Mixed-type autoimmune hemolytic anemia: differential diagnosis and a critical review of reported cases

Transfusion support and pre-transfusion testing in autoimmune haemolytic anaemia

Autoimmune haemolytic anaemia (AIHA) is characterized by an increased destruction of red blood cells due to immune dysfunction and auto-antibody production. Clinical manifestations are mainly related to anaemia, which can become life-threatening in case of acute haemolysis. Aiming at counterbalancing severe anaemia, supportive treatments for these patients frequently include transfusions. Unfortunately, free serum auto-antibodies greatly interfere in pre-transfusion testing, and the identification of compatible red blood cell units for AIHA patients can be challenging or even impossible. Problems faced in pre-transfusion testing often lead to delay or abandonment of transfusions for AIHA patients. In this review, we discuss publications concerning global transfusion management in AIHA, with a focus on pre-transfusion testing, and practical clues to manage the selection of transfusion units for these patients. Depending on the degree of transfusion emergency, we propose an algorithm for the selection and laboratory testing of units to be transfused to AIHA patients.

Autoimmune Hemolytic Anemias: Classifications, Pathophysiology, Diagnoses and Management

Autoimmune hemolytic anemias (AIHAs) are conditions involving the production of antibodies against one's own red blood cells (RBCs). These can be primary with unknown cause or secondary (by association with diseases or infections). There are several different categories of AIHAs recognized according to their features in the direct antiglobulin test (DAT). (1) Warm-antibody AIHA (wAIHA) exhibits a pan-reactive IgG autoantibody recognizing a portion of band 3 (wherein the DAT may be positive with IgG, C3d or both). Treatment involves glucocorticoids and steroid-sparing agents and may consider IVIG or monoclonal antibodies to CD20, CD38 or C1q. (2) Cold-antibody AIHA due to IgMs range from cold agglutinin syndrome (CAS) to cold agglutin disease (CAD). These are typically specific to the Ii blood group system, with the former (CAS) being polyclonal and the latter (CAD) being a more severe and monoclonal entity. The DAT in either case is positive only with C3d. Foundationally, the patient is kept warm, though treatment for significant complement-related outcomes may, therefore, capitalize on monoclonal options against C1q or C5. (3) Mixed AIHA, also called combined cold and warm AIHA, has a DAT positive for both IgG and C3d, with treatment approaches inclusive of those appropriate for wAIHA and cold AIHA. (4) Paroxysmal cold hemoglobinuria (PCH), also termed Donath-Landsteiner test-positive AIHA, has a DAT positive only for C3d, driven upstream by a biphasic cold-reactive IgG antibody recruiting complement. Although usually self-remitting, management may consider monoclonal antibodies to C1q or C5. (5) Direct antiglobulin test-negative AIHA (DAT-neg AIHA), due to IgG antibody below detection thresholds in the DAT, or by non-detected IgM or IgA antibodies, is managed as wAIHA. (6) Drug-induced immune hemolytic anemia (DIIHA) appears as wAIHA with DAT IgG and/or C3d. Some cases may resolve after ceasing the instigating drug. (7) Passenger lymphocyte syndrome, found after transplantation, is caused by B-cells transferred from an antigen-negative donor whose antibodies react with a recipient who produces antigen-positive RBCs. This comprehensive review will discuss in detail each of these AIHAs and provide information on diagnosis, pathophysiology and treatment modalities.

Systemic Lupus Erythematosus and Antiphospholipid Syndrome Accompanied by Mixed-Type Autoimmune Hemolytic Anemia

Systemic lupus erythematosus (SLE) is an autoimmune disease that leads to a wide spectrum of clinical and immunological abnormalities. Hematologic abnormalities are an important manifestation of SLE. The incidence of autoimmune hemolytic anemia (AIHA) has been reported in approximately 10% of patients with SLE. Among them, mixed-type AIHA, which is caused by warm autoantibodies and cold hemagglutinin, is relatively rarely reported. We report the case of a 72-year-old woman, who was admitted to our hospital due to shortness of breath, jaundice, and severe anemia, with SLE and antiphospholipid syndrome (APS) complicated by mixed-type AIHA. Laboratory data revealed severe hemolytic anemia (low hemoglobin, high indirect bilirubin, and high lactate dehydrogenase levels), low complement levels, and the presence of antinuclear antibodies and lupus anticoagulant. Imaging results revealed pleural effusion and pulmonary embolisms, and echocardiogram revealed high estimated right ventricular pressure. She was diagnosed with SLE and APS complicated by mixed-type AIHA based on positive direct antiglobulin and cold agglutinin tests (thermal amplitude ≥30°C). As mixed-type AIHA is a severe and chronic condition, she was administered potent treatments with immunosuppressants. However, because she was a carrier of human T-cell leukemia virus type-1, only a moderate amount of prednisolone was administered. She refused to take warfarin. Fortunately, her symptoms and laboratory abnormalities improved after prednisolone administration, and no relapse occurred after tapering the prednisolone dose. Although mixed-type AIHA is characterized by fewer clinical symptoms than cold agglutinin disease, hemolytic anemia is more severe and chronic. Therefore, it is important to confirm the presence of cold agglutinins, which are active at ≥30°C in patients with SLE and warm AIHA. In addition, it is important to consider that AIHA is associated with thromboembolism, and patients with lupus anticoagulant or anticardiolipin antibodies having a history of AIHA are at a high risk of developing thrombosis.

Management of Mixed Warm/Cold Autoimmune Hemolytic Anemia: A Case Report and Review of Current Literature

Background

Mixed warm/cold autoimmune hemolytic anemia (AIHA) is a rare diagnostic entity with limited therapeutic options. Previous literature has described the diagnostic difficulty in this pathology and the limited response rates to corticosteroids. Furthermore, there is limited evidence regarding the use of rituximab in this condition.

Methods

Alongside our case report, we conducted a scoping review of case reports/case series describing mixed AIHA, their treatment, and clinical outcomes since 2000. Inclusion criteria included a confirmed diagnosis of mixed AIHA (confirmed warm antibodies and cold agglutinins based on DAT). Case Summary/Results. We present a case of mixed AIHA in an 83-year-old female presenting with extensive, bilateral pulmonary embolisms and left renal vein thrombosis. The patient underwent extensive workup with no identifiable provoking etiology. Initial treatment involved prednisone therapy was transitioned to rituximab upon diagnosis of mixed AIHA. The patient demonstrated a mixed response with stable hemoglobin and transfusion independence; however, with persistently elevated hemolytic indices following completion of rituximab treatment. Our literature review identified 16 articles; two were excluded for unavailable clinical details. The most commonly associated conditions included autoimmune conditions (n = 5, 26%) and lymphoproliferative disorders (n = 3, 12%). The most common treatment involved corticosteroids; seven studies involved the use of rituximab.

Conclusion

Mixed AIHA represents a complex diagnosis and optimal management is not well established. Consistent with our case, recent literature suggests a promising response to rituximab and a limited response to steroid treatment. Given the limited literature, additional studies are required to elucidate optimal management of this unique pathology.

Ultrastructural analysis of nucleated erythrocyte in patients with autoimmune hemolytic anemia (AIHA)

Autoimmune hemolytic anemia (AIHA) is a group of diseases characterized by immune-mediated lysis of mature red blood cells (RBCs). It is mainly classified into primary and secondary types based on etiology and mechanisms underlying autoantibody production. AIHA is diagnosed using morphological observation of bone marrow smears under a light microscope and monospecific direct antiglobulin test to detect hemolysis. Here, we retrospectively studied ultrastructural abnormalities of nucleated erythroid cells in bone marrows from 10 patients with AIHA using transmission electron microscopy. Our results revealed severe damage and injury to nucleated erythroid cells, including morphological irregularity, pyknosis, karyolysis, expansion of perinuclear cisternae and cytoplasmic lysis. These results indicate that aberrant immunity attacks not only mature RBCs but also nucleated erythroid cells, and ineffective hematopoiesis is partly involved in the pathogenesis of AIHA.

The choice of new treatments in autoimmune hemolytic anemia: how to pick from the basket?

Autoimmune hemolytic anemia (AIHA) is defined by increased erythrocyte turnover mediated by autoimmune mechanisms. While corticosteroids remain first-line therapy in most cases of warm-antibody AIHA, cold agglutinin disease is treated by targeting the underlying clonal B-cell proliferation or the classical complement activation pathway. Several new established or investigational drugs and treatment regimens have appeared during the last 1-2 decades, resulting in an improvement of therapy options but also raising challenges on how to select the best treatment in individual patients. In severe warm-antibody AIHA, there is evidence for the upfront addition of rituximab to prednisolone in the first line. Novel agents targeting B-cells, extravascular hemolysis, or removing IgG will offer further options in the acute and relapsed/refractory settings. In cold agglutinin disease, the development of complement inhibitors and B-cell targeting agents makes it possible to individualize therapy, based on the disease profile and patient characteristics. For most AIHAs, the optimal treatment remains to be found, and there is still a need for more evidence-based therapies. Therefore, prospective clinical trials should be encouraged.

Three different pathways of IgM-antibody-dependent hemolysis are mainly regulated by complement

Antibodies to red blood cells (RBCs) may hemolyze erythrocytes via Fc-mediated phagocytosis or complement-dependent. Complement activation on RBCs can be detected by C3d-direct antiglobulin test (DAT), which is the only test in immune hematology that directly targets complement. However, a positive DAT with anti-C3d cannot distinguish between C3b-mediated extravascular hemolysis, C5b-C9-mediated intravascular hemolysis and C5b-C8-mediated eryptosis. Furthermore, DAT is not suitable to estimate the strength of hemolysis. Autoimmune hemolytic anemia (AIHA) is a rare disease that is caused by autoantibodies to red blood cells that is divided in warm AIHA and in cold agglutinin disease (CAD). The causative antibodies in CAD and sometimes in warm AIHA are from the IgM class. Depending on strength of complement activation they can induce extravascular hemolysis, intravascular hemolysis and eryptosis. We studied the three types of hemolysis by use of sera from patients with CAD under various conditions. We found that additionally to the routinely applied C3d-DAT, indirect tests for complement activity (free hemoglobin and Annexin V-binding to phosphatidylserine-exposing RBCs) should be used to determine the portion of extravascular, intravascular and eryptotic hemolysis. Eryptotic hemolysis may have a significant share in clinical relevant CAD or IgM warm AIHA, which should be considered for successful treatment.

A Rare Association of Mixed Autoimmune Hemolytic Anemia with Gastric Carcinoma

This case report outlines a 70-year-old female patient who presented with a concurrent mixed autoimmune hemolytic anemia (AIHA) and a gastric adenocarcinoma. Her treatment course of these two diseases is summarized, which included supportive care, neoadjuvant chemotherapy for her gastric adenocarcinoma, steroids, rituximab, and surgical resection of the tumor. This approach ultimately led to the stabilization of her AIHA and primary cure for her solid malignancy. We briefly review both AIHA and gastric adenocarcinoma as clinical entities, propose working causes of hemolytic anemia including gastric adenocarcinoma, and outline a successful treatment pathway for these two concurrent conditions.

Silvernanoparticle-induced hemolysis confounded with direct antiglobulin test-negative autoimmune hemolytic anemias diagnosis

BACKGROUND

We describe here the first patient with recurrent hemolysis related to disinfectant containing silver nanoparticles (AgNps).

METHODS

A 58-year-old chemist repeatedly experienced DAT-negative (Coombs-negative) hemolysis during the last 5 years. He was treated with a number of immunosuppressive drugs including 18 times rituximab. The attempt to treat him with cyclosporine A served only to increase the rate of hemolysis. Only by chance, we revealed that the patient regularly used a hand disinfectant containing AgNps. Serological testing was performed using standard techniques. Eryptosis was measured by binding annexin to exposed phosphatidylserine (PS) of the circulating red blood cells (RBCs).

RESULTS

Antiglobulin tests remained negative, and PS exposing RBCs were detected two times during the last hemolytic episodes. Hemolysis completely disappeared following discontinuation of AgNp containing products.

CONCLUSION

AgNps are increasingly being used in a large variety of products. Recently, it was reported that they induce in vitro prohemolytic and procoagulant effects via oxidative stress and eryptosis. The clinical findings imply the hemolysis was provoked by the patient's regular use of cleansing products containing AgNps. Our finding might help to explain the etiology of hemolytical disorders that may remain obscure in many cases.

Blood group discrepancy in mixed-type autoimmune hemolytic anemia in a pediatric patient

Autoimmune hemolytic anemia (AIHA) is characterized by the presence of antibodies directed against self-antigens on red blood cells (RBCs) leading to progressive RBC destruction along with reduced red cell survival. Mixed-type AIHA is characterized by the presence of both warm and cold-autoantibodies. These autoantibodies may cause blood-group discrepancy or cross-match incompatibility leading to delay in arranging suitable blood unit for transfusion. The detection of autoantibodies by monospecific-direct antiglobulin test showing positive reaction on immunoglobulin G and C3d and presence of cold-agglutinins leads to the diagnosis. We report a rare case of mixed AIHA in a 15 years female showing severe anemia, blood group discrepancy, and cross-match incompatibility. She received transfusion of least incompatible packed RBCs without any untoward effect.

A fluorometric erythrophagocytosis assay using differentiated monocytic THP-1 cells to assess the clinical significance of antibodies to red blood cells

BACKGROUND AND OBJECTIVES

The significance of antibodies to red blood cells (RBCs) is variable and cannot be predicted solely by serological testing. A flow cytometry-based erythrophagocytosis assay was established using phorbol 12-myristate 13-acetate (PMA)-treated THP-1 cells and RBCs labelled with PKH26 to assess allo- and autoantibodies to RBCs.

MATERIALS AND METHODS

THP-1 cells were differentiated into macrophage-like cells by treatment with PMA. RBC samples coated with alloantibodies or autoantibodies were obtained from 16 patients with autoimmune haemolytic anaemia of warm type (wAIHA) as well as from five pregnant women with warm autoantibodies. RBCs from healthy blood donors were used as controls. RBCs were labelled with the red lipophilic fluorescent dye PKH26 and incubated with PMA-treated THP-1 cells. After removal of nonadherent RBCs by washing and haemolysis of adherent RBCs, erythrophagocytosis was quantified by flow cytometry.

RESULTS

We observed significant phagocytosis of RBCs coated with clinically relevant alloantibodies (i.e. anti-D and anti-K) or autoantibodies from patients with active wAIHA, but not of those coated with alloantibodies (anti-Ch) or autoantibodies from patients and pregnant women without haemolysis.

CONCLUSION

The flow cytometry-based erythrophagocytosis test described here is quantitative, highly reliable, and may be helpful for the assessment of the clinical significance of antibodies to RBCs.

Defining autoimmune hemolytic anemia: a systematic review of the terminology used for diagnosis and treatment

The terminology applied to autoimmune hemolytic anemia (AIHA) seems inconsistent. We aimed to evaluate the consistency of definitions used for diagnosis and treatment. In this systematic review of literature from January 2006 to December 2015, we assessed heterogeneity in the definition of AIHA and its subtypes, refractory disease, disease phase, severity, criteria for treatment response, and response durability. A Medline search for anemia, hemolytic, autoimmune was supplemented with keyword searches. Main exclusions were conference abstracts, animal and non-English studies, and studies with <10 cases. Of 1371 articles retrieved, 1209 were excluded based on titles and abstracts. Two authors independently reviewed 10% and 16% of abstracts and full papers, respectively. After full-paper review, 84 studies were included. AIHA was most frequently (32 [52%] of 61) defined as hemolytic anemia with positive direct antiglobulin test (DAT) and exclusion of alternatives, but 10 of 32 also recognized DAT-negative AIHA. A lower threshold for diagnosis of DAT-negative AIHA was observed in literature on chronic lymphocytic leukemia. Definitions of anemia, hemolysis, and exclusion criteria showed substantial variation. Definitions of primary/secondary cold agglutinin disease/syndrome were not consistent. Forty-three studies provided criteria for treatment response, and other than studies from 1 center, these were almost entirely unique. Other criteria were rarely defined. Only 7, 0, 3, 2, 2, and 3 studies offered definitions of warm AIHA, paroxysmal cold hemoglobinuria, mixed AIHA, AIHA severity, disease phase, and refractory AIHA, respectively. Marked heterogeneity in the time period sampled indicates the need to standardize AIHA terminology.

Rare presentation of mixed autoimmune hemolytic anemia in children: Report of 2 cases

Immune hemolytic anemia is characterized by clinical and laboratory features of hemolytic anemia with direct antiglobulin test (DAT) positivity. It could be autoimmune hemolytic anemia (AIHA), alloimmune, or drug-induced hemolysis based on the antigenic stimulus. Furthermore, based on thermal amplitude of autoantibody, AIHA is classified as warm (65%), cold (30%), and mixed (5%) type. Mixed AIHA is extremely rare in children and must be differentiated from warm AIHA with clinically insignificant cold agglutinins and cold hemagglutinin disease as their treatment is different. It may present as blood group discrepancy or cross-match incompatibility leading to delay in arranging suitable blood unit for transfusion. Therefore, a thorough immunohematology workup including monospecific DAT, indirect antiglobulin test at 4°C and 37°C, determination of thermal amplitude and titer is essential. We hereby present two pediatric cases of mixed AIHA presenting as ABO forward and reverse blood group discrepancy and cross-match incompatibility.

Case report of mixed-type autoimmune hemolytic anemia in a patient with relapsing polychondritis

RATIONALE

Relapsing polychondritis (RP) is a rare autoimmune-related disease and may be associated with other autoimmune diseases.

PATIENT CONCERNS

Here we reported a case of RP patients with mixed-type AIHA. The patient was diagnosed with RP in March 2008 which was treated and the patient was in stable condition. Laboratory data revealed progressive decrease in hemoglobin during her hospitalization due to pulmonary infection in 2016. Positive Coombs' test and moderate titer of anti-cold agglutinin was detected.

DIAGNOSIS

Mixed-type AIHA was diagnosed as a comorbidity in this case given the circumstance that her RP was stable and low-dose oral corticosteroids was enough to maintain remission.

INTERVENTIONS

The patient was treated with intravenous immunoglobulin and steroids.

OUTCOMES

The patient's body temperature dropped and hemoglobin levels rose in 2 weeks.

LESSONS

Reports of RP patients with autoimmune hemolytic anemia (AIHA) are extremely rare and cases with the mixed-type AIHA has not been reported. Here we describe a case of RP with mixed-type AIHA which was considered as a comorbidity rather than a complication.

Complement Activation and Inhibition in Autoimmune Hemolytic Anemia: Focus on Cold Agglutinin Disease

The classical complement pathway and, to some extent, the terminal pathway, are involved in the immune pathogenesis of autoimmune hemolytic anemia (AIHA). In primary cold agglutinin disease (CAD), secondary cold agglutinin syndrome and paroxysmal cold hemoglobinuria, the hemolytic process is entirely complement dependent. Complement activation also plays an important pathogenetic role in some warm-antibody AIHAs, especially when immunoglobulin M is involved. This review describes the complement-mediated hemolysis in AIHA with a major focus on CAD, in which activation of the classical pathway is essential and particularly relevant for complement-directed therapy. Several complement inhibitors are candidate therapeutic agents in CAD and other AIHAs, and some of these drugs seem very promising. The relevant in vitro findings, early clinical data and future perspectives are reviewed.

Eryptosis in autoimmune haemolytic anaemia

OBJECTIVE

Haemolysis and anaemia related to autoimmune haemolytic anaemia (AIHA) of warm type (wAIHA) and of cold type (cAIHA) are believed to be solely due to antibody and/or complement-mediated destruction and clearance of red blood cells (RBCs). There is evidence that RBCs of affected patients may also undergo eryptosis, the suicidal death of RBCs.

METHOD

RBCs from 24 patients with wAIHA, 7 patients with chronic cAIHA and one patient with AIHA of mixed type were analysed for exposed phosphatidylserine (PS) by treatment with phycoerythrin-labelled Annexin V, and cell-associated fluorescence was measured using a MACSQuant flow cytometer.

RESULTS

PS-exposing RBCs were detected in 7 of 13 patients with clinically significant wAIHA. Haemolysis was mostly related to IgM or IgA autoantibodies (aab) in those patients. In contrast, PS exposure in 11 patients with wAIHA in complete remission was comparable to that in healthy blood donors. All patients with chronic cAIHA and the patient with AIHA of mixed type showed haemolytic activity and high numbers of PS-exposing RBCs. Patients with decompensated AIHA appear to respond to treatment with erythropoietin, which is a known inhibitor of eryptosis.

CONCLUSION

Eryptosis may frequently occur in AIHA related to IgM or IgA aab. Inhibition of eryptosis with erythropoietin may represent a new therapeutic option in the treatment of AIHA.

Warm Autoimmune Hemolytic Anemia: Clinical Profile and Management

Background

Autoimmune hemolytic anemia (AIHA) is a rare autoimmune disease in which autoantibodies target red blood cells leading to marked decrease in their lifespan. The classification of AIHA is based on the immunochemical properties of the RBC autoantibody. Warm antibody AIHA (wAIHA) accounts for 75-80% of all adult AIHA cases. The treatment of wAIHA is mainly corticosteroids. Our retrospective study aimed to study the clinical profile and management of wAIHA.

Methods

Data of 75 patients admitted with wAIHA or presented to outpatient department (previous medical records) with wAIHA between January 2003 and January 2016 were analyzed.

Results

In our study, females constituted 12 and 26 patients of primary and secondary wAIHA, while males constituted 17 and 20 patients of primary and secondary wAIHA, respectively. Mean hemoglobin level at AIHA onset was found to be 7.1 ± 1.7 g/dL in primary wAIHA group and 6.3 ± 1.2 g/dL in secondary wAIHA group, which is statistically significant. Splenectomy was used as mode of treatment in one (3.4%) patient of primary wAIHA group and 15 (32.60%) patients of secondary wAIHA group, which is statistically significant. Mean age of wAIHA onset was 69.7 ± 21.5 years in wAIHA group secondary to lymphoma and 54.3 ± 25.7 years in other wAIHA group, which is statistically significant.

Conclusion

The most common causes of secondary wAIHA are B-cell lymphoma, systemic lupus erythematosus, rheumatoid arthritis, chronic lymphocytic leukemia (CLL), common variable immune deficiency, renal cell carcinoma and secondary to drug usage (alpha methyldopa and carbamazepine), respectively. Reducing the cumulative dose of corticosteroids with second line treatment whenever possible and therefore reducing the risk of sepsis, specifically in older patients with comorbidities will reduce morbidity and mortality.

Systemic lupus erythematosus presenting with mixed-type fulminant autoimmune hemolytic anemia

We report the case of a 9-year-old girl who presented with mixed-type fulminant autoimmune hemolytic anemia (AIHA) at the onset of systemic lupus erythematosus (SLE). On admission, laboratory investigations indicated very severe anemia (Hb, 2.7 g/dL) with reticulocytosis and positive direct/indirect Coombs tests. In addition, agglutinative reaction was clinically observed. Based on further examinations, the patient was diagnosed with AIHA complicated with SLE, and mixed-type AIHA was clinically identified. With oral prednisolone and methylprednisolone pulse therapy, the patient entered remission.

Evidence Suggesting Complement Activation and Haemolysis at Core Temperature in Patients with Cold Autoimmune Haemolytic Anaemia

BACKGROUND

It is unclear why haemolysis may somewhat persist in patients with cold autoimmune haemolytic anaemia (cAIHA) at 37 °C (core temperature).

METHODS

Seven patients with cAIHA were included in this study. Serological testing was performed using standard techniques. Bound autoantibodies (aab) on patients' RBCs were analysed by the direct antiglobulin test (DAT), dual antiglobulin test (DDAT) and flow cytometry (FC) using pre-warmed RBCs (37 °C). Temperature-dependent complement binding was determined by incubation of patients' serum samples with group O RBCs and fresh serum complement.

RESULTS

The DAT was strongly positive with anti-C3d in all cases, independent of season and outside temperature. Haemolysis usually improved during warm periods of time, but decompensated following febrile infections, and persisted throughout the year, though exposure to the cold was strictly avoided. In addition, trace amounts of IgM aab were infrequently detectable on patients' RBCs even at 37 °C, and complement activation was demonstrated following incubation of RBCs with the causative aab at 37 °C.

CONCLUSIONS

Binding of trace amounts of IgM aab at 37 °C may provide an explanation for the durable C3d-positive DAT and haemolysis in patients with cAIHA.

Precautions surrounding blood transfusion in autoimmune haemolytic anaemias are overestimated

BACKGROUND

It is very evident that many precautions are taken regarding transfusion of red blood cells in patients with autoimmune haemolytic anaemia. Frequently, considerable efforts are made to examine the indication and serological compatibility prior to transfusion in such patients. However, at times, this may unnecessarily jeopardize patients who urgently require a red blood cell transfusion.

MATERIALS AND METHODS

Thirty-six patients with warm-type autoimmune haemolytic anaemia were included in this study. All patients had reactive serum autoantibodies and required blood transfusion. Standard serological assays were employed for the detection and characterization of antibodies to red blood cells.

RESULTS

A positive direct antiglobulin test was observed in all 36 patients, in addition to detectable antibodies in both the eluate and serum. Significant alloantibodies were detected in the serum samples of three patients (anti-c, anti-JK(a), and anti-E). In 32 patients, red blood cell transfusion was administered with no significant haemolytic transfusion reactions due to auto- and/or allo-antibodies. Due to overestimation of positive cross-matches three patients received no transfusion or delayed transfusion and died, and one patient died due to unrecognised blood loss and anaemia which was attributed to an ineffective red blood cell transfusion.

DISCUSSION

Many of the reported recommendations regarding transfusion of red blood cells in autoimmune haemolytic anaemia are highly questionable, and positive serological cross-matches should not result in a delay or refusal of necessary blood transfusions.

The Clinical Pictures of Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia is characterized by shortened red blood cell survival and a positive Coombs test. The responsible autoantibodies may be either warm reactive or cold reactive. The rate of hemolysis and the severity of the anemia may vary from mild to severe and life-threatening. Diagnosis is made in the laboratory by the findings of anemia, reticulocytosis, a positive Coombs test, and specific serologic tests. The prognosis is generally good but renal failure and death sometimes occur, especially in cases mediated by drugs.

Harmless Pregnancy-Induced Warm Autoantibodies to Red Blood Cells

Background

There is little information concerning the development and significance of autoantibodies (aab) to red blood cells (RBCs) during pregnancy.

Methods

Unselected pregnant women were routinely screened for the presence of unexpected antibodies to RBCs using standard techniques.

Results

Between 2009 and 2013, 153,612 pregnant women were tested. The antibody screening test was positive in 1,721 women (1.12%). In 1,602 (1.04%) cases, immune and/or non-immune alloantibodies and cold-reactive aab were detected, whereas warm-reactive aab were found in 119 women (0.08%). In almost all cases, warm-reactive aab belonged to the IgG class. No evidence of the presence of significant haemolysis in affected women was observed.

Conclusion

Pregnant women may rarely develop aab to RBCs, which do not appear to cause haemolytic anaemia. Further clarification is required on the reasons behind the development of these aab and their clinical insignificance.

Variability of Findings in Drug-Induced Immune Haemolytic Anaemia: Experience over 20 Years in a Single Centre

Background

Drug-induced immune haemolytic anaemia (DIHA) is difficult to diagnose, and its true incidence remains obscure. Here, we present cases of DIHA identified at our institute over the last two decades.

Methods

Serological tests were performed according to standard procedures. Detection of drug-dependent antibodies was performed in the presence and absence of the relevant drug and/or their ex vivo antigens.

Results

Over the last 20 years, 73 patients have been identified with DIHA in our institute, which was related to 15 different drugs. The most common single drugs identified were diclofenac (n = 23), piperacillin (n = 13), ceftriaxone (n = 12) and oxaliplatin (n = 10). As far as data were available, haemolysis was acute in all patients, and signs of intravascular haemolysis were present in 90% of the cases. Haemolysis resulted in death in 17 patients (23%). The remaining patients recovered, but haemolysis was complicated by transitory renal and/or liver failure or shock in 11 patients. Upon initial evaluation, the antibody screening test was positive in 36 cases. A positive direct antiglobulin test (DAT) at least with anti-C3d was found in 65 cases, with anti-IgG only in 6 cases, and with anti-IgA only in 1 case.

Conclusion

DIHA is a rare but potentially life-threatening disorder that should be considered if a patient develops haemolysis under drug treatment. The main serological finding is a positive DAT, primarily with anti-C3d.

Red blood cell destruction in autoimmune hemolytic anemia: role of complement and potential new targets for therapy

Autoimmune hemolytic anemia (AIHA) is a collective term for several diseases characterized by autoantibody-initiated destruction of red blood cells (RBCs). Exact subclassification is essential. We provide a review of the respective types of AIHA with emphasis on mechanisms of RBC destruction, focusing in particular on complement involvement. Complement activation plays a definitive but limited role in warm-antibody AIHA (w-AIHA), whereas primary cold agglutinin disease (CAD), secondary cold agglutinin syndrome (CAS), and paroxysmal cold hemoglobinuria (PCH) are entirely complement-dependent disorders. The details of complement involvement differ among these subtypes. The theoretical background for therapeutic complement inhibition in selected patients is very strong in CAD, CAS, and PCH but more limited in w-AIHA. The optimal target complement component for inhibition is assumed to be important and highly dependent on the type of AIHA. Complement modulation is currently not an evidence-based therapy modality in any AIHA, but a number of experimental and preclinical studies are in progress and a few clinical observations have been reported. Clinical studies of new complement inhibitors are probably not far ahead.

The effect of erythropoiesis-stimulating agents in patients with therapy-refractory autoimmune hemolytic anemia

BACKGROUND

Many patients with autoimmune hemolytic anemia (AIHA) do not respond to standard therapy and/or may develop severe complications which can be of fatal outcome. There is some evidence that erythropoiesis-stimulating agents (ESAs) may be helpful in the management of such patients.

METHODS

We describe the effect of ESAs in 12 new patients with therapy-refractory AIHA (7 of warm type and 5 of cold type) and review 5 previously reported cases. Serological testing was performed using standard methods.

RESULTS

All patients responded well to treatment with ESAs. At least 5 of the 17 patients demonstrated complete recovery, and none of the patients developed significant adverse reactions due to treatment with ESAs.

CONCLUSION

The mechanism by which ESAs improves hemolysis in AIHA is not completely clear. In addition to increased production and prolonged RBC survival, it may inhibit eryptosis (programmed cell death). ESAs represent a new option in the treatment of decompensated and/or refractory AIHA of warm and cold type. However, more information is required to assess which patients can be treated with ESAs.

Lethal autoimmune hemagglutination due to an immunoglobulin A autoagglutinin with Band 3 specificity

BACKGROUND

We describe a patient with a high-titer warm immunoglobulin (Ig)A autoantibody resulting in death due to hemagglutination rather than to hemolysis.

CASE REPORT

A 47-year-old male patient presented with an intriguing pronounced vascular erythema of the skin. A livedo reticularis associated with cold agglutinin of high thermal amplitude was suspected. The patient's condition unexpectedly and abruptly deteriorated resulting in death 3 days after admission.

STUDY DESIGN AND METHODS

Conventional serologic procedures and immunochemical methods were used.

RESULTS

Serologic and immunochemical examinations revealed a warm IgA autoantibody of high titer with anti-Band 3 specificity. Although the patient presented with severe anemia, only mild signs of hemolysis were observed, with no evidence of complement activation. The autopsy revealed an enormous accumulation of agglutinated red blood cells in liver and spleen and a B-cell lymphoma and cerebral edema. Thus, the patient's death was largely caused by hypoxia related to hemagglutination rather than to hemolysis and/or anemia per se.

CONCLUSION

Strongly hemagglutinating antibodies may not only cause immune hemolysis but also hypoxia due to intravascular hemagglutination.

Autoimmune hemolytic anemia: mixed type-a case report

Mixed autoimmune haemolytic anemia (AIHA) is defined by the presence of both warm and cold auto antibodies. Diagnosis is based on detection of autoantibodies by monospecific direct antiglobulin test showing a pattern of IgG and complement C3d and presence of cold agglutinins. We report a rare case of primary mixed AIHA in a 12 year old girl who responded to corticosteroids.

[Autoimmune thrombocytopenia, neutropenia and hemolysis]

Autoantibodies reduce the life span of platelets, granulocytes, and red blood cells. This may result in thrombocytopenia with bleeding, in neutropenia with infection, and in anemia, respectively. Immune-hemocytopenias can manifest as primary disease without another cause, or they are associated with other underlying morbidities such as autoimmune diseases, lymphoproliferative diseases, immune defects, or viral infections. Diagnosis is confirmed by laboratory tests showing autoantibodies against the respective blood cells. Indication for treatment is the clinical manifestation of symptoms: bleeding in autoimmune thrombocytopenia, infections in neutropenia, and symptomatic anemia, respectively. Especially in case of thrombocytopenia patients should not be treated because of abnormal laboratory values, only. To date steroids are the basic treatment in autoimmune thrombocytopenia and hemolytic anemia, while prophylactic antibiotics are the main treatment in autoimmune neutropenia. Growth factors like the new thrombopoietin receptor agnonists in autoimmune thrombocytopenia or G-CSF in autoimmune neutropenia, and anti-CD20 antibodies are new options for treatment.