Recurrent necrotizing cellulitis, multi-organ autoimmune disease and humoral immunodeficiency due to a novel NFKB1 frameshift mutation

Background: Mutations in NFKB1(nuclear factor of kappa light polypeptide gene enhancer in B-cells 1) are associated with a variety of clinical symptoms, including lymphadenopathy, splenomegaly, hepatomegaly, autoimmune haemolytic anaemia, arthralgia, recurrent respiratory tract infections and post-operative necrotizing cellulitis. Case presentation: We describe a case of a 47-year-old man, who presented with deep necrotizing cellulitis after incision of a submucous abscess by a dentist. Surgical intervention led to a massive progress. Pyoderma gangraenosum (PG) was diagnosed clinically and confirmed histopathologically. High dose corticosteroids and intravenous immunoglobulins (IVIG) improved wound healing dramatically. Until now, immune mediated inflammation events not only affected the skin, but also multiple inner organs, i.e. the heart, lungs and gut. Sequencing of all coding exons of NFKB1 revealed a heterozygous 1bp deletion in exon 23 predicting a frameshift starting at codon Ala891 and resulting in a subsequent stop codon at position 6 in the new reading frame: NM_003998.4: c.2671del; p.(Ala891Glnfs*6) Acute episodes were always successfully treated with corticosteroids, IVIG and concomitant antibiotics. To prevent further exacerbations, the patient receives IVIG once a month, low-dose corticosteroids and methotrexate. Conclusion: This is the first case of a patient with recurrent necrotizing cellulitis and immune mediated multi organ involvement (heart, lungs, intestine) carrying the novel frameshift mutation c.2671del (p. Ala891Glnfs*6) in NFKB1 effectively treated with IVIG, low-dose corticosteroids and methotrexate

Identification of markers to characterize and sort human articular chondrocytes with enhanced in vitro chondrogenic capacity

Objective. To identify markers associated with the chondrogenic capacity of expanded human articular chondrocytes and to use these markers for sorting of more highly chondrogenic subpopulations. Methods. The chondrogenic capacity of chondrocyte populations derived from different donors (n = 21) or different clonal strains from the same cartilage biopsy specimen (n = 21) was defined based on the glycosaminoglycan (GAG) content of tissues generated using a pellet culture model. Selected cell populations were analyzed by microarray and flow cytometry. In some experiments, cells were sorted using antibodies against molecules found to be associated with differential chondrogenic capacity and again assessed in pellet cultures. Results. Significance Analysis of Microarrays indicated that chondrocytes with low chondrogenic capacity expressed higher levels of insulin-like growth factor I and of catabolic genes (e.g., matrix metalloproteinase 2, aggrecanase 2), while chondrocytes with high chondrogenic capacity expressed higher levels of genes involved in cell-cell or cell-matrix interactions (e.g., CD49c, CD49f). Flow cytometry analysis showed that CD44, CD151, and CD49c were expressed at significantly higher levels in chondrocytes with higher chondrogenic capacity. Flow cytometry analysis of clonal chondrocyte strains indicated that CD44 and CD151 could also identify more chondrogenic clones. Chondrocytes sorted for brighter CD49c or CD44 signal expression produced tissues with higher levels of GAG per DNA (up to 1.4-fold) and type 11 collagen messenger RNA (up to 3.4-fold) than did unsorted cells. Conclusion. We identified markers that allow characterization of the capacity of monolayer-expanded chondrocytes to form in vitro cartilaginous tissue and enable enrichment for subpopulations with higher chondrogenic capacity. These markers might be used as a means to predict and possibly improve the outcome of cell-based cartilage repair techniques