Recurrent idiopathic membranous nephropathy in the renal allograft: successful treatment with the anti-CD20 monoclonal antibody rituximab

Idiopathic membranous glomerulonephritis (IMGN) is one of the most common causes of nephrotic syndrome in adults. Disease progression is associated with the magnitude and duration of proteinuria [Reichert LJ, Koene RA, Wetzels JF. Prognostic factors in idiopathic membranous nephropathy. Am J Kidney Dis 1998; 31: 1–11]. Membranous nephropathy is also one of the glomerular diseases that is well described to recur in the transplanted kidney [Kotanko P, Pusey CD, Levy JB. Recurrent glomerulonephritis following renal transplantation. Transplantation 1997; 63: 1045]. There is no definitive therapy for primary membranous glomerulonephritis or recurrent disease in the graft. Cyclophosphamide plus steroids or cyclosporine [Cattran DC, Greenwood C, Ritchie S et al. Canadian Glomerulonephritis Study Group. A controlled trial of cyclosporine in patients with progressive membranous nephropathy. Kidney Int 1995; 47: 1130–1135] have been the preferred agents for the treatment of MGN involving the native kidneys. More recently, several reports have described the use of the anti-CD20 monoclonal antibody rituximab in patients with IMGN. In the current report, we present a patient with ESRD secondary to IMGN who developed nephrotic range proteinuria 5 months after receiving a kidney transplant from a deceased donor. A biopsy of the allograft demonstrated changes compatible with recurrent membranous glomerulonephritis. The patient was treated with four weekly infusions of rituximab over a 1-month period with a significant decrease in proteinuria and an improvement in renal function.

B cell reductive therapy with rituximab in the treatment of rheumatoid arthritis

The approach to treating autoimmune disorders is currently undergoing a significant change in focus. As therapies are developed that are more precise in targeting the pathogenesis for these diseases, patients experience significantly fewer side effects. At the same time, as more precise therapies are discovered, the etiologies of these diseases become further elucidated. It is now widely accepted that B-lymphocytes play a significant role in the pathogenesis of various autoimmune diseases, the extent of which continues to be the focus of ongoing research. Rheumatoid arthritis is one such disease process that has been the focus of various B-lymphocyte-directed therapeutic trials. In this paper we review the current research available on rituximab as treatment for rheumatoid arthritis. This review details results from four main studies, as well as others, which used rituximab in at least one of the arms in treatment of rheumatoid arthritis. The results are promising and will likely lead to longer term studies as well as a potential focus on B cell subsets.

A case of adult atypical haemolytic uraemic syndrome related to anti-factor H autoantibodies successfully treated by plasma exchange, corticosteroids and rituximab

Complement factor H auto-antibodies (CFH-ab) are a rare cause (6-10%) of atypical haemolytic uraemic syndrome (aHUS). All observations previously described were retrospective and occurred in children or teenagers. We report the first case of aHUS associated with anti-CFH antibodies in an adult patient who was successfully treated by plasma exchange, corticosteroids and rituximab.

Breakthrough in diabetes therapy ... Just around the corner?

Inspired by the articles presented in this issue of The Review of Diabetic Studies, we considered it useful to summarize the latest achievements and current challenges we face in the search for a cure of type 1 diabetes. In this editorial article, we took into account how the research landscape has changed in only a few years. While modern lifestyles impose new concerns, now we have a better knowledge of the various aspects of the disease that can be used to treat our young patients with more appropriate approaches, thereby eliminating old and obsolete prejudices.

C1q nephropathy: a true immune complex disease or an immunologic epiphenomenon?

We describe a 16-year-old Caucasian boy who presented with steroid-sensitive nephrotic syndrome aged 2 years. His clinical course was one of frequent relapses and severe steroid dependence. To manage this, he was sequentially treated with levamisole, then oral cyclophosphamide before being started on ciclosporin. A renal biopsy performed prior to commencement of ciclosporin confirmed minimal change disease on light microscopy. The immunohistochemistry and electron microscopy findings were in keeping with this. His complement levels were normal and his lupus serology negative. He remained on ciclosporin therapy for 8 years and had two further renal biopsies to detect ciclosporin-induced renal damage. Both biopsies showed evidence of increasing amounts of C1q deposition on immunohistochemistry and the presence of immune deposits on electron microscopy. As he had continued negative lupus serology, this was compatible with a diagnosis of C1q nephropathy. In addition both biopsies had changes compatible with chronic mild ciclosporin nephrotoxicity. This case is the first report describing in detail a paediatric patient with evolving C1q nephropathy who was treated successfully with rituximab. We discuss the role of C1q in this clinicopathological entity and question its significance.

Use of rituximab for refractory cytopenias associated with autoimmune lymphoproliferative syndrome (ALPS)

BACKGROUND

ALPS is a disorder of apoptosis resulting in accumulation of autoreactive lymphocytes, leading to marked lymphadenopathy, hepatosplenomegaly, and multilineage cytopenias due to splenic sequestration and/or autoimmune destruction often presenting in childhood. We summarize our experience of rituximab use during the last 8 years in 12 patients, 9 children, and 3 adults, out of 259 individuals with ALPS, belonging to 166 families currently enrolled in studies at the National Institutes of Health.

METHODS

Refractory immune thrombocytopenia (platelet count <20,000) in nine patients and autoimmune hemolytic anemia (AIHA) in three patients led to treatment with rituximab. Among them, seven patients had undergone prior surgical splenectomy; three had significant splenomegaly; and two had no palpable spleen.

RESULTS

In seven out of nine patients with ALPS and thrombocytopenia, rituximab therapy led to median response duration of 21 months (range 14-36 months). In contrast, none of the three children treated with rituximab for AIHA responded. Noted toxicities included profound and prolonged hypogammaglobulinemia in three patients requiring replacement IVIG, total absence of antibody response to polysaccharide vaccines lasting up to 4 years after rituximab infusions in one patient and prolonged neutropenia in one patient.

CONCLUSION

Toxicities including hypogammaglobulinemia and neutropenia constitute an additional infection risk burden, especially in asplenic individuals, and may warrant avoidance of rituximab until other immunosuppressive medication options are exhausted. Long-term follow-up of ALPS patients with cytopenias after any treatment is necessary to determine relative risks and benefits.

Role of hematopoietic stem cell transplant in the management of follicular lymphoma

Despite decades of published data regarding the application of autologous and allogeneic stem cell transplant in patients with follicular lymphoma, there remain no uniform indications for its use in this disease. Autologous transplant has been shown to lead to longer progression-free survival times in randomized trials when compared with postremission interferon-based chemoimmunotherapy. However, the development of rituximab and its use in frontline, salvage, and maintenance therapy complicates the decision to pursue autologous transplant, a modality developed prior to the advent of anti-CD20 monoclonal antibodies. Allogeneic transplant offers the advantages of lymphoma-free grafts and the immunologic graft-versus-lymphoma effect. These factors may confer the possibility of long-term remission, though historically they have been accompanied by high rates of upfront morbidity and mortality, especially in heavily pretreated patients with a poor performance status or chemotherapy-refractory disease. Advances in patient selection, human leukocyte antigen (HLA) matching, conditioning regimens, and supportive care have reduced transplant-related mortality and the incidence of graft-versus-host disease. Recently published data focus on the incorporation of rituximab and radioimmunoconjugates prior to, during, and following autologous transplant. Furthermore, reduced-intensity allogeneic stem cell transplantation has increasingly been used for relapsed follicular lymphoma patients with comorbidities or advanced age. Several recent reports suggest that reduced-intensity regimens may provide a high likelihood of long-term disease-free survival for patients up to 70 years of age with a good performance status, chemotherapy-sensitive disease, and HLA-matched sibling donors. Such patients with relapsed disease should be referred to a transplant center that can enroll them in one of the forthcoming clinical trials that aim to confirm these outcomes.

Update on the use of rituximab for intractable rheumatoid arthritis

It has been 3 years since rituximab, a mouse x human chimeric anti-CD20 monoclonal antibody that selectively depleted B cells, was approved by the FDA for the treatment of moderate to severe rheumatoid arthritis (RA) with an inadequate response to anti-TNF therapies. Since approval rituximab has become a part of standard treatment, and additional data have become available on long-term efficacy and safety both from clinical trials and from post-marketing surveillance. In open long-term follow-up from clinical trials, patients treated with multiple courses of rituximab continued to respond in terms of signs and symptoms, and damage assessed radiographically was significantly inhibited. Moreover, the rate of serious infectious events was not increased as the number of courses increased. However, because of case reports of progressive multifocal leukoencephalopathy in patients treated with rituximab for non-malignant conditions, a black box warning has been added. Studies on the immunologic correlates of response to rituximab treatment including B cell subsets in peripheral blood and synovial biopsies are providing clues into how rituximab works for autoimmune disease. However, at this time we are not able to explain why some patients do not respond and cannot predict who will respond. Future challenges for the further development of rituximab for intractable RA will be discussed.

Efficacy, safety, and tolerability of abatacept in the management of rheumatoid arthritis

The management of rheumatoid arthritis (RA) has undergone an impressive transformation over the past few decades. Further understanding of the pathophysiology of the disease process has resulted in the development of biologic agents that target proinflammatory cytokines and both B and T lymphocytes. By blocking an important costimulatory pathway, abatacept leads to a dramatic reduction in T cell stimulation and proliferation. Multiple clinical trials have revealed consistent benefit with regards to clinical and radiographic efficacy, quality of life, and disability in patients suffering from RA who have had inadequate responses to methotrexate or tumor necrosis factor inhibitors. The possibility of remission when used early in the disease course has also been demonstrated. Importantly, abatacept has been very well tolerated with a low rate of serious infections and no apparent increase in malignancies to date. Continued surveillance of the benefits and risks will help to better define its place amongst the other biologic agents in the treatment of RA.

A phase I/II study of rituximab and etanercept in patients with chronic lymphocytic leukemia and small lymphocytic lymphoma

Rituximab has modest activity in relapsed chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma but is associated with tumor necrosis factor-alpha (TNF-alpha) release that can cause CLL proliferation and inhibit apoptosis. We examined whether disruption of TNF-alpha by etanercept improves response to rituximab in CLL. Eligible patients had previously treated CLL with performance status 0-3. Patients received etanercept 25 mg subcutaneously twice weekly (weeks 1-5) and rituximab 375 mg/m(2) intravenously thrice weekly (weeks 2-5) using a phase I/II design. Primary end points were response and toxicity. The 36 enrolled patients had a median of two prior treatments; 50% were fludarabine refractory and 22% had del(17p13.1). Of the 34 response-evaluable patients, 10 (29%) responded, including 9 partial responses and 1 complete remission. Response was not affected by prior rituximab or fludarabine-refractory status, but no patients with del(17p13.1) responded. Median progression-free survival for responders was 9.0 months (range 1-43). Ten patients have had treatment-free intervals exceeding 12 months, including four who have remained untreated for 32, 43, 46 and 56 months. Adverse events were mild, including mild infusion reactions, transient cytopenias and grade 3 infections in 14% of the patients. The combination of etanercept and thrice weekly rituximab produces durable remissions in non-del(17p13.1) CLL patients and is well tolerated.

A successful treatment of relapsed primary CNS lymphoma patient with intraventricular rituximab followed by high-dose chemotherapy with autologous stem cell rescue

The prognosis for patients with primary central nervous system (CNS) lymphoma (PCNSL) who relapse after the initial response is usually poor. A standard treatment for relapsed PCNSL has not yet been identified because of the heterogeneity of the therapies employed and the lack of large, prospective clinical trials. We describe a 46-year-old relapsed PCNSL patient who was successfully treated with intraventricular applications of rituximab to minimize neurotoxicity, 2 cycles of salvage chemotherapy with etoposide, ifosfamide, and cytarabine (VIA) regimen and high-dose chemotherapy with autologous stem cell rescue. The high-dose chemotherapy consisted of bischloroethylnitrosourea, etoposide, cytarabine, and melphalan (BEAM) regimen. Partial remission was detected after intraventricular rituximab therapy and the patient has been in complete remission without evidence of neurotoxicity for 28 months after high-dose chemotherapy with autologous stem cell rescue. This case indicates a new appropriate treatment guideline in relapsed PCNSL patient after initial intensive chemo-radiotherapy.

Expanded use of rituximab in the management of non-Hodgkin lymphoma

Rituximab is a chimeric monoclonal antibody targeting the B cell antigen CD20. Since its first approval for clinical use in 1997, rituximab has become an inherent part of the treatment of CD20-positive lymphoma. In previously untreated non-Hodgkin lymphoma (NHL) conventional chemotherapy supplemented by rituximab (R-chemotherapy) was shown to be more effective than chemotherapy alone. This holds true for indolent as well as aggressive NHL. Rituximab was also shown to be beneficial when used as maintenance therapy or part of salvage and re-induction regimens in relapsed NHL. Administration of rituximab is generally well tolerated. The most common side effects including fever, urticaria and bronchospasm are mostly mild, treatable and restricted to the infusion period. Thus, rituximab can usually be administered in an outpatient setting. Due to its favorable effect/side effect ratio, clinical trials are currently evaluating a possible role for rituximab in several other diseases such as Hodgkin lymphoma (HL) and non-malignant autoimmune disorders. This review aims at giving an overview of the pharmacological properties of rituximab and summarizing key publications and recent literature on its use in NHL.

Rituximab in two cases of Goodpasture's syndrome

We describe the effects of rituximab in two patients with refractory Goodpasture's syndrome. After one single 1000 mg dose administration, rituximab did not appear to improve renal function in either of our cases. Polyoma virus-negative leukoencephalopathy, a probable toxic side effect of rituximab, was seen in our first patient.

Sustained Remission After Combination Therapy with Rituximab and Etanercept in Two Patients with Rheumatoid Arthritis After TNF Failure: Case Report

Objectives:

Approximately up to 40% of patients with rheumatoid arthritis (RA) fail to respond to tumor necrosis factor (TNF) inhibitors, lose response over time or are unable to tolerate treatment.

Materials and Methodology:

We report two female patients suffering from active, refractory rheumatoid arthritis despite TNF blocking agents who have been treated with rituximab added to ongoing therapy with etanercept.

Results:

Combination therapy was tolerated without any acute side effects. Both patients improved with a significant, long lasting reduction of disease activity (DAS28, CRP). Evaluation of the immunological parameters showed the expected B-cell depletion and a transient reduction of immunoglobulin-levels. One patient developed four serious infections requiring antibiotic treatment (1 pneumonia, 3 exacerbations of her pre-existing chronic bronchitis) within follow up of 45 months.

Conclusion:

Combination therapy of rituximab and etanercept lead to a significant improvement of clinical disease activity and inflammatory parameters in two RA patients refractory to anti-TNF treatment.

Make the grade for Wegener's granulomatosis after kidney transplantation

Antineutrophil cytoplasmic antibodies-associated vasculitis (AAV) is a well-described cause of multiple organ involvement including rapidly progressive pauci-immune crescentic glomerulonephritis. Kidney transplantation (KTx) is considered the treatment of choice in patients with end-stage renal disease (ESRD) due to AAV. Patient and graft survival in AAV after KTx is favourable and comparable with other non-diabetic causes of ESRD. While relapse of AAV is high in dialysis patients (up to 50%), it decreases after KTx (8.6–22.2%). Yet, relapse may occur at any time after KTx and transplant involvement has been documented in at least 25 cases. Therapeutic guidelines for the management of AAV after KTx do not exist and clinical management is a controversial discussion. We present two unusual cases of young males with smouldering AAV who recently underwent KTx at our hospital. Case 1 experienced repeated relapses after KTx and was finally successfully treated with rituximab. Case 2 received rituximab pre-emptively before living kidney donation and remained free of flairs. Prompted by theses two cases, we reviewed the literature focusing on the right point of time for transplantation, risk assessment, role of antineutrophil cytoplasmic antibodies, clinical presentation of flairs and immunosuppression in smouldering Wegener's granulomatosis (WG) and in relapse, including individualized treatment with rituximab.

One year follow-up of children and adolescents with chronic immune thrombocytopenic purpura (ITP) treated with rituximab

BACKGROUND

We previously showed in a prospective study that rituximab appears to be effective in some children and adolescents with severe chronic immune thrombocytopenia. Eleven of 36 patients achieved and maintained platelet counts over 50,000/mm(3) within the first 12 weeks. These patients were followed for the next year.

METHODS

Platelet counts were monitored monthly and all subsequent bleeding manifestations and need for further treatment was noted.

RESULTS

Eight of the 11 initial responders maintained a platelet count over 150,000/mm(3) without further treatment intervention. Three patients had a late relapse. One initial non-responder achieved a remission after 16 weeks, and two additional patients maintained platelet counts around 50,000/mm(3) without the need for further intervention.

CONCLUSIONS

Rituximab resulted in sustained efficacy with platelet counts of 50,000/mm(3) or higher in 11 of 36 patients (31%).

Rituximab therapy in Greek patients with rheumatoid arthritis

OBJECTIVE

An open-label, prospective, uncontrolled study created to investigate clinical response, serological changes and side effects in Greek patients with rheumatoid arthritis (RA), after B-cell depletion with rituximab.

METHODS

Patients with high disease activity (disease activity score [DAS]-28 > 5.1) were selected for treatment with rituximab and received two infusions, 1 gr each, 2 weeks apart. Different disease parameters (visual analog scale, DAS-28, C-reactive protein [CRP], erythrocyte sedimentation rate, health assessment questionnaire, complement (C3), C4, rheumatoid factor [RF], anti-cyclic citrullinated peptide antibody [anti-CCP], swollen joint count, tender joint count, immunoglobulin M [IgM], IgG, IgA) were performed at base line, 2, 4, and 6 months post-treatment. Response was defined according to the American College of Rheumatology (ACR) criteria.

RESULTS

Seventeen patients received therapy. Treatment led to a reduction in various disease parameters. ACR20 was achieved in 41.11% of patients by week 8, 52.94% by week 16, and 82.35% by week 24. ACR50 was achieved in 5.88% by week 8, 41.17% by week 16, and 64.7% by week 24. ACR70 was achieved only by week 24 in 23.52% of patients. Statistical analysis has shown no differences in clinical response, between RF positive/negative patients, and anti-CCP-positive/negative patients, while decline of RF was better correlated with reduction of DAS-28 than with anti-CCP.

CONCLUSIONS

Rituximab is a well tolerated and effective treatment in RA. Response was not correlated to RF or anti-CCP positivity. Decline of RF was associated with clinical response and reduction of DAS-28 and CRP.

Direct and complement dependent cytotoxicity in CLL cells from patients with high-risk early-intermediate stage chronic lymphocytic leukemia (CLL) treated with alemtuzumab and rituximab

The mechanism of cytotoxicity of alemtuzumab and rituximab in chronic lymphocytic leukemia (CLL) is not well understood. We obtained fresh CLL cells from early-intermediate stage high-risk patients just prior to treatment with alemtuzumab and rituximab to study mechanisms of action and resistance. Alemtuzumab had minimal direct cytotoxicity but caused significant complement dependent cytotoxicity (CDC) although a subpopulation of CLL cells had intrinsic resistance. Rituximab had no direct cytotoxicity and caused minimal CDC in cells from most patients. These data suggest that CDC has a therapeutic role in patients treated with alemtuzumab and that measures to decrease resistance to CDC could increase efficacy.

Rituximab in the treatment of non-Hodgkin's lymphoma

Besides traditional cytostatic drugs the introduction of monoclonal antibodies has substantially influenced current treatment concepts of non-Hodgkin's lymphoma (NHL). Rituximab, a monoclonal anti-CD20 chimeric antibody, now has been widely evaluated in the various B-cell lymphatic neoplasms. Large phase III studies helped to prove the value of this drug in follicular lymphoma as part of induction or relapse treatment as well as maintenance treatment. The addition of rituximab to the well established CHOP regimens has increased achievable cure rates in diffuse large cell lymphoma, and this combination is now accepted worldwide as standard of care. Although conflicting results are available, rituximab is widely used for the treatment of mantle cell lymphoma. For the less frequent lymphoma entities phase 2 studies show a considerable efficiency for most of these B-NHL variants. Current research focuses on combined chemoimmunotherapy approaches, optimization of dosing regimens, and combination with novel agents.

Early treatment of high-risk chronic lymphocytic leukemia with alemtuzumab and rituximab

BACKGROUND

Patients with chronic lymphocytic leukemia (CLL) usually are treated only for progressive disease. However, the discovery of biologic predictors of a high risk of disease progression, together with the development of newer, more targeted therapies, could change this paradigm. In this phase 2 study, the authors tested the safety and efficacy of early treatment for patients with high-risk CLL using alemtuzumab and rituximab.

METHODS

Patients were eligible for treatment if they were 1) previously untreated, 2) had no National Cancer Institute-Working Group 1996 criteria for treatment, and 3) had at least 1 marker of high-risk disease 17p13-, 11q22-, or a combination of unmutated IgVH and CD38+/ZAP70+). Treatment consisted of subcutaneous alemtuzumab (initial dose escalation followed by 30 mg on Monday, Wednesday, and Friday for 4 weeks) and intravenous rituximab (375 mg/m(2) per week x4 doses). All patients received Pneumocystis pneumonia and herpes virus prophylaxis and were monitored for cytomegalovirus reactivation.

RESULTS

Twenty-seven of 30 patients (90%) responded to therapy with 11 (37%) complete responses (CRs). Five patients (17%) patients who had a CR had no detectable minimal residual disease. The median response duration was 14.4 months, and only 9 patients required retreatment for progressive disease at the time of the current report (median follow-up, 17.6 months). Study patients had a significantly longer time from diagnosis to first treatment for CLL according to conventional indications than a comparison cohort with similar biologic risk profiles.

CONCLUSIONS

The therapy regimen used was safe and effective for early treatment of patients with high-risk CLL. Further studies will be required to determine whether this early treatment strategy decreases morbidity and mortality for high-risk CLL.

Spontaneous bacterial peritonitis from Salmonella: an unusual bacterium with unusual presentation

Spontaneous bacterial peritonitis (SBP) is a common cause of morbidity and mortality in patients with advanced cirrhosis and portal hypertension. While gram-negative rods and Enterococcus species are the common offending organisms, Salmonella has also been recognized as a rare and atypical offending organism. Atypical features of Salmonella SBP include both its occurrence in cirrhotic patients with immunosuppressive state and its lack of typical neutroascitic response. Diagnosis is often delayed as it requires confirmation from ascitic fluid culture. We report a case of Salmonella SBP occurring in a patient with decompensated cryptogenic cirrhosis with concurrent low-grade non-Hodgkin lymphoma and prior treatment with rituximab. Physicians should be aware of the atypical presentation, especially in cirrhotic patients who are immunosuppressed.

Seeking approval: present and future therapies for pemphigus vulgaris

Pemphigus vulgaris is an autoimmune blistering disease of the skin and mucous membranes. Despite the potentially fatal prognosis, there are currently no FDA-approved treatments specifically for pemphigus. In 2006, the FDA designated orphan drug status to mycophenolate mofetil for the treatment of pemphigus vulgaris, indicating both federal and commercial interest in developing therapies for this devastating disease. This review focuses on pemphigus therapies that are currently in preclinical or clinical trials, as well as potential novel therapies based on recent advances in the understanding of the pathophysiology of this disease.

Immunotherapies for Hodgkin's lymphoma

Multiple immune evasion strategies characterize the pathobiology of Hodgkin's lymphoma. These must be considered when developing and testing immunotherapeutic approaches for this disease. The clinical experience with adoptive immunotherapy of Epstein-Barr virus positive tumors, and with monoclonal antibodies directed against CD30, CD20, and other antigens, is herein reviewed.

Rituximab therapy for juvenile-onset systemic lupus erythematosus

Rituximab (RTX), an anti-CD20 monoclonal antibody, has been proposed for use in the therapy of systemic lupus erythematosus (SLE). We present the initial long-term experience of the safety and efficacy of rituximab for treatment of SLE in children. Eighteen patients (mean age 14 +/- 3 years) with severe SLE were treated with rituximab after demonstrating resistance or toxicity to conventional regimens. There was a predominance of female (16/18) and ethnic African (13/18) patients. All had lupus nephritis [World Health Organization (WHO) classes 3-5] and systemic manifestations of vasculitis. Clinical disease activity of the SLE was scored with the SLE-disease activity index 2K (SLEDAI-2K). Patients were followed-up for an average of 3.0 +/- 1.3 years (range 0.5 to 4.8 years). B-cell depletion occurred within 2 weeks in all patients and persisted for up to 1 year in some. Clinical activity scores, double-stranded DNA (dsDNA) antibodies, renal function and proteinuria [urine protein to creatinine ratio (Upr/cr)] improved in 93% of the patients. Five patients required multiple courses of RTX for relapse, with B-cell repopulation. One died of infectious endocarditis related to severe immunosuppression. In conclusion, our data support the efficacy of rituximab as adjunctive treatment for SLE in children. Although rituximab was well tolerated by the majority of patients, randomized controlled trials are required to establish its long-term safety and efficacy.

Rituximab-CHOP induced interstitial pneumonitis in patients with disseminated extranodal marginal zone B cell lymphoma

A 69-year-old male was diagnosed in February 2004 with stage IV extranodal marginal zone B cell lymphoma involving the mediastinal nodes, lung parenchyma and bone marrow with high LDH. Shortness of breath developed following the 5th course of Rituximab-CHOP chemotherapy (cyclophosphamide, Vincristine, Doxorubicin, Prednisolone). Bronchoscopy guided transbronchial lung biopsy revealed interstitial thickening and type II pneumocyte activation, compatible with interstitial pneumonitis. After treatment with prednisolone a complete resolution of the dyspnea was observed. The patient was well on routine follow-up at the outpatient clinic, with no progression of lymphoma or interstitial pneumonitis.

The potential utility of B cell-directed biologic therapy in autoimmune diseases

Increasing awareness of the importance of aberrant B cell regulation in autoimmunity has driven the clinical development of novel B cell-directed biologic therapies with the potential to treat a range of autoimmune disorders. The first of these drugs-rituximab, a chimeric monoclonal antibody against the B cell-specific surface marker CD20-was recently approved for treating rheumatoid arthritis in patients with an inadequate response to other biologic therapies. The aim of this review is to discuss the potential use of rituximab in the management of other autoimmune disorders. Results from early phase clinical trials indicate that rituximab may provide clinical benefit in systemic lupus erythematosus, Sjögren's syndrome, vasculitis, and thrombocytopenic purpura. Numerous case reports and several small pilot studies have also been published reporting the use of rituximab in conditions such as myositis, antiphospholipid syndrome, Still's disease, and multiple sclerosis. In general, the results from these preliminary studies encourage further testing of rituximab therapy in formalized clinical trials. Based on results published to date, it is concluded that rituximab, together with other B cell-directed therapies currently under clinical development, is likely to provide an important new treatment option for a number of these difficult-to-treat autoimmune disorders.

Targeted therapies in rheumatoid arthritis: Focus on rituximab

B-cell depletion is a new strategy for treating patients with rheumatoid arthritis (RA). In the past years, several studies have proven the efficacy of anti-CD20 mediated B-cell depletion with rituximab (Mabthera((R))) in RA patients who failed TNF-blocking therapy. The important role of B-cells in the pathogenesis of RA is deducted from the specific detection of autoantibodies in RA and infiltration of B-cells and plasma cells in inflamed synovium. Pharmacological studies in RA patients treated with rituximab showed that half-life was approximately 3 weeks leading to a 6- to 8-month period of B-cell depletion in peripheral blood. Rituximab treatment led to significant improvements in disease activity of RA patients and the current review summarizes the results from phase III, randomized clinical trials that have been performed. Lastly, data on safety and quality of life are summarized. Although relatively low numbers of RA patients have been treated and long-term data are lacking, current data thus far suggest a relatively good safety profile for rituximab. Future studies will need to focus on predicting responsiveness to rituximab, investigating efficacy of re-treatment with rituximab and extending data on safety and patient-focused outcomes.

A case of nodular sclerosis Hodgkin's lymphoma repeatedly relapsing in the context of composite plasma cell-hyaline vascular Castleman's disease: successful response to rituximab and radiotherapy

We report the case of an Epstein-Barr virus (EBV)- and human immunodeficiency virus-serum negative patient suffering from repeatedly relapsing classical Hodgkin's Lymphoma (cHL) associated with a histological picture of plasma cell-hyaline vascular (PC-HV) form of Castleman's disease (CD). The CD30- and CD15-positive, Reed-Sternberg/Hodgkin cells, only occasionally expressed the CD20 molecule, but not leukocyte common antigen and latent membrane protein-1. Single-strand polymerase chain reaction failed to detect human herpesvirus 8 or EBV in the involved tissues. At the time of second relapse in July 2005, the clinical picture was characterized by a palpable right hypogastric mass, disclosed at physical exam, in the absence of other enlarged peripheral lymph nodes, subjective symptoms or laboratory profile alterations. Combined hybrid-(18)F-fluorodeoxyglucose positron emission-computerized tomography (18F-FDG PET/CT) showed increased radionuclide uptake in multiple external iliac lymph nodes [standardized uptake value (SUV) of 7.4] and non-palpable left supraclavicular lymph nodes (SUV of 5.8). Relapsing cHL in the context of mixed PC-HV CD was documented in two of three surgically excised abdominal lymph nodes never previously enlarged or involved by any lymphoproliferative disease. Because of the limited disease extension and failure to induce continuous remission with previous conventional chemoradiotherapy, the patient was treated with six rituximab injections. This immunotherapy induced significant reduction in size of supraclavicular lymph nodes as evident at ultrasound (US) scan (<1 vs. 2.5 cm, post- vs. pretherapy), which was confirmed by the 18F-FDG PET/CT in October 2005, despite no modification in SUV of 4.2. 18F-FDG PET/CT also disclosed no radionuclide uptake by abdominal lymph nodes. Thus, a second course of four additional rituximab injections was given and subsequent 18F-FDG PET/CT indicated persistent, but reduced incorporation of radionuclide compared to the pretherapy value (SUV of 2.7) in the supraclavicular area and confirmed a normal metabolic activity in the iliac external lymph nodes. Because of uncertain persistent disease in the supraclavicular nodal site, involved-field radiotherapy (RT) was delivered in that area as consolidation treatment. After completion of rituximab and RT for 16 and 14 months respectively, US and 18F-FDG PET/CT exams were indicative of complete remission. This case is in concordance with previously published data suggesting that rituximab immunotherapy might be a valid option in the treatment of CD and also have a role in the management of relapsing cHL.

Rituximab for refractory rheumatoid arthritis: a 24-week open-label prospective study

Objectives

To study the efficacy of rituximab in active rheumatoid arthritis (RA) patients refractory to disease modifying anti-rheumatic drugs (DMARDs) including the tumor necrosis factor (TNF)-α antagonists.

Methods

Adult patients with active RA despite adequate therapies with conventional DMARDs or anti-TNFα agents for at least 3 months were recruited. Inclusion criteria were: (1) Positive RF / anti-CCP; (2) ≥ 6 swollen joints and ≥ 8 tender joints; (3) ESR ≥ 28 mm/hr or CRP ≥ 10 mg/L. Eligible patients were given intravenous rituximab infusions at a dose of 1000 mg on days 1 and 15. Assessment was performed 4-weekly thereafter and included tender joint counts (TJC), swollen joint counts (SJC), physician’s and patient’s global assessment, patient’s pain assessment (VAS 0-100 mm), disability index (HAQ-DI), quality of life (SF36), fatigue score (FACIT-F), ESR and CRP. The DAS28, EULAR and ACR responses at week 24 were evaluated.

Results

10 patients (8 women and 2 men) were studied (mean age: 49 years; mean RA duration 7.4 years). Baseline TJC and SJC were 25.1 ± 13.2 and 12.8 ± 5.4 respectively. The mean DAS28 score was 7.1 ± 0.7, and the mean CRP and ESR levels were 52.3 ± 60 mg/L and 95.8 ± 32 mm/hr, respectively. The median number of failed DMARDs was 4 and two patients had failed anti-TNFα treatment. At week 24, there was a significant drop in TJC, SJC, ESR and CRP. The HAQ-DI score also decreased from 2.1 to 1.7 (p=0.04) while the total SF-36 score improved from 24.8 to 38.3 (p=0.008). Sixty percent of patients achieved EULAR moderate-to-good response. Half of the patients achieved ACR20 and two achieved ACR50 / 70 response. Only one patient experienced a minor infusion reaction.

Conclusions

Rituximab is effective and well tolerated in patients with refractory RA.

Ultrasound assessment of salivary glands in patients with primary Sjögren's syndrome treated with rituximab: Quantitative and Doppler waveform analysis

OBJECTIVES

Noninvasive objective tests are needed to diagnose primary Sjogren's syndrome (pSS) and to evaluate treatment responses. Ultrasound imaging of the salivary glands is rapid and noninvasive. Recent open-label studies suggested that anti-CD20 (rituximab) may be effective in pSS. The purpose of this study was to look for ultrasound evidence of the effects of rituximab in pSS.

METHODS

We compared 16 patients fulfilling the new American-European consensus group criteria for pSS to 9 controls, using B-mode ultrasound features (parenchymal homogeneity and gland size) and Doppler waveform analysis of the transverse facial artery of parotid glands. We compared the same parameters in the patients before and after 12 weeks of intravenous rituximab therapy.

RESULTS

Compared to controls, untreated patients had significant abnormalities in salivary gland structure (p < 0.0001) and parotid size (2.05 +/- 0.33 cm versus 1.70 +/- 0.28 cm; p = 0.001). Doppler waveform analysis showed significant differences before, but not after, lemon stimulation between untreated patients and controls. After rituximab treatment, significant size reductions were noted in the parotids (2.05 +/- 0.3 cm at baseline and 1.86 +/- 0.27 cm at week 12; p = 0.002) and submandibular glands (2.02 +/- 0.54 cm at baseline and 1.66 +/- 0.34 cm at week 12; p = 0.001). Doppler resistive indices after lemon stimulation were significantly increased after rituximab treatment.

CONCLUSION

Salivary gland measurements and blood inflow responses to salivary stimulation as assessed by ultrasound hold promise as objective noninvasive tools for evaluating rituximab effects in patients with pSS.

CD20-specific antibody-targeted chemotherapy of non-Hodgkin's B-cell lymphoma using calicheamicin-conjugated rituximab

Tumor-targeted delivery of a potent cytotoxic agent, calicheamicin, using its immunoconjugates is a clinically validated therapeutic strategy. Rituximab is a human CD20-specific chimeric antibody extensively used in B-NHL therapy. We investigated whether conjugation to calicheamicin can improve the anti-tumor activity of rituximab against human B-cell lymphoma (BCL) xenografts in preclinical models. BCL cells were cultured with rituximab or its calicheamicin conjugates and their in vitro growth was monitored. BCL cells were injected s.c. to establish localized xenografts in nude mice or i.v. to establish disseminated BCL in severe combined immunodeficient (scid) mice. I.p. treatment with rituximab or its calicheamicin conjugates was initiated and its effect on s.c. BCL growth or survival of mice with disseminated BCL was monitored. Conjugation of calicheamicin to rituximab vastly enhanced its growth inhibitory activity against BCL in vitro. Conjugation to calicheamicin had no deleterious effect on the effector functional activity of rituximab. Calicheamicin conjugated to rituximab with an acid-labile linker exhibited greater anti-tumor activity against s.c. BCL xenografts and improved survival of mice with disseminated BCL over that of unconjugated rituximab. Anti-tumor activities of rituximab conjugated to calicheamicin via an acid-stable linker were similar to that of unconjugated rituximab. Superior anti-tumor efficacy exhibited by a calicheamicin immunoconjugate of rituximab with an acid-labile linker over that of rituximab demonstrates the therapeutic potential of CD20-specific antibody-targeted chemotherapy strategy in the treatment of B-NHL.

Personalized medicine: the absence of 'model-changing' financial incentives

This perspective biases on the side that personalized medicine can contribute to a more efficient collective model; however, the hard economics need and deserve significantly more critical analysis and new data input than they are currently being given, to determine their role, or not, in driving change. Put simply, as with the birth of all new and promising developments in healthcare, myth, hope and trend-spotting are driving this market forward, rather than any hard evidence of a sustainable commercial business model for all stakeholders. While there are clear economic benefits to aspects of delivery along the way to personalized care, there may in fact be no compelling economic drivers for radical change for payers and the pharmaceutical industry. The best they can hope to achieve is that the balance sheet is, just that, in balance.

Rituximab maintenance in relapsed or refractory follicular non-Hodgkin's lymphoma: the evidence of its therapeutic value

INTRODUCTION

Non-Hodgkin's lymphoma (NHL) is the sixth most common malignancy, and follicular lymphoma (FL) is the second most common form of NHL. FL is generally considered to be incurable, and is characterized by periods of remission followed by episodes of relapse, with median survival of 8-10 years. Maintenance treatment is aimed at improving quality of life and survival.

AIMS

To review the current evidence for maintenance rituximab in patients with FL.

EVIDENCE REVIEW

Two randomized studies of rituximab maintenance or observation after induction therapy with single-agent rituximab, which were performed mainly in patients with relapsed/refractory disease, have demonstrated a two- to three-fold improvement in median progression-free survival (PFS) in the maintenance arm. Two further studies of rituximab maintenance or observation following induction chemotherapy with or without rituximab performed in patients with relapsed/refractory FL have shown a two- to four-fold increase in median PFS in the maintenance arm. In one of these studies an overall survival benefit has also been demonstrated. An additional study, this time in previously untreated patients, has demonstrated a four-fold improvement in median PFS as well as a significant overall survival benefit with rituximab maintenance following induction with chemotherapy alone.

PLACE IN THERAPY

Currently rituximab maintenance can be considered to be appropriate therapy for patients with relapsed/refractory disease who have not received rituximab previously and who are not suitable for autologous stem cell transplantation, and for patients who receive first-line therapy with chemotherapy without rituximab.

A patient with mixed type Evans syndrome: efficacy of rituximab treatment

Mixed type Evans syndrome is a very rare hematologic disease. Although mixed type Evans syndrome may initially respond well to steroids, this disease usually runs a chronic course with intermittent exacerbations. We describe here a 46-yr-old female with the steroid-refractory, mixed type Evans syndrome, and she had a prompt response to rituximab. She was diagnosed as having the mixed type Evans syndrome with the clinical features of symptomatic anemia, jaundice and thrombocytopenia. Prednisone therapy was commenced and her hemoglobin and platelet level returned to the normal. However, after 15 weeks, she relapsed with hemolytic anemia and thrombocytopenia. We started rituximab at the dose of 375 mg/m(2) once weekly for a total of 4 doses, which was well-tolerated and this induced the normalization of hemoglobin, bilirubin and lactic dehydrogenase, and there was also a significant increase of the platelet count.

ADAMTS13 and microvascular thrombosis

Interaction between platelet and von Willebrand factor, a circulating adhesive glycoprotein, is essential for hemostasis under the high shear environments of arterioles and capillaries. If unregulated, this interaction may lead to unwarranted platelet thrombosis. ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 motif, number 13), a plasma zinc metalloprotease synthesized primarily in the stellate cells of the liver, cleaves shear stress-activated von Willebrand factor, thereby preventing the occurrence of von Willebrand factor-platelet interaction in the circulation. A profound deficiency of ADAMTS13, due to genetic mutations or autoimmune inhibition, results in intravascular von Willebrand factor platelet aggregation and widespread microvascular thrombosis characteristic of thrombotic thrombocytopenic purpura. Cloning of ADAMTS13 and structure-function analyses of the enzyme are leading to exciting advances in the diagnosis and therapy of this hitherto mysterious disease.

Perioperative management of medications used in the treatment of rheumatoid arthritis

Patients with rheumatoid arthritis (RA), an inflammatory arthritis that can destroy joint structures, are often on multiple medications to control disease activity. These medications may have significant toxicities and side effects. Over the course of their lifetime, patients with this disease often require orthopedic procedures, including total joint arthroplasty, and the medications they are taking present management issues specific to the perioperative period. As many of these medications are immunosuppressive, the concern for postoperative infection and delayed wound healing are particularly worrisome. We conducted a review of the available literature pertaining to the perioperative use of the most commonly prescribed medications for RA. Although the existing data directly addressing perioperative complications in orthopedic surgery is sparse, information on relevant complications resulting from the general use of these drugs may be used as a basis for conservative recommendations.

Two cases of interstitial pneumonitis caused by rituximab therapy

Rituximab, a chimeric monoclonal antibody directed against CD20, has become a part of the standard therapy for patients with non-Hodgkin's lymphoma either in combination with other drugs or as a single agent. The CD20 antigen is expressed on 95% of B-cell lymphoma cells and normal B-cells but, is not found on precursor B-cells or stem cells. Rituximab is now approved for patients with diffuse large B-cell lymphoma when combined with standard CHOP chemotherapy (cyclophosphamide, doxorubicin, vincristine and prednisone) or patients with follicular lymphoma who have failed first line chemotherapy. The monoclonal antibody is generally well tolerated. Most of the adverse events are infusion-associated, mild to moderate non-hematological toxicities. Severe respiratory adverse events have been infrequent. Here, we report two patients with non-Hodgkin's lymphoma in whom interstitial pneumonitis developed with rituximab therapy.

Biologic therapies in autoimmune diseases

Over the past decade, the treatment of rheumatoid arthritis has been revolutionised by the development of therapies targeted at molecules involved in driving the inflammatory response. This review briefly summarises the established uses of biologic therapies in rheumatoid disease, and outlines other diseases in rheumatology and other fields where biologic agents are finding a role.

A DeImmunized chimeric anti-C3b/iC3b monoclonal antibody enhances rituximab-mediated killing in NHL and CLL cells via complement activation

Complement-dependent cytotoxicity (CDC) is a key mechanism of Rituximab (RTX) action in killing non-Hodgkin's lymphoma (NHL) cells both in vitro and probably in vivo. A DeImmunized, mouse/human chimeric monoclonal antibody (Mab), H17, specific for cell-associated complement C3 cleavage products, C3b and iC3b, was generated to enhance RTX-mediated killing of target cells by CDC. When NHL cell lines were treated with RTX and H17 in the presence of complement for 1 h, there was 40-70% more cell death than that observed with RTX alone. The enhancing effect of H17 was also seen over longer treatment periods. H17 was tested ex vivo against primary cells from NHL and chronic lymphocytic leukemia (CLL) patients. In RTX-resistant NHL samples, H17 enhanced RTX-mediated killing; in the remaining samples RTX + complement alone promoted more than 80% killing, and no significant enhancement was observed. The H17 antibody also increased RTX-mediated killing in four out of nine CLL samples. H17 may have therapeutic applications in NHL and CLL treatment as an adjunctive therapy to RTX. It might also enhance the activity of other therapeutic antibodies that work through CDC.

Rituximab induces different but overlapping sets of genes in human B-lymphoma cell lines

The therapeutic unconjugated anti-CD20 Mab rituximab is used for the treatment of B-non-Hodgkin's lymphomas. We have studied the direct biological effects, signalling and gene expression profiles induced by rituximab in two human B-lymphoma cell lines, DHL4 and BJAB, using microarray, quantitative PCR and gel shift analysis. Rituximab alone inhibited thymidine uptake and induced homotypic adhesion in DHL4 only, but not BJAB. Analysis of Affymetrix microchips carrying probes for about 10,000 human cDNAs, allowed us to identify 16 genes in DHL4 and 12 in BJAB induced by rituximab at 4 h. Eleven and seven of these genes were specific for DHL4 and BJAB, respectively; whereas the remaining five were up-regulated in both cell lines. Mean induction ranged from 2- to 16-fold. Real time PCR analysis allowed us to confirm up-regulation of all genes identified, except one in BJAB. Time course of induction of eight genes was studied, showing peak induction in most cases at 4 h. The up-regulation of 5/5 genes was also observed with the F(ab')(2) fragment of rituximab. Analysis of three further B-cell lymphoma lines showed that gene induction is not restricted to BJAB and DHL4. Finally, we show that rituximab alone can induce AP1 activation in both cell lines and provide evidence that the ERK1/2 pathway is involved in the rituximab-mediated up-regulation of gene expression. These data demonstrate that rituximab alone has direct signalling capacity in different B-lymphoma lines, inducing distinct but overlapping sets of genes which may play a role in the biological and/or therapeutic effect of the antibody.

Clinical use of rituximab in haematological malignancies

Rituximab is a chimeric human/mouse monoclonal antibody that is approved for the treatment of relapsed and refractory non-Hodgkin's lymphoma (NHL) and in combination with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy as first-line therapy for diffuse large B-cell NHL, where it has shown the first survival advantage over CHOP alone in more than 20 years. Strategies to help define the optimal therapeutic usage of rituximab are being assessed, including first-line and maintenance or extended therapy, and the combination of rituximab with chemotherapy in indolent NHL. Emerging data suggest that earlier use may yield higher response rates, extended therapy can prolong remission, and the addition of rituximab to chemotherapy can increase clinical and molecular remission rates when compared with those achieved using chemotherapy alone. Studies in the peritransplant setting suggest a role for rituximab in vivo purging prior to transplant and/or maintenance rituximab as a means of clearing minimal residual disease. Rituximab has also shown activity in other B-cell disorders such as chronic lymphocytic leukaemia. The full potential of this immunotherapeutic agent remains to be defined in ongoing and future clinical trials.

B cell depletion in autoimmune disease

The CD20 cell marker appears early in the process of B cell development. In this review we focus on the results of attempts to utilize B cell depletion based on the use of a chimeric monoclonal antibody (MAb) specific for human CD20, rituximab, for the treatment of patients with autoimmune diseases. In 1997, rituximab was approved for the treatment of low-grade B cell non-Hodgkin's lymphoma. Following these encouraging results, rituximab started to be used experimentally in other diseases presumed to be due to B cell pathology. The first autoimmune disease to be treated effectively was chronic idiopathic thrombocytopaenia. More recent success has been demonstrated in patients with rheumatoid arthritis and systemic lupus erythematosus.

Isolated EBV lymphoproliferative disease in a child with Wiskott-Aldrich syndrome manifesting as cutaneous lymphomatoid granulomatosis and responsive to anti-CD20 immunotherapy

Patients with primary immunodeficiencies such as the Wiskott-Aldrich syndrome (WAS) are prone to develop Epstein-Barr virus (EBV) related lymphoproliferative disorders (LPDs). EBV LPD is most frequently seen in patients receiving immunosuppressive treatment after organ transplantation (post-transplant lymphoproliferative disorder), but can also arise in the primary immunodeficiencies. Typically, EBV LPD presents as a diffuse systemic disease with lymphadenopathy and organ involvement. A rare angiocentric and angiodestructive form of EBV associated B cell LPD, lymphomatoid granulomatosis (LyG), has also been reported in association with WAS. LyG most commonly involves the lung, but can also be seen in brain, kidney, liver, and skin. This report describes the case of a 16 year old boy with WAS who presented with an isolated non-healing ulcerating skin lesion. Biopsy revealed an EBV related LPD with the histological features of LyG. This cutaneous lesion responded dramatically to treatment with specific anti-CD20 immunotherapy and the patient remains clinically free of LPD at 18 months.

SLE - Rituximab in lupus

B cells are essential to the development of systemic lupus erythematosus (SLE). The chimeric monoclonal antibody rituximab depletes B cells by targeting the pan-B-cell surface marker CD20. Preliminary experience with this agent in SLE and other autoimmune diseases has been encouraging. Controlled trials in SLE will be necessary to determine whether rituximab is useful therapy in this disease, and will teach us more about the roles of B cells in its pathogenesis.

First Isolation of West Nile virus from a patient with encephalitis in the United States

West Nile virus (WNV) was isolated from a patient who developed encephalitis while undergoing treatment with CHOP (cyclophosphamide, hydroxydoxorubicin, vincristine [Oncovin], predisone) and rituximab for a non-Hodgkin B-cell lymphoma. Both standard reverse transcription-polymerase chain reaction (RT-PCR) and Taqman RT-PCR established the diagnosis of WNV infection from cerebrospinal fluid (CSF). Several whole blood samples and one serum sample underwent further testing. CSF and serum samples were negative for WNV antibody; however, all samples were positive by both RT-PCR assays. Infectious virus was recovered from a blood sample, and its identity was confirmed by using a WNV-specific immunofluorescence assay. The complete WNV genomes determined from CSF and from the virus isolate adapted from cell culture were the same. The results represent the first complete WNV genome sequence obtained directly from human CSF and the first time that infectious WNV has been recovered from a patient with encephalitis in North America.

Lymphocyte subsets and viral load in patients with HIV-associated non-Hodgkin's lymphoma treated with anti-CD20 monoclonal antibody and chemotherapy

The anti-CD20 monoclonal antibody Rituximab is a novel antitumor agent used in association with chemotherapy (CT) for the treatment of high-grade/intermediate non-Hodgkin's lymphomas (NHL) in HIV-negative populations. This therapeutic combination is currently also being explored in HIV-positive patients with NHL (HIV-NHL). The objective of our study was to determine CD4 and CD8T cell counts, HIV plasma viremia and proviral load in patients with CD20-positive HIV-NHL treated with Rituximab plus CT and highly active antiretroviral therapy (HAART). We studied eight patients with HIV-NHL treated by anti-CD20 and CT before, after three, and after six cycles of therapy; CD4, CD8 and CD19 lymphocyte subsets were measured by monoclonal antibodies and flow cytometry. HIV plasma viremia was determined by the b-DNA assay, and proviral load by a quantitative competitive PCR. CD4T cell counts remained stable after three cycles of therapy, while a significant reduction of this subset was present at the end of therapy. HIV plasma viremia was significantly reduced after the third cycle, but returned to pretreatment levels at the end of therapy; we also observed individual fluctuations of proviral load during therapy, this marker being increased in two out of three patients at the end of therapy. These observations suggest that Rituximab plus CT accelerated the rate of CD4 depletion and of HIV replication in the peripheral blood of HIV-NHL patients and that HAART may be able to delay these effects.