HP and autoimmune hemolytic anemia: The absolute value of Ret in the secondary group [(134.55 ± 20.67) × 109/L] was significantly lower than in the primary group [(193.88 ± 27.32) × 109/L] (p = 0.09); the level of Hp in the secondary AIHA group [(0.75 ± 0.19) g/L] was higher than that in the primary AIHA group [(0.34 ± 0.05) g/L] (p = 0.004).