Panayiotis Panayiotidis

B-Cell Kinase Lyn Deficiency in Patients With Systemic Lupus Erythematosus

Background To better understand the molecular background of B-cell overactivity characterizing systemic lupus erythematosus (SLE), we examined the expression of the CD22 co-receptor and of kinase Lyn, which are involved in signaling inhibitory pathways, in B cells from patients with SLE. Methods Two-color flow cytometry was used to study the expression of surface antigens on freshly isolated peripheral B cells from patients with SLE, disease-control patients, and healthy volunteers. Intracellular kinases Lyn and Syk were analyzed using Western immunoblots, and differences at the messenger RNA (mRNA) level were evaluated using semiquantitative polymerase chain reaction (PCR). Results Expression of B-cell surface CD22 was intact in patients with SLE, but expression of the B-cell kinase Lyn was significantly decreased in resting, as well as in anti-sIgM-stimulated B-cell-enriched cell lysates obtained from 66% of patients with SLE. Lyn deficiency was disease-specific and unrelated to disease activity. Expression of B-cell kinase Syk was similar in all study groups. Semiquantitative PCR revealed that Lyn mRNA was significantly decreased in lupus patients with decreased Lyn protein expression, suggesting that Lyn deficiency may be caused at least in part by defects at the transcription level. Conclusions Decreased expression of Lyn in some patients with SLE represents a B-cell defect that may enhance our understanding of SLE molecular pathogenesis by providing rational therapeutic targets.

Treatment of Waldenstrom's macroglobulinemia with thalidomide

PURPOSE We performed a prospective phase II study to assess the activity of thalidomide in patients with Waldenstroms macroglobulinemia (WM). PATIENTS AND METHODS Twenty patients with WM were treated with thalidomide at a starting dose of 200 mg daily with dose escalation in 200-mg increments every 14 days as tolerated to a maximum of 600 mg. All patients were symptomatic, their median age was 74 years, and 10 patients were previously untreated. RESULTS On an intent-to-treat basis, five (25%) of 20 patients achieved a partial response after treatment. Responses occurred in three of 10 previously untreated and in two of 10 pretreated patients. None of the patients treated during refractory relapse or with disease duration exceeding 2 years responded to thalidomide. Time to response was short, ranging between 0.8 months to 2.8 months. Adverse effects were common but reversible and consisted primarily of constipation, somnolence, fatigue, and mood changes. The daily dose of thalidomide was escalated to 600 mg in only five patients (25%), and in seven patients (35%), this agent was discontinued within 2 months because of intolerance. CONCLUSION Our data indicate that thalidomide has activity in WM but only low doses were tolerated in this elderly patient population. Confirmatory studies as well as studies that will combine thalidomide with chemotherapy or with rituximab may be relevant.

Prognostic value of serum free light chain ratio at diagnosis in multiple myeloma

The prognostic value of baseline serum free light chain ratio (sFLCR) was investigated in 94 multiple myeloma (MM) patients. sFLCR was calculated as κ/λ or λ/κ, depending on the patients’ dominating monoclonal light chain. Median baseline sFLCR was 3·57 in κ‐MM patients, 45·09 in λ‐MM. ‘High’ sFLCR (≥ the observed median value for κ‐ and λ‐MM respectively) correlated with elevated serum creatinine and lactate dehydrogenase, extensive marrow infiltration and light chain type MM. The 5‐year disease‐specific survival was 82% and 30% in patients with sFLCR lower than and equal or greater than the median, respectively (P = 0·0001). sFLCR was an independent prognostic factor.

Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone with or Without Radiotherapy in Primary Mediastinal Large B-Cell Lymphoma: The Emerging Standard of Care

UNLABELLED More aggressive treatment approaches (methotrexate, cytarabine, cyclophosphamide, vincristine, prednisone, and bleomycin [the MACOP-B regimen] or consolidation with high-dose therapy and autologous stem cell transplantation) have been considered to be superior to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) in patients with primary mediastinal large B-cell lymphoma (PMLBCL). Rituximab-CHOP (R-CHOP) is the standard of care for diffuse large B-cell lymphoma, whereas efficacy in PMLBCL has not been adequately confirmed. PATIENT AND METHODS Seventy-six consecutive PMLBCL patients who received R-CHOP with or without radiotherapy (RT) were compared with 45 consecutive historical controls treated with CHOP with or without RT. Baseline characteristics of the two groups were balanced. RESULTS The rate of early treatment failure was much lower with R-CHOP with or without RT (9% versus 30%; p = .004). The 5-year freedom from progression rate after R-CHOP with or without RT was 81%, versus 48% for CHOP with or without RT (p < .0001). The 5-year event-free survival rates were 80% and 47% (p < .0001) and the 5-year overall and lymphoma-specific survival rates were 89% and 69% (p = .003) and 91% and 69% (p = .001), respectively, with only seven of 76 lymphoma-related deaths. Among R-CHOP responders, 52 of 68 received RT. CONCLUSIONS Based on these results, most patients with PMLBCL appear to be cured by R-CHOP in 21-day cycles with or without RT, which could be the current standard of care. Therefore, the need for more aggressive treatment strategies is questionable unless high-risk patients are adequately defined. Further studies are required to establish the precise role of RT.

Re-evaluation of prognostic markers including staging, serum free light chains or their ratio and serum lactate dehydrogenase in multiple myeloma patients receiving novel agents

International Staging System (ISS), serum free light chain ratio (sFLCR) and lactate dehydrogenase (LDH) are well known, easily assessed independent prognostic indicators of outcome in multiple myeloma (MM). The purpose of the study was to re‐examine the prognostic contribution of these variables in a multicenter setting with special attention to MM patients treated with autologous stem cell transplantation (ASCT) or novel agents (NA). Three hundred and five symptomatic newly diagnosed MM patients were retrospectively studied. Twenty‐seven per cent, 32% and 41% were in ISS stages 1, 2, and 3, respectively. Fifty‐six per cent of them presented kappa light chain monoclonality; median sFLCR was 27.04 (0.37–1.9 × 105) and 47.97 (0.26–2.3 × 107) for kappa patients and lambda patients, respectively; patients with sFLCR above median constituted the high sFLCR group. Thirty‐one per cent of patients had increased LDH. As first line treatment, 55.7% received conventional treatment and 44.3% NA. After induction, 24% underwent ASCT, whereas 76% received NA at any line, either bortezomib (82.5%), thalidomide (48%) or lenalidomide (27%). When the 305 patients were analyzed together, staging, high sFLCR and abnormal LDH were predictive of survival. The same was true for patients that never received NA, whereas neither high sFLCR nor abnormal LDH constituted adverse factors in patients that received NA frontline. In the last group of patients, no difference was observed between ISS stages 2 and 3. The median 5‐year survival of patients that never received NA versus those who did frontline was 29% vs 47%, 7% vs 52% and 24% vs 40% in patients with abnormal LDH, high sFLCR and ISS stage 3, respectively (p = 0.03, p < 0.00001 and p = 0.035). In conclusion, patients gaining the most from NA are those with an aggressive disease as reflected by advanced stage, abnormal LDH and high sFLCR. In addition, the adverse impact of these three variables is obscured by NA. Copyright

Favorable outcome of primary cutaneous marginal zone lymphoma treated with intralesional rituximab

Abstract:  Primary cutaneous marginal zone lymphoma (PCMZL) is an indolent disease. Treatment options include excision, local irradiation, interferon‐α or chemotherapy. We present two patients with PCMZL and multiple skin lesions successfully treated with intralesional administration of the anti‐CD20 monoclonal antibody rituximab. The first presented with four red skin lesions and the second with two. Biopsy of the largest lesion revealed marginal zone B‐cell lymphoma in both patients. There was no evidence of systemic involvement in either patient. Both patients were treated with intralesional rituximab for 18 consecutive weeks. Skin lesions gradually regressed. Apart from mild local pain during the injection, no other adverse effects were observed. In conclusion, rituximab can be safely administered intralesionally in patients with PCMZL and can produce disease remission.

mTOR signaling is activated by FLT3 kinase and promotes survival of FLT3-mutated acute myeloid leukemia cells.

Activating mutations of the FLT3 gene mediate leukemogenesis, at least in part, through activation of PI3K/AKT. The mammalian target of rapamycin (mTOR)-Raptor signaling pathway is known to act downstream of AKT. Here we show that the mTOR effectors, 4EBP1, p70S6K and rpS6, are highly activated in cultured and primary FLT3-mutated acute myeloid leukemia (AML) cells. Introduction of FLT3-ITD expressing constitutively activated FLT3 kinase further activates mTOR and its downstream effectors in BaF3 cells. We also found that mTOR signaling contributes to tumor cell survival, as demonstrated by pharmacologic inhibition of PI3K/AKT/mTOR, or total silencing of the mTOR gene. Furthermore, inhibition of FLT3 kinase results in downregulation of mTOR signaling associated with decreased survival of FLT3-mutated AML cells. These findings suggest that mTOR signaling operates downstream of activated FLT3 kinase thus contributing to tumor cell survival, and may represent a promising therapeutic target for AML patients with mutated-FLT3.

Serial determination of FLT3 mutations in myelodysplastic syndrome patients at diagnosis, follow up or acute myeloid leukaemia transformation: incidence and their prognostic significance

The incidence of FLT3 mutations (internal tandem duplication and Asp835) was investigated in bone marrow samples from 97 patients with myelodysplastic syndrome [(MDS); excluding cases with refractory anaemia with excess blasts in transformation] at the time of diagnosis and several time points thereafter. Three patients had FLT3 mutations at presentation. Forty‐two patients progressed to acute myeloid leukaemia (AML), including the three patients with FLT3 mutations at MDS diagnosis. Three additional patients acquired FLT3 mutations and progressed to AML in 1  month. FLT3 mutations seem to be a critical additional genetic event that transforms a minority of MDS patients to AML.

Combination of rituximab with chlorambucil as first line treatment in patients with mantle cell lymphoma: a highly effective regimen.

The optimal treatment approach for patients with mantle cell lymphoma (MCL) is not well defined. Intensive therapeutic regimens result in high response rates and prolonged progression-free survival but at the expense of significant toxicity. We report here our results of the administration of rituximab plus chlorambucil (R-Chl) as first line treatment in patients with MCL. Twenty consecutively diagnosed patients were treated with this combination in which an induction and a maintenance arm were included. During induction, rituximab was administered at a dose of 375 mg/m2 on day 1, while chlorambucil was given afterward at a dose of 10 mg/day for 10 consecutive days for eight cycles and then as a single agent for an additional four cycles. Maintenance consisted of rituximab administration every 2 months for 1 year. Most patients had indolent disease features such as a low mantle-cell international prognostic index (MIPI) score. The overall response rate was 95% (90% CR, 5% PR). Among patients in CR, 78% presented a molecular remission. The 3-year progression-free survival was 89%. There were no serious side effects. These results show that the R-Chl combination could be an effective therapeutic option as first line treatment in MCL, especially for patients with indolent disease characteristics.

Normalization of the serum angiopoietin-1 to angiopoietin-2 ratio reflects response in refractory/resistant multiple myeloma patients treated with bortezomib

Bortezomib is a proteasome inhibitor producing high response rates in patients with relapsed/resistant multiple myeloma patients. This study investigates the effect of bortezomib on circulating angiopoietins levels, and shows that the normalization of the angiopoietin-1/angiopoietin-2 ratio reflects the response to treatment. Neoangiogenesis is involved in the pathophysiology of multiple myeloma and angiopoietins possibly contribute to myeloma-induced neovascularization. Bortezomib’s antineoplastic potential includes an anti-angiogenic effect. We determined serum levels of angiopoietin-1 and angiopoietin-2 with ELISA pre- and post-bortezomib administration in 35 patients with relapsed/refractory multiple myeloma. Pre-bortezomib, serum angiopoietin-1 levels did not differ in patients and in healthy individuals, while serum angiopoietin-2 levels were elevated. Corresponding serum angiopoietin-1/angiopoietin-2 ratio was reduced in patients compared with controls. After treatment, serum angiopoietin-1 levels increased, while serum angiopoietin-2 levels decreased, therefore the angiopoietin-1/angiopoietin-2 ratio increased and normalized. This increase was significant in patients who responded to treatment. In conclusion, angiopoietin-1/angiopoietin-2 ratio normalization reflected response to bortezomib.