Expression of HLA class II (DR, DQ) determinants by normal and chronic myeloid leukemia granulocyte/monocyte progenitors.

It has been suggested that the expression of certain HLA class II antigens stemming from three distinct loci (DR, DP, and DQ) is important not only in the regulation of the immune response but also on the response of hemopoietic precursors to factors inhibiting myelopoiesis. Changes in the expression of DR antigens may be involved in the pathogenesis of altered cell proliferation in chronic myeloid leukemia, since they result in decreased sensitivity of the colony forming units, granulocyte-macrophage to prostaglandin E and acidic isoferritins. In studies using monoclonal antibodies against monomorphic DR or DQ determinants, in a complement-dependent cytotoxic assay, it was found that nearly all normal and chronic myeloid leukemia bone marrow colony forming units, granulocyte-macrophage express DR antigens. The dose response curve was similar for both normal and leukemic precursors. Leukemic peripheral blood precursors were more sensitive than were normal peripheral blood precursors. Normal colony forming units, granulocyte-macrophage did not express DQ antigens, whereas these were expressed in varying quantities by leukemic cells. This study shows that, in the patients we studied, leukemic cells express DR antigens in amounts comparable to normal. In addition, varying amounts of DQ antigens may be observed on leukemic but not on normal progenitors, perhaps as a consequence of an increase in the number of antigens also expressed by normal cells, though in an amount below the detection threshold of cytotoxicity techniques.

Intensified and high-dose chemotherapy with granulocyte colony-stimulating factor and autologous stem-cell transplantation support as first-line therapy in high-risk diffuse large-cell lymphoma.

PURPOSE: In our previous study with MACOPB, we identified a high-risk group of patients with a poor 3-year survival rate of 29%. These patients were defined as having at diagnosis advanced-stage disease with high tumor burden (TB) and elevated lactate dehydrogenase (LDH) level or bone marrow (BM) involvement. A novel therapeutic scheme was investigated to improve the outcome of these patients. PATIENTS AND METHODS: Fifty patients with high-risk diffuse large-cell lymphoma (DLCL) were enrolled. The therapeutic scheme includes three phases: induction with 8 weeks of MACOPB; intensification with a 3-day course of mitoxantrone 8 mg/m2 plus high-dose cytarabine (HDARA-C) 2 g/m2 every 12 hours plus dexamethasone 4 mg/m2 every 12 hours (MAD protocol) and granulocyte colony-stimulating factor (G-CSF) 5 microg/kg on days 4 to 17 to harvest peripheral-blood progenitor cells (PBPC); consolidation with carmustine (BCNU), etoposide, ARA-C, and melphalan (BEAM) regimen; plus autologous stem-cell transplantation (ASCT) with PBPC, marrow, or both. RESULTS: Thirty-six patients (72%) achieved a complete response (CR), 11 (22%) showed no response (NR), and three (6%) died of toxicity. Among the 22 PRs or NRs after the induction phase, 56% of patients achieved a CR with subsequent intensified therapy. With a median follow-up duration of 32 months, the overall survival and failure-free survival rates were 56% and 50%, respectively. The disease-free survival rate is 69% at 32 months. Leukapheresis after MAD and G-CSF yielded a median of 32 x 10(6)/kg CD34+ cells and 80 x 10(4)/kg granulocyte-macrophage colony-forming units (CFU-GM). Thirty-nine patients were autografted and 11 did not undergo ASCT: six because of disease progression, four due to toxicity, and one because of patient refusal. The median times to achieve engrafment were 11 days (range, 7 to 19) to a neutrophil count greater than 0.5 x 10(9)/L and 12 days (range, 8 to 60) to a platelet count greater than 50 x 10(9)/L. CONCLUSION: This sequential scheme with intensified and high-dose chemotherapy with ASCT is feasible with moderate toxicity and may improve the outcome in high-risk DLCL.

Treatment of acute non lymphoid leukemia (ANLL) in elderly patients. The GIMEMA experience.

The results of four consecutive trials designed by the GIMEMA group for the treatment of ANLL in elderly patients are reviewed. Complete remission (CR) has been achieved in 20.8% of patients older than 60 years treated with 5-day courses of ARA-C plus thioguanine, in 22.7% of patients treated with high dose ARA-C (HDARAC) plus Asparaginase, in 39.5% of patients aged 55 to 80 receiving either Idarubicin or Daunorubicin in combination with Cytarabine in a standard 3+7 protocol and in 51% of patients older than 60 years treated with intermediate dose ARA-A (IDARAC) plus Mitoxantrone. From 1988, patients ineligible for aggressive chemotherapy entered a study of palliative treatment with Thioguanine and ARA-C. This 18 year GIMEMA experience showed that: CR can be obtained only with regimens producing marrow aplasia, the inclusion of anthracyclines or Mitoxantrone improves the CR rate, without prohibitive toxicity, haematological toxicity is very high in elderly patients and account for the most frequent cause of treatment failure namely death in aplasia, palliative treatment does not improve the quality of life and prolongs median survival only slightly. When comparing the results of these trials, it appears that in the GIMEMA group the capability of offering effective treatment to elderly patients with ANLL has continuously improved and that IDARAC plus Mitoxantrone is so far the most active and best tolerated regimen. Death in aplasia remains a major problem and future trials will be aimed at exploiting the possibility of reducing the haematological toxicity by using recombinant colony stimulating factors.

MACOP-B for advanced stage large cell lymphoma (DLCL). More is better? Italian Multiregional Cooperative Study Group (IMCSGL).

A study of the predictive value for CR, DFS and OS of the presenting features was carried out on 180 patients with advanced stage DLCL treated with MACOP-B between June 1986 and March 1989. A multivariate regression analysis identified LDH level, bone marrow involvement and tumor burden as independent risk factors with a 4 year survival rate of 79%, 58% and 28% respectively. Therefore MACOP-B proved to be an adequate treatment for the first two groups of patients but not for the third which requires a more aggressive treatment. A sequential single drug high dose chemotherapy with collection of peripheral blood stem cell program followed by bone marrow harvesting, super-intensive radio-chemotherapy and bone marrow transplant has been activated. Seven patients have been so far enrolled: preliminary results demonstrated the feasibility of the program. A larger number of cases and a longer follow-up is required for assessing the efficacy of this approach.

Early intensification followed by allo-BMT or auto-BMT or a second intensification in adult ALL: a randomized multicenter study.

In January 1987 we started a multicenter study in order to evaluate in adult ALL patients the results of an intensive chemotherapy effected early after CR, and to compare the efficacy of allogeneic BMT vs autologous BMT vs prolonged intensive chemotherapy in the attempt to eradicate minimal residual leukemia. To September 1990 ninety-six patients entered this study; of the 87 evaluable for induction 25 were at low risk and 62 at high risk; 67 (77%) achieved CR by an induction chemotherapy including vincristine, adriamycin, cyclophosphamide, dexamethasone. Fifty-six out of 67 remitters were enrolled for the early intensification, which consisted of HDAra-C+amsacrine (or IDAra-C+mitoxantrone) followed by vincristine+adriamycin+cyclophosphamide and etoposide+Ara-C. During the early intensification an unexpectedly high number of relapses (10/56) was observed, showing that very intensive treatment with myelosuppressive agents is not useful at this point of the post-remission therapy. One patient suffered toxic death. Out of 45 patients who completed the early intensification 16 had a related well-matched donor and were selected for allogeneic BMT (performed in 11); of the remaining 29 patients, 14 were randomized for autologous BMT (performed in 9) and 15 for a second intensification. The overall DFS at 3 years is 35%. The high number of early relapses makes it difficult to draw conclusions from the comparison of the three eradication modalities. The best results, although without statistical significance, were obtained after allogeneic BMT; in high-risk patients this procedure should be effected as soon as possible after attainment of CR. Autologous BMT and prolonged intensive chemotherapy gave results similar to each other; both were sometimes followed by delayed relapses.

Idarubicin in combination with intermediate-dose cytarabine and VP-16 in the treatment of refractory or rapidly relapsed patients with acute myeloid leukemia. The GIMEMA Cooperative Group.

Ninety-seven patients with refractory or relapsed acute myelogenous leukemia (AML), median age 37 years, received as salvage therapy a single course of idarubicin 6 mg/m2 as an intravenous (i.v.) bolus daily for 5 days, cytarabine (Ara-C) 600 mg/m2 i.v. for a period of 2 hours daily for 5 days and etoposide (VP-16) 150 mg/m2 for a period of 2 hours daily for 3 days (ICE protocol). Thirty-six patients were primarily resistant to standard inductive therapy with daunorubicin and Ara-C; 50 patients were in first relapse, three patients in second or third relapse, and eight patients in relapse after transplants. Forty-two (43%) out of 97 patients achieved complete remission, 11 patients died of infection or hemorrhage during induction, and 44 patients (45%) had resistant disease. Of the various variables examined, only disease status (i.e. refractory versus relapsed AML) was predictive for a significantly lower response rate. The median remission duration was 16 weeks; the overall median survival was 10 weeks. Nausea, vomiting, and oral mucositis were common but were rarely severe. No patient experienced treatment-related cardiac toxicity. In conclusion, the ICE protocol is a tolerable regimen providing effective antileukemic activity in patients with advanced AML. The evolution of this protocol in previously untreated patients with AML appears indicated.

Effect of alpha-interferon on the immune system of patients with hairy cell leukemia.

The role of in vivo administration of lymphoblastoid alpha-interferon (IFN-alpha) on the immune status of 12 patients with hairy cell leukemia (HCL) was studied. In most cases an increase in T3(CD3), T4(CD4), and T8(CD8) lymphocyte subsets was documented at the same time as hairy cells disappeared from the circulation. This led in most cases to an improved T4/T8 ratio. The effect of treatment with IFN-alpha was particularly evident on the natural killer cell compartment, which is often functionally depressed in HCL at diagnosis. After therapy, a progressive increase in the cytotoxic activity was observed in most patients. This was more evident 6-9 months after commencing treatment. These findings suggest that, in addition to the known clinicohematological effects, IFN-alpha can improve both the T and natural killer compartments in patients with HCL.

Long-term results of a multicentre randomised, comparative phase III trial of CHOP versus CNOP regimens in patients with intermediate- and high-grade non-Hodgkin's lymphomas. Novantrone International Study Group.

59 previously untreated patients with intermediate- or high-grade, stage II-IV non-Hodgkin's lymphoma (NHL) were entered into an open-label, randomised, multicentre study to compare the efficacy and safety of CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) with that of CNOP (cyclophosphamide, mitoxantrone, vincristine and prednisolone). 10 patients refused treatment following randomisation. The remaining 349 patients received either the CHOP or CNOP regimen every 3 weeks for a maximum of six to eight cycles. The randomisation procedure was violated for 34 patients treated at two study centres. Data from these 34 patients were analysed separately for efficacy and survival. Data from the remaining 325 patients, 164 assigned to CHOP and 161 to CNOP, were used in the major efficacy and survival analyses. Of these 325 patients, 263 (81%) met the eligibility criteria of the protocol. Supplementary analyses of data from these 263 patients, 132 assigned to CHOP and 131 to CNOP, were conducted for efficacy and survival. Data from all 349 treated patients were analysed for safety. In the 325 randomised patients, the overall objective response rate was not significantly different between the two groups (chi 2 test, P = 0.35). The CHOP regimen had a 51% (83/164) complete remission (CR) rate compared with 40% (64/161) for the CNOP regimen (P = 0.05). Among those with CR, the median time to response was 104 days with the CHOP regimen and 77 days with the CNOP regimen, and the median duration of CR was 667 and 1833 days, respectively. The median time to progression was 449 days for CHOP patients and 564 days for CNOP patients. The median survival time was 932 days for CHOP patients and 1801 days for CNOP patients, with a risk of death on CNOP relative to CHOP of 0.93% (95% confidence interval 0.68-1.27). After 5 years, 50% of patients in the CNOP arm and 40% of patients in the CHOP arm were still alive; these differences between treatment groups were not statistically significant. The median time to treatment failure (TTF) was 285 days for patients on the CHOP arm and 282 days for patients on the CNOP arm. Separate analyses of 263 eligible randomised patients, and 34 patients in whom the randomisation procedure was not followed, yielded similar results for remission rate, TTF, duration of CR and estimated overall survival. The incidence of non-haematological events, such as severe nausea and vomiting (P < 0.01), mucositis (P < 0.05) and alopecia (P < 0.001), were significantly lower in were significantly lower in patients treated with CNOP as compared with those who received the CHOP regimen. The incidence of cardiovascular toxicity of any severity was similar in the two groups. While severe and potentially life-threatening neutropenia occurred more frequently in patients treated with CNOP compared with CHOP (0.05 > P > 0.10), the incidence of infection of any severity was similar in both arms. We conclude that CHOP and CNOP regimens were both efficacious in patients with previously untreated aggressive NHL.

Induction of proliferation of acute myeloblastic leukemia (AML) cells with hemopoietic growth factors.

Like their normal counterparts, leukemic blasts have recently been shown to respond to hemopoietic growth factors in both suspension culture and in semisolid media. In the present study, we have evaluated the proliferative response of 35 AML cases to colony-stimulating factors (CSFs) containing conditioned media derived from the human cell lines GCT, 5637, MO and MG U87, and to human recombinant IL-1 (rh-IL1), IL-3 (rhIL-3), GM-CSF (rhGM-CSF) and G-CSF (rhG-CSF). In the great majority of cases, an increase of 3H-thymidine (3H-TdR) uptake was obtained in response to at least one conditioned medium. The labeling index (LI) and the growth fraction (GF), evaluated in a restricted group of cases, were also increased by the growth factors, suggesting that they act by recruiting leukemic cells in cycle from the resting compartment. The ability of blast populations to form colonies was also studied. Conditioned media were found to induce or significantly increase the clonogenic capacity in 20 cases out of 22. The response of leukemic cells to human recombinant CSFs and rhIL-1, used alone or in combination, was also assayed. The results, in agreement with those obtained with conditioned media, show that each leukemic case displays a different pattern of response to CSFs, and that optimal growth conditions must be individually assessed. The possibility of increasing the fraction of cycling cells in AML populations may represent a way to render them more sensitive to cytostatic agents, with a view to new therapeutic strategies.

Gamma-IFN induces a differential expression of HLA-DR, DQ and DP antigens on peripheral blood myeloid leukemic blasts at various stages of differentiation.

Using specific monoclonal antibodies and the indirect immunofluorescence technique, peripheral blood myeloid leukemic blasts from 49 patients were studied for DR expression, 42 for DQ and nine for DP after four days of culture without and with gamma-IFN. The expression of class II molecules on untreated cells depended upon the stage of differentiation and was maximal for DR antigens and lower for DP, while DQ was present only in a small percentage of M2, M4 or M5 blasts. M3 blasts lacked both DR and DQ. Maximal increase of surface expression induced by gamma-IFN was observed for DR molecules independently from the differentiation stage. No significant modification was seen for DQ. Preliminary data concerning DP indicate an increased expression in some of the tested samples. Thus the results obtained on peripheral blood blasts parallel previous observations on leukemic cell lines.

Effect of interferon-gamma on HLA class II antigen expression and sensitivity to prostaglandin E1 by normal and leukemic myeloid progenitors.

Chronic myelogenous leukemia (CML) granulo-monocyte committed progenitors (CFU-GM) are markedly less sensitive than normal progenitors to the inhibitory action of prostaglandin E (PGE). This phenomenon has been ascribed to their abnormal expression of HLA class II (mainly DR) determinants. Since interferon gamma (IFN-gamma) is a potent inducer of the expression of HLA class II (DR and to a lesser extent DQ) antigens, we have sought to determine the extent to which this agent can modulate both the antigenic pattern of normal and leukemic progenitors and their sensitivity to PGE 1. 72-h preincubation of normal and CML bone marrow cells with or without IFN-gamma does not significantly change DR and DQ expression by CFU-GM. Pre-incubation for 72 h with and without IFN-gamma produces the following changes in PGE 1 sensitivity: (1) normal CFU-GM lose some sensitivity to PGE 1. This is only marginally counteracted by the presence of IFN-gamma. (2) CML CFU-GM, preincubated with IFN-gamma regain a significant sensitivity to high concentrations of PGE 1. Our data confirm the expression of DR molecules on normal and leukemic progenitors. They also show that, although incubation with IFN-gamma for 72 h in a liquid culture system does not significantly affect the expression of HLA class II molecules by progenitor cells, it may increase their sensitivity to PGE, particularly in the case of CML CFU-GM. Thus expression of HLA class II antigens and sensitivity to PGE may be dissociated.

Acid hydrolases in B-chronic lymphocytic leukemia (B-CLL): a comparison with normal peripheral B lymphocytes and normal B-cell subset with the phenotype of B-leukaemic cells.

The acid phosphatase (AP), beta-glucuronidase (BG), and alpha-naphthyl-acetate esterase (ANAE) distribution and the morphology of stage 0 B-CLL lymphocytes were studied. The results were compared with the same hydrolase equipment and morphology of normal B-cell populations showing the B-CLL-like phenotype, and thus regardable as the possible counterpart of leukaemic cells. The functional and structural characters of the former were strikingly different from those of the latter. In fact the normal B-cell population with B-CLL-like phenotype showed an homogeneous enzyme pattern with predominant ANAE and a strictly lymphocytic cell morphology. In contrast, the leukaemic cells showed various and unrelated morphological and cytochemical features, thus forming apparent subgroups of B-CLL. The development of an irregular "switch on" mechanism in the blocked malignant cell clone, may account for these functional and structural maturation discrepancies. Moreover, the fact that in the leukaemic cells ANAE activity could be demonstrated only after the appearance of the other hydrolases, makes it a marker of functionally differentiated B lymphocytes.

Should alpha interferon be used as primary treatment for hairy cell leukemia? Italian Cooperative Group for Hairy Cell Leukemia.

To answer the question of whether interferon (IFN) should replace splenectomy, we reviewed the Italian HCL Registry: the records of 450 patients with hairy cell leukemia (HCL), seen from 1975 to 1988 were analysed. Of these, 321 were considered for the study: 231 had been splenectomized, 46 of them receiving subsequently IFN and 90 patients had IFN as initial therapy. Patients treated with splenectomy showed different survival according to Jansen and Hermans' staging system, which identified two risk groups: stage 1 and stages 2 and 3, p = 0.0329. On the contrary, patients treated with IFN did not show significantly different survival according to stage. By the comparison of stage 1 patients, either treated with splenectomy or with IFN, no statistical difference in survival was registered. Different survivals emerged for patients stage 2 + 3, which improved when treated with IFN, p = 0.0324. The median failure free survival (FFS) after splenectomy resulted in 89 months versus 33 months after IFN. In conclusion, splenectomy still remains the primary therapy for HCL patients stage 1. For high risk patients, stages 2 and 3, IFN should be adopted as first line therapy, improving substantially the survival. The short duration of response to IFN suggests a sequential combination of the two treatments for this group of patients, IFN reducing tumor mass quite safely and splenectomy assuring long lasting stable disease.

Immunologic cell markers of peripheral blood and lymph node lymphocytes in chronic lymphocytic leukemia.

The immunologic phenotype of the lymphocytes of 100 patients with chronic lymphocytic leukaemia (CLL) was investigated. Peripheral blood lymphocytes (PBL) were examined in all cases; in 46 patients with lymphadenopathy, a lymph node was biopsied and the histologic and immunologic patterns were assessed: 24 had a lymphocytic-lymphoplasmocytoid histology and 22 the follicular variant of lymphocytic lymphoma (mantle zone lymphoma, MZL). For comparison, lymph node suspensions from 19 patients with non-leukemic centrocytic lymphoma (CCL) were also studied. Significant differences in the PBL immunologic features were found between stage O and stage I patients. The phenotype of the lymphocytes of patients with lymphocytic histology was similar to that of stage 0 CLL patients, whereas major differences were found between these patients and those with mantle zone histology. This enables these patients to be recognized easily on immunologic grounds.

Expression of HLA class II determinants by normal and chronic myeloid leukemia progenitors.

It has been suggested that the expression of some HLA class II antigens, derived from three loci (DR, DP, DQ) is important in the regulation of both the immune response and the response of haemopoietic progenitors to regulation factors, such as acidic isoferritins (AIF), as well as in the interaction between T lymphocytes and erythroid progenitors (BFU-E). Changes in the expression of class II antigens have been reported on the surface of granulo-monocyte progenitors in chronic myeloid leukemia (CML) and correlated to the abnormal proliferation of such cells. In this study, monoclonal antibodies against DR and DQ monomorphic determinants were used to investigate the expression of these antigens on the surface of normal and CML bone marrow and peripheral blood BFU-E by means of complement mediated cytotoxicity. It was found that most normal and leukemic BFU-E express DR antigens. Antigens density tends to be greater on marrow as opposed to peripheral precursors. In addition, leukemic BFU-E are more sensitive to cytolytic treatment than their normal counterparts. Normal BFU-E do not express detectable amounts of DQ antigens, whereas these are present on a proportion of leukemic BFU-E.

Quality of life in patients with acute myelogenous leukemia in prolonged first complete remission after bone marrow transplantation (allogeneic or autologous) or chemotherapy: a cross-sectional study of the EORTC-GIMEMA AML 8A trial.

A cross-sectional study of quality of life (QOL) was performed in 98 patients in continued first complete remission (CR) for 1-7.4 years, after inclusion in the AML 8A trial which prospectively compared allogeneic bone marrow transplantation (AlloBMT), autologous BMT (ABMT) and intensive consolidation chemotherapy. Several significant differences between the three treatment groups were observed, on the basis of patient self-reports, with regard to somatic symptoms (mouth sores, cough, hair loss, headache), repeated acute medical problems, physical functioning, role functioning, leisure activities and, above all, sexual functioning. There were also significant differences for overall physical condition, and overall quality of life. For all these parameters, the ranking was uniformly AlloBMT lower than ABMT lower than chemotherapy. These differences remain significant after adjustment for time interval between CR and QOL evaluation, sex or age. These results, confirming a higher risk of permanent impairment of QOL after BMT, may have an impact on medical decisions and warrant further studies.

Prognostic factors of patients with acute myeloid leukemia (AML) allografted in first complete remission: an analysis of the EORTC-GIMEMA AML 8A trial. The European Organization for Research and Treatment of Cancer (EORTC) and the Gruppo Italiano Malattie Ematologiche Maligne dell' Adulto (GIMEMA) Leukemia Cooperative Groups.

The Leukemia Cooperative Groups of the EORTC and the GIMEMA conducted a prospective randomized phase III trial, in order to assess the value of autologous BMT (ABMT) vs a second intensive consolidation course (IC2), following a common intensive consolidation course (IC1) for patients with AML. Patients with an HLA-identical sibling donor were not randomized, but were included in an allogeneic BMT (alloBMT) program. This is an analysis of prognostic factors which influence the outcome of treatment after alloBMT in first complete remission (CR). The study included 730 patients < 46 years of age in CR, 270 having a histocompatible sibling donor. In 169 of these patients alloBMT was performed in first CR. Early remitters (122 patients achieving CR with one course of treatment) had a DFS at 3 years of 67%, significantly longer than that of 44% for late remitters (47 patients achieving CR after more than one course of treatment) (P = 0.006). The relapse risk for early vs late remitters was 16 and 40% at 3 years (P = 0.001) and the treatment-related mortality (TRM) at 2 years was 21 vs 27%. Age appeared to be a prognostic factor for TRM, WBC for DFS, whereas the FAB classification was not of prognostic importance. Patients with poor risk cytogenetic abnormalities showed a trend towards a higher relapse risk. Patients transplanted shortly after achieving CR appeared to have a worse prognosis than those transplanted further into remission. Overall, the number of courses of induction therapy needed to achieve CR was the most important prognostic factor for outcome after allogeneic BMT.

Duplication of Ph and of 9q+ chromosomes during the blastic transformation of a CML case.

We describe the blastic transformation of a case of chronic myelocytic leukemia in which, among other abnormalities, one extra Philadelphia and one extra 9q+ were observed. Molecular studies and analysis of the clonal evolution of the karyotype led to the interpretation of such an unusual finding as the result of nondisjunction, rather than of a double t(9;22) translocation.

Long term results of interferon treatment in hairy cell leukemia. Italian Cooperative Group of Hairy Cell Leukemia (ICGHCL).

Eighty nine of 104 patients with hairy cell leukemia (HCL), enrolled between 1985 and 1987 in a multicenter prospective study on human lymphoblastoid IFN alpha-n1, were evaluable for long-term follow-up. The induction treatment, 3 MU/mq daily for a median of 5.7 months, produced a response of 93%, complete+partial response (CR+PR) = 80%, minor (MR) = 13%. Neither prior splenectomy nor pre-treatment variables were associated with the rate of response to IFN. However maintenance treatment of 3 MU/mq weekly given randomly had a slightly significant effect on failure free survival (FFS). Of the 43 patients who relapsed, 31/36 (86%) obtained a new response with IFN. No differences in FFS were recorded between first and second response. At the third induction 7/11 patients were treated again with IFN, 4/7 obtaining some response, but the FFS was significantly worse. The overall survival is still 85%. We conclude that (1) IFN should be used as chronic uninterrupted treatment for HCL, (2) reduced dosage is sufficient to prolong the disease free status and (3) continuous lymphoblastoid IFN administration seems not to be associated with the development of resistance to retreatment.

Hairy cell leukemia: a clinical review based on 725 cases of the Italian Cooperative Group (ICGHCL). Italian Cooperative Group for Hairy Cell Leukemia.

The Italian Registry for hairy cell leukemia (HCL) has recorded 725 patients with HCL diagnosed over 25 years. We analysed this large series of patients with the aim of providing an evaluation of changes in clinical presentation, impact of initial therapy and modifications in prognostic factors over the period of two decades. Over time, a progressive down-staging of the disease at the onset, along with a reduction of patients with severe anemia and marked splenomegaly, has been observed. A second malignancy was found in 3.7% of patients, mostly detected several years after the onset of HCL. A striking improvement of survival rates has been observed, from 58.9% survival at five years for patients diagnosed before 1985 to 87.5% at five years for patients diagnosed after 1985 (p < 0.0001). Before 1985 hemoglobin alone provided prognostic information, whereas after 1985, clinical stage and the number of leukocytes correlated better with patient outcome. Survivals at 5 and 10 years were 34.4% and 29.6% respectively for untreated patients, 58.8% and 44.1% for patients receiving chemotherapy, steroids or other drugs, 64.1% and 56.1% for splenectomized patients and 88.9% (at 5 years) for alpha interferon (IFN)-treated patients (p < 0.0001). Our findings suggest that IFN has improved the prognosis of HCL, and that it must be considered a good initial treatment for patients with HCL.