Spontaneous hematological remission of acute myeloid leukemia

[A case of spontaneous remission of acute myeloid leukemia with MLL-AF9 rearrangement and abnormal liver function]

Objective: To explore the clinical features and possible pathogenesis of spontaneous remission of acute myeloid leukemia (AML) . Methods: We retrospectively analyzed the clinical data of a patient with spontaneous remission of AML, MLL-AF9 rearrangement, and abnormal liver function in the First Affiliated Hospital of Zhengzhou University, and the relevant pieces of literature were summarized. Results: The patient experienced lung infection, fever, and liver dysfunction and was treated with anti-infection and blood transfusion. After complete response (CR) , the patient remained in CR with mild, indirect bilirubin elevation at 35 months of follow-up. Additionally, 56 cases of adult AML (non-acute promyelocytic leukemia) were reported in the literature from 1990 to June 2021. The cases were checked by bone marrow aspiration, and our patients were summarized and analyzed. Furthermore, 57 patients, including 37 males and 20 females, with a median age of 51 (20-83) years and a median remission time of five months; 52 patients achieved complete remission. In addition, there were five cases with long-term remission and a chromosomal record, with no recurrence so far, three with normal karyotype and two with t (9;11) (q21;q23) . Conclusion: The spontaneous remission of leukemia is rare and may be related to immunosuppression and genes.

Spontaneous Remission in a Patient With Acute Myeloid Leukemia Leading to Undetectable Minimal Residual Disease

Although rare, spontaneous remission (SR) of acute myeloid leukemia (AML) has been reported in the literature, the underlying mechanisms driving remission remain unknown. However, it is most commonly associated with a preceding severe infection. We present a case of a 40-year-old man with no past medical history who presented to our hospital with severe left hip pain and fevers and was found to have AML. Chemotherapy was delayed because the patient required extensive debridement and fasciotomy of his left hip and a prolonged course of antibiotics. After his acute illness had stabilized, a repeat bone marrow biopsy was performed which showed no abnormal myeloid blasts and resolution of his original cytogenetic and molecular abnormalities. At the time of this writing, our patient remains in remission with undetectable minimal residual disease (MRD), now 14 months from his initial diagnosis of AML.

The role of TLR8 signaling in acute myeloid leukemia differentiation

Acute myeloid leukemia (AML) is an aggressive disease with a poor 5-year survival of 21% that is characterized by a differentiation arrest of immature myeloid cells. For a rare subtype of AML (acute promyeloctyic leukemia, 5-10% of cases) all-trans retinoic acid therapy removes the differentiation block, yielding over a 90% cure rate. However, this treatment is not effective for the other 90-95% of AML patients, suggesting new differentiation strategies are needed. Interestingly, differentiation is induced in normal hematopoietic cells through Toll-like receptor (TLR) stimulation and TLRs are expressed on AML cells. We present evidence that the TLR8 activation promotes AML differentiation and growth inhibition in a TLR8/MyD88/p38 dependent manner. We also show that that TLR7/TLR8 agonist, R848, considerably impairs the growth of human AML cells in immunodeficient mice. Our data suggests TLR8 activation has direct anti-leukemic effects independent of its immunomodulating properties that are currently under investigation for cancer therapy. Taken together, our results suggest that treatment with TLR8 agonists may be a promising new therapeutic strategy for AML.