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lower extremity due to critical limb ischemia. The patient’s past medical history included asymptomatic subtotal occlusion of both internal carotid arteries which were treated by endovascular dilatation and stent implantation, CAD manifested as a past silent myocardial infarction (MI),as well as MDS (subtype RCMD) already treated with 5 cycles of azacitidine. Laboratory results included a platelet count of 23 G/L, a hemoglobin level of 8.2 g/dl and white blood cell count of 3 G/L. Digital subtraction angiography revealed an occlusion of the superficial femoral artery and the popliteal artery which was patent in its third segment . After an unsuccessful endovascular treatment of this type D (TASC classification) lesion, a reversed V. saphena magna below knee bypass was performed. Preoperatively an antibiotic regime with amoxicillin/clavulanic acid and clindamycin i.v was administered. Postoperatively IV heparin with a prolonged partial thromboplastin time and aspirin 100 mg once daily were started. A developing cellulitis forced a change of the antibiotic regimen to levofloxacin and clindamycin i.v. and a minor amputation of the first and the second toe of the foot was performed. After 6 months of follow up the patient presented with no episodes of bleeding, cardiovascular complication or infection and the bypass was patent as proven by duplex scan. Discussion

The immunosuppressant rapamycin is known to be a potent inhibitor of cytokine driven proliferation of T-lymphocytes and other cell types. Here we have examined the effect of rapamycin on the myeloblastic cell line M1 which responds to interleukin-6 (IL-6) with growth arrest and monocytoid differentiation. Single-agent rapamycin led to a retardation of M1 cell growth. In spite of this intrinsic antiproliferative effect, rapamycin was found to abrogate IL-6 induced growth arrest. Concomitant exposure to rapamycin and IL-6 also reduced the extent of monocytoid differentiation as compared to treatment with IL-6 alone. Excess levels of the FK-506 analogue ascomycin reversed the antagonistic effect of rapamycin on IL-6 mediated growth suppression, suggesting that this biological action of rapamycin is mediated by a rapamycin/immunophilin complex. The findings demonstrate that rapamycin can also act as an antagonist of cytokine induced growth arrest and differentiation.

Introduction: The PETAL trial is a multicenter randomized controlled study for patients with aggressive lymphomas of diverse histologies (EudraCT 2006-001641-33, NCT00554164). In the study population as a whole interim PET (iPET) reliably predicted time to treatment failure (TTTF) and overall survival (OS). Interim PET-based treatment changes, however, had no impact on outcome (ASH 2014, abstract 391). Here we report the exploratory analysis for peripheral T cell lymphomas (PTCL). Methods: Pts. aged 18 to 80 yrs. with newly diagnosed aggressive lymphomas and a positive baseline PET received 2 cycles of rituximab (R), cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) followed by iPET. R was omitted in pts. with CD20-negative lymphomas. The conditions of iPET were strictly defined: 3-week interval between the 2nd (R-)CHOP cycle and iPET to avoid inflammatory reactions (Eur J Nucl Med Mol Imaging 30:682, 2003), no G-CSF after the 2nd cycle to avoid altered glucose biodistribution (J Nucl Med 47:950, 2006), standardized uptake value (SUV)-based PET interpretation to improve reproducibility (favorable iPET response: reduction of maximum SUV by > 66 % compared to baseline; J Nucl Med 48:1626, 2007). PTCL pts. with CD20-negative lymphomas and a favorable iPET uniformly received 4 additional cycles of CHOP (part A of the trial). Pts. with an unfavorable iPET were randomized to continue CHOP for 6 additional cycles or receive 6 blocks of a more complex methotrexate-, cytarabine- and etoposide-based regimen originally designed for Burkitt lymphoma (Blood 124: 3870, 2014; part B). Sample size of the entire study population was based on the empirically derived assumption that treatment failure after 2 yrs. (progression, relapse, treatment discontinuation due to toxicity, start of alternative therapy, death of any cause) could be improved from 30 % to 45 % in part B (alpha=0.05, power=0.8). Secondary endpoints included OS and toxicity. Results: Fifty-seven oncological centers and 23 nuclear medicine institutions participated in the trial. Between 2007 and 2012 1072 pts. were registered, and 862 (80.4 %) had a positive baseline PET, received 2 cycles (R-)CHOP, underwent iPET and were allocated to one of the post-iPET treatment arms detailed above. Reference pathology was available in 98 %, and median follow-up is 52 months. All in all, there were 76 pts. (8.8 % of all treated pts.) with T-cell lymphomas of whom 21 had ALK+ anaplastic large cell lymphoma (ALCL), 13 ALK- ALCL, 18 angioimmunoblastic T-cell lymphoma (AITL) and 20 PTCL not otherwise specified (NOS). Interim PET was favorable in 57 pts. (75 %) and unfavorable in 19 pts. with T-cell lymphomas (25 %). It was highly predictive of outcome, TTTF and OS being significantly higher in part A than B (2-year probability for TTTF: 63 % vs. 21 %; univariate hazard ratio (HR) for B 3.4, 95 % confidence interval (CI) 1.8 - 6.4, p TTTF (2-year probability: 81 % vs. 46 % vs. 49 % vs. 35 %; p=0.0110) and OS (90 % vs. 69 % vs. 52 % vs. 50 %; p=0.0026) were better in ALK+ ALCL than in ALK- ALCL, AITL or PTCL NOS. In pts. with an unfavorable iPET response, a switch from CHOP to the alternative regimen failed to improve TTTF or OS. The latter was associated with more frequent grade 3/4 neutropenia (40 % vs. 0 % vs. 11 %, p=0.0279), thrombocytopenia (70 % vs. 33 % vs. 23 %; p=0.0106), infection (60 % vs. 44 % vs. 18 %, p=0.0057) and mucositis (40 % vs. 33 % vs. 4 %, p=0.0025) as compared to 6 or 4 post-iPET cycles of CHOP, respectively, but treatment-related mortality was similar in all treatment arms (2 vs. 1 vs. 2 deaths). Conclusion: In this large multicenter trial iPET proved highly predictive of outcome in PTCL. A favorable iPET was found in 75 % of pts., and this was associated with long-term survival in about 70 %. In pts. with an unfavorable iPET response, outcome was dismal and could not be improved by switching to a more aggressive regimen. Novel strategies are required for PTCL pts. failing to respond to the first 2 cycles of CHOP. Disclosures Hüttmann: Gilead, Amgen: Other: Travel cost; Bristol-Myers Squibb, Takeda, Celgene, Roche: Honoraria. Giagounidis:Celgene Corporation: Consultancy. Klapper:Roche, Novartis, Amgen, Takeda: Research Funding. Duehrsen:Roche: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Alexion Pharmaceuticals: Honoraria, Research Funding.

To assess the influence of pretransplant cytoreductive therapy with special reference to interferon-alpha (IFN-alpha) treatment on major endpoints of allogeneic bone marrow transplantation (BMT), we studied 133 consecutive patients with Philadelphia chromosome (Ph1)-positive chronic myelogenous leukemia (CML) in first chronic phase who received marrow grafts from HLA-identical family (n = 103) or alternative donors (n = 30) at a referral-based transplant center. Fifty of these patients (38%) were previously exposed to IFN-alpha for a median duration of 14 months (range, 1 to 61 months), whereas 83 patients (62%) exclusively received hydroxyurea and/or busulfan therapy between 1 and 129 months (median, 15 months) pretransplant. Using the categorized treatment duration with each pretransplant cytoreductive agent as a measure for individual patient exposure to each agent, prolonged ( > 12 months) IFN-alpha administration was identified as the sole significant pretransplant therapy-related predictor of transplant outcome by proportional hazards regression analysis. The adjusted risk ratio (RR) of transplant-related mortality (TRM) was 2.5-fold higher (95% confidence limits [95% CL], 1.4 to 4.5; P < .004) compared with other pretransplant therapy and this was mainly attributable to a 3.1-fold higher RR (95% CL, 1.4 to 6.4; P < .005) of fatal posttransplant infections after prolonged IFN-alpha treatment pretransplant. Marrow graft failure developed exclusively among 7 of 30 patients (23%) with donors other than HLA-identical family members and was further restricted to patients who had been previously exposed to IFN-alpha. The probability of graft failure was 49% +/- 28% in 17 patients pretreated with IFN-alpha compared with 0% for the other 13 patients with mismatched family or unrelated donors (P < .008). In addition, a significant delay in neutrophil and platelet count reconstitution was observed among patients with donors other than HLA-identical family members after pretransplant IFN-alpha exposure. No influence of pretransplant cytoreductive therapy on either acute and chronic graft-versus-host disease or leukemic relapse was detected in this study. As a consequence of its adverse effect on TRM, prolonged pretransplant IFN-alpha treatment was independently associated with a 2.5-fold lower likelihood (95% CL, 1.4 to 4.5; P < .003) of 5-year overall survival and with a 2.3-fold lower likelihood (95% CL, 1.3 to 4.2; P < .004) of 5-year disease-free survival postransplant after adjustment for other significant prognostic factors in multivariate analysis.(ABSTRACT TRUNCATED AT 400 WORDS)

Patients with Philadelphia-positive chronic-phase chronic myelogenous leukemia (CML) resistant to interferon (IFN) alpha were treated in a phase I/II study with recombinant human tumor necrosis factor alpha to overcome IFN alpha resistance. Doses of 40, 80, 120 or 160 micrograms/m2 TNF alpha were given as 2-h infusions on 5 consecutive days every 3 weeks. IFN alpha (4 x 10(6) IU/m2 s.c., daily) treatment was continued. Six patients were treated, completing 1-24 (median, 12) treatment cycles. Five of the six patients achieved partial hematological remission, while the remaining patient had to stop treatment because of WHO grade 4 thrombocytopenia following the first TNF alpha cycle. No complete hematologic remission or cytogenetic improvement was seen. Side-effects were similar to those described for both substances alone. Maximum tolerable TNF doses usually varied between 80 micrograms/m2 and 160 micrograms/m2. To examine possible pathways of TNF activity in these patients, interferon receptor status and (2'-5')-oligoadenylate synthetase levels were examined in peripheral blood mononuclear cells. Both parameters remained unchanged during TNF alpha treatment. These preliminary data point to significant clinical efficacy of additionally applied TNF alpha in IFN alpha-resistant CML patients.

Fifty-four patients with Ph 1 -positive chronic myelogenous leukaemia (CML) (48 with chronic-phase and six acute-phase disease) were treated with interferon alfa-2b subcutaneously (s.c.). The starting dose was 4 million units (MU)/m 2 body surface area daily. It was reduced in parallel with serially determined leucocyte counts, and minimal effective doses were given as maintenance after achieving remission. Haematological remissions were induced in 22 of the 48 patients (46%) with chronic-phase disease. Thirteen patients (27%) revealed partial haematological remission and another 13 no response to treatment. No complete remission could be induced, although minor or partial cytogenetic responses were seen in 16 patients (33%). Moreover, a bcr-abl reduction was detected on Southern blot analysis in two patients. In chronic-phase disease, results of treatment were influenced by elapsed time after diagnosis, extent of previous treatment and interferon dosage. No beneficial effects of interferon were detected in the six patients with acute-phase disease. Principal acute side effects were fever and flu-like symptoms at the beginning of the therapy, which usually subsided within 3–7 days. Chronic side effects, especially weakness and neuropathy, were less frequent but more severe and necessitated discontinuation of treatment in 10 patients. In summary, interferon alfa-2b seems to be an effective treatment in early chronic-phase CML. Long-term effects on the course of the disease, however, must be determined.

Interferon (IFN) therapy has become widely used for the treatment of chronic myelogenous leukemia. Hematologic remissions can be induced in about 60% of patients. Moreover, in a small number of patients loss of the Philadelphia (Ph) chromosome and of the BCR-ABL rearrangement is observed. We have used genomic Southern blotting as well as a two-step polymerase chain reaction (PCR) method to score for BCR-ABL messenger RNA (mRNA) in patients with hematologic remission induced by treatment with IFN alpha-2b alone or in combination with IFN gamma. Concomitantly, cytogenetic analysis was performed. In 11 of 115 patients reported here, a complete loss of rearranged BCR fragments was observed in Southern blots of peripheral blood (PB) and/or bone marrow (BM) cell samples. Malignant marker bands disappeared first in the PB. In six patients, this genotype remained stable, whereas in five patients, low-intensity, rearranged bands reappeared despite continuation of treatment. The reappearance of the malignant marker was not accompanied by a clinical relapse. Ph-negative metaphases were observed in PB cells of four patients and in the PB and BM cells of two of these patients. In the samples of the other patients, residual Ph- positive cells were detected. By two-step PCR, residual BCR-ABL rearranged transcripts were found in samples of 10 patients.

A total of 51 fully evaluable patients with advanced and intensively pretreated breast cancer were treated with a combination chemotherapy of ifosfamide plus mesna, methotrexate and 5-fluorouracil. All patients had received at least one series of combined chemotherapy, 30 patients had received more than one combination and 41 patients had had anthracyclines before. Metastatic lesions in more than one site were found in 42 patients, and 24 patients had metastatic liver lesions. Partial remission was achieved in 10 patients (20%) and no change in 16 patients (31%). Survival was almost identical in both groups of responding patients and significantly shorter in treatment failures. Response was favorable in patients without pretreatment with anthracyclines. Two patients who received this protocol directly after progression with cyclophosphamide, methotrexate and 5-fluorouracil (CMF protocol) responded with a partial remission. Median time to progression was 7 months for partial responders and 4.5 months for patients achieving a no-change status. Median survival was 8 months for all patients. Toxicity was tolerable. Leukocytopenia and thrombocytopenia were treatment-limiting parameters. Overall, this protocol is well tolerable and effective in breast cancer patients with advanced disease and in intensively pretreated patients.

Cell cycle distribution in bone marrow and peripheral blood mononucleated cells was studied in patients with chronic myelogenous leukemia (CML) before and during treatment with interferon (IFN) alpha-2b. DNA-flow cytometry with ethidium bromide fluorescence was used. Highly significant differences between mononucleated cells from CML patients and normal controls were seen in peripheral blood but not in bone marrow specimens. Patients achieving hematologic remission during IFN treatment showed a cell cycle distribution in bone marrow cells and peripheral blood cells similar to normal controls.

In chronic myelogenous leukemia (CML) malignant cells are characterised by the Philadelphia chromosome (Ph), resulting from a translocation t(9;22). The position of the breakpoint within the major breakpoint cluster region (M-bcr) on chromosome 22 has been shown to correlate with the clinical course of the disease or, more recently, thrombopoietic activity. We have therefore determined the breakpoint localisation in 53 Ph-positive CML patients. Following the 5′/3′-region definition of Inokuchi et al. Leukemia Research 15 , 1067 (1991) [1], 22 of our patients have 5′ and 31 of our patients have 3′ orientated breaks. No correlation was found between platelet counts and breakpoint localisation.

We have analysed the different regulation of cell-cycle-relevant proteins by interferon alpha (IFN alpha) in IFN alpha-sensitive and resistant U937 leukemic cell lines. In contrast to the INF alpha-sensitive U937 variant cell line U937V, the IFN alpha-resistant derivative (U937VR) is insensitive to the antiproliferative activity of IFN alpha. As we found no differences between these cell lines concerning the induction by IFN alpha of the pathway involving tyrosine-protein kinases and the signal transducer and activator of transcription (Jak-Stat), we examined whether cell-cycle-regulating proteins are differently affected by IFN alpha in U937VR and U937VR cells. In U937V cells IFN alpha induced the formation of the complex between early-region-2 transcription factor 1 (E2F-1) and retinoblastoma protein (RB) which is known to repress transcription of E2F-1-inducible genes, necessary for cell cycle progression. Formation of this complex was not inducible by IFN alpha in U937VR cells, although the suitable binding partners (E2F-1 and under-phosphorylated RB) were present. Interestingly, treatment of nuclear extracts from logarithmically growing U937V and U937VR cells with an antiserum against cyclin A that disrupts cyclin-A-containing complexes, led to the formation of the E2F-1-RB complex, suggesting the presence of under-phosphorylated (active) RB, trapped in nuclear complexes that contain cyclin A. This suggestion was supported by combined immunoprecipitation/western blot experiments that revealed a physical interaction between phosphorylated as well as under-phosphorylated forms of RB and cyclin A complex(es) in U937V and U937VR cells. RB, especially the under-phosphorylated form, was released by treatment with IFN alpha from this complex(es) in the case of U937V cells but not U937VR cells. We conclude that the missing induction of the E2F-1-RB transrepressor by IFN alpha and the failure to release RB from cyclin-A-containing complexes might contribute to the resistance of U937VR cells to the antiproliferative effects of IFN alpha.

The genes for the CDK4/6-inhibitors p16INK4A/MTS1 and p15INK4B/MTS2 are frequently deleted in hematological malignancies. A new member of this family of CDK4/6 inhibitors is p18. In order to assess p18 growth-suppressor gene alterations in hematological neoplasms, we investigated 31 lymphoma and leukemia cell lines by PCR for both exons of this gene. No homozygous deletions were observed. Investigation of a new intragenic restriction fragment length polymorphism revealed no differences in allele distribution between the tumor cell lines and healthy volunteers. Our results suggest that homozygous deletion of the p18 gene does not play a major role in leukemogenesis or lymphomagenesis.

In 55 patients with Ph1+ CML under interferon (IFN) monotherapy, an immunohistochemical and morphometric study on pretreatment bone marrow biopsies was performed to evaluate the prognostic impact of clinical as well as histological disease features. For identification of megakaryocytes we used the PAS stain and CD61 to calculate the subfraction of precursors (pro- and megakaryoblasts). Demonstration of macrophages and their different subsets was carried out by PG-M1 (CD68) and the GSA-1 lectin. The erythroid precursors were stained by Ret40f (anti-glycophorin C). Density of argyrophilic (reticulin plus collagen) fibers was determined by applying Gomori's silver impregnation method. Clinical variables like state of hematological response to IFN administration, age, spleen and liver size, myeloblasts plus promyelocytes, basophils as well as basophils and eosinophils exerted a predictive capacity by univariate statistical analysis. However, when entering these factors into previously published risk models, i.e., the so-called Sokal score and its modifications, to assess subgroups with different survival patterns or relative risk groups, a clear-cut discrimination was not feasible. Bone marrow features of prognostic value consisted of megakaryocytes and their precursors, fibers, and pro- and erythroblasts. Only when including histological variables into a formerly reported Cox model, could a significant separation of patients into the different categories or relative risk groups be computated. In conclusion, the present data emphasize the prognostic impact of histological parameters to be considered in all clinical trials on CML.

To evaluate treatment-related changes of the reticulin stain-measured fibrosis in Ph(1+)-CML, a clinicopathological study was performed on sequential trephine biopsies of the bone marrow following either interferon (IFN) or busulfan (BU) monotherapy. Using the monoclonal antibody CD61 for the identification of megakaryopoiesis and Gomori's silver impregnation method, number of megakaryocytes and density of argyrophilic (reticulin and collagen) fibers were determined by morphometry. We studied specimens from 26 patients with IFN-alpha 2b (including nine patients with additional IFN gamma) therapy and from 23 patients who had received BU. In both groups, repeated bone marrow biopsies (total 125) revealed a significant increase in the fiber content, as well as in the number of megakaryocytes during treatment. To assess the dynamics of myelofibrosis more precisely, computation of differences in the degree of fiber density between the first and last examination was carried out. Regarding the considerable variations in the biopsy intervals, a so-called myelofibrosis progression index (MPI) was calculated. Following this rationale, we were able to demonstrate that, in comparison to the BU-group, speed of progression of bone marrow fibrosis was significantly increased in CML patients treated with IFN. Preliminary statistical analysis indicated a relationship between myelofibrosis on admission, which was always associated with increased growth of megakaryocytes, and the MPI with survival. Even when these parameters were regarded, prognosis was significantly more favorable in the IFN-treated patients. The failure of IFN and BU to inhibit the evolution of myelofibrosis may be related to several conversely acting pathomechanisms. Among others, the inability of both therapeutic agents to reduce the number of megakaryocytes more effectively should be taken into consideration.

Summary. The objective of this study was to investigate the prognostic impact of the reduction of Philadelphia chromosome (Ph) positive metaphases by treatment of chronic myelogenous leukaemia (CML) with interferon (IFN) alpha. Therefore, we evaluated the outcome of patients with previously untreated chronic phase Ph-positive CML, enrolled from 1984 to 1990 into two consecutive IFN trials at our institution. Of a total of 71 patients, 62 (87%) were evaluable for cytogenetic response. No cytogenetic improvement was seen in 16 patients (23%), 28 patients (38%) had a decrease in Ph-positive bone marrow metaphases to levels ranging from 35% to 95%, and nine patients (13%) to levels between 5% and 34%. In nine patients (13%), Ph-positive metaphases were no longer detectable. After a median follow-up period of 33 months, the projected 5-year survival is 55% for the 62 patients evaluable for cytogenetic response. In this patient population there was no significant difference in the survival probability according to patients’risk status as defined by the Sokal score. Categorization according to the extent of Ph reduction, however, allowed three groups with significantly different prognoses to be identified. Patients achieving a Ph reduction to less than 35% were found to constitute a low risk group with a median survival not yet known and a projected 5-year survival of 90%. The 5-year survival rate was 55% for patients with a Ph reduction to levels between 35% and 95%, and less than 10% for those without any cytogenetic improvement. Thus, this study demonstrates that cytogenetic improvement on IFN treatment is an important prognostic factor for survival.

Symptoms of autoimmune disease were evaluated in 125 patients with chronic myelogenous leukemia (CML) and in 12 patients with essential thrombocythemia undergoing treatment with recombinant interferon (IFN)-α-2b plus/minus low-dose recombinant IFN-γ. Twenty-seven of 137 patients (20%) developed rheumatoid symptoms. Furthermore, the incidence of antinuclear antibody (ANA) formation was studied. Elevated ANA titers were found in 5 19 (26%) of CML patients at the time of diagnosis and in 3 18 (17%) of patients treated with hydroxyurea or busulfan. During IFN treatment, 18 of 25 tested patients (72%) had elevated ANA titers. In 15 of these ANA-positive patients, clinical signs of autoimmune disease appeared. All these patients were under long-term IFN treatment and were in remission of disease. In three patients criteria for systemic lupus erythematosus were fulfilled. Severity of side effects has led to the discontinuation of IFN treatment in these patients. The data indicate that IFN-α and IFN-γ can induce ANA associated with autoimmune disease in patients with myeloproliferative disorders.

Three variants of the human monoblastic cell line U937 with different degrees of sensitivity to the antiproliferative action of interferon-alpha (IFN-alpha were examined for phenotypic differences. The highly IFN-sensitive variant U937-V expressed twice as many IFN-alpha binding sites as both its IFN-alpha-resistant derivative U937-VR and the cell line U937 exhibiting a 20-fold reduction in IFN-alpha sensitivity as compared to U937-V cells. All three variants were IFN-reactive with regard to induction of 2',5'-oligoadenylate (2-5A) synthetase activity and were similarly sensitive to the growth-inhibiting action of IFN-gamma and tumor necrosis factor. Responsiveness to the antiproliferative effect of granulocyte-macrophage colony-stimulating factor (GM-CSF), however, was confined to cell lines U937 and U937-VR. Although expressing a comparable number of GM-CSF receptors, the highly IFN-sensitive variant U937-V was refractory to GM-CSF. Flow cytometry revealed a marked difference in the expression of the antigen CD11b which was detectable on 85% of cells of the U937-V line but only on approximately 25% of cells derived from the U937 and U937-VR lines. Results thus demonstrate opposite sensitivity of U937 cells to the growth-inhibiting action of IFN-alpha and GM-CSF, apparently dependent on the state of U937 differentiation as determined by expression of the CD11b antigen.

Between March 1988 and July 1990, 28 adults with chronic myelogenous leukaemia (CML) were treated with a combination of recombinant human interferon (IFN) alpha-2b s.c. (initial dose 4 x 10(6) U/m2) and recombinant human IFN gamma s.c. (50 micrograms totally) daily. All patients were in chronic phase disease and had been treated previously with chemotherapy or bone marrow transplantation. A complete haematologic remission was achieved in three patients (11%), a haematologic remission in 12 patients (43%), and a partial haematologic remission in seven patients (25%). Six patients did not respond to this schedule. Acute side-effects were flu-like symptoms, fever and chills. During long-term treatment six patients developed polyarthralgia. Haematotoxicity WHO grade III occurred in three patients, and WHO grade IV in two patients. One patient developed psychosis, and in another patient an exacerbation of a pre-existing sarcoidosis was observed. We conclude that this combination is tolerable and effective in inducing haematological remissions in pretreated CML patients.

A 23-year-old male patient with Philadelphia chromosome (Ph) positive chronic myelogenous leukemia (CML) was treated with both IFN alpha and IFN gamma. Normalization of leukocyte counts was reached after 3 months of treatment. Southern blot analysis failed to detect the neoplastic cell clone after 19 months of therapy. Cytogenetically, complete suppression of Ph positive cells in the patient's bone marrow and blood was observed after 20 months and 25 months, respectively. This response was achieved with doses of IFN alpha and IFN gamma which were considerably lower than the dosage of IFN used in single agent therapy of CML.

The anti-tumor activity of high-dose recombinant interleukin-2 (IL-2) has been demonstrated in several recent preclinical and clinical studies. In an attempt to study possible synergistic effects with low-dose cyclophosphamide (CYC), a phase II clinical trial was initiated in 32 patients, 18 with malignant melanoma (MM) and 14 with renal cell carcinoma (RCC). The recombinant IL-2 (Cetus Corp., Emeryville, Ca, U.S.A.) was given once daily at 3 × 10 6 U/m 2 , as a 30-min infusion for 14 days in cycle I and for five days twice in cycles II and III, respectively; if tolerated, the dose was escalated to a maximum of 6 × 10 6 U/m 2 /day; the cycles, separated by 1-week treatment-free intervals, were each preceded by a single i.v. bolus of CYC at 350 mg/m 2 . The most prominent side-effects encountered in this trial consisted of a capillary leak syndrome, myalgia and fever requiring dose reduction in half of the patients during the first cycle. Given the limit of tolerable toxicities in a standard care unit, the regimen employed achieved minor anti-tumor activity. No objective responses were achieved in patients with RCC and a 15% remission rate (PR + MR) was seen in melanoma patients.

The BCR gene on chromosome 22 has received increasing attention because of its involvement in the Philadelphia (Ph′) translocation. For most restriction enzymes, this locus has been found to be nonpolymorphic. Two alleles have only been found when Taql-digested DNA is hybridized to a 5′ bcr-specific probe. We describe another two-allele polymorphism detected by the same probe in PvuII-digested DNA. The polymorphism is characterized by an additional PvuII site in the bcr region: this causes the appearance of an additional band of about 2.3 kb or 2.5 kb besides a 4.8-kb fragment in hybridizations with the 5′ bcr or a 3′ bcr probe. The incidence of the second allele is very low. It has only been found in some patients with hematopoietic malignancies and in a group of volunteers having a leukemia patient in their families.

Using two H-2 congeneic mouse strain combinations, the effect of donor specific i.v. preimmunizations with allogeneic spleen cells was studied. Parameters analyzed were survival time of the subsequent skin graft, graft-induced delayed-type hypersensitivity (DTH) reactions, and humoral immune responses evoked by immunization and grafting. Depending on the dose of allogeneic cells used for preimmunization, a suppression of the DTH response was observed, commonly accompanied by a similarly dose-dependent antibody formation that was inversely related to the DTH response. Neither DTH reactivity nor the antibody response were correlated in this system with the survival time of the skin graft. The only modulation of the survival time to be observed was an accelerated rejection of the graft caused by nonirradiated, as compared with irradiated, donor spleen cells. The data are discussed with regard to the clinically observed effect of blood transfusions on the survival of renal transplants and the relationship between DTH and graft rejection.

Interferons have enjoyed increasing interest since their discovery in 1957 (1) and may be regarded as prototype biological substances in the systemic treatment of cancer. Besides natural interferon (IFN) alpha produced by leukocyte suspensions, highly purified material produced by recombinant DNA technology became available in 1981 (2–4). These different types of IFN have been shown to be effective against various malignancies. The most impressive results have been achieved in hematologic disorders (5–8). However, data are difficult to compare since in these phase I and II trials different products were used and, moreover, administered in different routes, doses and schedules. Here we will review clinical experience with IFNs in the treatment of hairy cell leukemia and chronic myelogenous leukemia.

Chronic myelogenous leukemia (CML) is a stem cell disorder characterized by the accumulation of immature precursors of the granulocytic and monocytic lineage. Most commonly, the disease is treated with chemotherapeutic agents, preferably busulfan and hydroxyurea. High-dose chemotherapy followed by allogeneic bone marrow transplantation may eradicate the malignant clone and offers the possibility of cure [1, 2].

Recent preclinical and clinical studies that have demonstrated antitumor activity of high-dose recombinant interleukin-2 (rIL-2), and animal models that demonstrated a synergistic effect of low-dose cyclophosphamide, led us to study rIL-2 (Cetus Corp., Emeryville, Calif) in a phase II clinical trial in combination with low-dose cyclophosphamide in 32 patients, 18 with malignant melanoma and 14 with renal cell carcinoma. rIL-2 was given once daily at 3 x 10(6) U/m2, as a 30-min infusion for 14 days in cycle I and for 2 x 5 days in cycles II and III respectively; if tolerated, the dose was increased to a maximum of 6 x 10(6) U m-2 day-1; the cycles, separated by 1 week treatment-free intervals, were preceded each by a single i.v. bolus of cyclophosphamide at 350 mg/m2. The most prominent side-effects encountered in this trial consisted of a capillary leak syndrome, myalgia and fever that required dose reduction during the first cycle in one-half of the patients. Given the limit of tolerable toxicities in a standard care unit, the regimen employed achieved minor antitumor activity. No remission was achieved in patients with renal cell carcinoma, and 15% of melanoma patients showed objective responses (partial response + minor response).

The BALB/c plasmacytoma ADJ-PC-5 induces in early stages of tumorigenesis specific T suppressor (Ts) cells apparently as the first reaction of the immune system towards the growing tumor. In attempts to apply the concept of early induction of Ts cells in neoplasia for the induction of tolerance to allografts we have tried to induce Ts cells against alloantigens by injecting allogeneic spleen cells in doses increasing exponentially from 10 to 10(5) cells/mouse. Experiments using various strain combinations failed to demonstrate induction of specific Ts cells by this procedure. To explain the apparent discrepancy between these and the tumor data the capacity of the ADJ-PC-5 tumor cells to induce Ts cells in allogeneic combinations was analyzed. ADJ-PC-5 cells are capable of inducing specific Ts cells in CBA/J mice. These Ts cells specifically suppress the induction of a primary cytotoxic T cell response of CBA/J spleen cells against BALB/c, BALB.B and (BALB/c X C57BL/6)F1 cells but not one against B10.D2 or C57BL/10 target cells. The ADJ-PC-5-induced CBA/J Ts cells have been further analyzed using a panel of different target or responder cells. From these experiments the following conclusions can be drawn: the CBA/J Ts cells are specific for an antigen which is shared by ADJ-PC-5 and normal BALB/c spleen cells. The antigen in question is not coded for by the H-2d major histocompatibility complex. The data suggest that the Ts cell-inducing antigen on ADJ-PC-5 tumor cells is not a tumor associated neoantigen but a self antigen also present on normal BALB/c lymphoid cells.

As conventional FUra monochemotherapy with remission rates of about 20% remained disappointing, the addition of CF to FUrd heralded an important step towards an improved therapy of advanced colorectal cancer (1). In a broad phase II study we evaluated response, toxicity and survival of patients receiving combination treatment of FUra and CF, primarily in colorectal cancer. In addition we treated pts with prostatic cancer, breast cancer, gastric cancer and various other poor risk malignancies with this combination. We used two different schedules of FUrd and CF. Our data indicate improved response in colorectal cancer as compared to FUra alone and are promising in breast cancer and adenocarcinoma of unknown primary.

Although T suppressor (Ts) cells have been described in a number of experimental tumor systems (Fujimoto et al. 1976; Berendt and North 1980; Haubeck and Kolsch 1982; Naor 1983; Roberts et al. 1983; Tilkin et al. 1984; Ullrich and Kripke 1984) the question remains whether activation of Ts cells is the primary cause for the progressive growth of immunogenic tumors or a secondary phenomenon induced during late stages of tumorigenesis. If specific Ts cells indeed prevent a protective immune response against the tumor, then it is most likely that these Ts cells are activated in early stages of tumorigenesis. To test this hypothesis we have used a model simulating the increase of antigenic load during early stages of tumorigenesis in order to analyze the immune response of BALB/c mice against the syngeneic plasmacytoma ADJ-PC-5 (Haubeck and Kolsch 1982). In this system we were able to demonstrate that tumor-specific Ts cells were indeed activated at very early stages of tumor growth when the cell burden is in the range of 103–104 tumor cells. The further analysis of Ts cells in tumorigenesis and of the antigens involved in their induction will now be facilitated by the isolation of a tumor-specific Ts clone.

A previously untreated patient with benign phase chronic myelogenous leukaemia (CML) was treated with recombinant Interferon alpha-2 b. Haematological remission was induced for a total of twelve months. Thereafter, the patient developed resistance to Interferon alpha manifested by an increase in leucocyte counts despite dose escalation (up to 7 x 10(6) IU/day s.c.). Subsequent treatment with recombinant Interferon gamma failed to control myeloid proliferation. However, combined administration of both Interferon alpha and Interferon gamma resulted in a renewed haematological remission which lasted six months.

Interferon alfa-2b (Intron A; Schering-Plough) was administered to 36 patients with chronic myeloid leukemia (CML) at an initial dose of 4 X 10(6) IU/m2 daily subcutaneously, adapted to changes in leukocyte counts during the course of treatment. Of 32 patients who could be fully evaluated (20 men and 12 women; median age, 34 years) 29 were in the chronic phase, one had a blast crisis and two had accelerated phase disease. Hematologic remission was achieved in 20 of the 32 patients, while a partial hematologic remission was obtained in 10. Elevated pretreatment white-cell counts returned to normal in 25 patients after 3-40 weeks. There was a parallel decrease in platelet counts after an average treatment time of six weeks and in lactate dehydrogenase, after 2-20 weeks. In conclusion, administration of interferon alfa-2b resulted in a relatively rapid cell reduction in chronic phase CML. The long-term effect of this treatment on the course of the disease and the place of interferon alfa-2b in the overall concept of CML treatment remains to be evaluated.

In fruheren Untersuchungen von Deaton et al. [2], Killingsworth et al. [6], Topel et al. [10] sowie Intorp et al. [4] konnte nachgewiesen werden, das die Laser-Nephelometrie eine empfindliche und verlasliche Methode zur quantitativen Bestimmung von Immunglobulinen und anderen Serumproteinen darstellt. Dieses Verfahren beruht auf der Reaktion von monospezifischen Antiseren gegen Immunglobuline und andere Proteine mit den korrespondierenden Antigenen. Unter entsprechenden Voraussetzungen werden Immunkomplexe in vitro gebildet. Diese rufen die Streuung eines Laserstrahls hervor, die mit einem empfindlichen photometrischen System gemessen werden kann (Killingsworth et al. [6], Lizana et al. [7]).