Phase II: Combination of cladribine, cyclophosphamide, mitoxantrone, rituximab (R-CCM) in patients with relapsed and refractory follicular and mantle cell lymphoma, results of a prospective study at Kitasato University

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Background: Indolent non-Hodgkin’s lymphoma (I-NHL) account for 20% of all of NHL in Japan, and they are increasing in number. More than 80% of the patients who achieve a complete remission with the initial treatment, will require salvage therapy. Recently, cladribine (2-CdA), a purine analogue is receiving much attention, because, even as a single agent, it has shown a high efficacy for I-NHL. The aim of our study was to determine the effectiveness and toxicity of combined chemotherapy consisting of 2-CdA, cyclophosphamide (CYP), mitoxantrone (MIT), rituximab (R-CCM) in the treatment of refractory or relapsed I-NHL. Methods: Patient eligibility criteria were: Previously treated patients with I-NHL, refractory or relapsed disease, no chemotherapy or irradiation within 4 weeks prior to the study, life expectancy of at least 3 months, age: 20–75, perfomance status of 0–3, adequate function ( bone marrow, liver, kidney, lung, heart) and written informed consent. The treatment regimen was: 2-CdA given at a dose of 0.09 mg/kg/day in a 2-h intravenous infusion from day 2–4, CYP 200 mg/m2/day from day 2–4, MIT 8 mg/m2/day on day 2 and rituximab 375 mg/m2/day on day .Primary end point was overall response rate. Results: 9 patients were enrolled, 7 (2 with mantle cell lymphoma, MCL; and 5 with follicular lymphoma, FL) were eligible. Mean Age was 63(51–72). The mean observation time was 121 days(47–314). Overall response rate (complete and partial) just after this therapy was 85.7%, one was progressive disease. One of PR one relapsed and died ten months after this regimen. The major toxicity was myelosuppression. Grade-III and -IV neutropenia was seen in 7 patients, grade-III thrombocytopenia in one and grade-III hemorrhagic cystitis in one, but all of them recovered from these toxicity. After the treatment, Grade-IV pneumonia and grade-III left-ventricular diastolic dysfunction was seen in the PD patient and passed away. Conclusions: the R-CCM is effective and safe in a combined regimen for relapsed and refractory I-NHL patients. We have just begun this new regimen, therefore, further investigations with larger population are warranted.

No significant financial relationships to disclose.

Citrullinated fibrinogen detected as a soluble citrullinated autoantigen in rheumatoid arthritis synovial fluids

BACKGROUND

Anti-citrullinated protein antibodies (ACPA) are specifically and frequently detected in sera of patients with rheumatoid arthritis (RA). Citrullinated fibrin or fibrinogen is a candidate autoantigen of such antibodies.

OBJECTIVE

To investigate the presence of citrullinated fibrinogen (cFBG) in the plasma or synovial fluid of patients with RA and control patients, and to determine cFBG levels and their relationship with serum markers for RA if it is present.

METHODS

A sandwich enzyme linked immunosorbent assay (ELISA) to measure cFBG was established using monoclonal antibodies cF16.1 and cF252.1, generated by immunising mice with R16Cit and R252Cit, the fibrinogen Aalpha chain derived sequences with citrulline at position 16 and 252, respectively, and the presence of cFBG was further investigated with immunoprecipitation-western blotting.

RESULTS

Positive signals were detected in 11/15 RA synovial fluids (RASFs), but not in osteoarthritis synovial fluids or RA plasma with sandwich ELISA for cFBG using cF16.1 and an anti-modified citrulline (AMC) antibody. The presence of cFBG in RASFs was confirmed by immunoprecipitation-western blotting. Furthermore, most RA sera strongly reacted against R16Cit. No relationship was seen between RASF cFBG levels and C reactive protein or anti-cyclic citrullinated peptide antibody levels of the paired sera.

CONCLUSION

cFBG is detected as a soluble citrullinated autoantigen in RASFs and may therefore be a genuine candidate antigen for ACPA in patients with RA.

Comparison of enzymatic properties between hPADI2 and hPADI4

In the sera of rheumatoid arthritis (RA) patients, autoantibodies directed to citrullinated proteins are found with high specificity for RA. Peptidylarginine deiminases (PADIs) are enzymes responsible for protein citrullination. Among many isoforms of PADIs, only PADI4 has been identified as an RA-susceptibility gene. To understand the mechanisms of the initiation and progression of RA, we compared the properties of two PADIs, human PADI2 and human PADI4, which are present in the synovial tissues of RA patients. We confirmed their precise distribution in the RA synovium and compared the stability, Ca2+ dependency, optimal pH range, and substrate specificity. Small but significant differences were found in the above-mentioned properties between hPADI2 and hPADI4. Using LC/MS/MS analysis, we identified the sequences in human fibrinogen indicating that hPADI2 and hPADI4 citrullinate in different manners. Our results indicate that hPADI2 and hPADI4 have different roles under physiological and pathological conditions. Further studies are needed for the better understanding of the role of hPADIs in the initiation and progression of RA.

Myosin light chain phosphorylation is correlated with cold-induced changes in platelet shape

Chilling induces shape changes in platelets from disks to spheres with abundant filopodia. Such changes were time-dependent and correlated well with the phosphorylation of 20-kDa myosin light chain (LC20). Both the shape changes and the phosphorylation were reversible. After the platelets had been chilled, myosin became incorporated into the Triton X-insoluble fraction. When the chilled platelets were immunocytochemically stained, anti-myosin antibody was localized with filamentous structures inside the filopodia. These results suggest that LC20 phosphorylation and subsequent interactions with actin filaments play a crucial role in the cold-induced changes in platelet shape and in the formation of filopodia.