Immune hemolytic anemia--selected topics

Thromboembolism Early After Glucocorticoid Administration in Patients with Autoimmune Hemolytic Anemia

Pulmonary embolism and deep venous thrombosis (PE/DVT) are well-known lethal complications in autoimmune hemolytic anemia (AIHA). However, the impact of their treatment is unclear. Here, we describe three elderly Japanese patients with AIHA who developed PE/DVT early after glucocorticoid administration. All patients presented with active hemolysis and high D-dimer levels upon admission. Thromboembolism was confirmed within 2 weeks after starting glucocorticoid, suggesting that both active hemolysis and glucocorticoid administration synergistically contributed to the development of PE/DVT. Clinicians should consider that such synergism may increase the risk of thromboembolism in patients with AIHA, and prophylactic anticoagulation is worth considering in patients after starting glucocorticoid.

Severe hemolysis with negative direct antiglobulin test: A case report

A 49-year-old woman with type 2 diabetes mellitus (T2DM) presented to the emergency department. Her examination showed marked pallor, exhaustion, lethargy, yellowish eyes, anorexia, nausea and vomiting.

Hematuria; negative standard direct antiglobulin test (DAT); normal glucose 6 phosphate dehydrogenase (G6PD); hemoglobin (Hb), 4.8 g/dl; Mean cell volume (MCV), 91fl; platelet count, 233 × 10⁶/L; Total bilirubin, 7.0 mg/dl; Glucose, 316 mg/dl; lactate dehydrogenase (LDH), 1750U/L. Undoubtedly, therapeutic panel should have been used for hemolytic anemia. Intravenous (IV) fluids and 2 units of packed cell were transfused. Methylprednisolone with rituximab were started for the patient. After 3 weeks of the patient admission, she was discharged home with stable vital signs and Hb, 10 g/dl. We concluded in the cases that presented along with a severe drop in Hb and evidence of hemolysis which non immune hemolytic anemia is excluded in spite of negative standard DAT limited transfusion besides corticosteroids combined with rituximab, could be helpful in saving the patient.

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Autoimmune hemolytic anemia (AIHA) is caused by increased erythrocyte destruction with autoantibodies directed against the person's own red blood cells and susceptible them to lyse and consequent insufficient number of red blood cells in the circulation.

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A diagnosis of DAT-negative AIHA can be made following careful exclusion of alternative causes of hemolysis, and confirmation by a sensitive technique and by a response to steroid therapy.

Thromboembolic complications in autoimmune hemolytic anemia: Retrospective study

Introduction

A small number of retrospective studies suggest AIHA to be associated with an increased risk to suffer from thromboembolic events. However, based on these studies it remains unclear whether the complement activation per is a risk factor to develop thromboembolic events in AIHA patients. The aim of this retrospective study is to investigate the incidence of thromboembolic events and the relation to complement activation in a cohort of AIHA patients.

Patients and Methods

We included 77 patients in this study with a positive DAT and hemolytic parameters or with AIHA diagnosis based on the medical report. The included patients were screened for thromboembolic events (TEE) and have been stratified in groups with and without complement activation based on the positivity for complement in the DAT.

Results

Of the 77 included patients, 51 (66%) had warm AIHA, 13 (17%) cold‐AIHA, 5 (7%) mixed AIHA, and 8 (10%) atypical AIHA, respectively. Primary and secondary AIHA was diagnosed in 44% and 56%, respectively. Twenty patients (26%) suffered from TEE. The majority (80%) of these patients suffered from warm AIHA and 10% from cold‐AIHA. Hemolysis parameters did not differ in patients with and without TEE. There was no correlation with complement activation as evidenced by a positivity for complement in the monospecific DAT with the occurrence of TEE.

Conclusion

AIHA is associated with an increased risk of TEE. Based on these results prophylactic anticoagulation might be considered as soon as the diagnosis of AIHA is confirmed.

Complement and the prothrombotic state

In 2007 and 2009 the regulatory approval of the first-in-class complement inhibitor Eculizumab has revolutionized the clinical management of two rare, life-threatening clinical conditions: paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS). While being completely distinct diseases affecting blood cells and the glomerulus, PNH and aHUS remarkably share several features in their etiology and clinical presentation. An imbalance between complement activation and regulation at host surfaces underlies both diseases precipitating in severe thrombotic events that are largely resistant to anti-coagulant and/or anti-platelet therapies. Inhibition of the common terminal complement pathway by Eculizumab prevents the frequently occurring thrombotic events responsible for the high mortality and morbidity observed in patients not treated with anti-complement therapy. While many in vitro and ex vivo studies elaborate numerous different molecular interactions between complement activation products and hemostasis, this review focuses on the clinical evidence that links these two fields in humans. Several non-infectious conditions with known complement involvement are scrutinized for common patterns concerning a prothrombotic statues and the occurrence of certain complement activation levels. Next to PNH and aHUS, germline encoded CD59 or CD55 deficiency (the latter causing the disease Complement Hyperactivation, Angiopathic thrombosis, and Protein-Losing Enteropathy; CHAPLE), autoimmune hemolytic anemia (AIHA), (catastrophic) anti-phospholipid syndrome (APS, CAPS) and C3 glomerulopathy are considered. Parallels and distinct features among these conditions are discussed against the background of thrombosis, complement activation, and potential complement diagnostic and therapeutic avenues.

Recurrent infection-induced autoimmune haemolytic anaemia complicated by pulmonary embolism: a case report and literature review

A 73-year-old woman presented with progressive dyspnoea up to type 1 respiratory failure. Laboratory values showed leucocytosis, reduced haemoglobin to 71 g/L, elevated indirect serum bilirubin and lactic dehydrogenase. Computed tomography pulmonary angiography (CTPA) revealed peripheral pulmonary embolism (PE). Echocardiography showed enlarged right ventricle, elevated estimated pulmonary arterial systolic pressure (57.2 mmHg) and normal left ventricular ejection fraction. The patient was diagnosed with autoimmune haemolytic anaemia (AIHA), which was induced by recurrent infections without standard treatment in the past year. AIHA is the cause of PE due to the absence of common predisposing factors and other thrombophilia. The patient became better after administration of glucocorticoids, intravenous immunoglobulin and rivaroxaban.

[Autoimmune hemolytic anemia: Case review]

INTRODUCTION

Autoimmune hemolytic anemia (AIHA) is a rare and generally self-limiting disease in children.

MATERIAL AND METHODS

A descriptive cross-sectional study was performed in children under 18 years diagnosed with AIHA from January/1997 to July/2019. Clinical variables were collected and AIHA was classified according to the direct antiglobulin test (DAT) in warm AIHA (IgG+/-C3d) and cold AIHA (C3d). Response to treatment and evolution were analyzed.

RESULTS

25 patients were included and 72% were males. The median age at diagnosis was 2 years (range 0.4 to 9). Fever (72%), pallor (68%), jaundice (64%), hepatosplenomegaly and coluria (48%) were the most common presenting symptoms. The median hemoglobin at diagnosis was 5.4 g/dl. DAT was positive in 96%, with detection of IgG antibodies in 76%. A single case presented negative DAT. 20% of the patients associated another cytopenia, one of which was subsequently diagnosed with common variable immunodeficiency. Concomitant viral infection was suspected or documented in 32%. Most of the cases were self-limiting and responded to corticosteroid treatment (72%). Those with partial response (24%), mainly those associated with other cytopenias, required other lines of treatment (rituximab, mycophenolate, immunoglobulins). Complications (32%) and relapses (26%) were detected only in warm AIHA.

CONCLUSIONS

Our case series confirms that AIHA is a very rare disease in childhood. Most cases evolve favorably, although up to a quarter of them require second lines of treatment and, in exceptional cases, they need very aggressive treatments. These latter cases generally correspond to patients who present more than one cytopenia in the course of the disease.

Passenger Lymphocyte Syndrome; a Review of the Diagnosis, Treatment, and Proposed Detection Protocol

Passenger lymphocyte syndrome (PLS) is caused by the transfer of B-lymphocytes present in the donor graft into the recipient circulation following solid organ or hematopoietic stem cell transplantation. These cells may produce antibodies against the recipient's red blood cells, thereby triggering antibody dependent cytotoxicity and erythroid clearance, with potential resulting hemolysis and jaundice. Although uncommon, the true incidence is unknown because many cases are subclinical, with only serologic findings or with non significant levels of hemolysis detectable clinically or by laboratory monitoring. Thus, these cases may not be detected in the immediate perioperative period. No standardized consensus exists on screening for PLS in patients. Through a review of the literature from 2009 to 2019, we aim to approximate the incidence of this condition in different solid organ transplant settings, as well as to streamline recognition, detection, and management of PLS early in the disease course to prevent adverse outcomes and minimize invasive therapy. The resultant literature review yielded 22 case reports and 8 case series comprising 71 solid organ transplant patients. Hematopoietic stem cell transplant cases were excluded, as PLS cases related to solid organ transplant were the primary focus of this review. Our institution has traditionally handled PLS on a case-by-case basis, although we hope to improve this process through an introduction of an algorithm based on review of the literature and formalized communication with primary caregivers.

Tolerization of recent thymic emigrants is required to prevent RBC-specific autoimmunity

Autoimmune hemolytic anemia (AIHA) leads to accelerated destruction of autologous red blood cells (RBCs) by autoantibodies. AIHA is a severe and sometimes fatal disease. While there are several therapeutic strategies available, there are currently no licensed treatments for AIHA and few therapeutics result in treatment-free durable remission. The etiology of primary AIHA is unknown; however, secondary AIHA occurs concurrently with lymphoproliferative disorders and infections. Additionally, AIHA is the second most common manifestation of primary immunodeficiency disorders and has been described as a side effect of checkpoint inhibitor therapy. Given the severity of AIHA and the lack of treatment options, understanding the initiation of autoimmunity is imperative. Herein, we utilized a well-described model of RBC biology to dissect how RBC-specific autoreactive T cells become educated against RBC autoantigens. We show that, unlike most autoantigens, T cells do not encounter RBC autoantigens in the thymus. Instead, when they leave the thymus as recent thymic emigrants (RTEs), they retain the ability to positively respond to RBC autoantigens; only after several weeks in circulation do RTEs become nonresponsive. Together, these data suggest that any disruption in this process would lead to breakdown of tolerance and initiation of autoimmunity. Thus, RTEs and this developmental process are potential targets to prevent and treat AIHA.

Passenger Lymphocyte Syndrome After Pediatric Liver Transplantation

BACKGROUND

Passenger lymphocyte syndrome (PLS) is a less known etiology of acute onset anemia following ABO-compatible (ABO-c) liver transplantation (LT). Available literature on PLS after pediatric LT is limited. Therefore, we evaluated the prevalence, clinical course, and risk factors of PLS in children following ABO-c LT.

METHODS

A single-center retrospective review of all children who underwent LT between 2000 and 2017 was performed. PLS was defined as a drop-in hemoglobin >20 g/L within 30 days of LT, with positive direct antiglobulin test and 1 laboratory test confirming hemolysis. Chi square and student t tests compared variables between subjects with and without PLS.

RESULTS

Amongst 333 pediatric LT performed, 51 children received an ABO-c graft. PLS was diagnosed in 7 (14%) subjects at a median of 10 days after LT. There were no significant differences in patient demographics, graft type, or immunosuppression between those who did and did not develop PLS. Recipient blood group A+ receiving a donor O+ graft was a risk factor for PLS (P = 0.015). All PLS subjects recovered with blood transfusions (median 2), and no additional interventions. Three subjects initially received recipient (instead of donor) blood group red cells.

CONCLUSIONS

We report a 14% prevalence of PLS following pediatric ABO-c LT. Recipient blood group A+ receiving a donor O+ graft is a risk factor for PLS. Recognition of PLS as a cause of early acute anemia in pediatric ABO-c LT enables timely transfusion with donor (rather than recipient) blood group red cells.

Indwelling Pleural Catheters for Patients with Hematologic Malignancies. A 14-Year, Single-Center Experience

RATIONALE

Placement of an indwelling pleural catheter is an established modality for symptom relief and pleurodesis in the treatment of malignant pleural effusion. Concerns remain regarding possible infectious complications, risk of hemorrhage, and the rate of pleurodesis with the use of pleural catheters in the treatment of hematologic malignancies.

OBJECTIVES

The goals of our study were: (1) to evaluate the safety and cumulative incidence of pleurodesis with indwelling pleural catheters for patients with hematologic malignancies, and (2) to evaluate overall survival of this cohort of patients with pleural effusions.

METHODS

We performed a retrospective review of 172 patients with a hematologic malignancy who underwent placement of an indwelling pleural catheter between September 1997 and August 2011 at the University of Texas MD Anderson Cancer Center in Houston, Texas. A competing risk model analysis was used for complications and pleurodesis. Analysis was based on each patient's first intrapleural catheter.

RESULTS

There were 172 patients with lymphoma (58%), acute (16%) or chronic leukemia (16%), or multiple myeloma (10%). The effusions were characterized as malignant (85.5%), infectious (4.1%), volume overload (4.7%), or therapy-related (4.7%). Chylothorax was found in 20.1%. Pleural biopsies were obtained from 13 patients. The cumulative incidence of all complications was 13.6%, and the cumulative incidence of all significant catheter-related complications was 9.5%. The incidence of empyema was 2.9%, and major bleeding (requiring transfusion or intervention) was 1.7%. Thirty-day procedure-associated mortality was 0.6%. The cumulative incidence of pleurodesis at 180 days was 50%, with a median time to pleurodesis of 81 days for the entire cohort.

CONCLUSIONS

Indwelling pleural catheters appear to be safe for patients with hematologic malignancies. Complications and the cumulative incidence of pleurodesis are comparable to those reported for patients with solid organ malignancies.

Innate B-1 B Cells Are Not Enriched in Red Blood Cell Autoimmune Mice: Importance of B Cell Receptor Transgenic Selection

Autoimmune hemolytic anemia (AIHA) results from breakdown of humoral tolerance to RBC antigens. Past analyses of B-cell receptor transgenic (BCR-Tg) mice that recognize RBC autoantigens led to a paradigm in which autoreactive conventional B-2 B cells are deleted whereas extramedullary B-1 B cells escape deletion due to lack of exposure to RBCs. However, BCR-Tg mice utilized to shape the current paradigm were unable to undergo receptor editing or class-switching. Given the importance of receptor editing as mechanism to tolerize autoreactive B cells during central tolerance, we hypothesized that expansion of autoreactive B-1 B cells is a consequence of the inability of the autoreactive BCR to receptor edit. To test this hypothesis, we crossed two separate strains of BCR-Tg mice with transgenic mice expressing the BCR target on RBCs. Both BCR-Tg mice express the same immunoglobulin and, thus, secrete antibodies with identical specificity, but one strain (SwHEL) has normal receptor editing, whereas the other (IgHEL) does not. Similar to other AIHA models, the autoreactive IgHEL strain showed decreased B-2 B cells, an enrichment of B-1 B cells, and detectable anti-RBC autoantibodies and decreased RBC hematocrit and hemoglobin values. However, autoreactive SwHEL mice had induction of tolerance in both B-2 and B-1 B cells with anti-RBC autoantibody production without anemia. These data generate new understanding and challenge the existing paradigm of B cell tolerance to RBC autoantigens. Furthermore, these findings demonstrate that immune responses vary when BCR-Tg do not retain BCR editing and class-switching functions.

Autoimmune hemolytic anemia in solid organ transplantation-The role of immunosuppression

Hemolysis after solid organ transplantation can be caused by both immune and non-immune-mediated mechanisms, and the evaluation must take into account issues distinctive to the post-transplant period. Autoimmune hemolytic anemia usually occurs within the first year and has been attributed to immunosuppressive treatment, infections, or underlying post-transplant lymphoproliferative disorder. Review of the literature revealed 59 cases with autoimmune hemolytic anemia mostly in children after liver transplantation. Almost all of the patients at the time of diagnosis received immunosuppression with tacrolimus, and first-line treatment with steroids and/or intravenous immunoglobulin was ineffective for complete remission. Rituximab was used as second-line treatment especially in patients with underlying lymphoproliferative disorders whereas sirolimus showed encouraging results.

Unusual underlying disorder for pulmonary embolism: Cold agglutinin disease

Cold agglutinin disease (CAD) is a form of autoimmune hemolytic anemia caused by cold-reacting autoantibodies. The manifestations of CAD are commonly anemia, acrocyanosis, and fatigue caused by hemolysis and agglutination of red blood cells (RBCs) at a temperature lower than normal body temperature. We report a case of CAD presenting with pulmonary embolisms in an 86-year-old man. The patient visited our emergency department complaining of acute chest pain and respiratory distress. Laboratory data showed decreased RBC and hematocrit and markedly elevated mean corpuscular hemoglobin (MCH) and MCH concentration (MCHC). A contrast-enhanced computed tomographic scan demonstrated bilateral massive pulmonary embolisms. After admission, diagnosis of CAD was made on the basis of a high cold agglutinin titer without other factors of coagulation. CAD can contribute to the onset of pulmonary embolisms. It is necessary to incubate blood samples at 37 °C when laboratory data show markedly elevated MCH and MCHC and to consider the presence of cold agglutinins as an underlying disorder for the formation of venous thrombosis. <Learning objective: Cold agglutinin disease can contribute to the onset of pulmonary embolisms. It is necessary to incubate blood samples at 37 °C when laboratory data showed markedly elevated mean corpuscular hemoglobin (MCH) and MCH concentration (MCHC) and to consider the presence of cold agglutinins as an underlying disorder for the formation of venous thrombosis. Complete blood count including MCH and MCHC is always ordered, but we may have overlooked the meaning of abnormal results. We must be aware of these parameters and carefully examine the underlying mechanisms of thrombosis.>.

Clinical characteristics and treatment outcomes of primary autoimmune hemolytic anemia: a single center study from South India

Background

Autoimmune hemolytic anemia (AIHA) is a less recognized, potentially fatal condition. There is a scarcity of data on clinicoserological characteristics and response to therapy concerning this disease from South India.

Methods

Data for 33 patients with primary AIHA recorded from July 2009 to June 2015 were retrospectively analyzed for clinical presentation, response to frontline therapy, durability of response, time to next treatment (TTNT), and response to second-line agents.

Results

The median follow-up period was 50 months. Among 33 patients, 48% of the cases were warm autoimmune hemolytic anemia (WAIHA), 46% were cold agglutinin disease (CAD), and 6% were atypical. Three-fourth of patients had severe anemia (<8 g/dL hemoglobin [Hb]) at onset; younger patients (age <40 yr) had more severe anemia. All of the patients who required treatment received oral prednisolone at 1.5 mg/kg/d as a frontline therapy, and the response rate was 90% (62% complete response [CR] and 28% partial response [PR]). The overall response to corticosteroids in WAIHA and CAD was 87% and 92%, respectively. The median corticosteroid duration was 14 months, and 50% of the patients required second-line agents. Fourteen patients received azathioprine as a second-line agent, and 11 of these patients responded well, with half of them not requiring a third agent. Four patients developed severe infections (pneumonia, sepsis, and soft tissue abscess) and two had life-threatening venous thrombosis. One case of death was recorded.

Conclusion

AIHA is a heterogeneous disease that requires care by physicians experienced in treating these patients.

New Insights in the Pathogenesis of Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia (AIHA) is caused by the increased destruction of red blood cells (RBCs) by anti-RBC autoantibodies with or without complement activation. RBC destruction may occur both by a direct lysis through the sequential activation of the final components of the complement cascade (membrane attack complex), or by antibody-dependent cell-mediated cytotoxicity (ADCC). The pathogenic role of autoantibodies depends on their class (the most frequent are IgG and IgM), subclass, thermal amplitude (warm and cold forms),as well as affinity and efficiency in activating complement. Several cytokines and cytotoxic mechanisms (CD8+ T and natural killer cells) are further involved in RBC destruction. Moreover, activated macrophages carrying Fc receptors may recognize and phagocyte erythrocytes opsonized by autoantibodies and complement. Direct complement-mediated lysis takes place mainly in the circulations and liver, whereas ADCC, cytotoxicity, and phagocytosis occur preferentially in the spleen and lymphoid organs. The degree of intravascular hemolysis is 10-fold greater than extravascular one. Finally, the efficacy of the erythroblastic compensatory response can greatly influence the clinical picture of AIHA. The interplay and relative burden of all these pathogenic mechanisms give reason for the great clinical heterogeneity of AIHAs, from fully compensated to rapidly evolving fatal cases.

Autoimmune haemolytic anaemia associated with Epstein Barr virus infection as a severe late complication after kidney transplantation and successful treatment with rituximab: case report

BACKGROUND

Autoimmune haemolytic anaemia (AIHA) is a rare complication following kidney transplantation and usually occurs early in its course. It is characterised by autoantibodies or alloantibodies directed against red blood cells (RBCs).

CASE PRESENTATION

We describe a 44 year old woman who presented 5 years after kidney transplantation with profound transfusion dependent warm AIHA. Investigations confirmed an IgG autoantibody against RBCs and high titre Epstein-Barr virus (EBV) viraemia. The patient was at higher risk for EBV disease being seronegative at the time of transplantation but had detectable EBV capsid IgG antibody at the time of presentation. The haemolysis was refractory to high dose steroid and intravenous immunoglobulin. There was a rapid and complete resolution of both the anaemia and the viraemia following rituximab therapy, with no adverse events. Twenty-six units of blood were required during the course of treatment.

CONCLUSIONS

To our knowledge this is the first reported case of EBV associated AIHA in a renal transplant recipient. It highlights a rare pathology associated with post-transplant EBV infection, of broad interest to transplant physicians, haematologists, and microbiologists, and the effective novel use of monoclonal anti-CD20 therapy.

Risk of venous thromboembolism among hospitalizations of adults with selected autoimmune diseases

Previous research has suggested autoimmune diseases are risk factors for developing venous thromboembolism (VTE). We assessed whether having diagnoses of selected autoimmune diseases associated with antiphospholipid antibodies--autoimmune hemolytic anemia (AIHA), immune thrombocytopenic purpura (ITP), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE)--were associated with having a VTE diagnosis among US adult hospitalizations. A cross-sectional study was conducted using the 2010 Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality. VTE and autoimmune diseases were identified using International Classification of Diseases, Ninth Revision, Clinical Modification coded diagnoses information. The percentages of hospitalizations with a VTE diagnosis among all non-maternal adult hospitalizations without any of the four autoimmune diseases of interest and among those with AIHA, ITP, RA, and SLE diagnoses were 2.28, 4.46, 3.35, 2.65 and 2.77%, respectively. The adjusted odds ratios (OR) for having a diagnosis of VTE among non-maternal adult hospitalizations with diagnoses of AIHA, ITP, RA, and SLE were 1.25 [95% confidence interval (CI) 1.05-1.49], 1.20 (95% CI 1.07-1.34), 1.17 (95% CI 1.13-1.21), and 1.23 (95% CI 1.15-1.32), respectively, when compared to those without the corresponding conditions. The adjusted OR for a diagnosis of VTE associated with a diagnosis of any of the four autoimmune diseases was 1.20 (95% CI 1.16-1.24). The presence of a diagnosis of AIHA, ITP, RA, and SLE was associated with an increased likelihood of having a VTE diagnosis among the group of all non-maternal adult hospitalizations.

Passenger lymphocyte syndrome in liver transplant recipients: a description of 12 cases

BACKGROUND

Passenger lymphocyte syndrome is an important cause of immune haemolysis after solid organ transplantation. It mainly occurs in minor ABO and Rh mismatched transplants. The haemolysis is usually mild and self-limited. We present our experience in passenger lymphocyte syndrome and liver transplantation and review the literature.

MATERIALS AND METHODS

We reviewed liver transplants performed in our centre from January 2002 to September 2013, searching for ABO or Rh incompatibility and serological findings of haemolysis. A direct antiglobulin test was systematically performed in each pre-transfusion assessment.

RESULTS

A total of 1,217 liver transplants were performed and 12 passenger lymphocyte syndromes were detected: of the 56 cases with minor ABO incompatibility, ten patients developed passenger lymphocyte syndrome (17.9%) and of 147 cases with minor Rh incompatibility, two patients developed the syndrome (1.40%). All patients with passenger lymphocyte syndrome had haemolysis, a decrease of haemoglobin (median 6.8 g/dL) and an increase of bilirubin (median 5.15 mg/dL). The treatment of passenger lymphocyte syndrome consisted of increasing the dose of corticosteroids that the patients were receiving as post-transplantation immunosuppressive therapy and, in the majority of cases, transfusion of donor compatible red blood cells.

DISCUSSION

Passenger lymphocyte syndrome in liver transplantation has significant clinical consequences. It is, therefore, important to make the diagnosis rapidly, performing pre-transfusion direct antiglobulin tests, and manage the problem correctly with donor compatible red blood cell transfusions and/or immunosuppressive treatment.

Passenger lymphocyte syndrome in ABO and Rhesus D minor mismatched liver and kidney transplantation: A prospective analysis

The increasing demand for solid organs has necessitated the use of ABO and Rhesus (Rh) D minor mismatched transplants. The passenger lymphocyte syndrome (PLS) occurs when donor lymphocytes produce antibodies that react with host red blood cell (RBC) antigens and result in hemolysis. Our aim was to evaluate prospectively the role of PLS in post transplant anemia and hemolysis in ABO and RhD minor mismatched recipients of liver and kidney grafts and to study the association of PLS with donor lymphocyte microchimerism. We examined 11 liver and 10 kidney recipients at Day +15 for anemia, markers of hemolysis, direct antiglobulin test and eluates, and serum RBC antibodies. Microchimerism was determined in peripheral blood lymphocytes by genotyping of simple sequence length polymorphisms encoding short tandem repeats. Immune hemolytic anemia and anti-recipient RBC antibodies were observed in 2 out of 11 liver (18.2%) and 2 out of 10 kidney (20%) transplants. RBC antibody specificity reflected the donor to recipient transplant, with anti-blood group B antibodies identified in 2 cases of O to B and 1 case of A to AB transplants while anti-D antibodies were detected in 1 case of RhD-negative to RhD-positive transplant. Donor microchimerism was found in only 1 patient. In conclusion, passenger lymphocyte mediated hemolysis is frequent in minor mismatched liver and kidney transplantation. Recognizing PLS as a potential cause of post transplant anemia may allow for early diagnosis and management to decrease the morbidity and mortality in some patients.

Autoimmune haemolytic anaemia: a review and report of four cases

Treatment of autoimmune haemolytic anaemia is still a challenge to clinicians. Even today it may be lethal. Half of the cases are secondary due to an underlying disease, and the others are primary or idiopathic cases. According to the specificity and type of autoantibodies there are warm and cold type forms of autoimmune haemolytic anaemia. The hallmark of the diagnosis is to detect the presence of haemolysis by clinical and laboratory signs and detect the underlying autoantibodies. Treatment of autoimmune haemolytic anaemia is still a challenge to clinicians. We still loose patients due to excessive haemolysis or severe infections caused by immunosuppression. First line treatment is corticosteroids. Other immunosuppressive agents like: cyclophosphamide, azathioprine, cyclosporine or the off label rituximab can be used in case of corticosteroid refractoriness. Splenectomy is a considerable option in selective cases. The authors discuss treatment options and highlight difficulties by presenting 4 cases. Orv. Hetil., 2015, 156(11), 449–456.

Treatment and outcomes of immune cytopenias following solid organ transplant in children

BACKGROUND

Immune cytopenias are a recognized life-threatening complication following pediatric solid organ transplants (SOT), but treatment responses and overall outcome are not well described. The aim of this study was to evaluate the demographic characteristics, response to treatments, and outcomes of a cohort of patients who developed immune cytopenias following SOT.

PROCEDURE

In this single center retrospective review, patients with immune cytopenias after SOT were identified by electronic medical record (EMR) search and transplant databases from 1995-2012.

RESULTS

Of 764 SOT patients, 19 (2.4%) developed immune cytopenias. Incidence varied widely by transplant type from 1.2% (renal) to 23.5% (multivisceral). Autoimmune hemolytic anemia (AIHA) was the most common immune cytopenia. Overall median time from transplant to immune cytopenia was 8 m and varied by transplant type from 3 m (liver) to 74 m (heart). Standard therapies for immune cytopenias were often used and ineffective. The most effective therapy for the immune cytopenia was changing immunosuppression from tacrolimus to another agent. Three of 19 patients died; none directly attributed to the immune cytopenia.

CONCLUSIONS

Immune cytopenias are not rare after SOT, and patients usually do not respond well to traditional first line therapies. Provided that the risk of organ rejection is otherwise manageable, temporary cessation of tacrolimus could be more widely explored in this challenging clinical context. Pediatr Blood Cancer 2015;62:214-218. © 2014 Wiley Periodicals, Inc.

Clinical heterogeneity and predictors of outcome in primary autoimmune hemolytic anemia: a GIMEMA study of 308 patients

The clinical outcome, response to treatment, and occurrence of acute complications were retrospectively investigated in 308 primary autoimmune hemolytic anemia (AIHA) cases and correlated with serological characteristics and severity of anemia at onset. Patients had been followed up for a median of 33 months (range 12-372); 60% were warm AIHA, 27% cold hemagglutinin disease, 8% mixed, and 5% atypical (mostly direct antiglobulin test negative). The latter 2 categories more frequently showed a severe onset (hemoglobin [Hb] levels ≤6 g/dL) along with reticulocytopenia. The majority of warm AIHA patients received first-line steroid therapy only, whereas patients with mixed and atypical forms were more frequently treated with 2 or more therapy lines, including splenectomy, immunosuppressants, and rituximab. The cumulative incidence of relapse was increased in more severe cases (hazard ratio 3.08; 95% confidence interval, 1.44-6.57 for Hb ≤6 g/dL; P < .001). Thrombotic events were associated with Hb levels ≤6 g/dL at onset, intravascular hemolysis, and previous splenectomy. Predictors of a fatal outcome were severe infections, particularly in splenectomized cases, acute renal failure, Evans syndrome, and multitreatment (4 or more lines). The identification of severe and potentially fatal AIHA in a largely heterogeneous disease requires particular experienced attention by clinicians.

Ibuprofen-induced hemolytic anemia

Drug-induced immune hemolytic anemia is a rare condition with an incidence of 1 per million of the population. We report the case of a 36-year-old female who presented to the emergency department complaining of shortness of breath and dark colored urine. Physical examination was significant for pale mucous membranes. The patient reported using ibuprofen for a few days prior to presentation. Complete blood count performed before starting ibuprofen revealed normal platelets and hemoglobin values. On admission, the patient had evidence of hemolytic anemia with hemoglobin of 4.9 g/dL, hematocrit of 14.2%, lactate dehydrogenase 435 IU/L, and reticulocytosis 23.2%. Further testing ruled out autoimmune disease, lymphoma, and leukemia as etiologies for the patient's new onset hemolytic anemia. Ibuprofen was immediately stopped with a gradual hematologic recovery within 3 days.

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.

Partial tolerance of autoreactive B and T cells to erythrocyte-specific self-antigens in mice

BACKGROUND

Breakdown of humoral tolerance to RBC antigens may lead to autoimmune hemolytic anemia, a severe and sometimes fatal disease. The underlying mechanisms behind the breakdown of humoral tolerance to RBC antigens are poorly understood.

DESIGN AND METHODS

In order to study the pathogenesis of autoimmune hemolytic anemia, we developed a murine model with RBC-specific expression of a model antigen carrying epitopes from hen egg lysozyme and ovalbumin.

RESULTS

Humoral tolerance was observed; this was not broken even by strong immunogenic stimulation (lysozyme or ovalbumin with adjuvant). Autoreactive CD4(+) T cells were detected by tetramer enrichment assays, but failed to activate or expand despite repeat stimulation, indicating a nonresponsive population rather than deletion. Adoptive transfer of autoreactive CD4(+) T cells (OT-II mice) led to autoantibody (anti-lysozyme) production by B cells in multiple anatomic compartments, including the bone marrow.

CONCLUSIONS

These data demonstrate that B cells autoreactive to RBC antigens survive in healthy mice with normal immune systems. Furthermore, autoreactive B cells are not centrally tolerized and are receptive to T-cell help. As the autoreactive T cells are present but non-responsive, these data indicate that factors that reverse T-cell non-responsiveness may be central to the pathogenesis of autoimmune hemolytic anemia.

Pathology consultation on drug-induced hemolytic anemia

Drug-induced immune hemolytic anemia is considered to be rare but is likely underrecognized. The consulting pathologist plays a critical role in integrating serologic findings with the clinical history, as drug-induced antibodies should be distinguished as either drug-dependent or drug-independent for appropriate clinical management. Drug-dependent antibodies (DDABs) are most commonly associated with cefotetan, ceftriaxone, and piperacillin, whereas fludarabine, methyldopa, β-lactamase inhibitors, and platinum-based chemotherapeutics are frequent causes of drug-independent antibodies (DIABs). DDABs usually demonstrate a positive direct antiglobulin test and a negative elution, while DIABs are serologically indistinguishable from warm autoantibodies and are similarly steroid-responsive. Drug cessation is always recommended.

[Autoimmune haemolytic anemia: diagnosis strategy and new treatments]

The pattern of autoimmune hemolytic anemia has changed significantly these last 15 years. With regard to the diagnosis strategy, the use of gel filtration technique to perform the direct antiglobulin test (DAT) has decreased the number of autoimmune haemolytic anemias with negative tests results. In recent years, autoimmune haemolytic anemia increased in patients receiving purine nucleoside analogues, blood transfusions, solid organ transplantation or hematopoietic stem cells transplantation. These difficult autoimmune haemolytic anemia cases need to use new kinds of treatments. With regard to the treatment, very little progress was made this latter 50 years. The discovery of the efficacy of anti-CD20 antibody in this disease represents a breakthrough. Nowdays, the second-line treatment includes rituximab or splenectomy. Sometimes, the anti-CD20 treatment could be proposed in first-line but some clinical trials are needed.

Glucocorticoid treatment skews human monocyte differentiation into a hemoglobin-clearance phenotype with enhanced heme-iron recycling and antioxidant capacity

Glucocorticoids are used extensively to treat autoimmune hemolytic anemias. Some beneficial effects of glucocorticoid pulse therapy have also been reported in sickle cell disease and paroxysmal nocturnal hemoglobinuria. Based on established concepts of hemoglobin (Hb) toxicity and physiologic Hb scavenger systems, we evaluated whether glucocorticoids could support an adaptive response to extracellular Hb independently of their immunosuppressive activities. Using global proteome and transcriptome analysis with mass-spectrometry (isobaric tag for relative and absolute quantitation and liquid chromatography-mass spectrometry) and gene-array experiments, we found that glucocorticoid treatment in vitro and in patients on glucocorticoid-pulse therapy polarized monocytes into a M2/alternatively activated phenotype with high Hb-scavenger receptor (CD163) expression and enhanced Hb-clearance and detoxification capability. Monocytes concurrently exposed to the interactive activity of glucocorticoids and extracellular Hb were characterized by high expression of a group of antioxidant enzymes known to be regulated by the conserved oxidative response transcription factor nuclear factor E2-related factor. Further, suppressed transferrin receptor, together with high ferroportin expression, pointed to a shift in iron homeostasis directed toward an increased cellular export of heme-derived iron. Therefore, stimulating Hb-endocytosis by CD163 and enhancing antioxidative homeostasis and iron recycling may be an essential activity of glucocorticoids that helps alleviate the adverse effects of extracellular Hb.

Hematologic Disorders after Solid Organ Transplantation

The evaluation of hematologic disorders after solid organ transplantation (SOT) must take into account issues unique to the post-transplant setting that influence the development of anemia and single or multi-lineage cytopenias. Attention to the time of onset of cytopenia(s) is important, because the disorders of passenger lymphocyte syndrome, transplant-related thrombotic microangiopathy, hemophagocytic syndrome, and graft-versus-host disease typically occur during the first few months after SOT, and post-transplant lymphoproliferative disorder usually occurs within the first year. Drug-related anemia and cytopenia(s) occur due to a variety of mechanisms, including drug-induced hemolysis and marrow suppression and perturbation of T-cell subsets by the immunosuppressive agents, leading to immune dysregulation and autoimmunity. Viral infections can cause direct suppression of hematopoiesis, and a variety of opportunistic infections can precipitate acquired hemophagocytic syndrome, a frequently lethal systemic inflammatory disorder. Early investigation of pancytopenia by bone marrow biopsy is warranted, because it is often the presenting symptom of one or multiple life-threatening pathologies after SOT, such as graft-versus host disease, post-transplant lymphoproliferative disorder, hemophagocytic syndrome, or severe opportunistic infections, and these entities may have a better prognosis if early interventions are undertaken.