Direct Coombs Test Positivity in B-Chronic Lymphoid Leukemia: a Marker of Advanced Clinical Disease

Background: Chronic lymphoid leukemia (CLL) is a malignant hematopoietic disorder, the most commonof all adult leukemias with a distinctive immunophenotype. It is well established that CLL patients can haveautoimmune complications, amongst them autoimmune hemolytic anemia as the most frequent. This studywas carried out to determine the frequency of direct Coombs Test positivity in CLL patients and its possiblecorrelation with Rai staging, hematological parameters and biochemical markers. Materials and
Methods: Thisdescriptive cross sectional study was carried at Liaquat National Hospital from January 2011 to June 2013. Sixtyuntreated patients with B- chronic lymphoid leukemia were enrolled. Complete blood count, direct Coombstest, serum urea, creatinine, uric acid and LDH levels were determined. Data were compiled and analyzed usingSPSS version 21.
Results: Out of 60 patients, 42(70%) were males and 18(30%) were females. Mean age was59±9.2 years. Male to female ratio was 2.1: 1. The frequency of direct antiglobulin test (DAT) positivity wasfound to be 23.3%. The monospecific IgG was positive in 11 patients (18.3%); C3d positivity was evident in 1patient (1.6%) and 2 patients (3.3%) had dual IgG and C3d positivity. The mean hemoglobin was 10.8±2.4gm/dl. Significantly low mean hemoglobin of 8.3±3.0 gm/dl was seen in Coombs positive patients compared withnegative patients having a mean hemoglobin level of 11.7±1.6 gm/dl (P<0.001). DAT positivity also demonstrateda positive association with advanced Rai stage III disease (P<0.01). No associations were noted with age, genderand biochemical markers.
Conclusions: Direct Coombs test positivity in CLL in our patients, unlike in Westernstudies, appears relatively high, indicating significant autoimmune hemolytic anemia and advanced Rai stagein our setting. DAT positivity can be considered as a surrogative marker for advanced clinical disease.