T-follicular helper cell expansion and chronic T-cell activation are characteristic immune anomalies in Evans syndrome

Pediatric Evans syndrome (pES) is increasingly identified as the presenting manifestation of several inborn errors of immunity. Despite an improved understanding of genetic defects in pES, the underlying immunobiology of pES is poorly defined, and characteristic diagnostic immune parameters are lacking. We describe the immune characteristics of 24 patients with pES and compared them with 22 patients with chronic immune thrombocytopenia (cITP) and 24 healthy controls (HCs). Compared with patients with cITP and HC, patients with pES had increased circulating T-follicular helper cells (cTfh), increased T-cell activation, and decreased naïve CD4+ T cells for age. Despite normal or high immunoglobulin G (IgG) in most pES at presentation, class-switched memory B cells were decreased. Within the cTfh subset, we noted features of postactivation exhaustion with upregulation of several canonical checkpoint inhibitors. T-cell receptor β chain (TCR-β) repertoire analysis of cTfh cells revealed increased oligoclonality in patients with pES compared with HCs. Among patients with pES, those without a known gene defect had a similar characteristic immune abnormality as patients with defined genetic defects. Similarly, patients with pES with normal IgG had similar T-cell abnormalities as patients with low IgG. Because genetic defects have been identified in less than half of patients with pES, our findings of similar immune abnormalities across all patients with pES help establish a common characteristic immunopathology in pES, irrespective of the underlying genetic etiology.

Autoimmune Cytopenia as an Early and Initial Presenting Manifestation in Activated PI3 Kinase Delta Syndrome: Case Report and Review

Activated PI3 kinase delta syndrome (APDS) is a combined immunodeficiency characterized by recurrent sinopulmonary infections, increased risk of herpesvirus infections, lymphoproliferation, autoimmunity, and increased risk of lymphoid malignancies. Gain-of-function mutations in PIK3CD and PIK3R1 result in increased phosphoinositide-3-kinase-delta activity which causes hyperactivation of lymphocytes and abnormal development and activation of T and B cells. Cytopenias are the most common autoimmune process occurring in patients with APDS and typically occur as a later manifestation of the disease. Here we present a female patient with an early autoimmune hemolytic anemia, hepatosplenomegaly, and frequent infections presenting in infancy, followed by development of significant lymphadenopathy before her diagnosis with APDS type 1. She had significant improvement in her infectious history with immunoglobulin replacement, and control of autoimmune hemolytic anemia with initiation of sirolimus after her diagnosis with APDS type 1. We utilize this case to review the literature on APDS and present the novel finding of early-onset autoimmune disease in the setting of APDS. Autoimmune cytopenias are seen in many primary immunodeficiencies, and workup of autoimmune cytopenias in young patients should include evaluation for underlying immune disorder.

In vitro Immunomodulatory Effects of Human Umbilical Cord-Derived Mesenchymal Stem Cells on Peripheral Blood Cells from Warm Autoimmune Hemolytic Anemia Patients

INTRODUCTION

Autoimmune hemolytic anemia is a potentially lethal disease characterized by autoimmune hemolysis. Although human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) have been reported as a promising therapy, there is limited evidence regarding warm autoimmune hemolytic anemia (wAIHA) patients. This study aimed to investigate the potential therapeutic effects of hUC-MSCs via immune regulation in wAIHA patients.

METHODS

Peripheral blood mononuclear cells (PBMCs) from 10 wAIHA patients and 8 healthy controls were isolated from peripheral blood and cultured for 3 days with or without the presence of hUC-MSCs; PBMCs were co-cultured with hUC-MSCs using Transwell assays. The supernatant cytokine levels were measured after culture through AimPlex Multiple Immunoassays for Flow, including IL-2, IL-4, IL-10, IFN-γ, TNF-α, and IL-17A. The percentages of regulatory T cells, regulatory B cells, and Th1/Th2 in PBMCs were also assessed before and after culturing.

RESULTS

In the wAIHA group, hUC-MSCs could upregulate the Treg and Breg proportions after culturing for 3 days, and the Treg and Breg percentages increased after co-culturing with hUC-MSCs in the wAIHA group compared with PBMC cultured alone for 3 days (8.29 ± 8.59 vs. 6.82 ± 1.32, 3.82 ± 1.87 vs. 1.75 ± 1.20, respectively). Compared with the PBMC wAIHA group, the levels of TNF-α (2.13 ± 2.07 vs. 16.20 ± 21.13 pg/mL, p = 0.019) and IL-10 (10.51 ± 18.42 vs. 37.78 ± 44.20 pg/mL, p = 0.012) were significantly elevated in the PBMC + hUC-MSCs wAIHA group.

CONCLUSION

The hUC-MSCs contributed to the increasing proportion of regulatory cell populations in PBMCs of wAIHA patients, thereby potentially regulating autoimmune response; thus, hUC-MSCs may be a promising approach for wAIHA treatment.

Bortezomib treatment of steroid-refractory Evans syndrome in children

Treatment of refractory Evans syndrome (ES) remains a challenge in hematology practice. Due to rarity of this condition, evidence-based approaches are limited and often treatment choices stem from small case series or anecdotal experiences. There is mounting evidence that some patients have genetic defects that could be targeted with promising preliminary results. Here, we describe three very refractory pediatric ES cases treated on bortezomib without adverse effects. Two of the three patients had dramatic and long-lasting recovery that started following the initial doses of the drug. Clinical trials to assess the role of bortezomib in ES treatment are warranted.

Role of complement in alloimmunization and hyperhemolysis

PURPOSE OF REVIEW

The purpose of this review is to summarize the role of complement in regulating the removal of a target alloantigen following an incompatible red blood cell (RBC) transfusion, the formation of alloantibodies following RBC alloantigen exposure, and the development of hyperhemolysis in patients with sickle cell disease (SCD).

RECENT FINDINGS

Recent studies demonstrate that complement can accelerate alloantibody-mediated removal of target alloantigens from the RBC surface following incompatible transfusion. Complement also influences alloantigen availability during developing alloimmune responses and serves as a unique mediator of CD4 T-cell-independent alloantibody formation following RBC alloantigen exposure. Finally, alternative complement pathway activation appears to play a key role in the development of acute hemolytic episodes in patients with SCD, providing a potential druggable target to prevent acute complications in patients with this disease.

SUMMARY

Recent studies suggest that complement can regulate a wide variety of processes germane to hematology, from transfusion complications to baseline hemolysis in patients with SCD. As the role of complement in various disease processes becomes more fully understood, the ability to leverage recently developed complement modulating drugs will only continue to enhance providers' ability to favorably intervene in many hematological diseases.

Clinical analysis of 20 patients with non-Hodgkin lymphoma and autoimmune hemolytic anemia: A retrospective study

Non-Hodgkin lymphoma (NHL) can co-exist with autoimmune hemolytic anemia (AIHA), a phenomenon known as AIHA-associated NHL (AIHA/NHL). However, few studies have reported AIHA/NHL incidence or its clinical characteristics. We conducted a retrospective analysis of 20 AIHA/NHL patients treated at our hospital from 2009 to 2018. AIHA/NHL was presented by only 0.91% of the NHL and 9.8% of the AIHA patients. In addition, AIHA occurred most frequently with angioimmunoblastic T-cell lymphoma (AITL) (7.31%), followed by marginal zone B-cell lymphoma (MZBL) (6.25%), B-cell lymphoma-unclassified (BCL-U) (4.25%), chronic lymphocytic leukemia/small lymphocyte lymphoma (CLL/SLL) (2.50%), and mantle cell lymphoma (MCL) (2.30%). In addition to the CLL/SLL patients with impaired bone marrow, 66.7% of the AIHA/NHL patients had lymphoma bone marrow infiltration (LBMI), of which 4 patients presented LBMI in bone marrow smears (BMS) but not in bone marrow biopsy (BMB) and 6 were positive for BMB but not BMS. The 1-, 3- and 5-year survival rates of AIHA/NHL patients were 70%, 30% and 20%, respectively, and they responded poorly to chemotherapy. In conclusion, AIHA can co-exist with various NHLs and the defining clinical characteristic of AIHA/NHL is the high incidence of LBMI. However, both BMS and BMB should be performed to avoid missed diagnosis.

Cold agglutinin disease: where do we stand, and where are we going?

Primary cold agglutinin disease (CAD) is characterized by a very indolent bone marrow clonal B-cell lymphoproliferative disorder that initiates an autoimmune hemolytic anemia. The clonal B cells produce a monoclonal autoantibody termed cold agglutinin, most often of the immunoglobulin (Ig) Mκ class. After binding to its antigen, the IgM initiates a complement classical pathway-driven erythrocyte destruction, predominantly mediated by opsonization with complement protein C3b and extravascular hemolysis in the liver. We review the molecular biology, histopathology, clinical features, and diagnostic procedures in CAD. Some patients are only slightly anemic and do not require treatment, but moderate or severe anemia frequently occurs, and the disease burden has been underestimated. CAD should not be treated with corticosteroids. Several B-cell-directed treatment options are available, and complement-directed approaches are being rapidly developed. Current and possible future therapies are reviewed.

Immune-mediated hemolytic anemia and thrombocytopenia in clonal B-cell disorders: a review

Autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia purpura (ITP) have been associated with B-cell lymphoproliferative disorders. Here, we review the epidemiology, pathogenesis, diagnosis, and treatment of these autoimmune disorders, specifically in the setting of B-cell malignancies. AIHA and ITP are classically associated with chronic lymphocytic leukemia (CLL) but have also been reported in plasmacytic and lymphoproliferative disorders. AIHA includes both warm AIHA and cold agglutinin disease, the latter of which is strongly associated with Waldenström macroglobulinemia. The pathogenesis of these cytopenias varies with the underlying disease, but malignant cells serving as antigen-presenting cells to T lymphocytes, with the generation of autoreactive lymphocytes, may be involved. The diagnosis requires the presence of hemolysis and a positive direct antiglobulin test result. In a minority of cases, the direct antiglobulin test result is negative, and more specialized testing may be required. Data on the prognostic effect of these comorbidities are conflicting, and the prognosis may vary depending on when in the B-cell malignant process the cytopenia(s) develops. The treatment of AIHA and ITP in the setting of B-cell lymphoproliferative disorders often involves treatment of the underlying disorder, although in some cases of CLL, treatment of the underlying disorder is not indicated, and management is similar to that for idiopathic AIHA or ITP.

An unusual association between hemophagocytic lymphohistiocytosis, mixed connective tissue disease, and autoimmune hemolytic anemia: A case report

RATIONALE

In the adult patient, hemophagocytic lymphohistiocytosis (HLH) is uncommon and frequently difficult to diagnose due to its nonspecific presentation and numerous complications.

PATIENT CONCERNS

Herein, we present the case of a 25-year-old female who initially presented for evaluation of persistent fevers and fatigue. She was found to have splenomegaly, generalized lymphadenopathy, pancytopenia, and acute hepatic failure.

DIAGNOSES, INTERVENTIONS, AND OUTCOMES

Her course was further complicated by the development of nephrotic syndrome and autoimmune hemolytic anemia (AIHA). Antinuclear antibody and ribonucleoprotein were positive, with concurrent physical examination findings, indicating underlying mixed connective tissue disease (MCTD). Ferritin was greater than 40,000 ng/dL. Viral studies, including hepatitis A, B, and C, cytomegalovirus, and Epstein-Barr virus were negative. On the basis of her clinical presentation, a diagnosis of HLH secondary to MCTD was made. This was later confirmed on liver biopsy. She was started on high-dose prednisone and her symptoms completely resolved. She was then transitioned to azathioprine, hydroxychloroquine, prophylactic antibiotics, and a prednisone taper for long-term management.

LESSONS

This case is notable for the association of both AIHA and MCTD with HLH, providing support for a possible relationship between these 3 conditions.

Distinct Host-Dependent Pathogenic Mechanisms Leading to a Similar Clinical Anemia After Infection with Lymphocytic Choriomeningitis Virus

The Docile strain of lymphocytic choriomeningitis virus (LCMV) induces anemia in a number of inbred strains of mice, including C3HeB/FeJ and CBA/Ht animals. A difference in the kinetics of anemia and in compensatory reticulocytosis suggested that impaired erythropoiesis was the major pathogenic mechanism Involved in CBA/Ht mice, but not in C3HeB/FeJ mice. In both mouse strains an antierythrocyte autoantibody production that depended on the presence of functional CD4+ T lymphocytes was observed. Although depletion of T helper lymphocytes prevented anemia in C3HeB/FeJ mice, this treatment largely failed to inhibit the development of the disease in CBA/Ht animals. This observation indicated that the antierythrocyte autoimmune response induced by the infection was at least Partly responsible for the anemia of C3HeB/FeJ mice, but not of CBA/Ht mice. Erythrophagocytosis was enhanced in both mouse strains after LCMV infection, but did not appear to be a major cause of anemia. These data clearly indicate that similar disease profiles induced by the same virus in two different host strains can be the result of distinctly different mechanisms.

Mean reticulocyte volume: a specific parameter to screen for hereditary spherocytosis

This study assessed the value of mean reticulocyte volume (MRV) for differential diagnosis of hereditary spherocytosis (HS) so as to develop conventional and new specific screen indexes. Subjects in this study were divided into three groups: 53 cases in HS group, 217 cases in hemolytic anemia control group (109 cases of thalassemia (THAL), 56 cases of glucose-6-phosphate dehydrogenase G6PD deficiency anemia, and 52 cases of autoimmune hemolytic anemia (AIHA)), and 100 cases in healthy control group. We analyzed erythrocyte and reticulocyte parameters including MRV, mean sphered corpuscular volume, mean corpuscular hemoglobin concentration, and immature reticulocyte fraction. Results demonstrated that MRV was significantly lower in the HS group but significantly higher in the AIHA and G6PD deficiency anemia groups than that in the healthy control group (P = 0.000). MRV was not significantly different between the AIHA and G6PD deficiency anemia groups (P = 0.977) and between the healthy control and THAL groups (P = 0.168). The area under the ROC curve of MRV for diagnosis of HS was 0.942, with a standard error of 0.019, 95% confidence interval of 0.905-0.979, and optimal critical diagnosis point of 95.77 fL. When the MRV was ≤95.77 fL, the sensitivity and specificity for diagnosis of HS were 86.80% and 91.20%, respectively. Therefore, MRV is a general and specific new index for screening HS and important for differential diagnosis of different types of hemolytic anemia.

Demographic Characteristics, Survival and Prognostic Factors for Mortality in Cats with Primary Immune-Mediated Hemolytic Anemia

BACKGROUND

Immune-mediated hemolytic anemia (IMHA) is uncommon in cats, but may result in severe disease. Demographic predispositions for development of the disease and prognostic factors for mortality have not been investigated previously.

HYPOTHESIS/OBJECTIVES

To explore possible demographic predispositions for development of primary IMHA in cats and to investigate possible prognostic factors for mortality.

ANIMALS

107 client-owned cats with IMHA, of which 72 had primary IMHA and 35 had secondary IMHA, and 9,194 control cats.

METHODS

Data were collected retrospectively from records of cats with IMHA, defined by the presence of anemia and concurrent autoagglutination, ghost cells without oxidative damage on fresh blood smear, positive titer in a direct antiglobulin test, or evidence of phagocytosis of erythroid precursors in bone marrow. Odds ratios were calculated to assess the risk of development of primary IMHA in different demographic groups and Cox proportional hazards analysis was conducted to evaluate prognostic factors.

RESULTS

No sex or breed predisposition was identified for the development of primary IMHA in comparison to the control cats, but cats in the age range 2.1-5.9 years were predisposed. Higher total bilirubin concentration and age were significant negative prognostic factors and higher lymphocyte numbers and serum globulin concentration were positive prognostic factors in a multivariable model.

CONCLUSIONS AND CLINICAL IMPORTANCE

Young adult cats were more likely to develop primary IMHA than other groups, but no apparent male predisposition was identified in this study, contrary to previous reports. Several prognostic factors were identified, which may be helpful in guiding clinical practice in the future.

[THE DIFFERENTIAL DIAGNOSTIC OF ANEMIA]

The article presents analysis of the publications' data of the recent years concerning regulation of iron metabolism and possibilities of application of indicators of iron metabolism in differential diagnostic of anemia. The original results of protein detection are described concerning bivalent transporter of metals and ferroportine under iron-deficiency anemia, anemia of chronic inflammatory diseases and autoimmune hemolytic anemia. The significance of these proteins in more profound comprehension of pathogenesis is demonstrated

Allogeneic red blood cell adsorption for removal of warm autoantibody

Adsorption studies are usually required to confirm or rule out the presence of underlying alloantibodies in samples containing warm autoantibody. Allogeneic adsorptions are necessary if the patient has been recently transfused. Most commonly, allogeneic adsorptions are performed using a trio of phenotyped reagent red blood cells to rule out clinically significant alloantibodies to common antigens. The adsorbing cells may be used untreated or treated with enzymes or with ZZAP before adsorption. Adsorption may also be performed using enhancement such as low-tonic strength saline or polyethylene glycol added to the mixture. Multiple adsorptions may be necessary to remove strongly reactive autoantibodies. Allogeneic adsorptions will not detect alloantibodies to high-prevalence antigens.

A review of autoimmune diseases associated with cancer

The focus of this review is on the relationships between autoimmune diseases and cancer from two closely related perspectives: 1.Those autoimmune diseases which are often associated with malignancies. 2.Those prevalent cancers which may increase the risks of developing autoimmune disorders. The review concludes with a brief discussion of some selected innovative approaches to cancer immunotherapy.

[Diabetic fetopathy in gravida with autoimmune hemolytic anemia complicated by steroid diabetes]

The authors made a clinicoanatomic analysis of fetal death in a 32-year-old diabetic gravida at 34-35 weeks gestational age. Fetal autopsy identified the characteristic signs of fetopathy: macrosomy, cardiomegaly, hepatomegaly, and brain weight reduction. Histological analysis revealed minute foci of leukomalacia with glial proliferation in the cerebral hemispheres; adipose and hyaline drop degeneration of cardiomyocytes in the heart, that of hepatocytes in the liver, the proximal renal tubular epithelial cells; hemorrhages in the respiratory portions of the lung. The pancreas displayed inflammation foci, hypertrophy and hyperplasia of the islets of Langerhans. Immunohistochemical studies identified cells with enlarged nuclei among the beta and alpha-cells. The placenta showed a large mass with pronounced changes. It has been demonstrated that steroid diabetes may lead to the development of diabetic fetopathy and placental changes, which are typical of maternal diabetes.

Autoimmune Hemolytic Anemia with Myelodysplastic Features Followed by Bilateral Adrenal Non-Hodgkin Lymphoma: A Case Report and Review of the Literature

Primary adrenal lymphoma is a rare entity characterized mainly by bilateral involvement, presenting predominantly diffuse large B-cell histology, adrenal insufficiency and poor prognosis. Approximately 85 cases have been described in the literature. We report here a case of a 77-year-old man who presented with autoimmune hemolytic anemia (AIHA), which preceded the diagnosis of lymphoma by more than 2 years. An ultrasound guided biopsy revealed diffuse, large B-cell, lymphoma; subsequent staging revealed no other disease site, and the patient was considered to have primary adrenal lymphoma. The patient had adrenal insufficiency at diagnosis. He received hormonal replacement and chemotherapy, but he succumbed to his disease because of sepsis and multi-organ failure a few days post diagnosis. To our knowledge, this is the first case in the literature in which AIHA preceded bilateral adrenal lymphoma. We also provide a summary of the current data for the clinical features, diagnosis and treatment of primary adrenal lymphoma.

New serologic findings in a patient with ulcerative colitis and a warm autoantibody

IgG-RBC sensitization associated with serine proteases is the current prevailing hypothesis used to explain an uncommon phenomenon in which a positive DAT is obtained using the RBCs from a patient's clotted blood sample but a negative DAT is obtained when testing RBCs from the patient's unclotted sample. Similarly, the patient's serum but not plasma will also be reactive by IAT against all RBCs tested. The majority of patients demonstrating this phenomenon have had a history of ulcerative colitis but no signs of hemolytic anemia. A case of IgG-RBC sensitization associated with serine proteases and a warm autoantibody in a 14-year old Hispanic girl with ulcerative colitis is reported. The patient was admitted for severe anemia (Hb, 6.9 g/dL). On admission,pretransfusion testing of the patient's serum and RBCs showed an ABO/Rh discrepancy between the forward typing and reverse grouping. The phenomenon of IgG-RBC sensitization associated with serine proteases was considered in the differential evaluation of the serum versus plasma typing discrepancy. To confirm the presence of the phenomenon of IgG-RBC sensitization associated with serine proteases, the plasma was clotted and converted to serum by the addition of thrombin. The initially nonreactive plasma was 2+ reactive when converted to serum. A warm autoantibody was also detected during the course of serologic evaluation. The patient was transfused with 2 units of incompatible RBCs with no adverse reaction observed.

[Severe anaemia caused by Human Parvovirus B19 infection in a patient with autoimmune haemolytic anaemia and a B-cell non-Hodgkin lymphoma]

A 65-year-old man with a 15-year history of 'leukemicised' low-grade lymphocytic B-cell non-Hodgkin lymphoma with a low-titre of IgM kappa paraprotein was admitted with severe anaemia and reticulocytopenia. Treatment with prednisone and chlorambucil had been started two weeks earlier because of a recently diagnosed Coombs-positive haemolytic anaemia. He also received a blood transfusion at that time. During his stay in the hospital, a crista biopsy was performed that revealed no signs of bone marrow suppression but markedly enlarged pro-erythroblasts. Although a serologic test for Human Parvovirus-B19 was negative, PCR showed a sharply increased viral load with more than 1 x 10(11) copies/ml, compatible with a primary parvovirus infection. In retrospect, an earlier transfusion of blood that had not been screened for parvovirus was probably the culprit. Treatment with human immunoglobulin was effective in lowering the viral load and normalising the haemoglobin. This case illustrates that reticulocytopenia in a patient with a haematologic disorder accompanied by a shortened erythrocyte life-span is suggestive for a primary parvovirus infection, especially following a recent transfusion. To prevent transmission of Human Parvovirus B19 via blood transfusion, the Health Council of the Netherlands published a guideline indicating that patients at high risk for a complicated infection with Human Parvovirus B19 should be given 'virus-free' blood products.

Unusual warm autoimmune hemolytic anemia in non-alcoholic steatohepatitis

Warm autoimmune hemolytic anemia (WAIHA), a rare disease (0.2-1 per 100,000 population), ranges from an indolent form with mild hemolysis to a life-threatening condition that necessitates transfusion of incompatible red cells. WAIHA can be either idiopathic or secondary to medications or to a lymphoproliferative disorder. We report a case of profound hemolytic anemia in a liver-transplant eligible patient who was diagnosed with cirrhosis secondary to non-alcoholic steatohepatitis (NASH). The patient initially was treated with red cell transfusion, iv immunoglobulin, and steroids. He developed acute renal failure that required dialysis. Subsequent management included plasmapheresis and rituximab therapy. The patient developed hepatorenal syndrome and died from progressive hepatic failure. To our knowledge, this is the first report of an association between NASH and WAIHA.

Prompt and sustained response of a steroid-refractory autoimmune hemolytic anemia to a rituximab-based therapy in a chronic lymphocytic leukemia patient

INTRODUCTION

Autoimmune hemolytic anemia (AIHA) is a rare and potentially life-threatening event which may complicate the course of chronic lymphocytic leukemia (CLL) at any time and steroid-refractory AIHA of CLL poses a therapeutic challenge for physicians. Here, we report the safety and efficacy of a rituximab-containing regimen in a CLL patient with steroid- and IVIg-refractory AIHA.

CASE REPORT

A 57-year- old man affected by CLL, presented with fatigue, dyspnoea, tachycardia and jaundice. His physical examination revealed overt jaundice, hepato- and splenomegaly, and enlargement of lymph nodes in all superficial sites. The blood chemistry showed severe anemia (Hb value 3.9 g/dL), high white blood cell count (89 x 10(9)/L), altered hemolysis markers and direct antiglobulin test (DAT) was positive for both complement and IgG. The patient failed to respond to both a 4-day course of high-dose dexamethasone IV (40 mg/day) and intravenous immunoglobulin (IVIg) (1 g/kg/day x 2 days). Thus, a schedule containing rituximab (375 mg/m(2) day +1), cyclophosphamide (750 mg/m(2) day +2) and prednisone (60 mg/m(2) from day +1 to day +7) (R-CP) were administered. Four cycles, repeated every 4 weeks, were administered. After 4 days from the infusion of this schedule, the patient showed a marked reduction of the lymphocytosis, and the hemoglobin level started to increase. No rituximab-related side effects were recorded. At the end of treatment DAT became negative and patient achieved a nodular Partial Remission (nPR).

CONCLUSION

Our data showed the safety and efficacy of a rituximab-containing regimen in a life-threatening CLL-related AIHA, refractory to steroid and IVIg therapy. This schedule has allowed the patient to obtain a prompt and dramatic rise in hemoglobin level and a response to both AIHA and CLL.

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

Chronic cold agglutinin disease (CAD) is a subgroup of autoimmune hemolytic anemia. Primary CAD has traditionally been defined by the absence of any underlying or associated disease. The results of therapy with corticosteroids, alkylating agents and interferon-a have been poor. Cold reactive immunoglobulins against erythrocyte surface antigens are essential to pathogenesis of CAD. These cold agglutinins are monoclonal, usually IgMκ auto antibodies with heavy chain variable regions encoded by the V_H4-34 gene segment. By flowcytometric and immunohistochemical assessments, a monoclonal CD20⁺κ⁺B-lymphocyte population has been demonstrated in the bone marrow of 90% of the patients, and lymphoplasmacytic lymphoma is a frequent finding. Novel attempts at treatment for primary CAD have mostly been directed against the clonal B-lymphocytes. Phase 2 studies have shown that therapy with the chimeric anti-CD20 antibody rituximab produced partial response rates of more than 50% and occasional complete responses. Median response duration, however, was only 11 months. In this review, we discuss the clinical and pathogenetic features of primary CAD, emphasizing the more recent data on its close association with clonal lymphoproliferative bone marrow disorders and implications for therapy. We also review the management and outline some perspectives on new therapy modalities.

Clonal regulatory T cells specific for a red blood cell autoantigen in human autoimmune hemolytic anemia

Regulatory T (Tr) cells have the potential to treat immune-mediated disease, but cloning such cells for study from patients with autoimmune disease has proven difficult. Here, we describe autoantigen-specific, interleukin-10 (IL-10)–secreting Tr cell clones recovered ex vivo from a patient with autoimmune hemolytic anemia (AIHA) and characterize their phenotype, origin, and regulatory function. These IL-10⁺ Tr cells recognized a peptide, 72H-86L, derived from the Rh red blood cell autoantigen and shared phenotypic characteristics with both natural and inducible Tr cells. The clones also expressed different Tr markers depending on activation state: high levels of CD25 and LAG-3 when expanding nonspecifically, but FoxP3 after activation by the autoantigen they recognize. Despite a discrete Tr phenotype, these cells stably expressed the T helper 1 (Th1) signature transcription factor T-bet, suggesting they derive from Th1 T cells. Finally, the contribution of CTLA-4 in activating these IL-10⁺ Tr cells was confirmed by analyzing responses to transgenic B7.1-like molecules that preferentially bind either CD28 or CTLA-4. Overall, these Tr cells have a functional phenotype different from those described in previous studies of human Tr populations, which have not taken account of antigen specificity, and understanding their properties will enable them to be exploited therapeutically in AIHA.

Two-Step Mechanism of Virus-induced Autoimmune Hemolytic Anemia

Viruses are associated with the development of autoantibody-mediated blood autoimmune diseases. A two-step mechanism could explain virus involvement in the development of experimental hemolytic anemia. Immunization of normal mice with rat erythrocytes results in an autoantibody production that could be enhanced by viral infection, without erythrocyte destruction. Inoculation of the same virus when autoantibodies are at high levels triggers clinical anemia. This results from macrophage activation by gamma-interferon, leading to exacerbated erythrophagocytosis. Thus the development of anemia during the course of viral infection may require two independent stimuli, in which the first triggers autoantibody production and the second enhances the pathogenicity of these autoantibodies.

Cold agglutinin induced autoimmune hemolytic anemia and NK-cell leukemia: a new association

Cold agglutinin induced autoimmune hemolytic anemia is uncommonly associated with leukemia and lymphomas. We present a case of a young Mexican female presenting with a cold agglutinin hemolytic anemia with expression of a rare Pr antigen specificity and an aggressive NK-cell leukemia. Our patient had a rapid fatal course. To our knowledge this is the first reported case of such an association.

Autoimmune hemolytic anemia in children

The clinical and hematological profile and treatment outcome of children with warm autoimmune hemolytic anemia (AIHA) were assessed using retrospective case record analysis. There were 26 (17 idiopathic; 9 secondary) patients with a median age of 11 years. Pallor (100%), fever (39%), and jaundice (59%) were the main presenting complaints. Jaundice was much more common in idiopathic (70%) compared to secondary (44%). Direct antiglobulin test was negative in 3 patients. Oral prednisolone produced remission in 81% patients. Four patients relapsed after a median period of 7 months (2 months to 2 year) after response. All responded to a second course of steroids in median 14 days. One child required cyclosporin A in addition. No correlation was found between response and parameters such as age, sex, jaundice, low pretreatment hemoglobin, reticulocyte count, total leukocyte count, platelet count, subtype of AIHA, and hepatosplenomegaly. Relapse correlated with increased duration between the onset of symptoms and treatment. This study indicates that oral prednisolone is an effective therapy for autoimmune hemolytic anemia. In refractory cases cyclosporine A may be useful.

Canine immune-mediated hemolytic anemia: pathophysiology, clinical signs, and diagnosis

Immune-mediated hemolytic anemia (IMHA) is a common type of anemia in dogs and cats that results from a type II hypersensitivity reaction. The disease is most common in middle-aged female dogs, especially American cocker spaniels. The common clinical signs are associated with severe anemia and the resultant inflammatory response. There is no pathognomonic test for IMHA, but the following are suggestive of it: the presence of hemolytic anemia in a young adult or middle-aged dog of a predisposed breed, autoagglutination and/or spherocytosis, positive results from a direct antiglobulin (Coombs') test, elimination of any other underlying cause of anemia, and an appropriate response to immunosuppressive therapy.

Canine immune-mediated hemolytic anemia: treatment and prognosis

The treatment of primary immune-mediated hemolytic anemia involves short-term oxygen-carrying support and long-term immunosuppressive therapy. Therapeutic options include blood transfusion, standard and more speculative immunosuppressive agents, splenectomy, and prevention of thromboembolic disease. This article also discusses the prognosis and prognostic indicators.

Autoimmune hemolytic anaemia in the antiphospholipid syndrome

Antiphospholipid syndrome (APS) is a multisystem disease with recurrent thrombosis in the presence of antiphosphlipid antibodies, which may include cardiac, neurological, gastrointestinal, hematologic or cutaneous manifestations. The occurrence of autoimmune hemolytic anaemia (AIHA) in APS has not been well established. The purpose of this study was to review the occurrence of AIHA in patients with APS and its relation to other disease manifestations. Three-hundred and eight patients with APS from seven medical centers in Israel, Serbia and the Slovac Republic were included and evaluated for associations between AIHA and various manifestations of APS. AIHA was documented in 32 patients (10.4%). The odds ration for AIHA was increased in the presence of anticardiolipin antibodies and livedo reticularis (5.4 and 7.8, respectively). There was a highly significant association between AIHA and cardiac valvular vegetations and thickening (P < 0.0001), arterial thrombosis (P < 0.02), livedo reticularis (P < 0.0001) and CNS signs of epilepsy or chorea (P < 0.02 and P < 0.03, respectively). Thus, APS patients with AIHA are at risk of developing these manifestations, and should therefore be investigated for them. In addition, the occurrence of AIHA may define a subgroup of patients with a significant risk for subsequent development of SLE.

Lack of clinical efficacy of rituximab in the treatment of autoimmune neutropenia and pure red cell aplasia: implications for their pathophysiology

We describe 11 patients with severe refractory autoimmune cytopenias treated with the anti-CD20 monoclonal antibody rituximab. Six patients had autoimmune neutropenia (AIN), two had pure red cell aplasia (PRCA), one had AIN and autoimmune haemolytic anaemia, one had AIN and immune thrombocytopaenia purpura (ITP) and one had PRCA and ITP. Rituximab was administered at a dose of 375 mg/m(2) as an intravenous infusion weekly for 4 weeks. Six of eight patients with AIN and all three patients with PRCA did not respond. Two patients died: one with resistant AIN and autoimmune haemolytic anaemia died of pneumocytis pneumonia infection, and one with PRCA and ITP died of an acute exacerbation of bronchiectasis. Rituximab in AIN and PRCA appears to be less effective than Campath-1H when compared to historical data from our group. This supports the hypothesis that T cells may be important in the pathophysiology of AIN and PRCA.

Evaluation of liposomal clodronate in experimental spontaneous autoimmune hemolytic anemia in dogs

OBJECTIVES

Liposomal clodronate (dichloromethylene diphosphonate) has been used to deplete macrophages and block clearance of opsonized cells in mouse models of autoimmune disease. However, liposomal clodronate (LC) has not been previously evaluated in a large-animal spontaneous autoimmune disease model. Therefore, the safety and efficacy of LC treatment was assessed in normal dogs and in dogs with spontaneous autoimmune hemolytic anemia (AIHA).

METHODS

LC was administered intravenously first to healthy dogs and then to dogs with spontaneous, severe AIHA to determine if the treatment was safe and could block clearance of opsonized red blood cells (RBCs) in vivo. Studies were also conducted to assess the in vitro effects of LC on dog macrophages and dendritic cells.

RESULTS

Intravenous infusion of low doses of LC was well tolerated and blocked clearance of opsonized RBCs in normal dogs in vivo. LC was taken up by splenic macrophages and dendritic cells in vivo, and induced killing of macrophages and dendritic cells in vitro. Seven dogs with severe, spontaneous AIHA were treated with LC in a pilot study. Treatment was well tolerated, 2 of 7 LC-treated dogs with AIHA had a decrease in RBC clearance, and LC-treated dogs had significantly increased survival times compared to historical control dogs matched for disease severity.

CONCLUSIONS

These results indicate that LC can be safely administered intravenously to dogs and that even relatively low doses are capable of blocking RBC clearance and improving outcomes in a spontaneous large-animal model of AIHA. Therefore, additional studies of LC for treatment of autoantibody-mediated cytopenias in dogs and humans may be warranted.

Chronic eosinophilic leukemia presenting with autoimmune hemolytic anemia and erythrophagocytosis by eosinophils

Eosinophils function primarily as secretory cells and phagocytosis by eosinophils is rarely seen. We describe a case of chronic eosinophilic leukemia (CEL) in a 72-year-old male with a history of previously treated non-Hodgkin's lymphoma (NHL) presenting with erythrophagocytosis by eosinophils and an associated autoimmune hemolytic anemia (AIHA). This patient did not show evidence of relapsed NHL. The patient's blood showed a markedly elevated eosinophil count of 16 x 10(9)/L [normal 0-0.45 x 10(9)/L] on a background of myelodysplasia and features of AIHA. Prominent erythrophagocytosis by eosinophils was visualized in the blood and in the bone marrow. Numerous Charcot-Leyden crystals were also seen in the bone marrow amid increased numbers of eosinophils and the presence of dysplastic granulopoiesis. AIHA is rarely described in the setting of CEL. More significantly, this represents the first case report to describe erythrophagocytosis by eosinophils.

Dry gangrene of the extremities in calves associated with Salmonella dublin infection; a possible immune-mediated reaction

Dry gangrene of the extremities in calves is a circulatory error that may occur after infection with Salmonella dublin. This report describes an examination of three affected, 12 in-contact and five control calves, a main objective being to investigate the possible role of cold agglutination in pathogenesis. The lesions included dry gangrene of the hind legs, ears and tail. A cold agglutination test gave positive results in all animals examined except the controls. The three affected calves had high titres of S. dublin antibodies, as also did four of the in-contact animals. The results suggested a relationship between cold agglutination and the occurrence of the disease.

Activity of Rituximab Monotherapy in Refractory Splenic Marginal Zone Lymphoma Complicated with Autoimmune Hemolytic Anemia

We describe the case of a 61-year-old patient with refractory splenic marginal zone lymphoma and secondary autoimmune hemolytic anemia, both successfully treated with rituximab. This case demonstrates that rituximab monotherapy might also be a valid therapeutic approach in marginal zone lymphoma and autoimmune hemolytic anemia after failure of first-line treatment. Maintenance therapy, although expensive, could be useful to improve event-free survival in patients with unfavorable clinical behavior.