ABSTRACT
Accurate monitoring of the t(14;18) translocation is regarded as highly desirable in patients with follicular lymphoma (FL) as absence of bcl-2/IgH positive cells has been correlated with a reduced risk of recurrence and, more recently, pre-treatment t(14;18) load with response to rituximab (R; Blood 2004;103:4416-23). With the arrival of R clinical and molecular remission rates for various lymphoma entities improved significantly, creating the need to carefully review and reassess the role of PCR negativity for clinical outcome, specifically when considering the prolonged presence of the drug as compared to chemotherapy. To determine the rate of molecular clearance achieved by the addition of different doses of R 16 newly diagnosed, t(14;18) positive patients with FL (Ann Arbor stages III/IV) were investigated before, during and after primary chemotherapy with six cycles of CHOP combined with varying (1, 3 or 6) cycle numbers of R (varR1-, varR3- or varR6-CHOP, respectively) regarding molecular remission status. For this purpose classic nested PCR as well as a newly established RQ-PCR employing juxtaposed hybridisation probes were employed to assess molecular remission prior, during and post therapy. Interestingly, administering just a single cycle of R (varR1-CHOP) in combination with a standard regimen of CHOP resulted in rapid and effective clearance of t(14;18) carrying cells from the peripheral blood of 4/5 patients in this treatment group. 6/8 (6/8) varR1-/varR3-CHOP patients were fully cleared and 8/8 (7/8) var6-CHOP patients as assessed by RQ- (nested) PCR. This indicates the high clearance capacity of this combination therapy approach even when adding a very low cycle number of R (1 and 3, respectively) to CHOP in primary therapy of FL. In summary, the relationship established between molecular clearance and minimal residual disease/risk of recurrence may have to be redefined in the times of R. Upcoming large prospective trials will have to elucidate to what degree the clearance of peripheral blood from t(14;18) positive cells can still be regarded as informative regarding absence of minimal residual disease, remission status and/or risk of recurrence.
Subject(s)
Antibodies, Monoclonal/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Genes, bcl-2/genetics , Immunoglobulin Heavy Chains/genetics , Lymphoma, Follicular/drug therapy , Adult , Aged , Antibodies, Monoclonal, Murine-Derived , Chromosomes, Human, Pair 14/genetics , Chromosomes, Human, Pair 18/genetics , Combined Modality Therapy , Cyclophosphamide/therapeutic use , Doxorubicin/therapeutic use , Female , Humans , Infusions, Intravenous , Lymphoma, Follicular/genetics , Male , Middle Aged , Prednisone/therapeutic use , Remission Induction , Reverse Transcriptase Polymerase Chain Reaction/methods , Rituximab , Sensitivity and Specificity , Treatment Outcome , Vincristine/therapeutic useABSTRACT
Phenotypic maturation, cytokine secretion, and migration are distinct functional characteristics of dendritic cells (DCs). These functions are independently regulated by a number of extracellular variables, such as type, strength, and persistence of an array of soluble and membrane-bound mediators. Since the exact composition of these variables in response to infection may differ between individuals, the intracellular signaling pathways activated by these extracellular networks may more closely correlate with DC function and predict the course of adaptive immunity. We found that activation of p38 kinase (p38K), extracellular signal-related kinase 1/2 (ERK1/2), and phosphatidylcholine-specific phospholipase C (PC-PLC) enhanced cytokine secretion, whereas p38K, cyclic adenosine monophosphate (cAMP), and PC-PLC enhanced migration. In contrast, phosphatidylinositol 3-kinase (PI3K)/Akt-1 and cAMP inhibited cytokine secretion while ERK1/2 inhibited migration. Migration and cytokine secretion further differed in their sensitivity to inhibition over time. However, although DCs could be manipulated to express migration, cytokine secretion, or both, the level of activation or persistence of intracellular pathway signaling was not predictive. Our results suggest a modular organization of function. We hypothesize that the expression of specific DC functions integrates a large variety of activating and inhibitory variables, and is represented by the formation of a functional unit of molecular networks-the signal response module (SRM). The combined activities of these modules define the functional outcome of DC activation.
Subject(s)
Cell Differentiation/immunology , Cell Movement/immunology , Dendritic Cells/immunology , Signal Transduction/immunology , Cells, Cultured , Cyclic AMP/immunology , Cytokines/immunology , Dendritic Cells/cytology , Humans , Mitogen-Activated Protein Kinase 1/immunology , Mitogen-Activated Protein Kinase 3/immunology , Oncogene Protein v-akt/immunology , Phosphatidylinositol 3-Kinases/immunology , Type C Phospholipases/immunology , p38 Mitogen-Activated Protein Kinases/immunologyABSTRACT
This study assessed prevalence, frequency, age and gender distribution and breakpoint locations, and detection method validity for the bcl-2/IgH rearrangement in 204 healthy individuals. For this purpose, both classic two-step, nested, semi-quantitative PCR as well as a newly established sequence-specific, hybridization probe-based real-time quantitative PCR (RQ-PCR) were employed and tested for their sensitivity and specificity for detecting t(14;18) positive cells in healthy blood donors. Interestingly, almost a quarter (24%; 39/204) of all healthy individuals carried the translocation, confirming data of one large prior report [Summers KE, Goff LK, Wilson AG, Gupta RK, Lister TA, Fitzgibbon J. Frequency of the Bcl-2/IgH rearrangement in normal individuals: implications for the monitoring of disease in patients with follicular lymphoma. J Clin Oncol 2001;19(2):420-4]. Regarding presence as well as frequency of the translocation, no correlation to age (mean frequency 2.0:10(4), with a median of