tissue compartments into the blood. The kinetics and degree of the treatment-induced lymphocytosis was highly variable; interestingly, in patients with a high baseline ALC the relative increase was mild and resolution rapid. After two cycles of treatment the disease burden in the LN, bone marrow and spleen decreased irrespective of the relative change in ALC. Whole-blood viscosity was dependent on both ALC and hemoglobin. No adverse events were attributed to the lymphocytosis.

Treatment of older patients with mantle-cell lymphoma.

BACKGROUND: The long-term prognosis for older patients with mantle-cell lymphoma is poor. Chemoimmunotherapy results in low rates of complete remission, and most patients have a relapse. We investigated whether a fludarabine-containing induction regimen improved the complete-remission rate and whether maintenance therapy with rituximab prolonged remission. METHODS: We randomly assigned patients 60 years of age or older with mantle-cell lymphoma, stage II to IV, who were not eligible for high-dose therapy to six cycles of rituximab, fludarabine, and cyclophosphamide (R-FC) every 28 days or to eight cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) every 21 days. Patients who had a response underwent a second randomization to maintenance therapy with rituximab or interferon alfa, each given until progression. RESULTS: Of the 560 patients enrolled, 532 were included in the intention-to-treat analysis for response, and 485 in the primary analysis for response. The median age was 70 years. Although complete-remission rates were similar with R-FC and R-CHOP (40% and 34%, respectively; P=0.10), progressive disease was more frequent with R-FC (14%, vs. 5% with R-CHOP). Overall survival was significantly shorter with R-FC than with R-CHOP (4-year survival rate, 47% vs. 62%; P=0.005), and more patients in the R-FC group died during the first remission (10% vs. 4%). Hematologic toxic effects occurred more frequently in the R-FC group than in the R-CHOP group, but the frequency of grade 3 or 4 infections was balanced (17% and 14%, respectively). In 274 of the 316 patients who were randomly assigned to maintenance therapy, rituximab reduced the risk of progression or death by 45% (in remission after 4 years, 58%, vs. 29% with interferon alfa; hazard ratio for progression or death, 0.55; 95% confidence interval, 0.36 to 0.87; P=0.01). Among patients who had a response to R-CHOP, maintenance therapy with rituximab significantly improved overall survival (4-year survival rate, 87%, vs. 63% with interferon alfa; P=0.005). CONCLUSIONS: R-CHOP induction followed by maintenance therapy with rituximab is effective for older patients with mantle-cell lymphoma. (Funded by the European Commission and others; ClinicalTrials.gov number, NCT00209209.).

Standard-dose anti-CD20 antibody rituximab has efficacy in chronic lymphocytic leukaemia: results from a Nordic multicentre study.

OBJECTIVES: This prospective multicentre study was conducted to assess the efficacy of the monoclonal anti-CD20 antibody rituximab in patients with chronic lymphocytic leukaemia (CLL). Secondary objectives were defined as the tolerability and feasibility of rituximab in patients with CLL. METHODS: Twenty-four heavily pretreated patients with CLL were treated with a standard dose of 375 mg m-2 of rituximab given once weekly for four doses. RESULTS: The overall response rate was 35% and all the responses were partial as defined by the revised NCI criteria. In 17 (85%) of 20 patients with initially measurable peripheral lymph nodes the size of lymph nodes decreased by at least 50%, while an improvement of the bone marrow infiltration was observed only in two (11%) of 18 evaluable patients. The median duration of the overall response was 12.5 wk. Rituximab was relatively well tolerated. Although side-effects were common (75%) they were usually mild or moderate. There was only one grade 3 adverse event and no grade 4 events. CONCLUSIONS: Standard-dose rituximab has activity in heavily pretreated patients with CLL, although the response is mainly limited to the lymph nodes and of short duration. Since rituximab has in vitro synergism with chemotherapeutic agents and is well tolerated by CLL patients, it is reasonable to investigate rituximab in combination with other treatments.

A Danish population-based analysis of 105 mantle cell lymphoma patients: incidences, clinical features, response, survival and prognostic factors.

This study presents the first large clinical analysis of 105 unselected mantle cell lymphoma (MCL) patients diagnosed from 1992 to 2000 in a well-defined Danish population. The annual incidences were 0.7/100000 for men and 0.2/100000 for women, with no significant change during the study period. Of 97 evaluable cases, 43% achieved a complete response (CR) after initial therapy. The median disease-free (DFS) and overall survival (OS) rates were 15 and 30 months, respectively. In multivariate analysis, splenomegaly (P=0.002), anaemia (P=0.0001) and age (P=0.002), but not the international prognostic index (IPI) and the Ann Arbor staging system, had an independent impact on survival. Moreover, in a sub-analysis of 45 younger MCL patients (<65 years), a trend towards an OS plateau of 58% was observed in cases without splenomegaly and anaemia (n=29). Thus, in contrast to previously suggested prognostic factors, these variables may prove useful for clinical decisions in a significant subset of MCL patients.

Recruitment of CD34+ cells during large-volume leukapheresis.

Mobilized peripheral blood stem and progenitor cells (PBPCs) are increasingly used to restore hematopoiesis after myeloablative treatment. To obtain a sufficient number of CD34(+) cells, many studies have focused on the improvement of the collection technique during the leukapheresis procedure (LP), and so-called large-volume leukapheresis (LVL) procedures have been developed. Such procedures can be performed by extending the duration of the LP and/or by increasing the inlet flow rate. However, no previous studies have compared the efficiency of these procedures. In the present study, we compared the kinetics of PBPCs recruitment (including CD34(+) cell subsets), the PBPCs yield, and the collection efficiency as well as the overall feasibility of the procedures during a single LVL performed by standard (group I) (median 85 ml/min; range 50-97 ml/min) and high inlet flow rates (group II) (median 130 ml/min; range 110-150 ml/min). Seven patients with hematological malignancies were enrolled and allocated to each group. The patients' blood volumes (BV) were processed four times. The apheresis product (AP) was collected in four separate bags, which were changed every time one BV had been processed. The CD34(+) cell number and CD34(+) cell subsets were assessed in the four collection bags and in peripheral blood (PB) before every time one BV had been processed and after the leukapheresis. The CD34(+) cell yield exceeded the pre-apheresis CD34(+) cell number per ml BV in 6 out of 7 patients in group I and in 3 out of 7 patients in group II. In group II, the recruitment of CD34(+) cells from the bone marrow (BM) to PB starts in the second collection period--as early as 30-60 min after initiating the procedure. No exhaustion in the recruitment was observed in the two groups for at least 5 h during the leukapheresis, and all CD34(+) cell subsets were recruited at a steady rate. However, the collection efficiency in group II was only half of that in group I. In addition, we experienced many technical problems during the leukapheresis in group II. Thus, in 4 out of 7 patients in this group, it was not possible to perform the maximal inlet flow rate because of catheter problems. In conclusion, due to the technical problems associated with the high inlet flow rate procedure and the fact that the relative number of CD34(+) cells harvested and recruited during the leukapheresis was higher in group I than II and, also reflected an approximately two-fold higher collection efficiency, we recommend that LVL be performed by standard inlet flow rate.

Soluble CD40 ligand induces selective proliferation of lymphoma cells in primary mantle cell lymphoma cell cultures.

Interaction between CD40 and the CD40 ligand (CD40L) is critical for the survival and proliferation of B cells during immunopoiesis. However, the role of CD40L in the pathogenesis of malignant lymphomas is ambiguous. Primary mantle cell lymphoma (MCL) cells were cultured in the presence of recombinant human CD40L trimer (huCD40LT), and a significant time- and dose-dependent induction of DNA synthesis was observed in thymidine incorporation assays (n = 7, P <.04). The maximal rate of DNA synthesis was reached at huCD40LT doses of 100 ng/mL and above after 4 days of culture, but a significant increase of DNA synthesis was detected already at doses of 1 ng/mL (P =.03). HuCD40LT never inhibited the basal level of DNA synthesis. These findings established 400 ng/mL of huCD40LT for 4 days as standard conditions in the system. Under these conditions, huCD40LT significantly increased the proportion of cells in the S/G(2)/M phases of the cell cycle in 4 of 7 studied cases, while the fraction of apoptotic cells remained unchanged (n = 7). HuCD40LT also induced expression of CD80/B7-1, CD86/B7-2, and CD95/Fas and up-regulated the expression of HLA-DR (n = 6). With the use of bromodeoxyuridine incorporation in triple-color flow cytometric analysis, it was found that huCD40LT induced cell-cycle progression in light chain-restricted cells only, of which a median of 14% (range, 0.5% to 29%; n = 4) returned to G(0/1) phase DNA content after bromodeoxyuridine incorporation, demonstrating completion of at least one cell cycle in the presence of huCD40LT. Thus, primary clonal MCL cells are activated and can proliferate in the presence of huCD40LT as a single agent.

S-phase induction by interleukin-6 followed by chemotherapy in patients with chronic lymphocytic leukemia and non-Hodgkin's lymphoma.

Interleukin-6 (IL-6) has in vitro demonstrated growth regulatory effects on tumor cells from patients with chronic lymphocytic leukemia (CLL) and lymphoma. The proliferation rate of these cells is usually very low and this is thought to be one of the reasons for the lack of a curative potential of cytostatic chemotherapy in CLL and low grade NHL. Recombinant human (rh) IL-6 might increase the in vivo proliferation rate leading to a higher sensitivity for chemotherapy. We tested this hypothesis by administering rhIL-6 to 9 CLL patients and 3 NHL patients in doses of 2.5 micrograms/kg, 5 micrograms/kg and 10 micrograms/kg s.c. daily for 5 days followed by CHOP chemotherapy on the last day of rhIL-6 injection. Six patients had two treatment cycles. The proportion of cells in S-phase was determined by the bromodeoxyuridine labeling index (LI). Three patients achieved a partial remission, one patient had progressive disease and the remaining patients demonstrated no change. Two patients, who received 10 micrograms/kg/day rhIL-6, demonstrated a significant increase in LI, one of these was first observed in the second treatment cycle. A significant decrease was seen in two patients receiving 2.5 micrograms/kg and 5 micrograms/kg respectively. Immunophenotypic assessment demonstrated that rhIL-6 increased the expression of CD20 in all CLL patients with a reversal after cessation of rhIL-6. We conclude that rhIL-6, in the dosage and schedule used in this study, did not increase the proportion of the cells in S-phase and that the growth stimulatory effects of rhIL-6 in CLL in vivo probably are insignificant. However, the role of rhIL-6 in CLL as inducer of increased CD20 expression prior to anti-CD20 antibody treatment remains to be determined.

Linear reduction of clonal cells in stem cell enriched grafts in transplanted multiple myeloma.

In 30 patients with multiple myeloma who were scheduled for peripheral blood stem-cell transplantation, a quantitative analysis of the stem cells following enrichment by anti-CD34 was carried out. To detect the cells of the specific myeloma clone, polymerase chain reaction (PCR) was performed using unique allele-specific oligo primers for the immunoglobulin heavy chain rearrangement. The clonogenic cells before and after stem-cell enrichment, were quantified by a limiting dilution assay and a highly sensitive semi-nested PCR combined with a real-time quantitative PCR. In order to accomplish a statistically adequate end-point analysis, a large number of PCR analyses (40 per sample) were performed. By this technique the lowest detection limit observed was one myeloma cell per 106 cells. Myeloma cells were detected in 29/30 samples from the CD34-enriched fraction. The CD34 selection procedure resulted in a median 28-fold enrichment of CD34+ haemopoietic precursor cells. The stem-cell selection reduced the median concentration of clonal cells per million total cells by half, with a highly significant linear relationship between the number of myeloma cells before and after stem cell enrichment. The median depletion of clonal cells by the overall procedure was 2.15 log units, corresponding to a reduction of the total quantity of clonal cells reinfused into the patients by at least 99.3%. We conclude that CD34+ cell enrichment led to a reliable tumour cell depletion of the order of 2 log, which may not be sufficient since the total number of tumour cells in the leukapheresis product was 7.2 log (median).

BEAM+autologous stem cell transplantation in malignant lymphoma: 100 consecutive transplants in a single centre. Efficacy, toxicity and engraftment in relation to stem-cell source and previous treatment.

One hundred consecutive patients with malignant lymphoma treated with high-dose chemotherapy and autologous stem cell transplantation, followed at least 1 yr post-transplant, are reported, 68 with non-Hodgkin's lymphoma and 32 with Hodgkin's disease. At transplant, 23 patients were in first remission, 69 in later chemosensitive disease and 8 were chemotherapy resistant. Based on previous treatment and stem-cell source, the patients were subdivided into 3 cohorts: BMT1: bone-marrow harvest and transplant after > or =3 treatment regimens (38 patients); BMT2: bone marrow harvest and transplant after less than 3 treatment regimens (24 patients); PBSCT: peripheral-blood stem cell transplant (38 patients, 5 of these with CD34+ cell selected PBSC). The 4-yr survival and progression-free survival of all patients was 45 and 40%, respectively. Forty-one patients have died, 27 of lymphoma, evenly distributed in the cohorts. Fourteen treatment-related deaths occurred, 13 of these in the BMT1 cohort, significantly more than in the other cohorts (p=0.001). In univariate survival analysis cohort, age, disease status at transplant and number of previous treatment regimens were significant. In multivariate survival analysis cohort, age and sex were independently significant, women having a shorter survival. The patients transplanted with unselected PBSC had significantly shorter duration of pancytopenia and hospital stay than the otherwise comparable BMT2 patients, but their progression-free survival was identical. We confirm that high-dose therapy with autologous stem cell transplant from blood or bone marrow in not-too-heavily pretreated patients is a safe procedure but will cure only half the patients.

The prognostic significance of chromosomal analysis and immunophenotyping in 117 patients with de novo acute myeloid leukemia.

Chromosomal abnormalities is one of the most important prognostic factors in acute myeloid leukemia (AML). Other parameters which may influence the prognosis include age, French-American-British-type, clinical variables and possibly the expression of certain immunophenotypic surface makers. However, only rarely has the expression of these markers been analyzed in multivariate models including the information from cytogenetics and clinical variables. We conducted a retrospective study of 117 consecutive adult patients with de novo AML diagnosed and treated in our institution during a 6-year period. Following standard induction chemotherapy with daunomycin and cytosine arabinoside 75 patients (64%) achieved complete remission (CR). The overall 5 year survival rate was 23% and, for patients achieving CR, 30%. When all patients were analyzed age, chromosomal aberration and lack of CD33 expression were of independent prognostic value. The overall 5 year survival rate was 28% for patients aged 55 years or younger, 25% for patients aged 56-65 years and 4% for those > 65 years, P = 0.041. Patients with good-risk chromosomal abnormalities presented an overall 5 year survival of 36%, compared to 25% in patients with normal karyotype, 22% in patients with intermediate risk abnormalities and 5% in patients with poor-risk abnormalities, P = 0.004. Patients with CD33+ myeloblasts had an overall survival of 25% at 5 years compared to 0% in the CD33- patients, P = 0.021. Analysis of the expression of CD7, CD34 and terminal deoxynucleotidyl transferase on myeloblasts had no impact on overall survival in a multivariate analysis. Thus, this study confirmed the prognostic value of age and cytogenetic risk group and defined CD33 as a novel factor of independent prognostic importance in adult de novo AML.

Characterization of interleukin-10 receptor expression on B-cell chronic lymphocytic leukemia cells.

B-cell chronic lymphocytic leukemia (B-CLL) cells accumulate in vivo in the G0/G1 phase of the cell cycle, suggesting that their malignant expansion is due, at least in part, to a delay in cell death. However, the cellular or molecular factors responsible for a delay in B-CLL cell death are unknown. B-CLL cells do express receptors for interferon-alpha (IFN-alpha) and IFN-gamma, and activation of both has been shown to promote B-CLL survival in vitro by preventing apoptosis. The interleukin-10 (IL-10) receptor is another member of the IFN receptor family, but its ligand, IL-10, has been reported to induce apoptosis in B-CLL cells. In the current study, we undertook a biochemical analysis of IL-10 receptor expression on freshly isolated B-CLL cells and characterized the functional responsiveness of IL-10 binding to its constitutively expressed receptor. We show that B-CLL cells bind IL-10 with significant specificity and express between 47 and 127 IL-10 receptor sites per cell, with a dissociation constant in the range of 168 to 426 x 10(-12) mol/L. Ligand binding and activation of the IL-10 receptor expressed on B-CLL cells results in the phosphorylation of signal transducer and activator of transcription 1 (STAT1) and STAT3 proteins. This pattern of STAT protein phosphorylation is identical to IL-10 receptor activation on normal cells and similar to IFN-alpha (STAT1 and STAT3) and IFN-gamma (STAT1) receptor activation in CLL. Further, in consecutive samples of fresh blood obtained from patients with B-CLL cells, the addition of IL-10 inhibited B-CLL proliferation, enhanced B-CLL differentiation, but did not induce apoptosis. Indeed, IL-10, like IFN-gamma, was able to significantly reduce the amount of B-CLL cell death caused by hydrocortisone-induced apoptosis. We conclude that cytokines, which signal through the interferon family of receptors, have comparable functional effects on B-CLL cells.

In B-cell chronic lymphocytic leukaemia chromosome 17 abnormalities and not trisomy 12 are the single most important cytogenetic abnormalities for the prognosis: a cytogenetic and immunophenotypic study of 480 unselected newly diagnosed patients.

Of 560 consecutive, newly diagnosed untreated patients with B CLL submitted for chromosome study, G-banded karyotypes could be obtained in 480 cases (86%). Of these, 345 (72%) had normal karyotypes and 135 (28%) had clonal chromosome abnormalities: trisomy 12 (+12) was found in 40 cases, 20 as +12 alone (+12single), 20 as +12 with additional abnormalities (+12complex). Other frequent findings included abnormalities of 14q, chromosome 17, 13q and 6q. The immunophenotype was typical for CLL in 358 patients (CD5+, Slg(weak), mainly FMC7-) and atypical for CLL in 122 patients (25%) (CD5-, or Slg(strong) or FMC7+). Chromosome abnormalities were found significantly more often in patients with atypical (48%) than in patients with typical CLL phenotype (22%) (P < 0.00005). Also +12complex, 14q+, del6q, and abnormalities of chromosome 17 were significantly more frequent in patients with atypical CLL phenotype, whereas +12single was found equally often in patients with typical and atypical CLL phenotype. The cytomorphology of most of the +12 patients was that of classical CLL irrespective of phenotype. In univariate survival analysis the following cytogenetic findings were significantly correlated to a poor prognosis: chromosome 17 abnormalities, 14q+, an abnormal karyotype, +12complex, more than one cytogenetic event, and the relative number of abnormal mitoses. In multivariate survival analysis chromosome 17 abnormalities were the only cytogenetic findings with independent prognostic value irrespective of immunophenotype. We conclude that in patients with typical CLL immunophenotype, chromosome abnormalities are somewhat less frequent at the time of diagnosis than hitherto believed. +12single is compatible with classical CLL, and has no prognostic influence whereas chromosome 17 abnormalities signify a poor prognosis. In patients with an atypical CLL immunophenotype, chromosome abnormalities including +12complex, 14q+, del 6q and chromosome 17 are found in about 50% of the patients, and in particular chromosome 17 abnormalities suggest a poor prognosis.

The bone-marrow infiltration pattern in B-cell chronic lymphocytic leukemia is not an important prognostic factor. Danish CLL Study Group.

In a multicentre study of 635 consecutive newly diagnosed patients with B-CLL, the histological bone marrow (BM) specimens were reviewed independently by each of 3 pathologists and found evaluable for BM infiltration pattern in 575 patients, 404 of whom had a CD5+, mainly FMC7-, faint surface-membrane immunoglobulin (SIg) fluorescence-intensity ppenotype. In these 404 patients the following BM infiltration patterns were found: mixed nodular-interstitial (30%), moderate interstitial (44%), heavy interstitial (20%) and diffuse packed (6%). In univariate survival analysis, significant differences were found according to BM pattern (p < 0.05), the presence of nodules being a favorable prognostic sign. In multivariate survival analysis in a model including age, clinical stage, BM pattern, BM lymphocytosis, WBC and sex, only age and stage but not BM pattern or BM lymphocytosis had independent prognostic significance. In stage A, progression-free survival was significantly longer in patients with nodular than in patients with non-nodular bone-marrow pattern. The overall survival of these patients, however, did not differ, possibly owing to the prompt and prolonged treatment given to most patients at the time of progression to stage B or C. We conclude that in CD5+, SIg(faint), mainly FMC7-B-CLL, bone-marrow histology may predict unstable disease in early clinical stage but is not important for treatment decisions, when these are based on clinical stage.

[Autologous stem cell transplantation. From bone marrow to selected blood stem cells: 100 consecutive procedures at a single center]. / Autolog stamcelletransplantation. Fra knoglemarv til oprensede blodstamceller: 100 konsekutive procedurer i et enkelt center.

One hundred consecutive autologous stem cell transplants are reported: Non-Hodgkin's lymphoma 51 cases, Hodgkin's disease 27 cases, acute leukaemia 14 cases, multiple myeloma seven cases and chronic myeloid leukaemia one case. Most patients were in their second or later remission. The overall three-year survival for all patients was 60% and the three-year disease-free survival was 50% for lymphoma patients and 30% for acute leukaemia patients. The dominant source of stem cells was bone marrow during 1993, but from 1994 it has been peripheral blood, now totalling 33 cases. There were 12 toxic deaths, all among patients who were heavily treated before bone marrow harvest and transplantation. The patients transplanted with blood stem cells had significantly shorter duration of pancytopenia, and hospital stay, but their disease-free survival was not longer than that of a comparable group of bone marrow transplanted patients. Six patients were transplanted with purified CD34+ cells (selected by avidity column (Ceprate (R)), and had duration of thrombocytopenia and hospital stay similar to the patients transplanted with unmanipulated blood stem cells, but slightly longer duration of neutropenia. We conclude that high-dose therapy with autologous stem cell transplantation in not too heavily pretreated patients is a safe procedure irrespective of the source of stem cells.

Improved vaccination response during ranitidine treatment, and increased plasma histamine concentrations, in patients with B cell chronic lymphocytic leukemia.

Patients with B cell chronic lymphocytic leukemia (B-CLL) have decreased capacity to mount relevant antibody responses upon immunization, and development of hypogammaglobulinemia is part of the natural history of the disease. We investigated the influence of histamine type-2 (H2) receptor blockade by ranitidine on the in vivo antibody production in B-CLL patients following vaccination. Anti-polysaccharide antibodies in B-CLL patients, vaccinated with a tetanus-toxoid conjugated vaccine against Haemophilus influenzae type-B (Hib), reached long-term protective levels in more than 90% of B-CLL patients randomized to ranitidine treatment, as compared to 43% of the untreated patients (P = 0.024). No difference in the response to vaccination against influenza virus types A and B protein could be detected between the two groups. Plasma histamine levels were 2-fold to 20-fold higher in 23 out of 31 B-CLL patients, compared to normal controls, and these levels showed a significant positive correlation to disease duration. These findings indicate the possibility of improving in vivo antibody production against a highly relevant pathogen in B-CLL patients by histamine type-2 receptor blockade, and the combined finding of an immune-stimulatory effect of ranitidine and increased plasma histamine levels, strongly suggests the involvement of histamine in the pathogenesis of B-CLL immunodeficiency.

Risk of kidney cancer and other second solid malignancies in patients with chronic lymphocytic leukemia.

Patients with chronic lymphocytic leukemia (CLL) are known to to have an increased incidence of secondary cancers. We investigated the occurrence of secondary cancers in 7391 patients with CLL diagnosed between 1955 and 1988. The observed number of cancer cases was compared with the expected number of cancers calculated from national cancer incidence rates. The overall risk of cancer was significantly increased among persons with CLL. The standardized incidence ratios (ratio between the observed and the expected numbers) were 2.0 for men and 1.2 for women. Increased risks were found for cancer of the lung and prostate in men (RR = 2.0 and 1.5 respectively), renal parenchyma in both sexes (RR = 2.8 for men, RR = 3.6 for women) non-melanoma skin cancer in both sexes (RR = 4.7 for men, RR = 2.4 for women) and sarcomas (RR = 3.3 for men, RR = 2.8 for women). Although an increased risk of cancer is to be expected solely because individuals with CLL are being physically examined frequently, it appears that the risk is significantly increased for a number of cancer sites in persons with CLL.

Treatment of hypogammaglobulinaemia in chronic lymphocytic leukaemia by low-dose intravenous gammaglobulin.

Intravenous immunoglobulin replacement therapy reduces the number of bacterial infections in B-cell chronic lymphocytic leukaemia (B-CLL) patients. However, due to the complexity of immunodeficiency in B-CLL and the cost-effectiveness of replacement therapy, it is important to identify patients who are likely to benefit from the treatment and to investigate which dose should be used. 15 patients with hypogammaglobulinaemia and a history of recurrent infections received a fixed dose of 10 grams of gammaglobulin intravenously every 3 weeks. Serum IgG levels were significantly higher after three doses (p = 0.0002), and stabilized just above lower reference value after 11 doses. The total number of infection-related events during 168 months before therapy was compared to the total number of infection-related events in 169 months during therapy. The number of antibiotic prescriptions was reduced from 78 to 54 (N.S.), the number of admissions to hospital due to infections was reduced from 16 to 5 (p = 0.047) and the number of febrile episodes was reduced from 63 to 31 (p = 0.004). We conclude that a fixed low dose of gammaglobulin intravenously can restore normal serum IgG levels in hypogammaglobulinaemic B-CLL patients, and leads to a decreased number of febrile episodes and admissions to hospital due infections.