Autoimmune Hemolytic Anemia In Cancer Patients At a Tertiary Center In Southern Nigeria

With the emergence of non-communicable diseases accounting for 63% of deaths globally in 2008, and about four-fifths of these deaths occurring in the low and middle income countries; Cancer has been identified as the second leading cause of death by the World Health Organization.

Anemia is one of the commonest symptoms of cancer and very frequently causes the patient to seek for medical attention even before the cancer is diagnosed. Anemia contributes tremendously to the co-morbidity of cancer, and proper treatment of anemia improves quality of life. Autoimmune haemolytic anemia (AIHA) is a heterogeneous group of diseases characterized by autoantibody production against red cell antigens, leading to their shortened survival. Autoimmunity and cancer are conditions associated with impaired cellular regulation. Immune dysregulation is believed to play a pathogenic role in the development of both autoimmunity and neoplasia. The objectives of this study are to provide baseline data on the prevalence of anemia in cancer in the Niger-Delta region of Nigeria, to determine if AIHA plays a significant role in anemia of cancer, and ascertain the cancers in which AIHA occurs in our environment.

This was a case-control study conducted on patients with confirmed diagnoses of solid, soft-tissue and haematological malignancies. Controls were healthy age, sex matched subjects. Cases with, and without exposure to chemotherapy were analyzed as sub groups.

Three hundred and seventy six (376) participants (188 cancer patients and 188 controls) were enrolled into the study. Complete blood count, reticulocyte count, peripheral blood film, direct antiglobulin test (DAT), indirect antiglobulin test (IAT) and bilirubin assays were done. The DAT was performed on fresh samples not more than 6 hours after collection using polyspecific antihuman globulin. Analysis was done using Microsoft Office Excel 2007®

Anemia was found in 124 (66%) of the total cancer population, while only 5 (2.7%) participants had anemia in the control group. Anemia was found in 98 of 149 (65.8%) in the cancer group not yet exposed to chemotherapy, while 26 of 39 cases (66.7%) in the cancer group who had received chemotherapy had anemia. Three (1.6%) of the 188 cancer patients (all not exposed to chemotherapy) were found to have a positive DAT, of which two were strongly positive with features of hemolysis and therefore had AIHA. The 2 patients with AIHA had chronic lymphocytic leukaemia. The third case of positive DAT had malignant teratoma and a weak DAT with no features of hemolysis. The 3 cases of positive DAT had positive IAT. AIHA was the aetiology of the anemia in 2 (2%) of the 98 cases with anemia in the group not yet exposed to chemotherapy. The group receiving chemotherapy had no positive DAT. There was no positive DAT in the control group, however there is no significant difference in the occurrence of AIHA in the cancer group from the controls (p= 0.08)

The data generated shows that anemia is common in patients with cancer as generally reported. The prevalence of anemia in the cancer group not yet exposed to chemotherapy and those on chemotherapy was about the same. Our data also suggests AIHA may play a role in the aetiology of anemia of cancer; however, patients with lymphoid malignancies are more predisposed. Our results show that a positive DAT may occur without hemolysis.

No relevant conflicts of interest to declare.