Autoantigen presentation by splenic dendritic cells is required for RBC-specific autoimmunity

BACKGROUND

Failure of humoral tolerance to red blood cell (RBC) antigens may lead to autoimmune hemolytic anemia (AIHA), a severe and sometimes fatal disease. Previous studies have shown that although tolerance is robust in HOD mice, autoantibodies are generated upon adoptive transfer of OTII CD4+ T cells, which are specific for an epitope contained within the HOD antigen. These data imply that antigen-presenting cells (APCs) are presenting RBC-derived autoantigen(s) and are capable of driving T-cell activation. Given that multiple APCs participate in erythrophagocytosis, we used a transgenic approach to determine which cellular subsets were required for autoantigen presentation and subsequent autoreactive T-cell activation.

STUDY DESIGN AND METHODS

HOD mice, which express an RBC-specific antigen consisting of hen egg lysozyme, ovalbumin, and human blood group molecule Duffy, were bred with IAbfl/fl and Cre-expressing transgenic animals to generate mice that lack I-Ab expression on particular cell subsets. OTII CD4+ T cell proliferation was assessed in vivo in HOD+ I-Abfl/fl xCre+ mice and in vitro upon coculture with sorted APCs.

RESULTS

Analysis of HOD+ I-Abfl/fl xCre+ mice demonstrated that splenic conventional dendritic cells (DCs), but not macrophages or monocytes, were required for autoantigen presentation to OTII CD4+ T cells. Subsequent in vitro coculture experiments revealed that both CD8+ and CD8- DC subsets participate in erythrophagocytosis, present RBC-derived autoantigen and stimulate autoreactive T-cell proliferation.

CONCLUSION

These data suggest that if erythrocyte T-cell tolerance fails, DCs are capable of initiating autoimmune responses. As such, targeting DCs may be a fruitful strategy for AIHA therapies.

Characteristics and outcome of warm autoimmune hemolytic anemia in adults: New insights based on a single-center experience with 60 patients

Warm autoimmune hemolytic anemia (wAIHA) is a rare autoimmune disease with poorly known natural history and management remaining mainly empirical. To better describe the characteristics and outcome of wAIHA in adults, we performed a single-center cohort study of patients diagnosed with wAIIHA from 2001 to 2012 in our center. Sixty patients (50% women) were included, the mean age at the time of wAIHA onset was 54 ± 23 years. wAIHA was considered "primary" for 21 patients (35%) and was associated with an underlying disorder in 39 (65%), including mainly lymphoproliferative disorders and systemic lupus. All patients but two needed treatment and received corticosteroids, with an overall initial response rate of 87%. However, 63% of the patients were corticosteroid-dependent and 56% required at least one second-line treatment including mainly rituximab (n = 19). At the time of analysis, after a mean follow-up of 46 months, 28 patients (47%) were in remission and off treatment and 5 (8%) had died. The presence of an underlying lymphoproliferative disorder was associated with reduced response to corticosteroids and increased need for second-line therapy. In conclusion, in the last decade and compared to a previous series from our center, the rate of secondary wAIHA has increased and the use of rituximab has emerged as the preferred second-line treatment and corticosteroid-sparing strategy; the overall mortality has significantly decreased (8 vs. 18%).

[Evaluation of different prognostic markers in dogs with primary immune-mediated hemolytic anemia]

Canine primary immune-mediated hemolytic anemia (IMHA) is associated with a high mortality rate. Hypothesis of this study was that laboratory parameters not only determined initially but also in the course of the disease might be useful as prognostic markers. Included in the study were dogs with primary IMHA. Inclusion criteria were anemia (PCV < 0.30 L/L), a positive Coombs'test or persistent autoagglutination of erythrocytes, and the exclusion of underlying diseases. Dogs were divided into two groups based on survival: dogs that were still alive 14 days after start of treatment (group 1) and dogs that died or were euthanized before day 14 (group 2). Hematological and biochemical analyses as well as a coagulation profile were performed initially and on day 3. Out of 37 dogs with primary IMHA 28 belonged to group 1 and 9 to group 2. Significantly associated with mortality were thrombocytopenia (p = 0.001), lymphopenia (p = 0.026), a prolonged PT (p = 0.003) and aPTT (p = 0.005), hypofibrinogenemia (p = 0.028), disseminated intravascular coagulation (DIC) (p = 0.019), and high plasma ALT (p = 0.003) and AST (p = 0.004) plasma activities on initial presentation, as well as a decrease in hemoglobin (p = 0.034) and an increase in WBC count (p = 0.034), plasma bilirubin (p = 0.012) and urea concentration (p = 0.003) between day 0 and 3. In conclusion various laboratory parameters were useful as prognostic

Immunosuppressive therapy for canine immune-mediated hemolytic anemia

The mortality for dogs with severe immune-mediated hemolytic anemia (IMHA) is unacceptably high, and better immunosuppressive regimens are needed to increase survival. Understanding the basic immunology of the disease and the mechanisms of action of the available immunosuppressive therapies will help clinicians choose an appropriate immunosuppressive protocol. Prospective, randomized clinical studies must be conducted to evaluate the efficacy and safety of different combined immunosuppressive modalities to treat canine IMHA and improve patients' outcomes.

Diagnosis and management of autoimmune complications of chronic lymphocytic leukemia/ small lymphocytic lymphoma

Autoimmune cytopenia is an important but poorly understood clinical complication of chronic lymphocytic leukemia/ small lymphocytic lymphoma. We review the pathogenesis, clinical presentation, and management of autoimmune hemolytic anemia, immune thrombocytopenia, and pure red blood cell aplasia in patients with chronic lymphocytic leukemia/ small lymphocytic lymphoma.

Autoimmune hemolytic anemia following allogeneic hematopoietic stem cell transplantation in adult patients

Autoimmune hemolytic anemia (AIHA) after allogeneic hematopoietic stem cell transplantation (HSCT) is still not well characterized. The aim of this study was to analyze the incidence and risk factors for the development of AIHA, as well as its prognosis and response to treatment in a series of patients undergoing allogeneic HSCT at a single institution. Between 1996 and 2004, 272 adult patients with a variety of malignant hematopoietic disorders underwent allogeneic HSCT. Direct antiglobulin testing was performed in routine pretransfusion compatibility testing or after clinical suspicion of AIHA. Twelve patients developed AIHA after HSCT at a median time of 147 days (range, 41-170). The 3-year cumulative incidence of AIHA was 4.44%. Eight cold antibodies and four warm antibodies were detected. Multivariate analysis shows that HSCT from unrelated donors (P=0.02) and the development of chronic extensive graft-versus-host disease (GVHD) (P=0.0004) were the only independent factors associated with AIHA. Two patients are still alive. AIHA was never the primary cause of death but added morbidity in patients with other concomitant complications. Patients undergoing HSCT from unrelated donors and those who develop chronic extensive GVHD are especially predisposed for this complication.

Vincristine-loaded platelet infusion for treatment of refractory autoimmune hemolytic anemia and chronic immune thrombocytopenia: rethinking old cures

We report our experience with vincristine-loaded platelet infusion in patients with refractory immune thrombocytopenia (ITP), autoimmune hemolytic anemia (AIHA), and Evans syndrome. Ten patients with symptomatic thrombocytopenia and/ or hemolytic anemia who failed to respond to two to six different treatment modalities, including corticosteroids and splenectomy, were treated with infusion of vincristine-loaded platelets. Platelets were harvested by plateletpheresis from a healthy ABO compatible blood donor and incubated with 5 mg vincristine. Excess of vincristine was removed, and platelets were resuspended in 50 ml plasma and infused over 30 min. All 10 patients responded, and 6 of them achieved complete remission. The response was prompt, occurring 3-8 days after vincristine-loaded platelet infusion. Two patients with AIHA are still in remission 9 and 8 years posttreatment with no maintenance treatment. Three ITP patients achieved persisted partial response for 6 years, 5 years, and 11 months; in the remaining 5 patients the response lasted for 2-5 months. No side effects were seen. Our results suggest that this inexpensive and well-tolerated treatment modality may be a useful approach in patients with ITP and AIHA refractory to primary therapy.

Evaluation of prognostic factors, survival rates, and treatment protocols for immune-mediated hemolytic anemia in dogs: 151 cases (1993-2002)

OBJECTIVE

To evaluate prognostic factors, survival, and treatment protocols for immune-mediated hemolytic anemia (IMHA) in dogs.

DESIGN

Retrospective study.

ANIMALS

151 dogs with IMHA not associated with underlying infectious or neoplastic disease.

PROCEDURE

lnformation recorded from review of medical records included signalment at the time of initial evaluation; vaccination history; 30-, 60-, and 365-day follow-up outcomes; laboratory data; results of imaging studies; and necropsy findings. Dogs were grouped according to the presence of spherocytes, autoagglutination, a regenerative erythrocyte response, and treatments received (azathioprine, azathioprine plus ultralow-dose aspirin, azathioprine plus mixed-molecular-weight heparin [mHEP], or azathioprine plus ultralow-dose aspirin plus mHEP) for comparisons. All dogs received glucocorticoids.

RESULTS

Cocker Spaniels, Miniature Schnauzers, neutered dogs, and female dogs were overrepresented. Alterations in certain clinicopathologic variables were associated with increased mortality rate. Rates of survival following treatment with azathioprine, azathioprine plus ultralow-dose aspirin, azathioprine plus mHEP, and azathioprine plus ultralow-dose aspirin plus mHEP were 74%, 88%, 23%, and 70%, respectively, at hospital discharge; 57%, 82%, 17%, and 67%, respectively, at 30 days; and 45%, 69%, 17%, and 64%, respectively, at 1 year. In comparison, mean survival rates at discharge and at 30 days and 1 year after evaluation collated from 7 published reviews of canine IMHA were 57%, 58%, and 34%, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Treatment with a combination of glucocorticoids, azathioprine, and ultralow-dose aspirin significantly improved short- and long-term survival in dogs with IMHA.

Differential activation of anti-erythrocyte and anti-DNA autoreactive B lymphocytes by the Yaa mutation

An as-yet-unidentified mutation, Y-linked autoimmune acceleration (Yaa), is responsible for the accelerated development of lupus-like autoimmune syndrome in mice. In view of a possible role for Yaa as a positive regulator of BCR signaling, we have explored whether the expression of the Yaa mutation affects the development and activation of transgenic autoreactive B cells expressing either 4C8 IgM anti-RBC or Sp6 IgM anti-DNA. In this study, we show that the expression of the Yaa mutation induced a lethal form of autoimmune hemolytic anemia in 4C8 transgenic C57BL/6 mice, likely as a result of activation of 4C8 anti-RBC autoreactive B cells early in life. This was further supported, although indirectly, by increased T cell-independent IgM production in spleens of nontransgenic C57BL/6 mice bearing the Yaa mutation. In contrast, Yaa failed to induce activation of Sp6 anti-DNA autoreactive B cells, consistent with a lack of increased IgM anti-DNA production in nontransgenic C57BL/6 Yaa mice. Our results suggest that Yaa can activate autoreactive B cells in a BCR-dependent manner, related to differences in the form and nature of autoantigens.

Autoimmunity in Wiskott-Aldrich syndrome: risk factors, clinical features, and outcome in a single-center cohort of 55 patients

OBJECTIVES

To evaluate the occurrence of autoimmune and inflammatory complications in Wiskott-Aldrich syndrome (WAS) and to determine risk factors and the prognosis of such complications with the aim of improving the definition of treatment options.

METHODS

We reviewed the records of 55 patients with WAS evaluated at Necker-Enfants Malades Hospital (Paris) from 1980 to 2000.

RESULTS

Forty patients (72%) had at least 1 autoimmune or inflammatory complication. Autoimmune hemolytic anemia was detected in 20 cases (36%); in all cases, onset occurred before the age of 5 years. Other complications included neutropenia (25%), arthritis (29%), skin vasculitis (22%), cerebral vasculitis (7%), inflammatory bowel disease (9%), and renal disease (3%). The median survival of the entire population was 14.5 years. Two autoimmune complications and 1 biological factor were predictive of a poor prognosis in this population: autoimmune hemolytic anemia, severe thrombocytopenia recurring after splenectomy, and high serum immunoglobulin M (IgM) levels before splenectomy. Autoimmune hemolytic anemia was significantly more observed in patients with high serum IgM level.

CONCLUSIONS

High serum IgM concentration before splenectomy was identified as a risk factor for autoimmune hemolytic anemia; however, it must be confirmed. Autoimmune hemolytic anemia and severe thrombocytopenia recurring after splenectomy were 2 indicators of a poor prognosis. Those results suggest that patients with WAS and IgM levels more than mean + 2 standard deviations before splenectomy should be placed under strict surveillance. Furthermore, severe autoimmune complications should lead, as early as possible, to hematopoietic stem cell transplantation using the best available donor.

Cefotetan-induced haemolytic anaemia. A review of 85 cases

OBJECTIVE

Reports of cefotetan-associated haemolytic anaemia have prompted a US Food and Drug Administration (FDA) review of the overall number, severity, and causality of such cases.

METHODS/RESULTS

A search of the FDA's Spontaneous Reporting System and the World Health Organization's database revealed 85 cases of haemolytic anaemia since the approval of cefotetan in 1985, 15 of them fatal. Moderate to severe haemolysis was reflected in a mean fall in haemoglobin levels by 6.65 mg/dl (n = 20) and a mean final haemoglobin concentration of 5.2 mg/dl (n = 52). Transfusion of packed red blood cells was required in 47 patients (55.3%). New onset renal dysfunction was noted in 7 patients (8.2%). The direct antiglobulin test was positive in 50 patients (59%), and serological studies revealed antibodies to cefotetan in 30 patients (35%).

CONCLUSION

These data suggest that treatment with cefotetan may induce severe autoimmune haemolytic anaemia.

Lethal autoimmune hemolytic anemia in CD47-deficient nonobese diabetic (NOD) mice

The glycoprotein CD47 (integrin-associated protein, IAP) is present on the surface of virtually all cells, including red blood cells (RBCs). CD47 acts like a marker of self by ligating the macrophage inhibitory receptor signal regulatory protein alpha (SIRPalpha). In this manner mild reactivity of wild-type RBCs with macrophage phagocytic receptors is tolerated, whereas otherwise identical CD47-deficient RBCs are rapidly eliminated. We show here that virtually all CD47-deficient nonobese diabetic (NOD) mice spontaneously develop severe lethal autoimmune hemolytic anemia (AIHA) at 180 to 280 days of age, whereas none of the control CD47(+) NOD mice develop lethal AIHA at least during the first year of life. This phenotype is at least partially due to a markedly increased rate of elimination of opsonized CD47(-/-) compared to CD47(+) RBCs. Similarly, CD47(-/-)C57BL/6 mice were much more sensitive than their wild-type counterparts to experimental passive AIHA induced by anti-RBC monoclonal antibodies. Thus, CD47-SIRPalpha signaling can have a profound influence on the severity of AIHA, making manipulation of this signaling pathway a theoretically appealing avenue in the treatment of the disease.

[Use of human intravenous immunoglobulin in dogs with primary immune mediated hemolytic anemia]

Immune mediated hemolytic anemia (IMHA) in dogs is a severe disease with a high mortality rate. As human immunoglobulin (HIG) was reported to be beneficial for the treatment of IMHA in dogs we examined the influence of HIG on the course of the disease in our dogs with IMHA. Of 22 dogs with primary IMHA 9 dogs received in addition to routine immunosuppressive therapy HIG at a dose of 0.19 to 0.68 g/kg (median 0.35 g/kg), 13 dogs did not receive HIG (-HIG group). Both groups were similar in terms of age, weight, the presence of autoagglutination, spherocytosis, positive Coombs' test, icterus and pigmenturia. The lowest hematocrit measured during the disease was significantly lower in the +HIG group compared to the -HIG group and dogs in the +HIG group received significantly more transfusions than those of the -HIG group. This is an indication for more severe disease signs of the +HIG group dogs. Although mortality during hospitalization and the time from hospital admission to release or death was not significantly different between the two groups, we interpret this similar course of the IMHA despite more severe signs of the +HIG group dogs as a potential positive effect of the HIG therapy.

Influence of drug treatment on survival of dogs with immune-mediated hemolytic anemia: 88 cases (1989-1999)

OBJECTIVE

To evaluate association of various treatments for immune-mediated hemolytic anemia with survival to discharge in dogs.

DESIGN

Retrospective cross-sectional analysis.

ANIMALS

88 dogs with idiopathic immune-mediated hemolytic anemia.

PROCEDURE

Medical records of dogs with immune-mediated hemolytic anemia treated between August 1989 and August 1999 were examined. Survival to discharge, PCV at referral, autoagglutination, and drug treatment and dosage were recorded.

RESULTS

Treatments included administration of prednisone, dexamethasone, azathioprine, danazol, cyclosporine, cyclophosphamide, bovine hemoglobin solution, and human immunoglobulin. Overall mortality rate was 50.5%. Significant associations with death were not detected for use of azathioprine, cyclosporine, danazol, or human immunoglobulin. A significant difference in mortality rate was not detected between use of multiple immunosuppressive drug treatments and use of single immunosuppressive drugs. Use of cyclophosphamide and bovine hemoglobin solution were associated with significant increases in relative risk of death

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that use of cyclophosphamide and bovine hemoglobin solution in treatment of idiopathic immune-mediated hemolytic anemia may be associated with increased risk of death.

Treatment of immune-mediated hemolytic anemia in dogs with cyclophosphamide

A review of 60 cases of immune-mediated hemolytic anemia (IMHA) in the dog was performed in order to characterize the disease and to identify potential prognostic indicators. Dogs ranged in age from 1 to 13 years, with a mean age of 6.5 years. The 2 most commonly affected breeds were Cocker Spaniels and Labrador Retrievers. Fifty-two of the 60 dogs tested (87%) were autoagglutination positive and spherocytes were present in 45 (75%). Forty-one (89%) of 46 patients tested positive for the presence of immunoglobulin on the red blood cell surface (Coombs assay). The most common clinical signs at presentation were lethargy, weakness, pale mucous membranes, icterus, hemoglobinuria, and anorexia. PCV less than 25% was present in 59 (98%) dogs. At the time of presentation, 35 dogs (58%) had a nonregenerative anemia, whereas 25 patients (42%) had a regenerative response. Thrombocytopenia was seen in 41 (68%) dogs. Nine of 34 dogs (26%) had a prolonged prothrombin time, 19 of 34 (56%) had a prolonged activated partial thromboplastin clotting time, and 12 of 34 (35%) had abnormal fibrinogen concentrations. All dogs received prednisone at immunosuppressive doses (2.2-4.4 mg/kg PO as a single or divided dose every 24 hours) and cyclophosphamide as primary therapy. Forty-one dogs (63%) received cyclophosphamide at 50 mg/m2 q24h for 4 days, whereas 9 dogs (15%) received an initial high dose (200 mg/m2) followed by 3 days of a lower dose (50 mg/m2 q24h). No statistical difference in survival times was found for either protocol. Thirteen dogs were treated with azathioprine in addition to cyclophosphamide and prednisone. The median survival time of dogs that received all 3 drugs was 370 days as compared to 9 days for those dogs that were treated with cyclophosphamide and prednisone alone. Thirty-one (52%) dogs died from the disease, 13 (22%) dogs were alive, and 15 (25%) dogs were lost to follow-up. The median length of survival for all dogs was 21 days. Eight dogs that were discharged from the hospital suffered a relapse (PCV < 25%).

Autoimmune hemolytic anemia in chronic lymphocytic leukemia: clinical, therapeutic, and prognostic features

Fifty-two cases of autoimmune hemolytic anemia (AHA) were observed within a series of 1203 patients (4.3%) with chronic lymphocytic leukemia (CLL) followed at a single institution. Nineteen were observed at the time of CLL diagnosis and 33 during the clinical follow-up. Ninety percent of the patients with CLL/AHA showed active CLL and 25% had been treated previously. The antierythrocyte autoantibody (AeAb) was an IgG in 87% of cases and an IgM in 13%. A lymphocyte count more than 60 x 10(9)/L (P <.00001), age above 65 years (P <.01), and male gender (P <.01) emerged as independent parameters that correlated significantly with an increased rate of AHA at CLL diagnosis. Patients previously treated with chlorambucil (CB) plus prednisone (PDN) and with fludarabine plus PDN showed a similar rate of AHA (1.8% and 2.5%, respectively). After steroid therapy associated with CB in case of active CLL, 70% of patients achieved the complete disappearance of the AeAb. The actuarial AHA relapse-free survival probability was 54% at 5 years and the median survival probability after AHA was 41 months. Infections represented the main cause of morbidity and mortality. IgG AHA and the occurrence of AHA at the same time of CLL diagnosis emerged as independent factors significantly correlated with a better survival probability of AHA/CLL patients. Taken together, this study indicates that in CLL, AHA is a rare event with no independent effect on survival for which steroids, associated with CB if required, and a careful management of infections may successfully control the 2 conditions. Cooperative studies are needed to better define the optimal steroid schedule and the therapeutic role of other immunosuppressive agents and splenectomy. (Blood. 2000;95:2786-2792)

Immune-mediated hemolytic anemia: 70 cases (1988-1996)

Survival times and mortality rates in dogs with idiopathic immune-mediated hemolytic anemia (IMHA) have been infrequently reported in the literature. This study evaluates survival and mortality in a large group of dogs with IMHA. The association of age, sex, and breed with IMHA was evaluated by comparing affected dogs to control dogs admitted to the hospital during the same time period. Treatment regimens were reviewed to determine the effects of different agents upon survival of dogs with IMHA during hospitalization and after discharge. Median survival times for each treatment group were 57 days (prednisone), 28 days (prednisone, cyclophosphamide), 974 days (prednisone, azathioprine), 15 days (prednisone, cyclophosphamide, azathioprine), and one day (no treatment). Overall mortality rate in the population of dogs studied was 70%. Twenty-nine (41.4%) dogs either died or were euthanized while hospitalized. Forty-one (59%) dogs were discharged from the hospital. Of the dogs discharged, 10 died within the first month, another five died within three months, and another five died within a year of discharge due to assumed complications of therapy or relapses of IMHA.

Severe autoimmune hemolytic anemia in eight patients treated with fludarabine

We have used fludarabine to treat 36 patients with various lymphoid malignancies, including 29 with chronic lymphocytic leukemia (CLL). All these patients were heavily pretreated, and FAMP was prescribed on a compassionate basis. Eight patients (22%) developed severe autoimmune hemolytic anemia (AIHA) during or after treatment, and one died. Five patients had no previous history of hemolysis. These cases confirm the high incidence of AIHA after FAMP and suggest that the use of highly effective lymphocytotoxic agents such as fludarabine in heavily pretreated patients increases the risk of AIHA in CLL and other lymphoproliferative disorders.

Generalized autoimmune disease in interleukin-2-deficient mice is triggered by an uncontrolled activation and proliferation of CD4+ T cells

Interleukin-2-deficient mice (IL-2-/-) crossed to a BALB/c genetic background develop a lymphoproliferative syndrome with severe hemolytic anemia and die within 5 weeks of age. The presence of autoantibodies of various specificities and inflammatory lesions in several organs are indicative of a generalized auto-immune disease. No alterations of the immune system were observed in 6-day-old animals, but 10-day-old mice already showed an increased proliferation and polyclonal activation of lymphocytes. The treatment of IL-2-/- mice with anti-gp39(CD40L) antibody prevented the disease and indicated that the appearance of activated CD4- T cells (CD44high, CD69-) represents the first alteration of the immune system in IL-2-/- mice. Collectively, our results suggest that an essential role of IL-2 in vivo, which is not compensated by other cytokines, is the maintenance of self tolerance.

Fatal immune hemolytic anemia due to cefotetan

In the first death associated with immune hemolytic anemia due to cefotetan, the patient developed hemolytic anemia and renal failure, dying 12 days after the beginning of 1 week's cefotetan therapy. The patient's serum contained strong antibodies reacting with cefotetan-treated red cells (RBCs) and with uncoated RBCs in the presence of cefotetan; a much weaker, drug-independent antibody was also detected. Three-days before the patient's death, the antibody reacting with cefotetan-coated RBCs rose to a titer of 262,144; the titer of the antibody to uncoated RBCs, in the presence of cefotetan, rose to 2048; the titer of the drug-independent antibody remained at 4.

Fatal immune hemolytic anemia and hepatic failure associated with a warm-reacting IgM autoantibody

Autoimmune hemolytic anemia (AIHA) caused by warm-reacting IgM autoantibodies is rare. We report a fatal case of primary AIHA with a warm-reacting IgM autoantibody. Recurrent episodes of intravascular hemolysis, unresponsive to all therapy and progressive hepatic dysfunction characterized the patient's clinical course. Despite corticosteroid therapy, splenectomy and multiple blood transfusions, the patient died from liver failure. The IgM autoantibody caused autoagglutination of the patient's red cells at 37 degrees C. Eluates prepared from the patient's red cells agglutinated saline-suspended test cells without the addition of antiglobulin reagent. We propose that warm-reacting IgM antibodies may lead to in vivo autoagglutination and may be associated with hepatic failure.

Significance of monospecific antisera in the diagnosis and prognosis of autoimmune haemolytic anaemias

The significance of the monospecific antiglobulin test in the diagnosis and prognosis of autoimmune haemolytic anaemia (AIHA) was tested in 74 patients with AIHA and 59 patients with secondary AIHA. There were 48 female and 26 male patients. Idiopathic AIHA patients more often had two or more positive monospecific reactions in the direct antiglobulin test than secondary AIHA patients. Increased serum lactate dehydrogenase levels, indicating increased intravascular haemolysis, were found more frequently in patients with two or more positive monospecific antiglobulin tests. The number of thromboembolic complications and deaths correlated positively with the number of positive monospecific reactions in antiglobulin test. In particular, positive direct antiglobulin test with monospecific anti-IgA was often combined with severe AIHA.

Immune haemolytic disease: the autoimmune haemolytic anaemias

The autoimmune haemolytic anaemias are common syndromes, with protean clinical features reflecting a variety of significant associated diseases. A diagnosis of this state should alert the clinician to the possibility of an aberrant immune mechanism. Years may elapse between development of the haemolytic process and the eventurl emergence of the entire disease pattern. The haemolytic anaemia should be considered as the easily diagnosed part of a complex, multisystem disease resulting from malfunction of the immune apparatus. Therapy can be exceedingly difficult. The following outline is suggested as a general approach: 1. Start prednisone 60 mg daily. If a therapeutic response occurs, continue this dosage until the haematocrit reaches 30 per cent. A slow but progressive reduction should then be initiated. 2. If prednisone dosages greater than 15 mg daily are required to maintain the remission, treat as a therapeutic failure. 3. If no response occurs after one week of prednisone, start azathioprine 2.0 to 2.5 mg/kg. 4. If no response is apparent after two additional weeks (three weeks of prednisone), progressively reduce and eventually discontinue prednisone. 5. If no response occurs after a total of four weeks of azathioprine, one of two alternative therapies should be started: (a) perform splenectomy, or (b) increase azathioprine by 25 mg daily, every one to two weeks, until either a response occurs or reduced bone marrow function is observed. 6. If azathioprine and splenectomy both fail, experimental therapies such as antithymocyte antiserum or thymectomy should be considered. 7. Transfusions are to be used only as temporary paliation in life-threatening neurological or cardiovascular complications.

The effect of induced chronic viral infections on the immunologic diseases of New Zealand mice

Chronic infections induced at birth with either LCM, an RNA virus, or polyoma, a DNA virus, in NZB, NZW, and NZB x W mice enhance ANA formation, aggravate the immune complex glomerulonephritis, and increase the associated mortality. The ANA titer was increased without apparent change in specificity of the antibodies involved in all three types of mice. Glomerulonephritis, while more severe in infected mice, was of the same type as occurred spontaneously and was characterized by a granular to lumpy accumulation of host IgG and C3 in the mesangia and along the capillary walls of the glomeruli. Of the LCM infected mice of all three types over 50% had died of glomerulonephritis by 6 months and over 85% by 9 months. Of the polyoma infected mice of all three types approximately 20% had died of glomerulonephritis by 6 months and over 40% by 9 months. Of the uninfected controls of all three types less than 10% had died by 6 months and less than 20% at 9 months except for the NZB x W females which had a 67% mortality at 9 months as a result of their spontaneous glomerulonephritis. The two viral infections had significant effect on the incidence of anti-red cell antibodies or the severity of autoimmune hemolytic anemia in any of the three NZ mice.