Alpha-interferon for severe cold agglutinin disease

New Insights in the Pathogenesis and Therapy of Cold Agglutinin-Mediated Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemias mediated by cold agglutinins can be divided into cold agglutinin disease (CAD), which is a well-defined clinicopathologic entity and a clonal lymphoproliferative disorder, and secondary cold agglutinin syndrome (CAS), in which a similar picture of cold-hemolytic anemia occurs secondary to another distinct clinical disease. Thus, the pathogenesis in CAD is quite different from that of polyclonal autoimmune diseases such as warm-antibody AIHA. In both CAD and CAS, hemolysis is mediated by the classical complement pathway and therefore can result in generation of anaphylotoxins, such as complement split product 3a (C3a) and, to some extent, C5a. On the other hand, infection and inflammation can act as triggers and drivers of hemolysis, exemplified by exacerbation of CAD in situations with acute phase reaction and the role of specific infections (particularly Mycoplasma pneumoniae and Epstein-Barr virus) as causes of CAS. In this review, the putative mechanisms behind these phenomena will be explained along with other recent achievements in the understanding of pathogenesis in these disorders. Therapeutic approaches have been directed against the clonal lymphoproliferation in CAD or the underlying disease in CAS. Currently, novel targeted treatments, in particular complement-directed therapies, are also being rapidly developed and will be reviewed.

Cold agglutinin disease: current challenges and future prospects

Cold agglutinin disease (CAD) is a complement-dependent, classical pathway-mediated immune hemolytic disease, accounting for 15–25% of autoimmune hemolytic anemia, and at the same time, a distinct clonal B-cell lymphoproliferative disorder of the bone marrow. The disease burden is often high, but not all patients require pharmacological treatment. Several therapies directed at the pathogenic B-cells are now available. Rituximab plus bendamustine or rituximab monotherapy should be considered first-line treatment, depending on individual patient characteristics. Novel treatment options that target the classical complement pathway are under development and appear very promising, and the C1s inhibitor sutimlimab is currently being investigated in two clinical Phase II and III trials. These achievements have raised new challenges and further prospects, which are discussed. Patients with CAD requiring therapy should be considered for clinical trials.

Cold agglutinin-mediated autoimmune hemolytic anemia

Cold antibody types account for about 25% of autoimmune hemolytic anemias. Primary chronic cold agglutinin disease (CAD) is characterized by a clonal lymphoproliferative disorder. Secondary cold agglutinin syndrome (CAS) complicates specific infections and malignancies. Hemolysis in CAD and CAS is mediated by the classical complement pathway and is predominantly extravascular. Not all patients require treatment. Successful CAD therapy targets the pathogenic B-cell clone. Complement modulation seems promising in both CAD and CAS. Further development and documentation are necessary before clinical use. We review options for possible complement-directed therapy.

Autoimmune hemolytic anemia: From lab to bedside

Autoimmune hemolytic anemia (AIHA) is not an uncommon clinical disorder and requires advanced, efficient immunohematological and transfusion support. Many AIHA patients have underlying disorder and therefore, it is incumbent upon the clinician to investigate these patients in detail, as the underlying condition can be of a serious nature such as lymphoproliferative disorder or connective tissue disorder. Despite advances in transfusion medicine, simple immunohematological test such as direct antiglobulin test (DAT) still remains the diagnostic hallmark of AIHA. The sensitive gel technology has enabled the immunohematologist not only to diagnose serologically such patients, but also to characterize red cell bound autoantibodies with regard to their class, subclass and titer in a rapid and simplified way. Detailed characterization of autoantibodies is important, as there is a relationship between in vivo hemolysis and strength of DAT; red cell bound multiple immunoglobulins, immunoglobulin G subclass and titer. Transfusing AIHA patient is a challenge to the immunohematologist as it is encountered with difficulties in ABO grouping and cross matching requiring specialized serological tests such as alloadsorption or autoadsorption. At times, it may be almost impossible to find a fully matched unit to transfuse these patients. However, transfusion should not be withheld in a critically ill patient even in the absence of compatible blood. The “best match” or “least incompatible units” can be transfused to such patients under close supervision without any serious side-effects. All blood banks should have the facilities to perform the necessary investigations required to issue “best match” packed red blood cells in AIHA. Specialized techniques such as elution and adsorption, which at times are helpful in enhancing blood safety in AIHA should be established in all transfusion services.

Autoimmune hemolytic anemia: classification and therapeutic approaches

Autoimmune hemolytic anemia (AIHA) is a relatively uncommon cause of anemia. Classifications of AIHA include warm AIHA, cold AIHA (including mainly chronic cold agglutinin disease and paroxysmal cold hemoglobinuria), mixed-type AIHA and drug-induced AIHA. AIHA may also be further subdivided on the basis of etiology. Management of AIHA is based mainly on empirical data and on small, retrospective, uncontrolled studies. The therapeutic options for treating AIHA are increasing with monoclonal antibodies and, potentially, complement inhibitory drugs. Based on data available in the literature and our experience, we propose algorithms for the treatment of warm AIHA and cold agglutinin disease in adults. Therapeutic trials are needed in order to better stratify treatment, taking into account the promising efficacy of rituximab.

Rituximab in chronic cold agglutinin disease: a prospective study of 20 patients

Chronic cold agglutinin disease (CAD) is an acquired autoimmune hemolytic anemia. Previous therapeutic modalities, including alkylating cytostatics, interferon and prednisolone, have been disappointing. However, several case reports and small-scaled studies have demonstrated promising results after treatment with rituximab. We performed a phase II multicentre trial to investigate the effect of rituximab in CAD, including 20 patients studied from October 2002 until April 2003. Thirteen patients had idiopathic CAD and seven patients had CAD associated with a malignant B-cell lymphoproliferative disease. Rituximab was given in doses of 375 mg/m(2) at days 1, 8, 15 and 22. Sixteen patients were followed up for at least 48 weeks. Four patients were excluded after 8, 16, 23 and 28 weeks for reasons unrelated to CAD. Nine patients (45%) responded to the treatment, one with complete response (CR), and eight with partial response. Eight patients relapsed, one patient was still in remission at the end of follow-up. There were no serious rituximab-related side-effects. Our study confirms previous findings of a favourable effect of rituximab in patients with CAD. However, few patients will obtain CR and, in most patients, the effect will be transient.

Catastrophic multiple organ ischemia due to an anti-Pr cold agglutinin developing in a patient with mixed cryoglobulinemia after treatment with rituximab

Cold agglutinin disease occurring with cryoglobulinemia is a rare occurrence. Here, we report a patient with mixed cryoglobulinemia that was treated with rituximab and, after response, developed an anti-Pr cold agglutinin that manifested with hemolysis and microvascular occlusion causing mesenteric ischemia and cerebral infarction. Unlike previous reports of patients with cryoglobulinemia and cold agglutinin disease, our patient did not have a detectable cryoprecipitate when his cold agglutinin manifested.

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

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-a have been poor. Cold reactive immunoglobulins against erythrocyte surface antigens are essential to pathogenesis of CAD. These cold agglutinins are monoclonal, usually IgMκ auto antibodies with heavy chain variable regions encoded by the V_H4-34 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 Last Resort Modality Using Cryofiltration Apheresis for the Treatment of Cold Hemagglutinin Disease in a Veterans Administration Hospital

Cold hemagglutinin disease is a cold autoimmune hemolytic anemia (cAIHA) caused by an autoantibody, such as IgM, directed against the I-antigen present on the surface of erythrocytes. Cold exposure can activate this system causing hemolysis, hemagglutination, microvascular thrombosis, or acrocyanosis. Thus, surgical procedures requiring hypothermia, such as coronary artery bypass surgery, present a significant problem in patients with cAIHA. The purpose of this study was to evaluate the safety and effectiveness of cryofiltration apheresis (CFA), used as a last resort, for the treatment of cAIHA. Effectiveness was evaluated by clinical assessment and laboratory evaluations of cold agglutinin titer, immunoglobulins, and other plasma proteins. Safety was evaluated by vital signs, monitoring, and laboratory measurements of complements, hematology and blood chemistry. Five patients with cAIHA were treated by CFA using the cryoglobulin (CG) filter (Pall Medical, Ann Arbor, MI, USA). Four patients received only one CFA procedure, while one patient received four CFA treatments. The cold agglutinin titers were fairly low, ranging from 1 : 1 to 1 : 2048. However, a wide thermal amplitude(4-37 degrees C) was observed in most patients. Two out of five patients responded favorably with reduction in titer. The two responders had acute forms of cAIHA with serum positive for cryoglobulins. The three non-responders had chronic forms of cAIHA with negative cryoglobulins. CFA effectively removed cryoprotein precipitates while conserving other plasma components. The CG filter was biocompatible with no complement activation or observed complications due to CFA or CG filter. While the mechanism of action in treating this type of patient population with CFA is unknown, the plausible theories are discussed.

Autoimmune hemolytic anemia

Red blood cell (RBC) autoantibodies are a relatively uncommon cause of anemia. However, autoimmune hemolytic anemia (AIHA) must be considered in the differential diagnosis of hemolytic anemias, especially if the patient has a concomitant lymphoproliferative disorder, autoimmune disease, or viral or mycoplasmal infection. Classifications of AIHA include warm AIHA, cold agglutinin syndrome, paroxysmal cold hemoglobinuria, mixed-type AIHA, and drug-induced AIHA. Characteristics of the autoantibodies are responsible for the various clinical entities. As a result, diagnosis is based on the clinical presentation and a serologic work-up. For each classification of AIHA, this review discusses the demographics, etiology, clinical presentation, laboratory evaluation, and treatment options.

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(+)kappa(+) B-cell proliferation received seven courses of rituximab 375 mg/m(2), 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.

Cold haemagglutinin disease: clinical significance of serum haemolysins

Two hundred and twenty-one patients with cold haemagglutinins of thermal amplitude > or = 30 degrees C (considered to be a reasonable indicator of clinical significance) were classified by in vitro haemolysin activity into three groups. Group 1 contained 116 individuals in whom haemolysins were never detected; the 74 patients in Group 2 had monophasic haemolysins alone; whereas both monophasic and biphasic haemolysins were detected in the 31 Group 3 patients. There was a significantly higher proportion of patients in Groups 2 and 3 with haptoglobin levels < 0.1 g/l compared with Groups 1 and 2, respectively (P < 0.005 and P < 0.001). Direct antiglobulin test results showed that the autoimmune response became more complex and IgM predominant through Groups 1-3, resulting in an increasing ability to activate complement which was reflected in increasing haemolysin activity and number of patients with active haemolysis. The 31 patients in Group 3 were mostly elderly (median age 71 years at presentation) and the majority had chronic cold haemagglutinin disease (CHAD), several in association with lymphoid neoplasms or carcinomas; only four had acute CHAD. The natural history of idiopathic chronic CHAD was of mild, well compensated haemolysis, punctuated by severe acute episodes necessitating intensive therapy. The condition often remained active for long periods and did not appear to affect natural lifespan. In some cases, no treatment (or just warmth) was needed; in others continuous or intermittent prednisolone and/or chlorambucil were effective; yet others required a greater variety and more intense therapy, or treatment of associated conditions. Blood transfusion support was frequently required when haemolysis was severe.

Autoimmune hemolytic anemia

Immune hemolytic anemia can be either isoimmune or autoimmune. Autoimmune hemolytic anemias (AIHA) consist of group of disorders whose common characteristics are the presence of an antibody which in turn causes short red blood cell (RBC) life. The rate and site of hemolysis and hence the clinical manifestations depends on the type of antibody attached and its propensity to fix complement. Antibodies of the IgG class are most commonly responsible for AIHA in children. Rh erythrocyte antigen is involved in more than 70% of cases. Since the antibody has its maximal activity at 37 degrees C, the resultant hemolysis is called warm antibody induced hemolytic anemia. This is a severe life threatening condition, the clinical features are: sudden onset of pallor, jaundice and dark urine. The cornerstone of diagnosis is a positive Coomb's antiglobulin test in the presence of hemolysis. Coomb's test has false negative and false positive rates in about 2-4% and 8% of all cases respectively. The modalities for treatment of warm AIHA include blood transfusion, steroid therapy, intravenous gammaglobulin, plasma-pheresis and splenectomy. The choice depends on the severity of the disease and child's response to therapy.

Chronic cold agglutinin disease of the "idiopathic" type is a premalignant or low-grade malignant lymphoproliferative disease

We investigated the clinical, pathological, and immunological features of "idiopathic" cold agglutinin disease (CAD) in a population-based study. Fourteen patients were studied, giving a prevalence of about 14 per million with a mean age of 75 years. Haemolysis was present in all cases, but only eight patients had clinical symptoms of peripheral haemagglutination. Serum electrophoresis, immunofixation, morphological bone marrow evaluation, and flow cytometric immunophenotyping were used to detect any monoclonal lymphoproliferative disorder. Flow cytometry seemed to be a sensitive way to demonstrate a clonal B-cell proliferation. Some evidence of clonality was found in 13 patients, and a clonal lymphoproliferative disease was documented by flow cytometry or biopsy in 10 out of 11 patients. We conclude that CAD is a symptom-producing monoclonal lymphoproliferative disorder in nearly all patients.

Successful response to alpha-interferon 2b in a refractory IgM autoagglutinin-mediated hemolytic anemia

We describe the beneficial effect of recombinant alpha 2b interferon in a woman with an idiopathic and refractory IgM-mediated autoimmune hemolytic anemia due to low-titer, high-thermal-amplitude cold agglutinins. The response was partial but sustained, 2 months after interruption of interferon, with hemoglobin concentrations ranging between 8.5 and 10 g/dl. In the literature, such rarely encountered hemolyzing warm-reacting agglutinins are described as causing severe hemolysis with a frequently fatal clinical outcome.

Cryoglobulinemia in chronic liver diseases: role of hepatitis C virus and liver damage

BACKGROUND/AIMS

Mixed cryoglobulinemia is frequently associated with liver diseases. The respective role of hepatitis C virus (HCV) and liver damage in the pathogenesis of cryoglobulinemia is investigated in this study.

METHODS

The prevalence of cryoglobulinemia in 226 consecutive patients with chronic liver diseases (hepatitis C, 127; hepatitis B, 40; other diseases, 59) was studied, and the epidemiological, biological, histological, and virological features in these three groups were analyzed. Anti-HCV antibodies, HCV proteins, and HCV RNA were searched in the cryoprecipitates.

RESULTS

The prevalence of mixed cryoglobulinemia was high (41.5%) in patients with liver diseases and higher in patients with hepatitis C (54.3%) than in patients with hepatitis B (15%) or other causes of liver disease (32%). Patients with cryoglobulinemia had cirrhosis more frequently and had a longer history of hepatitis. In patients with hepatitis C, HCV RNA sequences and HCV proteins were detected in the cryoprecipitate. Cryoglobulins became undetectable in 21 of 43 patients treated with interferon.

CONCLUSIONS

These findings suggest that HCV is a major cause of cryoglobulinemia. Besides viral infection itself, multiple factors appear to be responsible for the production of cryoglobulins, including cirrhosis and duration of liver disease.

Low-dose interferon-alpha in stage-I multiple myeloma and in IgM monoclonal gammopathy. Eastern Cooperative Study Group on Monoclonal Gammopathies

Interferon (IFN)-alpha can induce objective responses in advanced-stage multiple myeloma (MM) and can delay disease progression in patients responsive to chemotherapy. We studied the effects of low-dose (3 MU daily) human recombinant IFN-alpha 2b for 6-12 months in 29 consecutive cases of previously untreated, stable-phase, early stage, monoclonal gammopathy (MG) (23 cases of stage I MM and six cases of IgM MG). In 25/29 patients, the disease remained stable throughout the study period. A major objective response was observed in one of five cases of IgA MG. Normal Ig levels increased in all five cases of IgA MG. A significant disease progression occurred in 2/29 cases during the 1-year study period. These data showed that the objective response rate of early-stage MG to low-dose IFN was low and suggested that further investigation should focus on IgA MG.

A fatal case of low titer anti-PR cold agglutinin disease

Cold agglutinin disease typically produces a low-grade hemolytic anemia. We describe herein the unusual occurrence of an anti-PR cold agglutinin with high thermal amplitude which caused significant and ultimately fatal hemolytic anemia at very low titers.