IGF-I increases markers of osteoblastic activity and reduces bone resorption via osteoprotegerin and RANK-ligand.

BACKGROUND: Bone is one of the major target tissues for Insulin-like Growth Factor I (IGF-I). Low doses of IGF-I were able to improve liver-associated osteopenia. In the present work, a model of partial IGF-I deficiency was used in order to provide insight into the mechanisms of the beneficial actions of IGF-I replacement therapy in bone. METHODS: Several proteins involved in osteoblastic/osteocyte and osteoclastic differentiation and activity were studied in the three experimental groups: control (CO) group (wild type mice, Igf+/+, n=10), heterozygous Igf+/- group with partial IGF-I deficiency (Hz, n=10), and heterozygous Igf+/- mice treated with IGF-I for 10 days (Hz+IGF-I, n=10). RESULTS: Data in this paper confirm that the simple partial IGF-I deficiency is responsible for osteopenia, determined by densitometry and histopathology. These findings are associated with a reduced gene expression of osteoprotegerin, sclerostin, calcitonin receptor (CTR), insulin-like growth factor binding protein 5 and RUNX2. IGF-I replacement therapy normalized CTR gene expression and reduced markers of osteoclastic activity. CONCLUSIONS: Low doses of IGF-I constituted a real replacement therapy that normalized IGF-I serum levels improving the expression of most of these proteins closely involved in bone-forming, and reducing bone resorption by mechanisms related to osteoprotegerin, RANKL and PTH receptor.

IgM to phosphatidylcholine in multiple sclerosis patients: from the diagnosis to the treatment.

Multiple sclerosis (MS) is a demyelinating and neurodegenerative disease of the central nervous system. It affects young people, and a considerable percentage of patients need the help of a wheelchair in 15 years of evolution. Currently, there is not a specific technique for the diagnosis of MS. The detection of oligoclonal IgG bands (OIgGBs) is the most sensitive assay for it, but it is not standardizable, only reference laboratories develop it, and uses cerebrospinal fluid. To obtain this sample, a lumbar puncture is necessary, an invasive proceeding with important side effects. It is important to develop and implement standard assays to obtain a rapid diagnosis because the earlier the treatment, the better the evolution of the disease. There are numerous modifying disease therapies, which delay the progression of the disease, but they have important side effects, and a considerable percentage of patients give up the treatment. In addition, around 40% of MS patients do not respond to the therapy and the disease progresses. Numerous researches have been focused on the characterization of predictive biomarkers of response to treatment, in order to help physicians to decide when to change to a second-line treatment, and then the best therapeutic option. Here, we review the new biomarkers for the diagnosis and response to treatment in MS. We draw attention in a new assay, the detection of serum IgM to phosphatidylcholine, that showed a similar sensitivity as OIgGBs and predicts the response to disease modifying treatments.

Deficiency in the production of antibodies to lipids correlates with increased lipid metabolism in severe COVID-19 patients.

Background: Antibodies to lipids are part of the first line of defense against microorganisms and regulate the pro/anti-inflammatory balance. Viruses modulate cellular lipid metabolism to enhance their replication, and some of these metabolites are proinflammatory. We hypothesized that antibodies to lipids would play a main role of in the defense against SARS-CoV-2 and thus, they would also avoid the hyperinflammation, a main problem in severe condition patients. Methods: Serum samples from COVID-19 patients with mild and severe course, and control group were included. IgG and IgM to different glycerophospholipids and sphingolipids were analyzed using a high-sensitive ELISA developed in our laboratory. A lipidomic approach for studying lipid metabolism was performed using ultra-high performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS). Results: Mild and severe COVID-19 patients had higher levels of IgM to glycerophosphocholines than control group. Mild COVID-19 patients showed higher levels of IgM to glycerophosphoinositol, glycerophosphoserine and sulfatides than control group and mild cases. 82.5% of mild COVID-19 patients showed IgM to glycerophosphoinositol or glycerophosphocholines plus sulfatides or glycerophosphoserines. Only 35% of severe cases and 27.5% of control group were positive for IgM to these lipids. Lipidomic analysis identify a total of 196 lipids, including 172 glycerophospholipids and 24 sphingomyelins. Increased levels of lipid subclasses belonging to lysoglycerophospholipids, ether and/or vinyl-ether-linked glycerophospholipids, and sphingomyelins were observed in severe COVID-19 patients, when compared with those of mild cases and control group. Conclusion: Antibodies to lipids are essential for defense against SARS-CoV-2. Patients with low levels of anti-lipid antibodies have an elevated inflammatory response mediated by lysoglycerophospholipids. These findings provide novel prognostic biomarkers and therapeutic targets.

Learning and assessment strategies to develop specific and transversal competencies for a humanized medical education.

Introduction: Medical education should promote the development of skills and abilities that can be applied to real-world work performance. The aim of this study is to evaluate technical and methodological knowledge, as well as physician-patient communication skills, as one of the most important transversal competencies that a good physician should acquire; all this in a reliable, accurate and objective way. Methods: We present a rubric specifically designed and implemented for the evaluation of specific and transversal competencies in the physiology practical sessions, during the second year of the medical degree. The assessment consists in two evaluation tests: 1) a theoretical test that consists of multiple-choice questions. Students must demonstrate that they have acquired adequate theoretical knowledge (specific competency "to know"); 2) a practical test, in which students are evaluated by the rubric through the simulation of a medical consultation. Thus, demonstrating their ability to execute/apply what they have learned in class (specific competency "to know how to do"). They are also evaluated on the transversal competencies that we call "communication with the patient" (transversal competency "to know how to be there") and "dealing with the patient" (transversal competency "to know how to be"). Results: We evaluated whether there were differences in the grades obtained by students when the transversal competencies were not assessed (academic years 2017-2018 and 2018-2019; n = 289), and when the transversal competencies were assessed by applying the rubric in the academic years 2019-2020, 2021-2022, and 2022-2023 (n = 526). Furthermore, we present a student perception that supports the use of clinical simulation and our rubric as a good method within the competency learning process. Discussion: The acquisition of these competencies, starting from the first courses of undergraduate education, helps to raise the students' awareness in the development of a more humanized medicine, allowing a better response to the patients' needs. Our rubric, which clearly indicate the performance criteria, have become an excellent method to carry out the assessment of competencies, both for students and teachers, since they allow to obtain clear evidence of the level of acquisition and application of knowledge.

High prevalence of intrathecal IgA synthesis in multiple sclerosis patients.

The detection of intrathecal IgA synthesis (IAS) in multiple sclerosis (MS) could be underestimated. To assess it, we develop a highly sensitive assay based on isoelectric focusing (IEF). 151 MS patients and 53 controls with different neurological diseases were recruited. IgA concentration was analyzed using a newly developed in house ELISA. IgA oligoclonal bands to detect IAS were determined by IEF. Most individuals showed an IgA concentration within normal range in serum samples (90.69%) but 31.37% of individuals had a IgA concentration below the normal range in the cerebrospinal fluid (CSF). No significant differences were observed between MS and control groups, neither in CSF nor in serum. The new IEF was more sensitive than those previously described (0.01 mg/dl of IgA), and clearly identified patients with and without IAS, that was not related with IgA concentration. Using IEF, MS patients showed higher percentage of IAS-IEF (43.00%) than the control group (16.98) (p = 0.001). The incidence was especially higher in patients with clinically isolated syndrome (66.00%). The new IFE demonstrated a higher percentage of IAS in MS patients than assumed in the past. The presence of IAS-IEF in MS is higher than in other neurological diseases.

Immunological mechanisms that associate with oligoclonal IgM band synthesis in multiple sclerosis.

We described previously that multiple sclerosis (MS) patients with oligoclonal IgM against myelin lipids (M+) develop an aggressive disease. Our aim was to assess possible mechanisms regulating the production of these antibodies. We studied B cell subsets in 180 patients with MS, and 69 with other neurological diseases. M+ MS patients showed a moderate increase of CD5(+) B-cell percentage in peripheral blood and a considerable augment of these cells in cerebrospinal fluid (CSF) that correlated with intrathecal IgM production. The appearance of CD5(+) B cells into the central nervous system (CNS) was related to increased CXCL13 and TNF-alpha levels in CSF. Moreover, the presence of oligoclonal IgM associated with a SNP at position -376 of the TNF-alpha promoter. These results help to elucidate the B lymphocytes responsible for intrathecal IgM secretion in MS and the origin of this abnormal B-cell response in patients with aggressive MS.

Intrathecal synthesis of oligoclonal IgM against myelin lipids predicts an aggressive disease course in MS.

Oligoclonal IgM bands restricted to cerebrospinal fluid are an unfavorable prognostic marker in MS, the most common demyelinating disease of the CNS. We have attempted to identify the B cell subpopulation responsible for oligoclonal IgM secretion and the specificity of these bands. In addition, we explored the relationship between specificity and disease evolution. Intrathecal B cell subpopulations present in 29 MS patients with oligoclonal IgM bands and 52 without them were analyzed. A considerable increase in CD5(+) B lymphocytes was found in patients with oligoclonal IgM bands. These cells mostly secrete IgM antibodies recognizing nonproteic molecules. We also studied whether oligoclonal IgM bands present in cerebrospinal fluid of 53 MS patients were directed against myelin lipids. This was the case in most patients, with phosphatidylcholine being the most frequently recognized lipid. Disease course of 15 patients with oligoclonal IgM against myelin lipids and 33 patients lacking them was followed. Patients with anti-lipid IgM suffered a second relapse earlier, had more relapses, and showed increased disability compared with those without anti-lipid IgM. The presence of intrathecal anti-myelin lipid IgM antibodies is therefore a very accurate predictor of aggressive evolution in MS.

Accuracy of CSF and MRI criteria for dissemination in space in the diagnosis of multiple sclerosis.

Demonstration of lesion dissemination in space (DIS) and time (DIT) is necessary for the diagnosis of multiple sclerosis (MS) in clinically isolated syndromes (CIS). The McDonald criteria accepted two methods to demonstrate DIS. The fulfillment of at least three of four MRI Barkhof criteria (MRI-BC) or, alternatively, the finding of at least two MRI lesions on T2-weighted images (T2 lesions) plus the presence of oligoclonal IgG bands (OCGB) in cerebrospinal fluid (CSF). We aimed to evaluate the accuracy of both methods for DIS demonstration to predict conversion of CIS to MS using a new OCGB test. We studied fifty-eight CIS patients with OCGB detection and brain MRI, and followed them up during 6 years. Twenty-eight patients fulfilled MRI-BC. Twenty-five of them converted to MS during follow-up (sensitivity 73.53%, specificity 87.50%, accuracy 79.31%). Thirty-four patients had at least two T2 lesions plus oligoclonal bands. Thirty-three converted to MS during follow-up (sensitivity 94.29%, specificity 95.65%, accuracy 94.82%). The presence of oligoclonal IgG bands plus two T2 lesions accurately predicts CIS conversion to MS. MRI-BC criteria have a high specificity but less sensitivity and accuracy. These results reinforce the role of CSF study in MS diagnosis.

Partial IGF-1 deficiency induces brain oxidative damage and edema, which are ameliorated by replacement therapy.

Insulin-like growth factor 1 (IGF-1) induces multiple cytoprotective effects on every tissue, including the brain. Since the mechanisms by which IGF-1 produces neuroprotection are not fully understood, the aim of this work was to delve into the underlying mechanisms. IGF-1 deficient mice (Hz) were compared with wild type (WT) and Hz mice treated with low doses of IGF-1 (2 µg/100 g body weight/day) for 10 days (Hz + IGF). Gene expression, quantitative PCR, histology, and magnetic resonance imaging were performed in the three groups. IGF-1 deficiency induced increased oxidative damage determined by markers of lipid peroxidation and hypoxia, as well as gene expression of heat shock proteins, antioxidant enzymes, and molecules involved in inflammation, apoptosis, and mitochondrial protection. These changes correlated with edema and learning impairment in Hz mice. IGF-1 therapy improved all these alterations. In conclusion, IGF-1 deficiency is responsible for increased brain oxidative damage, edema, and impaired learning and memory capabilities which are rescued by IGF-1 replacement therapy.

Early differential diagnosis of multiple sclerosis using a new oligoclonal band test.

BACKGROUND: Intrathecal IgG synthesis (ITGS), in conjunction with magnetic resonance imaging, can help in the early diagnosis of multiple sclerosis (MS). Recently, we developed a new oligoclonal IgG band (OCGB) test for ITGS detection that is more sensitive and easier to interpret than previously described methods. OBJECTIVE: To assess the accuracy of a new OCGB detection test in the diagnosis of MS. DESIGN: Prospective observational study. SETTING: A hospital neurology department. Patients A total of 385 patients with various neurologic disorders. MAIN OUTCOME MEASURES: The sensitivity and specificity of the OCGB detection test for MS diagnosis. RESULTS: Intrathecal IgG synthesis was found in 127 patients with MS (96.2%), 18 (35.3%) with central nervous system infections, and 1 with motor neuron disease. Two patterns reflected ITGS. One pattern, showing OCGBs restricted to cerebrospinal fluid, was predominantly found in MS. The other pattern, with OCGBs in serum and additional bands in cerebrospinal fluid, was mostly found in central nervous system infections. No patients with other inflammatory neurologic diseases showed ITGS. These patients frequently displayed a mirror pattern, with identical bands in serum and cerebrospinal fluid. Considering all patients, the sensitivity for the diagnosis of MS was 96.2%, and the specificity was 92.5%. Excluding infections, which usually do not present a differential diagnosis problem with MS, the sensitivity was still 96.2%, and the specificity increased to 99.5%. CONCLUSION: The accuracy of this OCGB method reinforces the value of cerebrospinal fluid studies in the early differential diagnosis of MS.

Axonal and oligodendrocyte-localized IgM and IgG deposits in MS lesions.

BACKGROUND: Recent findings support the important role of antibodies in multiple sclerosis (MS) physiopathology. Thus, local IgG synthesis is a hallmark of the disease, and intrathecal IgM synthesis associates with a poor disease outcome. METHODOLOGY: The aim of this study was to investigate the presence of IgM and IgG in demyelinating lesions using high sensitivity immunohistochemistry techniques in necropsies from fourteen MS patients, four controls without neurological disease and four cases with non MS CNS inflammatory disease. RESULTS: IgG and IgM were absent in controls. Conversely, we found IgM in about 50% and IgG in 75% of MS patients. The presence of IgM and IgG antibodies was independent of disease duration, clinical disease type or lesion stage. IgM and IgG were present in acute, chronic active and chronic inactive lesions. Double immunofluorescence showed that IgM and IgG were detected on axons and oligodendrocytes in demyelinated areas. Moreover, we observed immunoglobulin deposits on oligodendrocytes in NAWM in some cases. IgG and IgM colocalized with complement C3b on demyelinated axons and oligodendrocytes and antibody-antigen immunocomplexes were detected in foamy macrophages in active lesion areas. These findings were absent from cases of non-neurological disease and cases with non-MS CNS inflammatory disease. SIGNIFICANCE OF THE STUDY: These observations provide further evidence on the role of antibodies, complement and macrophages in plaque development, and strongly suggest they can induce axonal injury, an important cause of disability in MS. They may provide novel therapeutic strategies to limit tissue degeneration in the disease.

CSF oligoclonal band patterns reveal disease heterogeneity in multiple sclerosis.

Oligoclonal IgG bands (OCGB) are characteristic of multiple sclerosis (MS). Most patients show OCGB exclusively in cerebrospinal fluid (CSF). Others have serum bands with additional ones in CSF. Moreover, IgM bands against myelin lipids (LS-OCMB) associate with aggressive relapsing-remitting MS (RRMS). We studied oligoclonal bands in 424 MS patients. Most primary progressive (PPMS) patients showed serum OCGB with additional bands in CSF. Conversely, most RRMS and secondary progressive (SPMS) patients showed OCGB exclusively in CSF (p<0.0001). Moreover, no PPMS patient presented LS-OCMB, while 31% of RRMS and 60% of SPMS groups showed these antibodies (p<0.0001). This suggests heterogeneous autoimmune mechanisms in MS.

Intrathecal IgM synthesis is a prognostic factor in multiple sclerosis.

Intrathecal IgM synthesis (ITMS) predicts a worse evolution in the first stages of multiple sclerosis (MS). The aim of this study was the follow-up of a group of relapsing-remitting MS patients for a longer time to evaluate whether the ITMS implies a poor prognosis. Oligoclonal IgM bands were performed in 29 MS patients followed up from 5 to 16 years. Time to conversion to secondary-progressive MS (SPMS), time elapsed to reach a disability of 6 in the Expanded Disability Status Scale (EDSS), percentage of patients with a benign MS, and changes in EDSS score were evaluated. During the follow-up, 70.8% of patients with ITMS converted to SPMS. None of the patients without ITMS did. At the end of the study, 63.6% of patients with ITMS had reached EDSS 6, whereas none of the patients lacking ITMS reached values above EDSS 3. When patients with benign MS were analyzed, 82% lacked ITMS. All patients with a nonbenign MS had ITMS. At the end of the study, the mean EDSS score was 4.64 in patients with ITMS and 1.31 in those without. The presence of oligoclonal IgM bands in cerebrospinal fluid is an unfavorable prognostic marker in MS.