Autoimmune cytopenia, including autoimmune hemolytic anemia (AIHA), pure red cell aplasia (PRCA), Evans syndrome (ES), usually has good responses to steroids therapies as first line, but there is a considerable percentage of patients who relapse, become refractory or dependent on steroids to maintain an acceptable level of hemoglobin or platelets. The effects of the second line therapy are also not satisfactory and sometimes not available. The investigators aim to explore the efficacy and side-effect of tacrolimus for refractory autoimmune cytopenia.

Tacrolimus binds FKBP12 with high affinity after entry into cytoplasm, suppresses calcineurin activity and prevents nuclear translocation of transcription factors such as NF-AT that are involved in IL-2 gene transcription. As a result, T-cell activation is inhibited with a subsequent reduction in the production of cytokines that include IL-2, TNF-α, IL-3, IL-4, IFN-γ, IL-6 and IL-10; B-cell activation, class-switching and immunoglobulin production are also attenuated. Reports on the use of tarcrolimus in the treatment of autoimmune cytopenia are anecdotal and describe therapy with a variety of drug dosages.

The purpose of this study is to evaluate the effect of tacrolimus on patients with refractory autoimmune cytopenia, the side-effects will be documented and plasma concentration of tacrolimus will be monitor.

Inclusion Criteria:

• Refractory autoimmune cytopenia, including autoimmune hemolytic anemia, pure red cell aplasia, Evans syndrome.
• 18-80 years old.
• No response or intolerant to first and second line therapies.
• ECOG Performance Status of 0-2
• Written informed consent.

Exclusion Criteria:

• Other diseases which might cause hematological abnormalities.
• Response and well tolerate to first or second line therapy.
• Patients who are under 18-year-old or over 80-year-old.
• Pregnant or lactating.
• Patients unwilling to or unable to comply with the protocol.