Paola Masolini

A randomized controlled trial of rituximab for the treatment of severe cryoglobulinemic vasculitis

OBJECTIVE To conduct a long-term, prospective, randomized controlled trial evaluating rituximab (RTX) therapy for severe mixed cryoglobulinemia or cryoglobulinemic vasculitis (CV). METHODS Fifty-nine patients with CV and related skin ulcers, active glomerulonephritis, or refractory peripheral neuropathy were enrolled. In CV patients who also had hepatitis C virus (HCV) infection, treatment of the HCV infection with antiviral agents had previously failed or was not indicated. Patients were randomized to the non-RTX group (to receive conventional treatment, consisting of 1 of the following 3: glucocorticoids; azathioprine or cyclophosphamide; or plasmapheresis) or the RTX group (to receive 2 infusions of 1 gm each, with a lowering of the glucocorticoid dosage when possible, and with a second course of RTX at relapse). Patients in the non-RTX group who did not respond to treatment could be switched to the RTX group. Study duration was 24 months. RESULTS Survival of treatment at 12 months (i.e., the proportion of patients who continued taking their initial therapy), the primary end point, was statistically higher in the RTX group (64.3% versus 3.5% [P < 0.0001]), as well as at 3 months (92.9% versus 13.8% [P < 0.0001]), 6 months (71.4% versus 3.5% [P < 0.0001]), and 24 months (60.7% versus 3.5% [P < 0.0001]). The Birmingham Vasculitis Activity Score decreased only after treatment with RTX (from a mean ± SD of 11.9 ± 5.4 at baseline to 7.1 ± 5.7 at month 2; P < 0.001) up to month 24 (4.4 ± 4.6; P < 0.0001). RTX appeared to be superior therapy for all 3 target organ manifestations, and it was as effective as conventional therapy. The median duration of response to RTX was 18 months. Overall, RTX treatment was well tolerated. CONCLUSION RTX monotherapy represents a very good option for severe CV and can be maintained over the long term in most patients.

Rheumatoid factor positivity rather than anti-CCP positivity, a lower disability and a lower number of anti-TNF agents failed are associated with response to rituximab in rheumatoid arthritis

OBJECTIVES We explored clinical factors associated with a major response to rituximab (RTX) (e.g. ACR >/=50, and European League against Rheumatism (EULAR) moderate to good response) in patients with active long-standing RA and inadequate response to anti-TNF agents or traditional DMARDs. METHODS RTX was used in 110 RA patients in six different Italian centres. The mean disease activity score on 28 joints (DAS28) was 6.4 +/- 0.99 and the mean HAQ was 1.63 +/- 0.68 at baseline. Thirty-two patients (29.1%) underwent RTX after the failure of DMARD therapy, 37 (33.6%) had failed or were intolerant to at least two anti-TNF agents, and 41 (37.3%) had failed or were intolerant to one anti-TNF agent. Univariate and multivariate analyses were performed. RESULTS The number of previous anti-TNF agents (P = 0.043), HAQ (P = 0.023), RF positivity (P < 0.0001) and anti-cyclic citrullinated peptide (anti-CCP) positivity (P = 0.003) were associated with ACR response >or=50 between month +4 and month +6 after starting RTX by univariate analysis. Multivariate analysis confirmed that a lower HAQ, a lower number of anti-TNF agents failed before RTX and RF positivity, but not anti-CCP positivity, were the selected variables associated with an ACR response >or=50, with an accuracy of 84% of the model. Only RF positivity correlated with EULAR moderate to good response both in the univariate and in the multivariate analysis, with an accuracy of 79% of the model. CONCLUSION RF-positive rather than anti-CCP-positive RA patients with lower baseline disability and a lower number of previously failed TNF blockers may be the best candidates to RTX.

P-glycoprotein (PGP) and lung resistance-related protein (LRP) expression and function in leukaemic blast cells

P‐glycoprotein (PGP) lung resistance protein (LRP) and multidrug resistance associated protein (MRP) expressions and function were evaluated by flow cytometry in 65 leukaemic patients (38 acute non‐lymphocytic leukaemias, eight acute lymphocytic leukaemias, 19 Ph‐positive chronic myeloid leukaemias in blastic phase). By using the MRK‐16, the LRP‐56 and the MRPm6 MoAbs, 34% of the cases did not over‐express any proteins (−); 24.5% over‐expressed (+) only PGP, 11% only LRP, 1.5% only MRP, 24.5% both PGP and LRP, and 4.5% both PGP and MRP. The mean intracellular daunorubicin accumulation (IDA) and rhodamine 123 (Rh123) retention in the presence or absence of the reversal agent SDZ PSC 833 (PSC) of the PGP−/LRP−/MRP− cases were comparable to the ones observed in normal leucocytes. With respect to the non‐over‐expressing cases, the PGP−/LRP+/MRP− cases showed only an impaired IDA (mean 204 ± 29; P < 0.001). The PGP+/LRP+/MRP− cases had a defect both in IDA (mean 166 ± 47, P < 0.001) and Rh123 retention (mean 0.42 ±0.14; P < 0.001), which were both corrected by PSC. All the PGP+/LRP+/MRP− cases had a defect in IDA (mean daunorubicin (DNR) accumulation 192 ± 44; P < 0.001. However, only in 8/16 of them an evident defect in Rh123 retention was found. In conclusion, both PGP and LRP over‐expression were common in leukaemia. An impaired IDA was found in all cases over‐expressing PGP, LRP or both. The study of Rh123 retention could give incorrect information about the blast cells’ ability to accumulate cytotoxic drugs in patients over‐expressing both PGP and LRP.

Liposome-encapsulated daunorubicin for PGP-related multidrug resistance.

The possibility that Daunoxome (DNX), a combination of daunorubicin (DNR) with a liposomal targeting system, escapes PGP was tested. Two pairs of leukaemic cell lines, each consisting of the parental non‐multidrug resistance (MDR) line and of a MDR variant, were studied for cytotoxicity (MTT test) and for cellular DNR kinetic and accumulation (flow cytometry). DNX and free DNR were equally toxic against non‐MDR cells, whereas the liposomal anthracycline was more toxic than the free drug against the MDR variant. Non‐MDR cells accumulated DNR more rapidly when they were exposed to free DNR than to DNX, but MDR cells accumulated more DNR when they were exposed to DNX. The kinetics of DNX and free DNR were also studied in the blast cells of 41 cases of acute leukaemia and they were found to be related to blast cell PGP expression. In 15 cases with a low PGP expression intracellular DNR accumulation was faster and higher with free DNR than with DNX. In 26 cases with a high PGP expression the area under the curve was similar with DNX and free DNR, but the kinetics of intracellular DNR accumulation showed an early low plateau with free DNR and a slow and continuous increase with DNX. In MDR cell lines the ratio was more favourable to DNX than to free DNR. We conclude that liposome encapsulated DNR is partially protected from PGP and that it is worth testing for the treatment of PGP‐positive acute leukaemia.

P-glycoprotein (PGP), lung resistance-related protein (LRP) and multidrug resistance-associated protein (MRP) expression in acute promyelocytic leukaemia

We analysed the expression of three drug transporter proteins [p‐glycoprotein (PGP), lung resistance‐related protein (LRP) and multidrug resistance‐associated protein (MRP1)] involved in anthracycline resistance that are frequently overexpressed in poor‐risk adult acute non‐lymphocytic leukaemia (ANLL), in 23 acute promyelocytic leukaemia (APL) patients at onset managed at a single institution. Cellular daunorubicin accumulation was also evaluated. At onset, no case had PGP or MRP1 expression that exceeded that of non‐multidrug‐resistant (MDR) cell lines. Only one case showed LRP overexpression. No peculiar MDR features distinguished the seven patients who relapsed from those who maintained complete remission. In the onset vs. first relapse, only one patient showed an increased (threefold) PGP expression at relapse. At second relapse, three out of four patients showed a PGP expression two‐ to threefold higher than baseline values. These results are consistent with the view that low PGP, LRP and MRP1 expression and the absence of defects in intracellular drug accumulation may account for the peculiarly high sensitivity of APLs to anthracycline. It does not support the screening of MDR markers in APL patients at onset as predicting factors of early relapse. The results suggest that no significant changes in PGP, LRP or MRP1 expression are likely to occur at first relapse. In contrast, PGP expression is likely to increase later in the patient history as a result of additional chemotherapy courses.

P-glycoprotein, lung resistance-related protein and multidrug resistance-associated protein in de novo adult acute lymphoblastic leukaemia

Summary.  P‐glycoprotein (P‐gp), lung resistance‐related protein (LRP) and multidrug resistance‐associated protein (MRP) expression, and blast cell intracellular daunorubicin accumulation (IDA) were evaluated in 95 previously untreated cases of adult acute lymphoblastic leukaemia (ALL) using flow cytometry. Forty‐five out of 95 (47%) patients were P‐gp positive (+), 12/66 (18%) were LRP+ and 11/66 (17%) were MRP+. Eighteen out of 66 (28%) patients showed a simultaneous multidrug resistance (MDR)‐related protein expression higher than controls for more than one protein, while 24/66 (36%) cases did not overexpress any protein. Twenty‐one out of 24 (87%) cases overexpressing at least one MDR‐related protein had a defect in accumulating daunorubicin into their blast cells, while only 4/24 (16%) cases who did not overexpress any protein had similar features. The complete remission rates were similar in MDR‐positive and ‐negative (–) patients but relapses within 6 months were more frequent in P‐gp+ cases, and therefore the disease‐free survival duration was shorter in P‐gp+ than in P‐gp– patients (P = 0·01). The number of MRP+ and/or LRP+ cases was too small to be able to draw any conclusion on their role in affecting or predicting therapy outcome. In conclusion, P‐gp overexpression associated with a defect in daunorubicin accumulation is a frequent feature in adult ALL at onset and seems to be related to poorer therapy outcome and, consequently, a shorter disease‐free survival. LRP and MRP overexpression seems to be a rare event and no conclusion can be drawn on its prognostic role.

Dendritic cell recovery after autologous stem cell transplantation

There is persistent immunosuppression not only in allogeneic but also in autologous stem cell transplantation because humoral and cellular immunity may take a year or more to return to normal, with increased risk of infectious complications. This immune defect may also involve antigen presentation, in particular dendritic cell (DC) function. We evaluated DC subset reconstitution in 58 patients who underwent bone marrow (BM) or peripheral blood (PB) autologous haematopoietic stem cell transplantation (HSCT). In all patients DC type 1 (DC1) and DC type 2 (DC2) were already significantly lower than in normal individuals before conditioning therapy (DC1/μl 3.1 ± 1.0, DC2/μl 3.0 ± 1.1). On day 0 and day +7 the mean DC1 and DC2 numbers were very low in both groups. Patients who received unmanipulated marrow or peripheral blood stem cells reached pre-conditioning levels of DC1 and DC2 cells on day +20. In patients receiving selected CD34 cells, DC increased slowly and pre-transplant counts were observed only on day +60. Nearly ‘normal’ levels of DC1 and DC2 could be observed in the first group from day +180, and were maintained thereafter; in CD34+ selected patients DC1 and DC2 counts remained lower than normal. Our data emphasise that circulating antigen presenting cells (APC) recover quickly. It remains to be determined if DC frequency in PB reflects their tissue function. The relatively low incidence of infections in patients undergoing autologous transplantation, despite defective lymphocyte reconstitution, could be related to functionally efficient DC.

Clinical characteristics, prognostic factors and multidrug‐resistance related protein expression in 36 adult patients with acute promyelocytic leukemia

Abstract: We report on a single‐center experience about the characteristics and outcome of 36 acute promyelocytic leukemia (APL) patients observed at our Department of Hematology between 1990 and 2002. The expression, of multidrug‐resistance (MDR) associated proteins (PGP, LRP, MRP1) was also analyzed. There were 12 males and 24 females (median age 37 yr), 89% (32 of 36) with classic morphology, and 11% (four of 36) with a microgranular variant. Risk class (according to GIMEMA/PETHEMA): 25% (nine of 36) high risk (HR), 53% (nineteen of 36) intermediate risk (IR), 22% (eight of 36) low risk (LR). PGP, LRP, and MRP1 expression at onset and at first relapse was low. CD33 antigen expression was high in all cases. The patients were treated according to GIMEMA protocols (LAP0389 and AIDA) including ATRA in induction in 75% (27 of 36) of cases and 94% (34 of 36) achieved a complete remission (CR) after induction therapy while 6% (two of 36) died early (DDI) of hemorrhage. Outcome: 71% (24 of 34) of evaluable patients remain in CR at a median follow‐up of 57 months (range 4–158 months) while 29% (10 of 34) relapsed at a median time of 12 months (range 8–43 months) and, of them, eight of 10 died early. The majority of patients that relapsed were in high‐risk group. The overall survival (OS) of the whole population at 32 months was 66% and the DFS at 42 months was 62%. A statistically significant difference in terms of DFS was observed between HR and IR/LR patients (P = 0.04 by log‐rank). DFS was not affected by age, sex, Hb levels, karyotype, and BCR isoform. At conclusion, our data confirm that despite the high rate of success with ATRA plus chemotherapy as induction (more than 90% of CR), about 30% of APL patients have a relapse (without a long‐lasting second remission) and underline the importance of patient stratification in distinct risk groups at diagnosis in order to better adapt the type and intensity of treatment (risk‐adapted therapy). Taking into account the high expression of CD33 and the low expression of MDR proteins in APL, new and investigational approaches like gemtuzumab–ozogamicin, with or without ATRA and other new drugs, should be strongly considered expecially in HR APL.

Long-term effects of rituximab in rheumatoid arthritis: clinical, biologic, and pharmacogenetic aspects.

Rituximab selectively targets the B‐cell compartment, including rheumatoid factor‐positive B cells. Short‐term efficacy and safety of rituximab in rheumatoid arthritis (RA) has been established by multicenter randomized placebo‐controlled studies. Results of long‐term follow‐up of the phase II/III clinical trials have confirmed the efficacy and safety of repeated courses of rituximab in the responders. However, mechanisms of action in humans, retreatment regimens, biologic effects on memory B cells and on immunoglobulin levels of prolonged exposure of the immune system to B‐cell depletion over time, and pharmacogenetic aspects remain open and intriguing issues of rituximab therapy. Several studies are ongoing to clarify possible clinical and biologic predictors of response to rituximab in RA and in other autoimmune diseases where rituximab has been proven to be effective. Preliminary clinical and pharmacogenetic results of our cohort of RA patients managed with rituximab from the year 2000 are presented.

Aberrant expression of TRAIL in B chronic lymphocytic leukemia (B-CLL) cells.

Analysis of peripheral blood (>85% CD19+/CD5+ B) lymphocytes, obtained from 44 patients affected by B chronic lymphoid leukemia (B‐CLL), showed that surface TNF‐related apoptosis inducing ligand (TRAIL) was expressed in all samples and at higher levels with respect to unfractionated lymphocytes and purified CD19+ B cells, obtained from 15 normal blood donors. Of note, in a subset of B‐CLL samples, the addition to B‐CLL cultures of a TRAIL‐R1‐Fc chimera, which binds at high affinity to surface TRAIL, significantly decreased the percentage of viable cells with respect to untreated control B‐CLL cells, suggesting that surface TRAIL may play an unexpected role in promoting B‐CLL cell survival. In spite of the majority of B‐CLL lymphocytes expressed variable surface levels of “death receptors” TRAIL‐R1 and TRAIL‐R2, the addition in culture of recombinant TRAIL increased (>20% vs. controls) the degree of spontaneous apoptosis in only 11/44 of the B‐CLL samples, had no effect in 19/44, while it significantly increased leukemic cell survival in 14/44. Taken together, these findings suggest that an aberrant expression of TRAIL might contribute to the pathogenesis of B‐CLL by promoting the survival in a subset of B‐CLL cells.