A Unique Case of Primary Extranodal Marginal Zone Lymphoma of the Anal Canal.

Marginal zone lymphomas represent approximately 10-12% of all B-cell lymphomas. Extranodal marginal zone lymphomas (EMZL) or mucosa-associated lymphoid tissue (MALT) lymphomas are the most common subtype. Almost half of all MALT lymphomas arise in the gastrointestinal (GI) tract and, while the stomach is the most common site of GI involvement, the small and large intestines can also be involved. Rare cases of MALT lymphoma involving the rectum have been reported; however, to our knowledge, involvement of the anal canal has never been reported in the literature. Here, we describe a unique case of MALT lymphoma of the anal canal. Infectious agents have been implicated in the pathogenesis of MALT lymphomas, possibly through persistent antigenic stimulation of the area; however, in our case no such infection was documented.

Bone metabolism markers and angiogenic cytokines as regulators of human hematopoietic stem cell mobilization.

Hematopoietic stem cell (HSC) mobilization involves cleavage of ligands between HSC and niche components. However, there are scarce data regarding the role of bone cells in human HSC mobilization. We studied biochemical markers of bone metabolism and angiogenic cytokines during HSC mobilization in 46 patients' sera with lymphoma and multiple myeloma, by ELISA. Significant changes between pre-mobilization and collection samples were found: (1) Bone alkaline phosphatase (BALP) increased, indicating augmentation of bone formation; (2) Receptor activator of Nf-κB ligand/osteoprotegerin ratio (RANKL/OPG) increased, showing osteoclastic differentiation and survival; however, there was no evidence of increased osteoclastic activity; and (3) Angiopoietin-1/Angiopoietin-2 ratio (ANGP-1/ANGP-2) decreased, consistent with vessel destabilization. Poor mobilizers had significantly higher carboxy-terminal telopeptide of collagen type I (CTX) and lower ANGP-1 at pre-mobilization samples, compared to good ones. CTX, amino-terminal telopeptide of collagen type I (NTX) and ANGP-1 pre-mobilization levels correlated significantly with circulating CD34+ peak cell counts. Our results indicate that bone formation and vessel destabilization are the two major events during human HSC mobilization. Osteoblasts seem to be the orchestrating cells, while osteoclasts are stimulated but not fully active. Moreover, ANGP-1, CTX and NTX may serve as predictors of poor mobilization.

Study of bone metabolism and angiogenesis in patients undergoing high-dose chemotherapy/autologous hematopoietic stem cell transplantation.

OBJECTIVES: As the interaction between hematopoietic stem cells (HSCs) and endosteal and endothelial niches in HSCs homing is essential, we aimed to study bone turnover and angiogenesis in 29 patients with lymphoma/multiple myeloma undergoing hematopoietic stem cell transplantation (HSCT). METHODS: Serum samples were collected before high-dose chemotherapy (HDT), at the end of HDT, after HSC infusion, at the nadir of myelotoxicity, and at engraftment. Bone metabolism (CTX, TRACP-5b, bALP, OC, DKK1, RANKL, OPG), and angiogenesis (Ang1, Ang2) markers were measured. These markers were also measured in 21 control patients before and after conventional chemotherapy. RESULTS AND CONCLUSIONS: Bone resorption declined during HSCT (decrease in TRACP-5b [P < .001] and CTX [P = .006]). Bone formation declined as well (decrease in bALP and OC [P < .001 for both]). RANKL/OPG ratio, an indicator of osteoclastic activation, did not change significantly (P = .5). Ang1/Ang2 ratio, a vessel equilibrium marker, decreased significantly (P < .001) suggesting endothelial destabilization. The changes observed in the control group were similar except of bALP and RANKL/OPG ratio. Moreover, Ang1/Ang2 ratio on the day after HSC infusion strongly correlated with time to neutrophil and platelet engraftment (P < .001 for both). Conclusively, bone turnover and vessel destabilization represent important events during HSCT probably reflecting the effect of chemotherapy.

Protein Z (PZ) and plasminogen activator inhibitor-1 (PAI-1) plasma levels in patients with previously untreated Hodgkin lymphoma (HL).

PURPOSE: The role of Protein Z (PZ) in conditions, such as thrombosis, inflammation or cancer, is under investigation. Plasminogen Activator Inhibitor-1 (PAI-1) is an acute phase reactant that promotes thrombosis and tumorigenesis. Subject of this work was to study PZ and PAI-1 in patients with Hodgkin Lymphoma (HL), a malignancy with inflammatory background and relatively low incidence of thrombosis. METHODS: Newly diagnosed patients were enrolled in the study. Healthy individuals were used as controls. RESULTS: PZ levels were higher in patients compared to controls (not significantly), while PAI-1 levels were significantly higher in patients. Both PZ and PAI-1 concentrations did not correlate with most of patients' characteristics. Lower PZ levels at diagnosis were associated with presence of B symptoms and positive final positron emission tomography (PET) and higher baseline PAI-1 levels with positive final PET, too. PZ had a declining trend, but PAI-1 increased initially and decreased thereafter, during the treatment period. CONCLUSIONS: Conclusively, PAI-1, but not PZ, seems to be an acute phase protein in HL. Lower PZ and higher PAI-1 levels at diagnosis may be indicative of aggressive disease. These results need further verification.

New insights in the mobilization of hematopoietic stem cells in lymphoma and multiple myeloma patients.

Following chemotherapy and/or the administration of growth factors, such as granulocyte-colony stimulated factor (G-CSF), hematopoietic stem cells (HSC) mobilize from bone marrow to peripheral blood. This review aims to systematically present the structure of the HSC "niche" and elucidate the mechanisms of their mobilization. However, this field is constantly evolving and new pathways and molecules have been shown to contribute to the mobilization process. Understanding the importance and the possible primary pathophysiologic role of each pathway is rather difficult, since they share various overlapping components. The primary initiating event for the mobilization of HSC is chemotherapy-induced endogenous G-CSF production or exogenous G-CSF administration. G-CSF induces proliferation and expansion of the myelomonocytic series, which leads to proteolytic enzyme activation. These enzymes result in disruption of various receptor-ligand bonds, which leads to the disanchorage of HSC from the bone marrow stroma. In everyday clinical practice, CXC chemokine receptor-4 (CXCR4) antagonists are now being used as mobilization agents in order to improve HSC collection. Furthermore, based on the proposed mechanisms of HSC mobilization, novel mobilizing agents have been developed and are currently evaluated in preclinical and clinical studies.

Omitting or reducing radiotherapy in childhood or adolescence Hodgkin Lymphoma.

Despite high cure rates, treatment of childhood Hodgkin Lymphoma (HL) is associated with late effects caused mainly by radiotherapy (RT). In the GPOH-HD95 trial of the German Society of Pediatric Oncology and Hematology that was recently published in the Journal of Clinical Oncology, RT was spared in patients achieving a stringently defined complete remission (CR) with chemotherapy and reduced in patients with a good partial remission (PR). Overall, RT-treated patients had superior PFS, but overall survival (OS) was almost identical within each risk-stratified treatment group irrespectively of the use of RT. In the low-risk group, RT could be safely omitted in 20% of patients. In contrast, failure rates were considered unacceptable, when RT was omitted in intermediate or high risk patients achieving a CR. However, salvage therapy was successful, equalizing overall survival between irradiated and non-irradiated patients. Although GPOH-HD95 points out to the omission of RT in selected patients achieving a CR after chemotherapy, especially those in the low-risk group, more than 80% of the patients are still irradiated. Notably, the GPOH-HD95 was not a randomized trial. In conclusion, according to the GPOH-HD95 trial, RT can be safely omitted in pediatric and adolescent patients with low-risk, early stage HL achieving a stringently defined CR after 2 cycles of OPPA or OEPA chemotherapy. RT dose could also be reduced in case of good PR by conventional imaging. However, conventional response assessment is not the optimal means to decide whether RT is needed or not. It is now increasingly recognized that RT can be omitted in many patients with HL without compromising the final outcome and it appears wise to try to stringently limit RT in those patients who really need it. This might be achieved through the use of modern functional imaging (PET/CT). Such efforts are already in progress and results regarding efficacy are awaited relatively soon.

Serum Dickkopf-1 is increased and correlates with reduced bone mineral density in patients with thalassemia-induced osteoporosis. Reduction post-zoledronic acid administration.

Dickkopf-1 is an inhibitor of Wnt signaling, which is crucial for osteoblast differentiation. We evaluated serum levels of Dickkopf-1 in 66 patients with thalassemia-induced osteoporosis who received therapy with zoledronic acid in a placebo-controlled, randomized trial. At baseline, thalassemia patients had increased serum levels of Dickkopf-1 that correlated with reduced bone mineral density of the lumbar spine and the distal radius. High Dickkopf-1 also correlated with increased bone resorption and reduced bone formation markers. Zoledronic acid produced a reduction in serum Dickkopf-1, which was associated with bone mineral density increase after 12 months of therapy. On the contrary, placebo group showed a borderline increase of Dickkopf-1, which was higher in patients who showed deterioration in pain scores. These results suggest that Dickkopf-1 is implicated in the pathogenesis of osteoporosis in thalassemia and reveal Dickkopf-1 as a possible target for the development of novel agents for the management of thalassemia-induced osteoporosis.