Geir E. Tjønnfjord

Favourable response to therapy with the anti-CD20 monoclonal antibody rituximab in primary chronic cold agglutinin disease

The ‘primary’ form of chronic cold agglutinin disease is a clonal B‐cell lymphoproliferative disorder that is notoriously difficult to treat with drugs, including corticosteroids, alkylating agents, alpha‐interferon and purine analogues. We performed a small, open, uncontrolled, prospective study to evaluate the effect of therapy with the monoclonal anti‐CD20 antibody rituximab. Six patients with clonal CD20+κ+ B‐cell proliferation received seven courses of rituximab 375 mg/m2, d 1, 8, 15, and 22. One patient achieved a complete response. Four partial responses were observed, including a response to re‐treatment in one patient. Two patients were categorized as non‐responders. Haemoglobin levels increased by a median of 4·1 g/dl in the total group and 4·7 g/dl in the responders, who also experienced a substantial improvement of clinical symptoms. The treatment was well tolerated. We discuss the effect of rituximab therapy compared with other treatment options, and try to explain why two individual patients did not respond. Despite the small numbers, the results are very encouraging. Further studies of rituximab therapy for chronic cold agglutinin disease are warranted.

Acquired haemophilia: management of bleeds and immune therapy to eradicate autoantibodies

Summary.  Acquired haemophilia is a rare, but often severe bleeding disorder caused by autoantibodies against a coagulation factor, usually factor VIII (FVIII). Between 1997 and 2004 we observed 14 patients (mean age of 78 years) with acquired haemophilia. The aim of the present study was to investigate the effect of activated prothrombin complex concentrate (aPCC) for bleeds and the response to corticosteroids and cyclophosphamide to eradicate the offending autoantibodies. The most common clinical presentations were severe profuse bruising (12) and haematuria (5). Ten patients were classified as idiopathic. At the time of diagnosis all patients had a very low FVIII level, and one patient also showed factor IX < 1%. High levels of antibodies to FVIII varying from 10 to 1340 Bethesda units (BU) and prolonged activated partial thromboplastin time were disclosed in all patients. Eight severe bleeds were treated with aPCC (FEIBA®) at a dosage of 70 IU kg−1 every 8 h until haemostasis. Ten patients received corticosteroids and cyclophosphamide as immunomodulatory therapy. Effective haemostasis was achieved in all bleeds after aPCC. Ten of 11 patients responded either completely or partially to the immunomodulatory regime within 6 months. Five patients achieved complete response (CR) whereas partial responses were seen in five patients. The anti‐CD20 monoclonal antibody rituximab was given to two patients in conventional doses and a CR was seen in one patient. aPCC is effective in treating acute bleeds in patients with acquired haemophilia with high inhibitor levels. The combination of oral corticosteroids and cyclophosphamide seems to be effective to eradicate the inhibitor.

High response rate and durable remissions following fludarabine and rituximab combination therapy for chronic cold agglutinin disease

Most patients diagnosed with primary chronic cold agglutinin disease (CAD) have a clonal lymphoproliferative bone marrow disorder. Treatment with rituximab is the only well-documented effective therapy, leading to 45%-60% partial responses (PR). Complete responses (CR) are rare, and median response duration is only 11 months. In a prospective multicenter trial, 29 patients received rituximab 375 mg/m(2) on days 1, 29, 57 and 85; and fludarabine orally, 40 mg/m(2) on days 1-5, 29-34, 57-61 and 85-89. Twenty-two patients (76%) responded, 6 (21%) achieving CR and 16 (55%) PR. Among 10 patients nonresponsive to rituximab monotherapy, 1 achieved CR and 6 PR. Median increase in hemoglobin level was 3.1 g/dL among the responders and 4.0 g/dL in those who achieved CR. Lower quartile of response duration was not reached after 33 months. Estimated median response duration was more than 66 months. Grade 3-4 hematologic toxicity occurred in 12 patients (41%). In conclusion, fludarabine and rituximab combination therapy is very efficient in patients with CAD. Toxicity may be a concern, and benefits should be carefully weighed against risks in very old and comorbid patients. It remains to be established whether the combination should be first-line or an efficient second-line therapy in CAD patients requiring treatment.

Diagnosis and treatment of cold agglutinin mediated autoimmune hemolytic anemia

Exact diagnosis of the subtype has essential therapeutic consequences in autoimmune hemolytic anemia. Cold-antibody types include primary chronic cold agglutinin disease (CAD) and rare cases of cold agglutinin syndrome (CAS) secondary to cancer or acute infection. Primary CAD is a clonal lymphoproliferative disorder. Not all patients require pharmacological therapy, but treatment seems indicated more often than previously thought. Corticosteroids should not be used to treat primary CAD. Half of the patients respond to rituximab monotherapy; median response duration is 11 months. The most efficient treatment to date is fludarabine and rituximab in combination, resulting in responses in 75%, complete responses in 20% and median response duration of more than 66 months. Toxicity may be a concern, and an individualized approach is discussed. Erythrocyte transfusions can be given provided specific precautions are undertaken. No evidence-based therapy exists in secondary CAS, but optimal treatment of the underlying disorder is essential when feasible.

Primary chronic cold agglutinin disease: An update on pathogenesis, clinical features and therapy

Abstract Chronic cold agglutinin disease (CAD) is a subgroup of autoimmune hemolytic anemia. Primary CAD has traditionally been defined by the absence of any underlying or associated disease. The results of therapy with corticosteroids, alkylating agents and interferon-α have been poor. Cold reactive immunoglobulins against erythrocyte surface antigens are essential to pathogenesis of CAD. These cold agglutinins are monoclonal, usually IgMκ autoantibodies with heavy chain variable regions encoded by the VH4-34 gene segment. By flowcytometric and immunohistochemical assessments, a monoclonal CD20+κ+B-lymphocyte population has been demonstrated in the bone marrow of 90% of the patients, and lymphoplasmacytic lymphoma is a frequent finding. Novel attempts at treatment for primary CAD have mostly been directed against the clonal B-lymphocytes. Phase 2 studies have shown that therapy with the chimeric anti-CD20 antibody rituximab produced partial response rates of more than 50% and occasional complete responses. Median response duration, however, was only 11 months. In this review, we discuss the clinical and pathogenetic features of primary CAD, emphasizing the more recent data on its close association with clonal lymphoproliferative bone marrow disorders and implications for therapy. We also review the management and outline some perspectives on new therapy modalities.

A dominant STIM1 mutation causes Stormorken syndrome.

Stormorken syndrome is a rare autosomal‐dominant disease with mild bleeding tendency, thrombocytopathy, thrombocytopenia, mild anemia, asplenia, tubular aggregate myopathy, miosis, headache, and ichthyosis. A heterozygous missense mutation in STIM1 exon 7 (c.910C>T; p.Arg304Trp) (NM_003156.3) was found to segregate with the disease in six Stormorken syndrome patients in four families. Upon sensing Ca2+ depletion in the endoplasmic reticulum lumen, STIM1 undergoes a conformational change enabling it to interact with and open ORAI1, a Ca2+ release‐activated Ca2+ channel located in the plasma membrane. The STIM1 mutation found in Stormorken syndrome patients is located in the coiled‐coil 1 domain, which might play a role in keeping STIM1 inactive. In agreement with a possible gain‐of‐function mutation in STIM1, blood platelets from patients were in a preactivated state with high exposure of aminophospholipids on the outer surface of the plasma membrane. Resting Ca2+ levels were elevated in platelets from the patients compared with controls, and store‐operated Ca2+ entry was markedly attenuated, further supporting constitutive activity of STIM1 and ORAI1. Thus, our data are compatible with a near‐maximal activation of STIM1 in Stormorken syndrome patients. We conclude that the heterozygous mutation c.910C>T causes the complex phenotype that defines this syndrome.

A common origin of the 4143insA ADAMTS13 mutation

Severely deficient activity of the von Willebrand Factor (VWF) cleaving metalloprotease, ADAMTS13, is associated with thrombotic thrombocytopenic purpura (TTP). The mutation spectrum ofADAMTS13 is rather heterogeneous, and numerous mutations spread across the gene have been described in association with congenital TTP. The 4143insA mutation is unusual with respect to its geographic concentration. Following the initial report from Germany in which the 4143insA mutation was detected in four apparently unrelated families, we have now identified this mutation in a further eleven patients from Norway, Sweden, Poland, Germany, the Czech Republic and Australia. Confirmation that the Australian patient is of German ancestry, together with the Northern and Central European origin of most of the other patients, suggests that the 4143insA mutation has a common genetic background. We established ADAMTS13 haplotypes by analyzing 17 polymorphic intragenic markers. The haplotypes linked to 4143insA were identical in all informative families. Three novel candidate mutations, C347S, P671L and R1060W, as well as the known mutation R507Q, were also identified during the course of the study. We conclude that 4143insA has a common genetic background and is frequent among patients with hereditary ADAMTS13 deficiency in Northern and Central European countries.

Rituximab as second-line treatment for adult immune thrombocytopenia (the RITP trial): a multicentre, randomised, double-blind, placebo-controlled trial.

BACKGROUND Immune thrombocytopenia is characterised by immune-mediated destruction and suboptimum production of platelets. Despite the absence of supporting evidence, rituximab is frequently used off-label in patients with immune thrombocytopenia. We aimed to assess the efficacy of rituximab as compared with placebo as a splenectomy-sparing treatment in patients who were previously treated with corticosteroids. METHODS In this multicentre, randomised, double-masked, placebo-controlled trial, we enrolled corticosteroid unresponsive adult patients (aged ≥18 years) with primary immune thrombocytopenia and a platelet count of less than 30 × 10(9) platelets per L. Patients were randomly assigned (1:1) to four weekly infusions of 375 mg/m(2) rituximab or placebo. Concurrent treatment with corticosteroids only was allowed during the study. The primary endpoint was rate of treatment failure within 78 weeks--a composite of splenectomy or meeting criteria for splenectomy after week 12 if splenectomy was not done, assessed in all patients who received at least one dose of study treatment. Secondary endpoints were response rates, relapse rates, and duration of response. Efficacy endpoints were assessed with the Kaplan-Meier method. Safety endpoints were assessed in all patients who received at least one dose. This trial is registered with ClinicalTrials.gov, number NCT00344149. FINDINGS Between Aug 17, 2006, and June 30, 2011, we enrolled 112 patients. 32 (58%) of 55 patients in the rituximab group and 37 (69%) of 54 patients in the placebo group had treatment failure within 78 weeks (Kaplan-Meier cumulative incidence 46% for rituximab vs 52% for placebo (hazard ratio [HR] 0·89, 95% CI 0·55-1·45; p=0·65). The cumulative incidence of overall response was 81% in the rituximab group versus 73% in the placebo group (p=0·15) and complete response was 58% in the rituximab group versus 50% in the placebo group (p=0·12). Of those achieving an overall response, 68% relapsed in the rituximab group and 78% relapsed in the placebo group, and of those achieving complete response, 50% relapsed in the rituximab group and 62% relapsed in the placebo group. Time to relapse in the rituximab group was longer in patients who achieved overall response (36 vs 7 weeks; p=0·01) but not complete response (76 vs 49 weeks; p=0·19). Rates of bleeding were similar in the two groups (21 [38%] in the rituximab group vs 27 [50%] in the placebo group; p=0·08) as were rates of infection (22 [40%] vs 13 [24%]; p=0·09). INTERPRETATION Despite no reduction in the rate of long-term treatment failure with rituximab, a small benefit cannot be ruled out, as suggested by an apparently longer duration of response and numerically higher response rates with rituximab. FUNDING South-East Regional Health Authority and Østfold Hospital, Norway; Roche, France; and Roche, Norway.

Activated prothrombin complex concentrate (FEIBA) treatment during surgery in patients with inhibitors to FVIII/IX.

Summary.  Non‐activated and activated prothrombin complex concentrates (PCC/aPCC) have been used successfully to treat bleeds in haemophilia patients with inhibitors, but most physicians do not consider these products as effective as factor VIII/IX (FVIII/IX) concentrates in non‐inhibitor patients. Thus, surgical procedures in inhibitor patients have been performed reluctantly. We have performed 14 minor and five major surgical and invasive diagnostic procedures in eight patients with congenital haemophilia A and inhibitors and in two patients with acquired haemophilia. When a loading dose of 100 U kg−1 of FEIBA® was given followed by 200 U kg−1 day−1 in three divided doses every 8 h for 3 days, and then, when the daily dose was tapered to 100–150 U kg−1, no severe or unexpected bleeding complications were observed. However, one adverse event was observed. A 69‐year‐old man who suffered a myocardial infarction the third postoperative day following sigmoidectomy was managed safely with opiate analgesia, nitrates and diuretics, and the continued use of FEIBA®.

Chronic Lymphocytic Leukemia Cells Are Activated and Proliferate in Response to Specific T Helper Cells

There is increasing interest in the chronic lymphocytic leukemia (CLL) microenvironment and the mechanisms that may promote CLL cell survival and proliferation. A role for T helper (Th) cells has been suggested, but current evidence is only circumstantial. Here we show that CLL patients had memory Th cells that were specific for endogenous CLL antigens. These Th cells activated autologous CLL cell proliferation in vitro and in human → mouse xenograft experiments. Moreover, CLL cells were efficient antigen-presenting cells that could endocytose and process complex proteins through antigen uptake pathways, including the B cell receptor. Activation of CLL cells by Th cells was contact and CD40L dependent. The results suggest that CLL is driven by ongoing immune responses related to Th cell-CLL cell interaction. We propose that Th cells support malignant B cells and that they could be targeted in the treatment of CLL.