Combined NGS Approaches Identify Mutations in the Intraflagellar Transport Gene IFT140 in Skeletal Ciliopathies with Early Progressive Kidney Disease

Ciliopathies are genetically heterogeneous disorders characterized by variable expressivity and overlaps between different disease entities. This is exemplified by the short rib‐polydactyly syndromes, Jeune, Sensenbrenner, and Mainzer‐Saldino chondrodysplasia syndromes. These three syndromes are frequently caused by mutations in intraflagellar transport (IFT) genes affecting the primary cilia, which play a crucial role in skeletal and chondral development. Here, we identified mutations in IFT140, an IFT complex A gene, in five Jeune asphyxiating thoracic dystrophy (JATD) and two Mainzer‐Saldino syndrome (MSS) families, by screening a cohort of 66 JATD/MSS patients using whole exome sequencing and targeted resequencing of a customized ciliopathy gene panel. We also found an enrichment of rare IFT140 alleles in JATD compared with nonciliopathy diseases, implying putative modifier effects for certain alleles. IFT140 patients presented with mild chest narrowing, but all had end‐stage renal failure under 13 years of age and retinal dystrophy when examined for ocular dysfunction. This is consistent with the severe cystic phenotype of Ift140 conditional knockout mice, and the higher level of Ift140 expression in kidney and retina compared with the skeleton at E15.5 in the mouse. IFT140 is therefore a major cause of cono‐renal syndromes (JATD and MSS). The present study strengthens the rationale for IFT140 screening in skeletal ciliopathy spectrum patients that have kidney disease and/or retinal dystrophy.     

Ex vivo treatment of proliferating human cord blood stem cells with stroma-derived factor-1 enhances their ability to engraft NOD/SCID mice

Ex vivo proliferation of hematopoietic stem cells (HSCs) is important for cellular and gene therapy but is limited by the observation that HSCs do not engraft as they transit S/G(2)/M. Recently identified candidate inhibitors of human HSC cycling are transforming growth factor-beta(1) (TGF-beta(1)) and stroma-derived factor-1 (SDF-1). To determine the ability of these factors to alter the transplantability of human HSCs proliferating in vitro, lin(-) cord blood cells were first cultured for 96 hours in serum-free medium containing Flt3 ligand, Steel factor, interleukin-3, interleukin-6, and granulocyte colony-stimulating factor. These cells were then transferred to medium containing Steel factor and thrombopoietin with or without SDF-1 and/or TGF-beta(1) for 48 hours. Exposure to SDF-1 but not TGF-beta(1) significantly increased (> 2-fold) the recovery of HSCs able to repopulate nonobese diabetic/severe combined immunodeficiency mice. These results suggest new strategies for improving the engraftment activity of HSCs stimulated to proliferate ex vivo.     

Diagnostic accuracy for lupus and other systemic autoimmune diseases in the community setting

BACKGROUND: Most individuals with autoimmune and other immune disorders undergo initial evaluation in the community setting. Since misdiagnosis of systemic autoimmune diseases can have serious consequences, we evaluated community physicians' accuracy in diagnosing autoimmune diseases and the consequences of misdiagnosis. METHODS: We studied the patients referred to our Autoimmune Disease Center for 13 months (n = 476). We estimated the degree of agreement with the final diagnosis (kappa statistic) and the accuracy indexes (sensitivity, specificity, and predictive values) of the referring physicians' diagnoses. RESULTS: We found a 49% agreement between the referring and final diagnoses (kappa = 0.36). Of 263 patients referred with a presumptive diagnosis of systemic lupus erythematosus (SLE), 125 received a diagnosis of other conditions (kappa = 0.34). Of those referred with SLE, 76 (29%) were seropositive for antinuclear antibodies but did not have autoimmune disease. The degree of agreement for referring rheumatologists (kappa = 0.55) was better than that for nonrheumatologists (kappa = 0.32). Stepwise logistic regression indicated that rheumatologists were 4 times more likely to make an accurate diagnosis of SLE than were nonrheumatologists (P<.003). Thirty-nine patients who were seropositive for antinuclear antibodies but had no autoimmune disease had been treated with corticosteroids at dosages as high as 60 mg/d. CONCLUSIONS: Many patients with a positive antinuclear antibody test are incorrectly given a diagnosis of SLE and sometimes treated with toxic medications. The data support the importance of continuing medical education for community physicians in screening for autoimmune diseases and identifying patients who may benefit from early referral to a specialist.     

Impact of a prior medical degree on students' dental school performance in Innsbruck, Austria

The purpose of this study was to identify the performance differences between two groups of Austrian dental students (one with a prior medical degree and one without a medical degree) during their dental school training and final dental licensure examination. A specific aim was to determine if having a medical degree is a predictive factor for dental students' scores on the Austrian Dental Admission Test (Austrian DAT), performance in the dental clinic, and scores on final exam. The study consisted of a retrospective analysis of 122 students (thirty-nine with a medical degree and eighty-three without a medical degree) who were enrolled in the Dental Clinic at Innsbruck Medical University, Innsbruck, Austria, between 2001 and 2006. Three performance categories were considered: Austrian DAT results, clinical performance after the first clinical year in dental school, and performance on the final dental licensure examination. Information on students' age, gender, and previous medical degree was collected from official records. Analyses with student's t-test and Pearson's chi-square test revealed that the students with a medical degree had significantly higher Austrian DAT total test scores, grade point averages after the first clinical year, and scores on the final exam. Additionally, those students had significantly better performance on the final exam in prosthodontics and oral and maxillofacial surgery. The linear regression analysis showed that a medical degree had an independent effect on average scores on the final exam, age, and Austrian DAT test scores, while gender showed no statistically significant effect. Overall, the study found that dental students with a prior medical degree had significantly higher Austrian DAT total test scores and performed significantly better in the first clinical year and on the final exam than those without a prior medical degree.     

A comparative study of the secretory IgA immunoglobulins (s.IgA) in mothers and children with SECC versus a caries free group children and their mothers

Early childhood caries (ECC) is recognized as an infectious disease. The first step in its development is primary infection by the bacterium S. mutans which has been identified as the primary etiologic factors in dental caries. Lactobacilli were also found to play a role in the progression of disease. However the underlying mechanism of immune response to caries is unclear. The association between secretory IgA (s.IgA) and cariogenic microorganisms is still controversial. The purpose of this study was to assess the level of salivary IgA in caries free children, and children with SECC and their corresponding mothers. The study also aims at correlating the children's levels to their mothers'. Sixty children and their mothers attending the dental clinic in King Abdulaziz University participated in our study. Their age ranged from 3 - 5 years. The study groups consisted of thirty children with SECC and a control group consisting of thirty caries free children. Children together with their mothers were examined and their caries level was recorded. Stimulated saliva was collected from each participant for immunological assessment. The secretory IgA (s. IgA) level was assessed by ELISA test. Our study has shown that children with SECC and their mothers had higher levels of s. IgA than the caries free children and their mothers. A positive high correlation was found between secretory IgA of mothers and children in both groups.     

In vivo detection of the lumbar intraforaminal ligaments by MRI

Purpose

Intraforaminal ligaments (IFL) are of great interest to anatomists and clinicians to fully understand the detailed anatomy of the neuroforamina and to diagnose unclear radicular symptoms. Studies published until now have described radiological imaging of the IFLs using magnetic resonance imaging (MRI) on donor bodies. In the present study, we investigated the detectability of lumbar IFLs in vivo in adults using the high spatial resolution of the constructive interference in steady state (CISS) sequence.

Methods

A total of 14 patients were studied using a 1.5 T MRI scanner. The lumbar spine was imaged using the parasagittal CISS sequence, and the detectability of the IFLs was assessed for each lumbar level. All image datasets were analyzed by a radiologist, an orthopedic surgeon, and an anatomist. Interrater reliability was expressed as Fleiss’ Kappa. Using a single data set, a three-dimensional (3D) model was created to map the location of the IFLs within the intervertebral foramen (IF) and the immediate surrounding vessels.

Results

Overall, the radiologist was able to detect IFLs in 60% of all imaged IFs, the orthopedic surgeon in 62%, and the anatomist in 66%. Fleiss’ Kappa for the various segments varies from 0.71 for L4/5 up to 0.90 for L3/4.

Conclusion

Lumbar IFLs were successfully detected in vivo in every patient. The detection frequency varied from 42–86% per IF. We demonstrated reproducible imaging of the IFLs on MRI, with good interrater reliability. The present study was a launching point for further clinical studies investigating the potential impact of altered IFLs on radicular pain.