Idiopathic Acquired Osteosclerosis in a Middle-Aged Woman With Systemic Lupus Erythematosus

Autoimmune myelofibrosis associated with systemic lupus erythematosus: a case report

A 66-year-old woman presented with severe anaemia, thrombocytopenia and lymphopenia. The bone marrow biopsy demonstrated hypocellular marrow with myelofibrosis (MF); there was no evidence of malignancy, but infiltration of peripheral T and B cells were noticed. Magnetic resonance imaging (MRI) revealed that bone marrow of the spine exhibited low signal intensity (SI) with spotty high SI in T1- and T2-weighted images. Because there was evidence of autoimmune abnormality, she had fulfilled the classification criteria for systemic lupus erythematosus (SLE). She was diagnosed with autoimmune myelofibrosis (AIMF) associated with SLE and was treated with corticosteroid. Cytopenia improved after 1 month of corticosteroid therapy. A repeated bone marrow biopsy demonstrated that cellularity had increased and that the amount of reticulin fibre had reduced after treatment. Compared with primary MF, AIMF has generally a favourable prognosis and is often associated with autoimmune diseases, especially SLE. Bone marrow biopsy, but not aspiration, was useful for diagnosing bone marrow fibrosis. Although the association between SLE and MF has been rarely reported, we should pay attention to MF as a possible cause of pancytopenia.

Absence of an osteopetrosis phenotype in IKBKG (NEMO) mutation-positive women: A case-control study

BACKGROUND

NF-κB essential modulator (NEMO), encoded by IKBKG, is necessary for activation of the ubiquitous transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Animal studies suggest NEMO is required for NF-κB mediated bone homeostasis, but this has not been thoroughly studied in humans. IKBKG loss-of-function mutation causes incontinentia pigmenti (IP), a rare X-linked disease featuring linear hypopigmentation, alopecia, hypodontia, and immunodeficiency. Single case reports describe osteopetrosis (OPT) in boys carrying hypomorphic IKBKG mutations.

METHOD

We studied the bone phenotype in women with IP with evaluation of radiographs of the spine and non-dominant arm and leg; lumbar spine and femoral neck aBMD using DXA; μ-CT and histomorphometry of trans-iliac crest biopsy specimens; bone turnover markers; and cellular phenotype in bone marrow skeletal (stromal) stem cells (BM-MSCs) in a cross-sectional, age-, sex-, and BMI-matched case-control study. X-chromosome inactivation was measured in blood leucocytes and BM-MSCs using a PCR method with methylation of HpaII sites. NF-κB activity was quantitated in BM-MSCs using a luciferase NF-κB reporter assay.

RESULTS

Seven Caucasian women with IP (age: 24-67 years and BMI: 20.0-35.2 kg/m²) and IKBKG mutation (del exon 4-10 (n = 4); c.460C>T (n = 3)) were compared to matched controls. The IKBKG mutation carriers had extremely skewed X-inactivation (>90:10%) in blood, but not in BM-MSCs. NF-κB activity was lower in BM-MSCs from IKBKG mutation carriers (n = 5) compared to controls (3094 ± 679 vs. 5422 ± 1038/μg protein, p < 0.01). However, no differences were identified on skeletal radiographics, aBMD, μ-architecture of the iliac crest, or bone turnover markers. The IKBKG mutation carriers had a 1.7-fold greater extent of eroded surfaces relative to osteoid surfaces (p < 0.01), and a 2.0-fold greater proportion of arrested reversal surface relative to active reversal surface (p < 0.01).

CONCLUSION

Unlike mutation-positive males, the IKBKG mutation-positive women did not manifest OPT.

Gnathodiaphyseal dysplasia: Severe atypical presentation with novel heterozygous mutation of the anoctamin gene (ANO5)

Gnathodiaphyseal dysplasia (GDD; OMIM #166260) is an ultra-rare autosomal dominant disorder caused by heterozygous mutation in the anoctamin 5 (ANO5) gene and features fibro-osseous lesions of the jawbones, bone fragility with recurrent fractures, and bowing/sclerosis of tubular bones. The physiologic role of ANO5 is unknown. We report a 5-year-old boy with a seemingly atypical and especially severe presentation of GDD and unique ANO5 mutation. Severe osteopenia was associated with prenatal femoral fractures, recurrent postnatal fractures, and progressive bilateral enlargement of his maxilla and mandible beginning at ~2months-of-age that interfered with feeding and speech and required four debulking operations. Histopathological analysis revealed benign fibro-osseous lesions resembling cemento-ossifying fibromas of the jaw without psammomatoid bodies. A novel, de novo, heterozygous, missense mutation was identified in exon 15 of ANO5 (c.1553G>A; p.Gly518Glu). Our findings broaden the phenotypic and molecular spectra of GDD. Fractures early in life with progressive facial swelling are key features. We assessed his response to a total of 7 pamidronate infusions commencing at age 15months. Additional reports must further elucidate the phenotype, explore any genotype-phenotype correlation, and evaluate treatments.