Calreticulin mRNA expression and clinicopathological characteristics in acute myeloid leukemia

Calreticulin, encoded by CALR, is a multifunctional protein with roles in calcium homeostasis and chaperoning molecular processes. This study aimed to evaluate calreticulin mRNA expression levels in acute myeloid leukemia (AML) compared with other hematologic malignancies, and to investigate the clinicopathological characteristics associated with expression in AML patients. The study group included 43 patients diagnosed with AML, 57 with other hematologic malignancies, and 21 benign hematologic conditions. CALR mRNA quantification using real-time polymerase chain reaction revealed it to be significantly higher in AML compared with other hematologic malignancies (P < 0.0001). There was no difference in CALR mRNA expression between AML subgroups by karyotype (P = 0.3201). No differences were found in age, white blood cell counts, platelet counts, bone marrow blast percentage, calcium, lactate dehydrogenase or CD34 expression rate between the high and low CALR groups (CALR mRNA ≥ 1.2 fold and <1.2 fold, respectively), although hemoglobin and sex differences were observed. Although statistically not significant, there was a trend that Relapse rate was lower (54.5% vs. 84.6%) (P = 0.1063) and disease-free survival was longer (22 months vs. 7 months) (P = 0.0784) in low CALR group, whereas overall survival was similar between the two groups (11 months and 8 months). The clinical relevance of CALR expression in AML remains to be clarified in a larger cohort.