Oral 2-chlorodeoxyadenosine in psoriatic arthritis. A preliminary report

Treatment of autoimmunity: The impact of disease-modifying therapies in multiple sclerosis and comorbid autoimmune disorders

More than 10 disease-modifying therapies (DMT) are approved by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) for the treatment of multiple sclerosis (MS) and new therapeutic options are on the horizon. Due to different underlying therapeutic mechanisms, a more individualized selection of DMTs in MS is possible, taking into account the patient's current situation. Therefore, concomitant treatment of various comorbid conditions, including autoimmune mediated disorders such as rheumatoid arthritis, should be considered in MS patients. Because the pathomechanisms of autoimmunity partially overlap, DMT could also treat concomitant inflammatory diseases and simplify the patient's treatment. In contrast, the exacerbation and even new occurrence of several autoimmune diseases have been reported as a result of immunomodulatory treatment of MS. To simplify treatment and avoid disease exacerbation, knowledge of the beneficial and adverse effects of DMT in other autoimmune disorders is critical. Therefore, we conducted a literature search and described the beneficial and adverse effects of approved and currently studied DMT in a large number of comorbid autoimmune diseases, including rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel diseases, cutaneous disorders including psoriasis, Sjögren´s syndrome, systemic lupus erythematosus, systemic vasculitis, autoimmune hepatitis, and ocular autoimmune disorders. Our review aims to facilitate the selection of an appropriate DMT in patients with MS and comorbid autoimmune diseases.

Durable Resolution of Severe Psoriasis in a Patient Treated with Pentostatin for Hairy Cell Leukemia: A Case Report

Introduction

Pentostatin (2′-deoxycoformycin) and cladribine (2-chlorodeoxyadenosine) are adenosine analogues widely used to treat lymphoid malignancies, mainly hairy cell leukemia (HCL). Oral or parenteral adenosine analogues have been also used as immunomodulatory agents in multiple sclerosis and in acute graft-versus-host disease.

Case Report

Here, we report the case of a 43-year-old patient with a history of extensive psoriasis who later developed HCL.

Results

The patient had achieved complete remission of both psoriasis and HCL after receiving intravenous infusions of pentostatin. It is worth noting that cladribine has already been reported to treat plaque psoriasis lesions in two patients with HCL and in a third patient with gastric marginal zone B cell lymphoma [1].

Conclusion

We believe that adenosine analogues constitute a promising therapeutic option for moderate to severe psoriasis, especially for severe and refractory psoriasis, as well as for patients with adjacent lymphoid malignancies.

Immunosuppressive and Cytotoxic Drugs in Dermatology: A Practical Overview and Personal Perspective

Background:

Cytotoxic/immunosuppressive drugs are regularly used to treat proliferative diseases of the skin and immunologically mediated inflammatory disorders.

Objective:

The rational use of cytotoxic/immunosuppressive drugs, which depends on the proper selection of both the patient and the drug, is discussed.

Conclusion:

Methotrexate, azathioprine, cyclophosphamide, chlorambucil, cyclosporine, and other related drugs have potential benefits in the treatment of severe recalcitrant cutaneous disease. Patients may survive otherwise fatal disorders, or may improve their life-style and become productive again. However, the beneficial effect of these agents is achieved when the blood level is at or near toxic level. Thus, the prescribing physician should have a familiarity with the potential toxicities and a knowledge of proper monitoring techniques.

Intrinsic apoptosis pathway in fallopian tube epithelial cells induced by cladribine

Cladribine is a purine nucleoside analog which initiates the apoptotic mechanism within cells. Moreover, the available data confirms that cladribine, with the participation of the p53 protein, as well as the proapoptotic proteins from the Bcl-2 family, also induces the activation of the intrinsic apoptosis pathway. However, while there has been a lot of research devoted to the effect of cladribine on lymphatic system cells, little is known about the impact of cladribine on the reproductive system. The aim of our study was to evaluate apoptosis in oviduct epithelial cells sourced from 15 different female rats. In so doing, the sections were stained with caspases 3, 9, and 8. Results suggest that cladribine also induces apoptosis in the oviduct epithelial cells by way of the intrinsic pathway. Indeed, the discontinuing of the administration of cladribine leads to a reduction in the amount of apoptotic cells in the oviduct epithelium.

Immunohistochemical evaluation of cell proliferation and apoptosis markers in ovarian surface epithelial cells of cladribine-treated rats

Cladribine has been used in the treatment of hairy cell leukemia for about 30 years. In addition, the number of indications for the application of 2-CdA is constantly increasing. The treatment with cladribine, of younger persons and even children, appears to be a major factor stimulating the more exact recognition of its activities. However, till now, little has been known about the impact of cladribine on the reproductive system. The aim of the study was to evaluate the immunohistochemical expression of cell proliferation and apoptosis markers in ovarian surface epithelial (OSE) cells. In our study, ten rats were placed into two equal groups. The study group received daily subcutaneous injections of cladribine in a dose of 0.10 mg/kg of weight/day for one cycle lasting 7 days. The control group received only saline injections. The rats were sacrificed 24 h after the last injection, and their ovaries were extracted. The sections were immunohistochemically stained with cell proliferation marker Ki-67 and the apoptosis marker caspase 3. The expressions of the markers were evaluated using a light microscope. An analysis was made using an image analysis system and the CellAD software. The results were then statistically explored by way of the Mann-Whitney U test. The proliferative index (Ki-67) of ovarian surface epithelial cells was significantly lower in the study group than in the control group (p < 0.05). These results suggest that cladribine treatment has a potential to inhibit the OSE cell proliferation in rats. The apoptosis marker demonstrated a significant increase after the cladribine treatment. These suggest that cladribine induces apoptosis in OSE cells.

Cladribine for multiple sclerosis: review and current status

In the 1990s, cladribine was developed as an adenosine deaminase-resistant nucleoside analog with selective lymphotoxic specificity in the hope that it might become useful in the treatment of some lymphoid neoplasms and autoimmune disorders. Several clinical trials demonstrated very significant effectiveness and safety of cladribine in the cure of hairy-cell leukemia, and the control of many other lymphoid malignancies. Cladribine was also extensively tested in selected autoimmune disorders, most notably in multiple sclerosis, with evidence of efficacy, tolerability and acceptable side effects/toxicity. The previous clinical studies and current status of cladribine for the treatment of multiple sclerosis are considered in this drug profile. In January 2005, Serono and IVAX announced plans to initiate a Phase III study of a specially formulated oral tablet of cladribine (Mylinax, Serono and IVAX) for the treatment of relapsing forms of multiple sclerosis. The proposed study will be the first large multicenter randomized controlled clinical trial of oral cladribine in multiple sclerosis.

Newer Therapeutic Approaches: Spondyloarthritis and Uveitis

Over the last 5 years considerable progress has taken place in the therapeutic approach to spondyloarthritis (SpA). This progress is due in large part to the development of effective biologic therapies and to improved clinical trial design and implementation. This article summarizes treatment advances in SpA with emphasis on the efficacy and safety of biologic agents in the treatment of psoriatic arthritis, ankylosing spondylitis, undifferentiated spondyloarthropathy, and uveitis.

Cladribine in the treatment of hairy-cell leukaemia

Cladribine, a purine nucleoside analogue, is a safe and effective treatment for patients with hairy-cell leukaemia. It is administered at a dose of 0.09 mg/kg daily as a continuous intravenous infusion over 7 days. This chapter discusses the history, rationale, chemical structure and mechanism of action of cladribine. The indications for therapy and guidelines for clinical usage are reviewed. The response of hairy-cell leukaemia to cladribine, the acute and chronic complications and the risk for second malignancies are summarized. The chapter concludes with a section on salvage therapy.

Hematological effects of intermittent 2-hour infusions of cladribine in multiple sclerosis patients: a comparison of 2 dosage patterns

Cladribine is a lymphocytotoxic purine nucleoside with potential for treatment of autoimmune diseases. However, optimal administration regimens remain to be established. Twenty multiple sclerosis patients enrolled into this study were given 30 intermittent 2-hour cladribine infusions (0.07 mg/kg per infusion) each. Ten patients received cycles of 5 consecutive daily infusions at 5-week intervals (clustered dosage) on an inpatient basis; the other 10 patients received 1 infusion weekly (nonclustered dosage) on an outpatient basis. Red blood cell (RBC), platelet, and total white blood cell (WBC) counts were assessed at 5-week intervals during the treatment and at 13-week intervals during a 26-week follow-up period. Major WBC and lymphocyte subsets were assessed cytometrically at 15-week intervals during the treatment and at 13-week intervals thereafter. The clustered dosage produced a lasting decline in granulocyte count, a delayed decrease in monocyte count, and a transient decrease in RBC count. The nonclustered dosage caused a larger and persistent decline in RBC count, a smaller (P = .051. compared over the study period) decrease in monocyte count, and no change in granulocyte count. Both regimens transiently reduced natural killer and B-cell subsets (by 40%-60% and >80%, respectively) and caused lasting declines in CD4+ T-cell subsets (by >50%). No significant change was found in CD8+ T-cell subsets. These results show similar potency of these regimens with respect to major lymphocyte subsets, while suggesting that the nonclustered dosage is less toxic to myeloid precursors and more toxic to erythroid lineage precursors.

Immunosuppressive and cytotoxic drugs in the treatment of rheumatic skin disorders

Cytotoxic and immunosuppressive drugs are regularly used to treat proliferative, immunologically mediated inflammatory disorders and some neoplastic diseases of the skin. Methotrexate, azathioprine, mycophenolate mofetil, cyclosporin cyclophosphamide, chlorambucil, and other related drugs have potential benefits in the treatment of severe and/or recalcitrant rheumatic skin diseases. The therapeutic window for these agents is narrow. The major uses of these drugs are for life-threatening cutaneous disorders or as steroid-sparing agents.

Successful treatment of lupus with fludarabine

We describe a 58-year old patient with chronic lymphocytic leukemia (CLL) who developed systemic lupus erythematosus (SLE) with severe joint involvement. Dilated myocardiopathy precluded the use of high corticoid doses and a 15 days of prednisone (15mg/d) had no effect on the polyarthritis. Therefore, fludarabine (25mg/m2) was administered for 5 d. One month after the first cycle, fever, muscle stiffness and polyarthritis resolved. A total of 6 cycles were administered. The evolution was complicated by herpes zoster infection and left pneumococcal pneumonia. At this time of writing (July 1999), the patient is symptom free but is profoundly lymphopenic.

Distribution of 2-chloro-2'-deoxyadenosine, 2-chloro-2'-arabino-fluoro-2'-deoxyadenosine, fludarabine and cytarabine in mice: a whole-body autoradiography study

The distribution characteristics of tritiated nucleoside analogs, 2-chloro-2'-deoxyadeonosine (CdA), 2-chloro-2'-arabino-fluoro-2'-deoxyadenosine (CAFdA), 2-fluoroarabinosyladenine (F-ara-A) and cytosine arabinoside (ara-C) were compared in mice using whole-body autoradiography. CdA, CAFdA and F-ara-A have quite similar molecular structures, but they differ substantially in clinical activity as well as the side effects. Eight mice were injected intravenously in couples. One mouse from each pair was killed 20 min postinjection and the other mouse from each pair 4 h after the injection. The distribution of the label was then analyzed by whole-body autoradiography. The distribution of the nucleoside analogs was rapid and uniform. High concentrations were found in highly perfused organs. After 4 h the overall concentration had decreased but relatively high activities were found in the skin for CdA and CAFdA, in the thymus for ara-C and the bone marrow for CdA. Both CdA and CAFdA were found in the brain, but the concentration was surprisingly lower after 4 h for CAFdA, a lipophilic and more stable analog as compared to CdA. There was an uptake of CdA, F-ara-A and CAFdA in the skin. There were signs of retention of ara-C in parts of the thymus. The present investigations indicate that the nucleoside analog transport to the brain in mice is not primarily dependent upon passive diffusion over a lipophilic barrier, but suggestive of a specific transport mechanism.

Remission of psoriasis after treatment with interferon-alfa and 2-chlordeoxyadenosine for hairy cell leukemia

2-Chlordeoxyadenosine (2-CdA) is an antineoplastic/immunosuppressive agent used to treat hairy cell leukemia (HCL), chronic lymphocytic leukemia, and low-grade lymphomas. Its immunomodulatory properties, however, may allow its future use in the treatment of psoriasis. We report a patient with psoriasis and HCL who was treated for 1 week with continuous intravenous infusion of 2-CdA for recurring HCL. Both the psoriasis and the HCL cleared. Four years after 2-CdA treatment, the patient has psoriasis on only 1% of his body surface area. 2-CdA induces lymphocytopenia, which may explain the improvement in this patient's psoriasis.

A pilot study of 2-chloro-2'-deoxyadenosine in the treatment of systemic lupus erythematosus-associated glomerulonephritis

OBJECTIVE

To determine the safety and tolerability, as well as the clinical and immunologic effects, of 2-chloro-2'-deoxyadenosine (2-CdA) in patients with systemic lupus erythematosus-associated glomerulonephritis.

METHODS

In a phase I study, 12 patients with proliferative lupus nephritis received 2-CdA either in weekly escalating intravenous treatments (0.15 mg/kg/week x 4, 0.1875 mg/kg/week x 4, 0.225 mg/kg/week x 4; n = 5) or in a continuous 7-day infusion (0.05 mg/kg/day; n = 7). Safety, renal improvement, and immunologic effects were evaluated for 12 months.

RESULTS

Patients treated with 2-CdA showed peripheral lymphocyte depletion without a significant reduction in neutrophil, monocyte, or platelet numbers or hematocrit levels. Naive and memory T cells were decreased, as were lymphocytes with markers of early and late activation. Peripheral B cell depletion was not associated with significant decreases in serum immunoglobulin levels. Continuous infusion induced better clinical responses than weekly infusions, as evidenced by 1) the percentage of patients showing complete response (43% versus 0%), 2) the percentage with at least 50% reduction in proteinuria (43% versus 20%), 3) the percentage with at least a 50% reduction in urinary dysmorphic red cells (57% versus 0%), and 4) the percentage in whom cellular casts disappeared (43% versus 0%). Several infections occurred; these responded to standard antibiotic therapy.

CONCLUSION

In this pilot study, 2-CdA was safely administered to 12 patients with lupus nephritis. It induced prolonged reductions in lymphocyte populations and may be efficacious in selected patients with lupus nephritis when administered as a continuous infusion.

Effects of 2-chlorodeoxyadenosine and gold sodium thiomalate on human bcl-2 gene expression

Aberrant expression of apoptosis-related genes, including the "cell death suppressor gene" bcl-2, may play an important pathogenetic role in cancer and autoimmune diseases, In vivo upregulation of bcl-2 mRNA in synovial lining cells of patients with rheumatoid arthritis but not in patients with osteoarthritis has been recently found. In the present study we investigated whether agents exerting beneficial effects in patients with rheumatoid arthritis, namely the long used Gold Sodium Thiomalate (GST) and the novel immunosuppressive, purine analogue 2-chlorodeoxyadenosine (2-CdA), a lymphocyte apoptosis-inducing agent interfere directly with induction of bcl-2 mRNA expression. The phytohemagglutinin (PHA)-induced in vitro proliferation of normal human peripheral blood lymphocytes was significantly inhibited by non-toxic concentrations of 2-CdA and GST which are within the range of in vivo plasma concentrations in patients receiving the respective treatment. Using mRNA dot-blot analysis and hybridization with an IL-2-specific probe we found that GST, similarly to dexamethasone that served as control, suppressed the PHA-induced IL-2 mRNA accumulation dose-dependently. In contrast, 2-CdA (0.1 microgram/ml) at concentrations that inhibit by 80-90% the PHA-induced proliferative responses of lymphocytes did not affect IL-2 mRNA accumulation. Hybridization with a bcl-2-specific probe showed that the activation-induced accumulation and kinetics of bcl-2 mRNA were not changed in the presence of a wide range of concentrations of either GST or 2-CdA. Similarly, the mRNA accumulation of the "house-keeping" control gene beta-action remained unchanged by both agents. These findings indicate that biosynthesis of bcl-2 is not specifically affected by GST and CdA, suggesting that the immunomodulating effects of these agents, including their efficacy in suppressing chronic arthritis, are not related with a bcl-2-dependent mechanism.

The safety profile of low-dose cladribine in refractory rheumatoid arthritis. A pilot trial

Cladribine (2-chlorodeoxyadenosine, 2-CdA) is a newer purine analog with specific toxicity to lymphocytes. As lymphocytes play a major role in rheumatoid arthritis (RA), we assessed the safety profile of low-dose 2-CdA in patients who were refractory to more than three disease-modifying drugs. Five patients were given a subcutaneous dosage of 0.05 mg/kg 2-CdA weekly over a period of 8 weeks. Of the lymphocyte subsets, both T and B cells decreased below the normal range, whereas natural killer cells remained stable. These changes were the only side-effects noted during treatment and 4 weeks afterwards. In one patient a pacemaker was implanted for reasons unlikely to be related to 2-CdA administration. We conclude that even low-dose 2-CdA (0.05 mg/kg) can decrease T and B cell populations in patients with refractory RA, but other side-effects are unlikely. For assessing the possible clinical efficacy of low-dose 2-CdA further studies are warranted.