Long-Term Follow-Up of Tufting Enteropathy Caused by EPCAM Mutation p.Asp253Asn and Absent EPCAM Expression.

Tufting enteropathy (TE) is caused by recessive epithelial cell adhesion molecule (EPCAM) mutations, features congenital intractable diarrhea, growth retardation, and a characteristic disorganization of surface enterocytes. TE generally requires parenteral nutrition (PN) throughout childhood and into adulthood or a small bowel transplantation. We report 2 siblings with TE; a 3-year-old patient 1 intermittently receives partial PN, monthly somatostatin therapy, tolerates a normal diet and has a normal stool output. However, she is the sixth patient of 90 TE patients in literature, to develop a chronic arthritis. A 12-year-old patient 2 is on a normal diet, and did not require PN for the past 8 years. Duodenal biopsies showed characteristic tufts, and a complete lack of EPCAM staining. Both siblings were homozygous for EPCAM mutation c.757G>A (p.Asp253Asn). This observation shows that an overall favorable outcome can be obtained in TE, even with abrogated intestinal EPCAM expression.

The FMS like Tyrosine Kinase 3 (FLT3) Is Overexpressed in a Subgroup of Multiple Myeloma Patients with Inferior Prognosis.

Therapy resistance remains a major challenge in the management of multiple myeloma (MM). We evaluated the expression of FLT3 tyrosine kinase receptor (FLT3, CD135) in myeloma cells as a possible clonal driver. FLT3 expression was analyzed in bone marrow biopsies of patients with monoclonal gammopathy of undetermined significance or smoldering myeloma (MGUS, SMM), newly diagnosed MM (NDMM), and relapsed/refractory MM (RRMM) by immunohistochemistry (IHC). FLT3 gene expression was analyzed by RNA sequencing (RNAseq) and real-time PCR (rt-PCR). Anti-myeloma activity of FLT3 inhibitors (midostaurin, gilteritinib) was tested in vitro on MM cell lines and primary MM cells by 3H-tymidine incorporation assays or flow cytometry. Semi-quantitative expression analysis applying a staining score (FLT3 expression IHC-score, FES, range 1-6) revealed that a high FES (>3) was associated with a significantly shorter progression-free survival (PFS) in NDMM and RRMM patients (p = 0.04). RNAseq and real-time PCR confirmed the expression of FLT3 in CD138-purified MM samples. The functional relevance of FLT3 expression was corroborated by demonstrating the in vitro anti-myeloma activity of FLT3 inhibitors on FLT3-positive MM cell lines and primary MM cells. FLT3 inhibitors might offer a new targeted therapy approach in a subgroup of MM patients displaying aberrant FLT3 signaling.