Epidemiology of Secondary Warm Autoimmune Haemolytic Anaemia—A Systematic Review and Meta-Analysis

Abstract

Background: Warm autoimmune haemolytic anaemia (wAIHA) is a haemolytic disorder, most commonly seen among adults and is classified as either primary or secondary to an underlying disease. We describe the age and sex distribution and the proportion of secondary wAIHA. Method: We retrieved 2635 published articles, screened abstracts and titles, and identified 27 articles eligible for full-text review. From these studies, we extracted data regarding number of patients, sex distribution, age at diagnosis, number of patients with secondary wAIHA, and whether the patients were diagnosed through local or referral centres. All data were weighted according to the number of included patients in each study. Results: 27 studies including a total of 4311 patients with wAIHA, of which 66% were females, were included. The median age at diagnosis was 68.7 years, however, wAIHA affected all ages. The mean proportion of secondary wAIHA was 49%, most frequently secondary to systemic lupus erythematosus. The proportions of secondary wAIHA reported from primary vs. referral centres were 35% vs. 59%, respectively. Conclusion: This review consolidates previously reported gender distribution. The higher proportion of secondary wAIHA in referral centres suggests that the most severely affected patients are disproportionally more frequent in such facilities.

Survival in autoimmune hemolytic anemia remains poor, results from a nationwide cohort with 37 years of follow‐up

“…2,23,26 We disaggregated patients with the AIHA diagnosis into primary and secondary types based on specified diagnoses, such as chronic lymphocytic leukemia or systemic lupus erythematosus, as described previously. 3 A patient qualified as having secondary AIHA diagnosis if a defining associated diagnosis was identified in the Patient Register before or up to 30 days following the first diagnosis registration of AIHA (Table S1). However, due to limitations in diagnosis registrations, it was not possible to disentangle cold agglutinin syndrome from CAD, and therefore we classified all these as CAD.…”

“…1,2 Warm type AIHA may be primary without associated explanatory diseases or secondary AIHA where an underlying disease, most frequently systemic lupus erythematosus or lymphoproliferative disorders initiate the autoimmune RBC reaction. 3 Cold type AIHA encompass different clinical phenotypes of which the predominant form is cold agglutinin disease (CAD) a monoclonal disease arising from clonal lymphoproliferative cells in the bone marrow. 4,5 The difference in etiology gives rise to differences in treatment.…”

The Risk of Developing Osteoporosis in Hemolytic Anemia—What Aggravates the Bone Loss?

“…Comorbidities were important confounding factors in this study. We defined comorbidities as occurring before the index date and included inflammatory bowel disease (ICD-9-CM 555 and 556) [ 15 ], diabetes (ICD-9-CM 250) [ 7 ], cholelithiasis (ICD-9-CM 574), and peptic ulcer disease (ICD-9-CM 533) [ 16 ].…”

“…Warm-reactive autoimmune hemolytic anemia (AIHA) is the most common autoimmune-related anemia and mostly affects women. It may arise spontaneously or can be associated with diseases such as SLE, lymphoma, and chronic lymphocytic leukemia, among others [ 6 , 7 ]. Glucocorticoids are the first-line therapies for warm-reactive AIHA, although long-term use of glucocorticoids is associated with osteoporosis and osteonecrosis of the femoral head [ 8 , 9 ].…”

Diagnosis and Management of Autoimmune Hemolytic Anemias

“…In the former, the autoantibody is an IgG that binds erythrocytes at 37 °C, may activate complement in few cases, and determines extravascular hemolysis mainly in the spleen via Fc-mediated phagocytosis. wAIHA is the most frequent form, and it can be primary or secondary to several conditions, as highlighted in the meta-analysis of a total of 4311 patients [ 2 ]. CAD is the second-most frequent AIHA form due to an IgM autoantibody that spontaneously agglutinates erythrocytes at cold temperatures and strongly activates complement.…”