Gerlando Quintini

Relapsing or refractory idiopathic thrombotic thrombocytopenic purpura-hemolytic uremic syndrome: the role of rituximab

Idiopathic thrombotic thrombocytopenic purpura–hemolytic uremic syndrome (TTP‐HUS) is a rare disease responsive to treatment with plasma exchange (PE) but with a high percentage of relapse or refractory patients. A severe deficiency of ADAMTS‐13 (<5% of normal activity), congenital or caused by an autoantibody, may be specific for TTP and it has been proposed that severe ADAMTS‐13 deficiency now defines TTP. B cells play a key role in both the development and the perpetuation of autoimmunity, suggesting that B‐cell depletion could be a valuable treatment approach for patients with idiopathic TTP‐HUS. This review of the literature focuses on the role of rituximab, a chimeric monoclonal antibody directed against CD20 antigen expressed by B lymphocytes, in patients with relapsing or refractory TTP‐HUS with or without ADAMTS‐13 deficiency, suggesting that rituximab may produce clinical remission in a significant proportion of patients. Rituximab therapy reduces plasma requirement and avoids complications related to salvage‐immunosuppressive therapy. In conclusion, rituximab provides an effective, well‐tolerated, and safe treatment option for patients with idiopathic TTP‐HUS, thus giving an alternative approach to the current treatment based on PE.

Rituximab for managing relapsing or refractory patients with idiopathic thrombotic thrombocytopenic purpura--haemolytic uraemic syndrome.

Thrombotic thrombocytopenic purpura (TTP) is a rare disorder characterized by thrombocytopenia, microangiopathic haemolytic anaemia, neurological and renal abnormalities and fever1, with a mortality rate, in the absence of treatment, of almost 90%. Since such criteria do not distinguish TTP from haemolytic uraemic syndrome (HUS), the comprehensive term TTP-HUS is more approriate2. The standard therapy is urgent plasma exchange (PE)1, which reduces mortality to 10% or less3–9. Because of its dramatic effect on short and long-term outcome, it is now accepted that PE can be begun, in the absence of an alternative diagnosis, even when not all of the above criteria are fulfilled3,4,6,9,10. The evident advantage of early initiation of therapy along with the decreased diagnostic threshold has resulted in a 7-fold increase of patients treated with PE for TTP-HUS from 1981 to 199711. The symptoms of TTP are related to the presence of von Willebrand factor (VWF)-rich platelet thrombi in arterioles and capillaries. VWF is a multimeric plasma glycoprotein crucial for both platelet adhesion and aggregation, especially at the high shear rates present in the microvasculature. The size of VWF multimers is physiologically regulated in vivo by a specific metalloprotease, ADAMTS-13 (a disintegrin-like and metalloprotease with thrombospondin type 1 repeats)12. A severe deficiency of ADAMTS-13 (< 5% of normal activity) may be specific for TTP13 and it has been proposed that severe ADAMTS-13 deficiency now defines TTP14,15. Because ADAMTS-13 deficiency, whether idiopathic or caused by an autoantibody, provides a possible explanation for the effectiveness of PE (removal of the autoantibody by apheresis; supply of ADAMTS-13 by plasma replacement), it has been suggested that the levels of this metalloprotease can be used to guide treatment decisions14,16–19. At present it is not possible to establish the sensitivity of ADAMTS-13 deficiency for identifying patients who may respond to PE. In seven reports, 45% to 100% of patients with TTP were reported to have severe deficiency of ADAMTS-13 activity19–25 while such a high rate has not been described in those with HUS19,20,23. However, the interpretation of these studies is limited by the absence of explicit criteria for distinguishing patients with TTP from patients with HUS. PE has been proven effective even in patients without deficiency of ADAMTS-13 activity, which makes it difficult to understand how PE is benificial2. In conclusion, the role of ADAMTS-13 activity in the diagnosis and treatment decisions in patients with TTP or HUS remains unknown. Therapy with PE should be implemented in all patients with TTP-HUS and continued until the resolution of signs and/or symptoms and normalisation of laboratory tests; this can require long-term therapy. PE has some other disadvantages: first of all, it is not a risk-free procedure since a substantial number of major complications have been reported26,27. Furthermore, about 10% to 20% of TTP-HUS patients do not respond or have only an incomplete response2. Various different types of immunosuppressive treatment have been proposed for refractory patients14,29,30,32, including steroids and immunosuppressive or immune-modulating agents; however, the lack of robust data does not allow proper suggestion of such agents in the setting of acute refractory or chronic relapsing TTP28,32. Splenectomy has been proposed for patients with refractory or relapsing TTP, with reported remission rates of 50–100%29, but relapses have occurred in a considerable proportion of patients, most of them with severe ADAMTS-13 deficiency2,29,33,35. It has recently been shown that splenectomy can cause the disappearance of antibodies, normalisation of ADAMTS-13 activity and clinical remission in cases of refractory/relapsing TTP associated with anti-ADAMTS-13 autoantibodies. Other authors reported a low frequency of relapses in a large cohort of patients who underwent splenectomy30. Rituximab, a chimaeric monoclonal antibody directed against the CD20 antigen present on B lymphocytes, is used in lymphoma patients and those with rheumatoid arthritis33. Its action relies on clearance of the B lymphocytes responsible for antibody production by complement-dependent cytotoxicity, antibody-dependent cellular cytotoxicity or directly by inducing apoptosis31,33. The understanding that ADAMTS-13 deficiency could be antibody-mediated first provided the rationale for the use of rituximab in TTP-HUS12, but its reported effectiveness even in TTP-HUS patients without antibody-mediated ADAMTS-13 deficiency as well as in cases of refractory/relapsing cases makes this monoclonal antibody a very attractive therapeutic agent33–35. The data suggest that the drug may not simply decrease ADAMTS-13 autoantibody production by depleting B cells, but that it may have additional mechanisms of action. Kameda et al.34 suggested that B-cell depletion by rituximab reduces excessive cytokine production in patients with secondary TTP, thus containing the level of VWF multimers within the normal range. At present, only data from case series have been published and many questions remain open regarding the target population, timing of initiation, duration of treatment and concomitant PE34–49. Here we describe four patients with refractory/relapsing idiopathic TTP-HUS who were successfully treated with rituximab (Table I). Table I Patients’ characteristics

Deoxycoformycin (pentostatin) in the treatment of splenic marginal zone lymphoma (SMZL) with or without villous lymphocytes

Abstract:  Background: Splenic marginal zone lymphoma (SMZL) is an infrequent B‐cell neoplasm that pursues an indolent course. Signs and symptoms, mostly related to hypersplenism, are successfully managed by splenectomy. However, the therapy of patients who are not fit for a surgical procedure or who relapse after splenectomy, is still an unsettled issue. Patients and methods: We report a phase‐II study on 16 patients with SMZL, three therapy naïve and 13 pretreated, all showing systemic symptoms or progressive worsening of peripheral cytopenia, who were treated with pentostatin at a dose of 4 mg/m2 every other week for 6–10 wk. In relapsed patients, the median interval between diagnosis and treatment was 26 month (range: 8–49). Results: Overall, 68% of the patients showed a clinical response. Two out three patients, who received pentostatin as first line therapy, attained a complete response (CR). One CR and seven minor or good haematological responses were recorded in relapsed patients. Treatment toxicity, mostly haematological, proved manageable. With a median follow‐up of 35 month the median overall survival (OS) is 40 month and the median progression free survival (PFS) is 18 month. Conclusion: Our data show that pentostatin administered every other week has a good degree of activity in the treatment of SMZL and suggest that this schedule could be considered a possible therapeutic option for patients who are not fit for splenectomy or have relapsed.

Assessment of the frequency of additional cancers in patients with splenic marginal zone lymphoma

Abstract:  Objectives: Solid second primary cancers (SPC) have become an issue of extensive research. The purpose of the present study was to estimate the standardised incidence ratio (SIR) and the absolute excess risk (AER) of SPC in patients with splenic marginal zone lymphoma (SMZL).Methods: We investigated the incidence of additional cancers in 129 patients consecutively diagnosed with SMZL in three Italian haematological centres, asking the cooperating doctors for additional information on initial and subsequent therapies and on the onset and type of second cancers.Results: Twelve SPC were recorded (9.3%); the 3‐ and 5‐yr cumulative incidence rates were 5.5% and 18.3% respectively, with an SIR of 2.03 [95% confidence interval (CI): 1.05–3.56; P < 0.05; AER = 145.81]. Of 12 SPC observed, four were urinary tract neoplasms (SIR, 3.70; 95% CI: 1.01–9.48; P < 0.05; AER = 70.06), four were lung cancers (SIR, 9.16; 95% CI: 1.41–13.25; P < 0.05; AER = 85.50) and the other four were hepatic carcinoma, endometrial cancer, breast cancer and colorectal cancer. Conclusions: Our findings evidence a high frequency of additional cancers in patients with SMZL and suggest that the incidence rate of SPC is significantly different from that expected in the general population. The frequency of cases with urinary tract and lung malignancies in our series is higher than expected. Although confirmatory data are needed, it is our opinion that SMZL patients are at risk of second cancer and should be carefully investigated on diagnosis and monitored during the follow‐up.

Reversible posterior leukoencephalopathy syndrome in a patient with thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is an autoimmune disorder characterised by fever, microangiopathic haemolytic anaemia, renal insufficiency, and thrombocytopenia. Neurological involvement, a prominent component of TTP, is characterised by a variety of brain lesions which include reversible cerebral oedema or magnetic resonance imaging (MRI) features of reversible posterior leukoencephalopathy syndrome (RPLS). TTP is frequently associated with deficiency of the von Willebrand factor-cleaving protease, ADAMTS13.Here, we report a case of TTP with severe acute encephalopathy. Posterior leukoencephalopathy and brainstem oedema with triventricular hydrocephalus were observed on MRI. The low activity of ADAMTS13 was not observed and ADAMTS-13 antibodies were absent. Neurological symptoms and patient’s condition were completely resolved by plasma exchange therapy in addition to high dose of methylprednisolone.

Bone marrow granulomas in hairy cell leukaemia following 2‐chlorodeoxyadenosine therapy

Ben-Izhak 0. Auslander L. Rabmson S, Lichtig C. Sternberg A. Epithelioid angiosarcoma of the adrenal gland with cytokeratin expression. Cancer 1992: 67; 1808-1812. Albores-Saavedra J, Henson DE. Tumours of the gallbladder and extra-hepatic bile ducts. Atlas of Tumour Pathology. 2nd series, fascicle 22. Washington, D.C.: Armed Forces Institute of Pathology, 1986. Willen R. Willen H. Primary sarcoma ofthe gallbladder. A light and electronmicroscopica1 study. Virchows Arch. [ A ] 1982: 396; 91102. Kumar A, La1 BK. Singh MK. Kapur BML. Angiosarcoma of the gallbladder. Am. 1. Gastroenterol. 1989; 84: 1431-1433. Banerjee SS. Eyden BP. Wells S, McWilliam LJ. Harris M. Pseudoangiosarcornatous carcinoma: a clinico-pathological study of seven cases. Histopathology 1992: 21: 13-23. 489-501.

Absolute lymphocyte count is unrelated to overall survival in newly diagnosed elderly patients with multiple myeloma treated with immunomodulatory drugs

1 Cattedra ed U.O. di Ematologia con trapianto, Policlinico Universitario di Palermo, Palermo, Sicily, 2 Divisione di Ematologia, Ospedale Ferrarotto, Universit à di Catania, Catania, Sicily, 3 Azienda Ospedaliera “ Ospedali Riuniti Villa Sofi a-Cervello ” , Palermo, Sicily, 4 Cattedra ed U.O. di Ematologia con trapianto, Policlinico Universitario di Bari, Bari, Italy and 5 Istituto Italiano di Statistica (ISTAT)-Palermo, Palermo, Sicily

Continuous intravenous infusion of dipyridamole as adjunctive therapy in the treatment of thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) is an uncommon hematologic thrombotic disorder characterized by fever, hemorrhagic and neurologic signs. The advent of plasma exchange has dramatically improved the prognosis of this disease, which was once inevitably fatal. However, mortality rates remain significant. Antiplatelet drugs have been widely used in combination with plasma exchange. In this pilot study we investigated the effects of an adjunctive therapy consisting of the continuous, intravenous infusion of dipyridamole, a modality of administration that has not been previously tested in this setting. Sixteen untreated TTP patients, diagnosed consecutively at our clinic, received daily plasma exchange together with intravenous methylprednisolone (1-2 mg/kg/twice daily) and a continuous i.v. infusion of dipyridamole (100 mg/day). A complete response was defined as an improvement in the platelet count to more than 150 x 10(9)/l for two consecutive days and no neurologic deterioration. The overall response rate was 87.5%. One patient failed to respond to the combination therapy but attained a consistent remission after autologous stem cells transplant. One patient was refractory to the combination therapy and died, after an initial but unsustained response. The results of this pilot study suggest that the continuous infusion of dipyridamole is safe and might provide additional benefit in the treatment of TTP when combined with plasma exchange and steroids. However, a randomized study will be necessary to properly test whether the addition of dipyridamole improves the efficacy of plasma exchange in patient with TTP.

Are blood donors an adequate control group to ascertain HCV prevalence in non-Hodgkin's lymphoma patients.

Consequently, the authors concluded that the high prevalence of HCV or HBV infection in the study population provides epidemiologic evidence that HCV and HBV infection may be involved in the development of a subgroup of NHL in males. We would like to focus on the HCV prevalence rate data because this is a critical issue and to clarify the existing relationship between HCV infection and NHL. In fact, the epidemiologic studies conducted so far are rather contradictory: studies conducted in southern Europe have reported a high prevalence (9–37%) of HCV infection in patients with B cell NHL, whereas those performed in western Europe and in Canada have failed to confirm this association. 2