Efficacy of intravenous immunoglobulin in the treatment of autoimmune hemolytic anemia: results in 73 patients

Diagnostic and therapeutic challenges of primary autoimmune haemolytic anaemia in children

Autoimmune haemolytic anaemias (AIHAs) are extracorpuscular haemolytic anaemias produced by antierythrocyte autoantibodies which cause a shortened red blood cell life span. There are several reasons why the diagnosis and treatment of AIHAs in children represent a bigger challenge than in adult patients, including the presence of particular AIHA types, the uncertainty of serological tests and the limited clinical experience. All these facts have added up to a poor understanding and management of some topics in childhood AIHA. We discuss some of these questions, for example, the occurrence of AIHA with negative direct antiglobulin (Coombs) test, the correct diagnosis and actual incidence of paroxysmal cold haemoglobinuria, the most appropriate second-line therapy of AIHA in childhood or the management of transfusion procedures in these patients. This review takes a practical point of view, providing with some ground rules on how to identify and deal with these paediatric patients.

[Are intravenous immunoglobulins useful in severe episodes of autoimmune hemolytic anemia?: Comparative results in 21 episodes from a single centre]

BACKGROUND AND OBJECTIVE

To analyze haemolytic episodes in patients with warm antibody autoimmune haemolytic anemia (AIHA) and compare corticosteroids treatment with intravenous immunoglobulins (IVIG) (group A) or without IVIG (group B).

PATIENTS AND METHODS

Observational study that includes 21 haemolytic episodes occurred in 17 patients (9 males and 12 females), with a median age of 59 years (26-82). In group A, 8 episodes received IGIV + corticosteroids and in group B, 12 episodes received only corticosteroids and one rituximab.

RESULTS

Hemoglobin (Hb) value at diagnosis was 1.8 g/dl lower (95% confidence interval: 0.6 to 3.1; P = .007) in group A, with a median Hb of 6.3g/dl in this group vs 7.9 g/dl in group B. There were non-significant differences in red blood cells transfusion (50 vs 23%; P > .20) and global increase of Hb values (7.3 vs 5.6; P > .20). Overall hematological responses were similar: 88 vs 92% (P > .20).

CONCLUSIONS

Hematological response achieved in more severe episodes with the use of IVIG was similar to non-severe episodes treated without IVIG.

Pulse cyclophosphamide therapy in refractory warm autoimmune hemolytic anemia: a new perspective

Treatment of steroid refractory autoimmune hemolytic anemia (AIHA) is challenging especially with no evidence based consensus guide lines and limited resources. The aim of this study was to evaluate the efficacy of pulse cyclophosphamide therapy in patients with severe refractory warm AIHA. The prospective study was designed to evaluate the efficacy of pulse cyclophosphamide-1 g/month for four consecutive months-in 17 patients (10 males and 7 females) with severe refractory warm AIHA [13 primary AIHA and 4 (females) secondary to SLE], all studied patients failed to respond to high dose of steroid therapy ± azathioprine ± intravenous immunoglobulin ± oral cyclophosphamide. Mean hemoglobin level, reticulocytic count and direct antiglobulin test were assessed before and after cyclophosphamide treatment every month. After the 4th cycle of cyclophosphamide (82 %, 14 patients) achieved partial response while the remaining (17 %, 3 patients) showed no response, while after 6 months follow up 47 % (8 patients) show complete response, while 53 % (9 patients) showed partial response. The mean hemoglobin levels were significantly increased after the 1st, 2nd, 3rd and 4th months of pulse cyclophosphamide therapy when compared to before treatment (P < 0.01, P < 0.001, P < 0.001 and P < 0.001) respectively, and the mean reticulocyte (%) were significantly decreased after the 2nd, 3rd and 4th months (P < 0.05, P < 0.01 and P < 0.001) respectively. We conclude that pulse cyclophosphamide therapy is well tolerated and induces good response in patients with severe refractory warm AIHA.

Antibody specific for the glycophorin A complex mediates intravenous immune globulin-resistant anemia in a murine model

BACKGROUND

Therapy for patients with autoimmune hemolytic anemia (AHA) remains a major challenge. Patients with glycophorin A (GPA)-specific immunoglobulin G antibodies can have severe hemolysis, which may occur by mechanisms independent from traditional macrophage-dependent Fcγ receptor (FcγR)-mediated extravascular hemolysis. As intravenous immune globulin (IVIG) is known to display its beneficial effects in FcγR-mediated cytopenias, and IVIG responses in AHA are inconsistent at best, we sought to gain insight into the mechanism of anemia by a GPA complex-specific monoclonal antibody (TER119) in a mouse model of immune hemolytic anemia and evaluate the therapeutic effect of IVIG.

STUDY DESIGN AND METHODS

The anemic effect of the TER119 antibody was studied in vitro by incubation of mouse RBC with the antibody and in vivo by infusing the antibody into normal mice versus mice genetically deficient for the Fc receptor γ chain (Fcγ), complement C3, mice naturally deficient in complement C5, and splenectomized mice. IVIG efficacy in anemia was determined by treating mice with an intensive IVIG dosing regimen.

RESULTS

The TER119-mediated anemia was independent of classical FcγR-, C3-, and C5-dependent mechanisms, but occurred by a mechanism consistent with RBC agglutination. In accordance with agglutination, the presence of the spleen accelerated the anemia observed but anemia could still occur in splenectomized mice. IVIG did not significantly affect the induction of anemia by TER119.

CONCLUSION

The mechanism of anemia induced by AHA-causing antibodies may be an important factor to consider in the response to therapy with IVIG.

Clinical applications of immunoglobulin: update

Human immunoglobulin is the most used blood product in the clinical practice. Immunoglobulin applications have increased quickly since the elucidation of its immunomodulatory and antiinflammatory properties which turned this blood product into a precious tool in the treatment of numerous diseases that present with humoral immune deficiency or that cause immune system dysfunction. Currently, the approved indications for Ig are: primary immunodeficiencies, secondary immunodeficiencies (multiple myeloma or chronic lymphoid leukemia), Kawasaki syndrome, immune thrombocytopenic purpura, Guillain Barré syndrome, graft-versus-host disease following bone marrow transplantation and repeat infections in HIV children. On the other hand, there are numerous "off-label" indications of immunoglobulin, which represent 20-60% of all clinical applications of this drug. It is important to study all these indications and, above all, the scientific evidence for its use, in order to provide patients with a new therapeutic option without burdening the health system. This review results from a wide selection of papers identified in the Pubmed and Lilacs scientific electronic databases. A group of descriptors were used from human immunoglobulin to the names of each disease that immunoglobulin is clinically applied. Our main objective is to list the numerous indications of immunoglobulin, both authorized and "off-label" and to analyze these indications in the light of the most recent scientific evidence.

Pegylated interferon de novo-induce autoimmune haemolytic anaemia in chronic hepatitis C patient

A 55-year-old Egyptian woman with chronic hepatitis C undergoing treatment with pegylated interferon (Peg-IFN) alfa-2a plus ribavirin was referred to our hospital on November 2010 with prolonged easy fatigability and an attack of syncope; she had no prior history of autoimmune disorders or allergy. Laboratory investigations documented the presence of Peg-IFN induced autoimmune haemolytic anaemia and autoimmune thyroiditis. Intravenous γ globulin (IVGG) failed to correct the autoimmune process; on the other hand steroid therapy dramatically corrected both haematological and thyroid values, and step down the immune process. Our report indicated that Peg-IFN de novo-induce autoimmune haemolysis, documenting a previous report. IVGG failed to step down the immune process in our case.

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.

Evidence for the use of intravenous immunoglobulins--a review of the literature

Intravenous immunoglobulins (IVIg) were first introduced in the middle of the twentieth century for the treatment of primary immunodeficiencies. In 1981, Paul Imbach noticed an improvement of immune-mediated thrombocytopenia, in patients receiving IVIg for immunodeficiencies. This opened a new era for the treatment of autoimmune conditions with IVIg. Since then, IVIg has become an important treatment option in a wide spectrum of diseases, including autoimmune and acute inflammatory conditions, most of them off-label (not included in the US Food and Drug Administration recommendation). A panel of immunologists and internists with experience in IVIg therapy reviewed the medical literature for published data concerning treatment with IVIg. The quality of evidence was assessed, and a summary of the available relevant literature in each disease was given. To our knowledge, this is the first all-inclusive comprehensive review, developed to assist the clinician when considering the use of IVIg in autoimmune diseases, immune deficiencies, and other conditions.

Long-term remission of severe refractory dermatopolymyositis with a weekly-scheme of immunoglobulin followed by rituximab therapy

We report on a 44-year-old woman affected by dermatopolymyositis resistant to conventional therapies who experienced long-term clinical improvement and remission after treatment with intravenous polyvalent immunoglobulin in a weekly schedule followed by rituximab therapy.

Immune hemolytic anemia--selected topics

Autoimmune hemolytic anemia (AIHA) is most often idiopathic. However, in recent years, AIHA has been noted with increased incidence in patients receiving purine nucleoside analogues for hematologic malignancies; it has also been described as a complication of blood transfusion in patients who have also had alloimmunization. As the technology of hematopoietic stem cell transplantation has become more widespread, immune hemolysis in the recipients of ABO-mismatched products has become better recognized. The syndrome is caused by passenger lymphocytes transferred from the donor and, although transient, can be quite severe. A similar syndrome has been observed in recipients of solid organ transplants when there is ABO-incompatibility between donor and recipient. Venous thromboembolism is a little-recognized, though likely common, complication of AIHA, and may in some instances be related to coexistent antiphospholipid antibodies. While AIHA is a well-documented complication of malignant lymphoproliferative disorders, lymphoproliferative disorders may also paradoxically appear as a consequence of AIHA. A number of newer options are available for treatment of AIHA in patients refractory to corticosteroids and splenectomy. Newer immunosuppressives such as mycophenolate mofetil may have a role in such cases. Considerable experience has been accumulating in the last few years with monoclonal antibody therapy, mainly rituximab, in difficult AIHA cases; it appears to be a safe and effective option.

Hemolytic anemia due to warm autoantibodies

The diagnosis of autoimmune hemolytic anemia (AHA) requires evidence of shortened red blood cell (RBC) survival mediated by autoantibodies directed against autologous RBCs. About 80 percent of patients with AHA have warm-reactive antibodies of the IgG isotype; the remainder exhibit cold-reactive autoantibodies. Typical patients exhibit anemia, reticulocytosis, spherocytes and polychromasia on the blood film and a positive direct antiglobulin test (DAT). Increased indirect serum bilirubin, urinary urobilinogen and serum lactate dehydrogenase (LDH), and decreased serum haptoglobin are not required for the diagnosis, but are frequently present. Patients with AHA and no underlying associated disease are said to have primary or idiopathic AHA. AHA in patients with associated autoimmune disease and certain malignant or infectious diseases is classified as secondary. The etiology of AHA is unknown. Patients with symptomatic anemia require transfusion of RBCs. Prednisone and splenectomy may provide long term remission. Rituximab, intravenous immunoglobulin, immunosuppressive drugs and danazol have been effective in refractory cases and for patients who are poor candidates for surgery.

[Warm autoimmune hemolytic anemias and Evans syndrome in adults]

PURPOSE

The outcome of autoimmune hemolytic anemia (AIHA) and Evans syndrome (ES) in adults is not well-known and their management is mainly based on empirical data.

CURRENT KNOWLEDGE AND KEY POINTS

The main characteristics of both AIHA and ES are reviewed in this article, based on the data available in the literature and on our experience. Although controlled studies and evidence-based data are lacking, some recommendations regarding the minimal workup useful to search for an underlying disease can be made as well as proposals for a better therapeutic strategy of both disorders.

FUTURE PROSPECTS AND PROJECTS

A better knowledge of the mechanisms triggering AIHA and ES as well as therapeutic trials are needed in order to better stratify treatment taking into account the promising efficacy of rituximab.

Guidelines on the Use of Intravenous Immune Globulin for Hematologic Conditions

Canada's per capita use of intravenous immune globulin (IVIG) grew by approximately 115% between 1998 and 2006, making Canada one of the world's highest per capita users of IVIG. It is believed that most of this growth is attributable to off-label usage. To help ensure IVIG use is in keeping with an evidence-based approach to the practice of medicine, the National Advisory Committee on Blood and Blood Products of Canada (NAC) and Canadian Blood Services convened a panel of national experts to develop an evidence-based practice guideline on the use of IVIG for hematologic conditions. The mandate of the expert panel was to review evidence regarding use of IVIG for 18 hematologic conditions and formulate recommendations on IVIG use for each. A panel of 13 clinical experts and 1 expert in practice guideline development met to review the evidence and reach consensus on the recommendations for the use of IVIG. The primary sources used by the panel were 3 recent evidence-based reviews. Recommendations were based on interpretation of the available evidence and where evidence was lacking, consensus of expert clinical opinion. A draft of the practice guideline was circulated to hematologists in Canada for feedback. The results of this process were reviewed by the expert panel, and modifications to the draft guideline were made where appropriate. This practice guideline will provide the NAC with a basis for making recommendations to provincial and territorial health ministries regarding IVIG use management. Specific recommendations for routine use of IVIG were made for 7 conditions including acquired red cell aplasia; acquired hypogammaglobulinemia (secondary to malignancy); fetal-neonatal alloimmune thrombocytopenia; hemolytic disease of the newborn; HIV-associated thrombocytopenia; idiopathic thrombocytopenic purpura; and posttransfusion purpura. Intravenous immune globulin was not recommended for use, except under certain life-threatening circumstances, for 8 conditions including acquired hemophilia; acquired von Willebrand disease; autoimmune hemolytic anemia; autoimmune neutropenia; hemolytic transfusion reaction; hemolytic transfusion reaction associated with sickle cell disease; hemolytic uremic syndrome/thrombotic thrombocytopenic purpura; and viral-associated hemophagocytic syndrome. Intravenous immune globulin was not recommended for 2 conditions (aplastic anemia and hematopoietic stem cell transplantation) and was contraindicated for 1 condition (heparin-induced thrombocytopenia). For most hematologic conditions reviewed by the expert panel, routine use of IVIG was not recommended. Development and dissemination of evidence-based guidelines may help to facilitate appropriate use of IVIG.

Autoimmune hemolytic anemia in India: clinico-hematological spectrum of 79 cases

The clinico-hematological profile and treatment outcome of patients with autoimmune hemolytic anemia (AIHA) were assessed using a retrospective case record analysis. There were 79 (52 primary; 27 secondary) consecutive patients identified with a median age of 30.5 years. The main presenting complaints were pallor (94%), fever (46%), jaundice (51%), bleeding manifestations (10%) and splenomegaly (68%). Jaundice was much more common in primary (63%) as opposed to secondary (26%) disease. The direct antiglobulin test was negative in six patients. Oral prednisolone produced remission in 87.5% patients. Six patients (three children, three adults) relapsed after a median period of 2 months after response. All of these responded to a second course of steroids, in a median period of 14 days. No correlation was found between response and the parameters of age, sex, jaundice, low pretreatment hemoglobin, reticulocyte count, total leucocyte count (TLC), platelet count, subtype of AIHA and hepatosplenomegaly. Relapse correlated with increased duration between the onset of symptoms and treatment (r = 0.996; p = 0.0001).

Plasma exchanges do not increase red blood cell transfusion efficiency in severe autoimmune hemolytic anemia: A retrospective case-control study

Severe autoimmune hemolytic anemia (AIHA) can cause life-threatening hemolysis requiring red blood cell transfusions (RBT). The efficiency of RBT could be improved with the use of plasma exchanges (PEx) before RBT. The objective of this study was to assess the effectiveness of PEx in severe AIHA of adults. All adult patients with severe AIHA requiring RBT were included in this single center retrospective case-control study. The end point was change in hemoglobin (Hb) level after RBT, depending on whether PEx was done (experimental group) or not (control group). Thirty-one sessions of RBT following PEx were performed on the 5 patients of the experimental group and were compared with the 7 sessions of BT without PEx performed on the 4 patients of the control group. Despite a lower mean Hb value before the session of RBT (5.7 g/dl vs. 7.2 g/dl, P = 0.04) in the control group, the mean Hb value 5 (4-7) days following RBT (8.7 g/dl vs. 8.6 g/dl, P = 0.85) was not different in the experimental and in the control group, respectively. In a second analysis in which each patient was his own control (31 sessions of RBT following PEx vs. 51 sessions of RBT alone), the gain in Hb was not different (1.4 g/dl vs. 1.9 g/dl, P = 0.67). When RBT are required in severe AIHA of adults, the use of a single PEx before BT does not increase the efficiency of RBT based on day 5 evaluation.

Current usage of intravenous immune globulin and the rationale behind it: the Massachusetts General Hospital data and a review of the literature

BACKGROUND

Intravenous immune globulin (IVIG) has been approved by the Food and Drug Administration (FDA) for use in 6 conditions: immune thrombocytopenic purpura (ITP), primary immunodeficiency, secondary immunodeficiency, pediatric HIV infection, Kawasaki disease, prevention of graft versus host disease (GVHD) and infection in bone marrow transplant recipients. However, most usage is for off-label indications, and for some of these comprehensive guidelines have been published.

STUDY DESIGN AND METHODS

We retrospectively reviewed all approved IVIG transfusions at Massachusetts General Hospital in 2004 to identify the current usage pattern and completed a literature review.

RESULTS

IVIG was most commonly used in the treatment of chronic neuropathy, which included chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy. For such patients, the annual cost of IVIG can exceed 50,000 dollars per patient. Other common indications were the treatment of hypogammaglobulinemia, ITP, renal transplant rejection, myasthenia gravis, Guillain-Barre syndrome, necrotizing fasciitis, autoimmune hemolytic anemia, and Kawasaki disease. IVIG was administered in a variety of other indications each representing <3% of the total treated patients.

CONCLUSION

Only a few indications account for most of the usage for IVIG. Reports concerning IVIG continue to grow at a tremendous pace but few high-quality randomized controlled trials have been reported. Randomized trials are especially needed for conditions such as CIDP, which consume large quantities of product.

Immune Hemolytic Anemia—Selected Topics

Autoimmune hemolytic anemia (AIHA) is most often idiopathic. However, in recent years, AIHA has been noted with increased incidence in patients receiving purine nucleoside analogues for hematologic malignancies; it has also been described as a complication of blood transfusion in patients who have also had alloimmunization. As the technology of hematopoietic stem cell transplantation has become more widespread, immune hemolysis in the recipients of ABO-mismatched products has become better recognized. The syndrome is caused by passenger lymphocytes transferred from the donor, and although transient, can be quite severe. A similar syndrome has been observed in recipients of solid organ transplants when there is ABO-incompatibility between donor and recipient.

Venous thromboembolism is a little-recognized, though likely common, complication of autoimmune hemolytic anemia (AIHA), and may in some instances be related to coexistent antiphospholipid antibodies. While AIHA is a well-documented complication of malignant lymphoproliferative disorders, lymphoproliferative disorders may also paradoxically appear as a consequence of AIHA.

A number of newer options are available for treatment of AIHA in patients refractory to corticosteroids and splenectomy. Newer immunosuppressives such as mycophenolate may have a role in such cases. Considerable experience has been accumulating in the last few years with monoclonal antibody therapy, specifically rituximab, in difficult AIHA cases; it appears to be a safe and effective option.

Immunomodulatory Effects of Intravenous Immunoglobulins as a Treatment for Autoimmune Diseases, Cancer, and Recurrent Pregnancy Loss

Intravenous immunoglobulin (IVIG) is a safe preparation, made of human plasma of thousands of healthy donors. The fascinating history of gamma globulin therapy begins in 1930 when Finland treated pneumococcal pneumonia patients with equine serum, which prolonged their survival from pneumonia. Since then, significant breakthroughs were achieved by Cohn, Bruton, Imbach, and others, whose clinical contribution to the world of medicine was of great importance. Originally IVIG was used to treat immunodeficiencies. Later on the use of IVIG extended to autoimmune diseases as well. The efficacy of IVIG has been established only in several autoimmune diseases; clinical reports of trials, series, and case reports indicate significant improvement in many more autoimmune diseases. IVIG have also showed antimetastatic effects in a variety of cancer cell lines, as well as in a few case reports. The efficiency of IVIG has also been observed in recurrent pregnancy loss (RPL), either as a result of an autoimmune disease or spontaneous. Several attempts were made to discover the immunomodulatory effects of IVIG, but it is still not fully understood. Clearly IVIG has multiple mechanisms of actions, which are thought to cooperate synergistically. One of the main mechanisms of actions of IVIG is its ability to neutralize pathogenic autoantibodies via anti-idiotypic antibodies within IVIG preparation. The ability of IVIG to neutralize pathogenic autoantibodies is of great importance in many autoimmune diseases, as well as in RPL. In cancer cell lines, IVIG modulates the immune system in a few ways, including the induction of IL-12 secretion, which consequently activates natural killer cells, and the induction of expression of proapoptotic genes only in cancer cells. Side effects from IVIG are rare and mostly mild and transient. More importantly adverse effects can be minimized by administration to a selective patient population in a proper way: slow infusion rate of 0.4 g/Kg body weight IVIG for 5 consecutive days, given in monthly cycles. The only downside of IVIG therapy is its high price. Therefore, clinicians should balance efficiency versus cost in deciding whether or not to treat certain conditions with IVIG.

Suppressive effect of intravenous immunoglobulin on peripheral blood neutrophil count in patients with idiopathic thrombocytopenic purpura

PURPOSE

To determine the effect of intravenous immunoglobulin (IVIG) on neutrophil count, the authors studied patients with idiopathic thrombocytopenic purpura (ITP).

PATIENTS AND METHODS

Thirty-one of 40 patients with ITP were treated with an IVIG regimen (400 mg/kg/daily for 5 days), while the other 9 were observed without any medications. Peripheral samples were examined during the clinical course.

RESULTS

The absolute neutrophil count in 22 patients with no fever as a side effect decreased significantly by day 2 after the start of IVIG, but in most patients it began to increase soon after the last IVIG. There was also a significant difference between the decreased level of the absolute neutrophil count in patients with and without IVIG. However, re-administration of IVIG within 2 weeks did not significantly suppress the neutrophil count. In contrast, the neutrophil count increased in every patient with a fever as a side effect of IVIG.

CONCLUSIONS

IVIG induced a decrease in peripheral blood neutrophil count in patients with ITP.

21. Immunohematologic disorders

Immunohematologic disorders are a broad group of entities in which hematologic diseases, usually cytopenias, are caused by immune reactions. These reactions lead to the development of hemolytic anemia, thrombocytopenia, or neutropenia, either separately or in combination. Common underlying mechanisms include immunodeficiency, systemic autoimmunity, and drug-induced reactions. Transplacental transfer of maternal alloantibodies can lead to fetal and neonatal cytopenias. Other immune reactions include antibodies to clotting factors, which result in both thrombosis and hemorrhage, and hemolytic and nonhemolytic reactions during transfusion of blood products.

Durable response to combination therapy including staphylococcal protein A immunoadsorption in life-threatening refractory autoimmune hemolysis

BACKGROUND

Few therapeutic options are available for severe, life-threatening, refractory autoimmune hemolytic anemia.

CASE REPORT

A 53-year-old 110-kg man was seen with acute onset of symptomatic severe anemia with syncope, unstable angina, and jaundice. His nadir Hct was 8.3 percent with a peak total bilirubin of 44 mg per dL. The DAT was positive but the IAT was negative. Elution studies demonstrated an IgG pan-agglutinin antibody reactive at 37 degrees C. Treatment with high-dose corticosteroids and IVIG was instituted. An accessory spleen measuring 2 cm was identified and surgically removed, but the patient continued to have intense hemolysis. Cyclophosphamide at 200 mg per day was started. Apheresis with a staphylococcal protein A immunoadsorption column (Prosorba, Cypress Bioscience, Inc.) was initiated on Day 18 and was performed twice weekly for a total of six treatments. Cyclophosphamide was continued for a total of 14 days. His transfusion requirement ceased by the third immunoadsorption treatment. Forty units of RBCs were required over 23 days in an attempt to maintain a Hct greater than or equal to 15 percent.

CONCLUSION

Refractory autoimmune hemolysis can be a life-threatening event. The patient did not achieve a response until after several different therapeutic modalities were instituted, including plasmapheresis with a staphylococcal protein A column (Prosorba). A complete response continues to be durable for more than 1 year after therapy.

High-dose cyclophosphamide for refractory autoimmune hemolytic anemia

High-dose cyclophosphamide, without stem cell rescue, has been used successfully to treat aplastic anemia and other autoimmune disorders. To determine the safety and efficacy of high-dose cyclophosphamide among patients with severe refractory autoimmune hemolytic anemia, we treated 9 patients with cyclophosphamide (50 mg. kg(-1). d(-1) for 4 days) who had failed a median of 3 (range, 1-7) other treatments. The median hemoglobin before treatment was 6.7 g/dL (range, 5-10 g/dL). The median time to reach an absolute neutrophil count of 500/microL or greater was 16 days (range, 12-18 days). Six patients achieved complete remission (normal untransfused hemoglobin for age and sex), and none have relapsed after a median follow-up of 15 months (range, 4-29 months). Three patients achieved and continue in partial remission (hemoglobin at least 10 g/dL without transfusion support). High-dose cyclophosphamide was well tolerated and induced durable remissions in patients with severe refractory autoimmune hemolytic anemia.

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.

Treatment of autoimmune hemolytic anemias

Treatment of autoimmune hemolytic anemias varies depending on whether the patient has autoimmune hemolytic anemia of warm antibody type, cold agglutinin syndrome, paroxysmal cold hemoglobinuria, or autoimmune hemolytic anemia secondary to an underlying disorder. Initial therapy for warm antibody autoimmune hemolytic anemia should be corticosteroids, such as prednisone at conventional doses of 1 to 1.5 mg/kg/d orally. Criteria must be established to determine whether the therapeutic response is adequate, because long-term therapy may lead to significant detrimental side effects. Splenectomy has the advantage over therapeutic options in that it has the potential for complete and long-term remission. The major adverse effect is the syndrome of overwhelming postsplenectomy infection. Other therapeutic options, which are less likely to have long-term benefit, are immunosuppressive drugs, danazol, intravenous immunoglobulin, and plasma exchange. Therapy of cold agglutinin syndrome often is unsatisfactory. All patients should avoid exposure to cold, and if additional therapy is necessary, the therapies used for warm antibody autoimmune hemolytic anemia may be tried with less likelihood of response. Paroxysmal cold hemoglobinuria requires aggressive supportive therapy, generally supplemented by corticosteroids. Hemolysis usually terminates spontaneously. Patients with secondary autoimmune hemolytic anemia may be treated similarly to those with idiopathic autoimmune hemolytic anemia, and additional therapy for the underlying disorder also may result in remission of the hemolysis.

Treatment of hematologic disorders other than immune thrombocytopenic purpura with intravenous immunoglobulin (IVIg) - report of seven cases and review of the literature

Background: Intravenous immunoglobulin (IVIg) is a standard therapeutic modality for a few autoimmune diseases, such as immune thrombocytopenic purpura. However, in other hematologic autoimmune conditions its role is still controversial. Methods: Seven patients with either autoimmune hemolytic anemia, Evans' syndrome, aplastic anemia, pure red cell aplasia, thrombotic thrombocytopenic purpura, or acquired factor VIII inhibitors were treated with a single course of high-dose (2 g/kg) IVIg. Results: A good response was observed in all seven patients, except the one with thrombotic thrombocytopenic purpura, and there were no adverse effects related to IVIg use. The literature reports on IVIg therapy in these conditions and the mechanisms of action of IVIg in autoimmune diseases are discussed. Conclusions: IVIg might be a useful agent in the treatment of several hematologic disorders other than immune thrombocytopenic purpura. Future aims of clinical research in this respect would be to identify the patient subgroups that might benefit more from IVIg in these conditions.

In vivo administration of intravenous immunoglobulin (IVIg) can lead to enhanced erythrocyte sequestration

Enhanced erythrocyte sequestration is one of the very few major adverse effects of intravenous immunoglobulin (IVIg). IVIg contains high molecular weight IgG complexes ( approximately 300 kDa) which, in the presence of serum, mimic immune complexes by activating complement, binding to CR1 of red blood cells (RBC) (CD35) and mediating erythrophagocytosis. Four of seven patients undergoing IVIg therapy showed significant drops in haematocrit and haemoglobin that were not due to isoantibodies in the IVIg. Prior to treatment, patients' RBC carried IgG and complement (C') 3d that were not bound as immune complexes via CR1 (CD35). The patients whose RBC bound immune complex-like moieties and showed drops in haematocrit and haemoglobin subsequent to IVIg were young adults (22-35 years); older patients (50-69 years) showed no ill effects. In the presence of complement, RBC of young patients bound IVIg complexes in vitro while those of older patients did not. It is not the absolute levels of erythrocyte-associated IgG or C'3 fragments, neither pre- nor post-therapy, which are predictive of IVIg associated decreases in haematocrit and haemoglobin levels. Patient age and RBC inability to bind the IVIg immune complex-like moieties in vitro both appear to be predictors of resistance to sequestration after in vivo treatment with IVIg.

Inhibition of IL-12 synthesis of peripheral blood mononuclear cells (PBMC) stimulated with a bacterial superantigen by pooled human immunoglobulin: implications for its effect on Kawasaki disease (KD)

The aim of this study was to further assess the role of pooled human immunoglobulin (PHIG) on cytokine production from PBMC stimulated with a bacterial superantigen. Human PBMC were cultured with Streptococcus pyrogenic exotoxin A (SPE-A) with or without PHIG and several proinflammatory cytokine levels of culture supernatants were measured. Serum cytokine levels of KD patients before and after PHIG therapy were also examined. PHIG greatly reduced the production of IL-12, interferon-gamma (IFN-gamma) and other cytokines from SPE-A-stimulated PBMC, while exogenous IL-12, but neither IL-1 nor tumour necrosis factor-alpha (TNF-alpha), restored IFN-gamma production inhibited by PHIG. Although PHIG partially adsorbed SPE-A, its inhibitory effect on cytokine production was not played by anti-SPE-A antibody. Although purified CD4+ T cells cultured with human HLA-DR-transfected mouse L cells and SPE-A could not effectively produce IFN-gamma, they produced large amounts of IFN-gamma if exogenous IL-12 was introduced. KD patients in the acute phase had higher levels of serum IFN-gamma than did controls and patients with bacterial infection. Although IL-12 levels of children with or without KD were not significantly different, IL-12 levels of children were much higher than those of adults. However, serum levels of IL-12 of KD patients were transiently but significantly decreased by PHIG therapy and IFN-gamma amounts subsequently reverted to basal levels thereafter. These findings indicate that PHIG inhibits IL-12 production of SPE-A-activated monocytes and thereby decreases IFN-gamma synthesis by T cells and suggest that inhibition of IL-12 and IFN-gamma production is an important part of the mechanisms underlying PHIG therapy on KD.

Human IgG Fc receptors

Human IgG receptors constitute a family of glycoprotein complexes consisting of ligand-binding, and associated signaling chains. Three leukocyte classes (Fc gamma RI, II, and III) and one separate endothelial Fc gamma R class (FcRB) are defined which are expressed on hematopoietic and endothelial cells. Upon interaction with IgG, Fc gamma R initiate a plethora of signaling cascades involving receptor signaling motifs, and protein tyrosine kinases and phosphatases. These cascades ultimately culminate in activation or deactivation of effector cells, resulting in initiation or down-modulation of cellular processes. Recent evidence points to a crucial in vivo role of Fc gamma R in both initiation and regulation of inflammatory and cytotoxic responses. These Fc gamma R-mediated immune responses can be exploited to develop novel immunotherapies.

Immune complex-like moieties in immunoglobulin for intravenous use (i.v.Ig) bind complement and enhance phagocytosis of human erythrocytes

Treatment with i.v.Ig can, on rare occasions, lead to detrimental effects such as enhanced erythrocyte sequestration and an increase in serum immune complexes with inflammatory sequellae such as exacerbation of glomerular nephritis. In this study, i.v.Ig (Sandoglobin) was examined for complement binding moieties which resemble immune complexes and can mediate the binding of IgG and C'3b to human erythrocytes via CR1 and enhance erythrocyte susceptibility to sequestration. Sephacryl S-200 HR separated i.v.Ig into two fractions: monomeric IgG (74%) and larger complexes of the molecular weight of an IgG dimer or greater (> or = 300 kD) (26%). In the presence of complement, the 'dimers' bound to human erythrocytes, rendering them susceptible to phagocytosis in vitro. Removal of erythrocyte-specific isoantibodies from the i.v.Ig had no effect on 'dimer' binding to the erythrocytes. Monomeric IgG contained virtually no complement-activating, erythrocyte-binding activity. Erythrocyte binding of complement-bearing IgG 'dimers' and subsequent phagocytosis resembles the binding of complement-bearing immune complexes to erythrocyte CR1. Exposure to Factor I leads to the release of complement-bearing IgG 'dimers' from erythrocyte CR1 and to the abrogation of erythrophagocytosis. Binding of complement-bearing IgG 'dimers' to the erythrocyte is blocked by To5, a CR1-specific monoclonal antibody.

Intravenous immunoglobulin treatment in hematological diseases

In the last decade large amounts of intravenous immunoglobulin (i.v.Ig) have been used worldwide. Doubts exist as to whether this increased use is paralleled by a comparable growth of reliable data on the therapeutic effectiveness of i.v.Ig. We performed a literature search using MEDLINE from January 1981 to January 1997 and analysed articles on the use of i.v.Ig in hematological disorders and searched for published guidelines. For most hematological disorders, evidence to use i.v.Ig as first line therapy is not very strong. For many disorders no controlled trials have been performed. In published guidelines, i.v.Ig is only recommended, with a few exceptions, when other treatments have failed or are contraindicated. Therefore the increase of consumption of i.v.Ig can not be explained by an increase in established indications in hematology.

Intravenous human immunoglobulin for the treatment of immune-mediated hemolytic anemia in 13 dogs

Intravenous immunoglobulin (IVGG) was administered to 13 of 37 dogs with immune-mediated hemolytic anemia. All dogs received concurrent prednisone therapy, 14 dogs also received cyclophosphamide; and a single dog each received cyclosporine, azathioprine, and danazol. Dogs that responded to prednisone therapy without IVGG generally did so within 7 days (mean +/- standard deviation = 5.6 +/- 2.9 days). Intravenous immunoglobulin was administered after 10.4 +/- 6.6 days of prednisone therapy as an intravenous infusion of 0.5 g/kg (range 0.25 to 0.73 g/kg). Eleven dogs received a single treatment, 2 dogs each received 2 treatments. No relevant adverse effects were noted. Eleven dogs had an increase in PCV of at least 4% 2.2 +/- 1.5 days after IVGG infusion. In 10 of these dogs, the PCV continued to increase until the time of hospital discharge. One responder died 1 hour after the increase in PCV, 1 dog was euthanized within 24 hours of IVGG administration, and 1 dog had no response over a period of 13 days. Results of this study suggest that IVGG therapy may be of value in dogs with immune-mediated hemolytic anemia that do not respond within 7 days of appropriate corticosteroid therapy.

Human intravenous immunoglobulin therapy

Human intravenous immunoglobulin (hIVIG) is a preparation of normal polyspecific IgG obtained from the plasma of healthy blood donors. Although purified immunoglobulins were initially developed for treatment of primary immunodeficiency syndromes, they have since been documented to be effective in the treatment of some immune-mediated diseases such as immune-mediated thrombocytopenia purpura and autoimmune hemolytic anemia. Blockade of Fc receptors on mononuclear phagocytic cells has been proposed as the most likely mechanism for the rapid early response to hIVIG treatment. Human IVIG has been used to treat canine immune-mediated hemolytic anemia (IMHA), anemia with myelofibrosis, and immune-mediated thrombocytopenia. Doses from 0.5 to 1.5 g/kg may be effective, although most studies have used a dose of 1 g/kg. Human IVIG is administered as an intravenous infusion over 6 to 12 hours, and dogs should be carefully monitored for adverse reactions during administration. The possibility of a increased risk of thromboembolism should be considered when undertaking hIVIG treatment. The safety of multiple treatments of hIVIG has not been established. In most dogs with IMHA, benefit may be limited to short-term improvement in hematocrit, which may allow time for other treatment modalities to become effective. Dogs with nonregenerative anemia and associated myelofibrosis may have longer-term responses to hIVIG treatment.

Modulation of an acquired coagulation factor V inhibitor with intravenous immune globulin

PURPOSE

We report that treatment of an immune mediated postoperative Factor V (FV) deficiency with intravenous immune globulin (IVIg) resulted in serological and clinical disappearance of the inhibitor.

PATIENTS AND METHODS

A 9-year-old girl was exposed to bovine thrombin during cardiovascular surgery and subsequently developed severe, refractory hemorrhage caused by acquired FV deficiency (FV activity < 5%). Despite blood product transfusions, hemorrhage continued, and the patient was given IVIg, 400 mg/kg daily, for 9 day.

RESULTS

Prolonged clotting times immediately trended toward normal, and the hemorrhage ceased by the fifth IVIg treatment day, concomitant with increasing plasma FV activity and disappearance of human FV inhibitor activity. The patient's plasma initially had a much higher inhibitor titer against bovine FV (122-215 Bethesda units) than against human FV (3-4 Bethesda units). Circulating antibodies (IgM and IgG) to bovine and human thrombin and FV were detected by enzyme-linked immunosorbent assay (ELISA). After completion of IVIg treatment, IgG antibodies to bovine FV and thrombin persisted, as did high-titer inhibition of bovine FV, whereas the subpopulation of IgG and IgM antibodies reactive with human FV were undetectable.

CONCLUSIONS

The inhibitor likely developed from a heterogenetic immune response to bovine FV contaminating the topical thrombin preparation used during surgery. To our knowledge, this is the first demonstration of immunological clearance of an acquired FV antibody associated with the use of IVIg. The data suggest an antiidiotypic mechanism of IVIg in modulating clearance of antihuman FV antibodies.