Liver function test abnormalities and their clinical relevance in primary myelofibrosis

Effectiveness of leukapheresis on early survival in acute myeloid leukemia: An observational propensity score matching cohort study

BACKGROUND

The association between leukapheresis (LK) as a treatment option for hyperleukocytosis (HL) in patients with acute myeloid leukemia (AML) remains controversial.

METHODS

Data were extracted from the electronic medical record for 2801 patients with AML between April 2009 and December 2019. LK was performed when the leukocyte count was ≥100 × 109 /L at the time initial bone marrow examination.

RESULTS

A comparison between the patients with HL in the non-LK (n = 1579) and LK (n = 208) groups revealed survival probabilities (%) of 93.2% and 90.4% (P = .130) for day 30 (D30), 85.4% and 84.2% (P = .196) for D60, and 83.6% and 80.8% (P = .258) for D90, respectively. After propensity score matching, a comparison between the patients with HL in the non-LK (n = 192) and LK (n = 192) groups revealed survival probabilities (%) of 83.9% and 91.2% (P = .030) for D30, 75.0% and 84.9% (P = .015) for day 60 (D60), and 62.4% and 81.3% (P = .034) for day 90 (D90), respectively. After D150, the observed effect of LK appeared to be mitigated without a survival benefit.

DISCUSSION

LK was associated with improved early survival outcomes at D30, D60, and D90 among patients with AML exhibiting HL. Thus, it may be considered a treatment option for reducing cell mass in such patients.

A Case Report on Hepatic Extramedullary Hematopoiesis as the Manifestation of Progression to Secondary Myelofibrosis in a Patient with Essential Thrombocytopenia

Myeloproliferative neoplasms (MPN), which include primary myelofibrosis (PMF) and essential thrombocytopenia (ET), are characterized by the clonal proliferation of mature blood cells as a result of the overactivation of the JAK/STAT pathway. Extramedullary hematopoiesis (EMH), a common complication of PMF, occurs due to the dysregulation of the bone marrow microenvironment. We report an interesting case of a 73-year-old female with a working diagnosis of ET who was found to have EMH in the liver on biopsy after she had newly onset elevated liver enzymes and her ET had progressed to secondary myelofibrosis. We conclude that in patients with MPN who have rising liver enzymes, EMH in the liver should be part of the differential diagnosis. In addition, we believe that EMH is a sign of progression from MPN to secondary myelofibrosis and that it is imperative for performing bone marrow aspiration and biopsy in order to reassess hematopoiesis and to look for bone marrow fibrosis as well as evidence of progression.

Tet2 deficiency drives liver microbiome dysbiosis triggering Tc1 cell autoimmune hepatitis

The triggers that drive interferon-γ (IFNγ)-producing CD8 T cell (Tc1 cell)-mediated autoimmune hepatitis (AIH) remain obscure. Here, we show that lack of hematopoietic Tet methylcytosine dioxygenase 2 (Tet2), an epigenetic regulator associated with autoimmunity, results in the development of microbiota-dependent AIH-like pathology, accompanied by hepatic enrichment of aryl hydrocarbon receptor (AhR) ligand-producing pathobionts and rampant Tc1 cell immunity. We report that AIH-like disease development is dependent on both IFNγ and AhR signaling, as blocking either reverts ongoing AIH-like pathology. Illustrating the critical role of AhR-ligand-producing pathobionts in this condition, hepatic translocation of the AhR ligand indole-3-aldehyde (I3A)-releasing Lactobacillus reuteri is sufficient to trigger AIH-like pathology. Finally, we demonstrate that I3A is required for L. reuteri-induced Tc1 cell differentiation in vitro and AIH-like pathology in vivo, both of which are restrained by Tet2 within CD8 T cells. This AIH-disease model may contribute to the development of therapeutics to alleviate AIH.

Marked Hyperbilirubinemia Associated with Primary Myelofibrosis Responsive to Ruxolitinib

Primary myelofibrosis (PMF) is a chronic myeloproliferative disorder seen in older adults which can present both with hepatosplenomegaly as well as mild nonspecific liver enzyme abnormalities. Mild elevations in bilirubin can occasionally be seen due to both intravascular hemolysis as well as extramedullary hematopoiesis. Marked hyperbilirubinemia as a presenting sign of PMF progression, however, has not been reported. We present the case of a patient with a remote diagnosis of PMF, who presented with marked hyperbilirubinemia with a notable response to ruxolitinib.

The Implications of Liver Biopsy Results in Patients with Myeloproliferative Neoplasms Being Treated with Ruxolitinib

Ruxolitinib is increasingly being utilized for the treatment of myelofibrosis and polycythemia vera, but the potential for hepatic toxicity is poorly understood. We performed a retrospective review of hepatic damage occurring in patients with myeloproliferative neoplasms receiving ruxolitinib. Relevant histologic images of liver biopsies were reviewed by an experienced liver pathologist and reported to a multidisciplinary team including hepatology and hematology. A variety of liver pathology was observed including extramedullary hematopoiesis, obliterative portal venopathy, and drug-induced liver injury. In all cases reviewed, the liver biopsy had significant treatment implications. We conclude that hepatology referral and liver biopsy in patients receiving ruxolitinib therapy with biochemical evidence of liver injury reveals a variety of etiologies which have significant treatment impact. Clinicians should be aware of the potential causes of liver damage in this population and initiate prompt referral and liver biopsy.