Vitamin D is the main hormone of bone metabolism. However, the ubiquitary nature of vitamin D receptor (VDR) suggests potential for widespread effects, which has led to new research exploring the effects of vitamin D on a variety of tissues, especially in the skeletal muscle.In vitrostudies have shown that the active form of vitamin D, calcitriol, acts in myocytes through genomic effects involving VDR activation in the cell nucleus to drive cellular differentiation and proliferation. A putative transmembrane receptor may be responsible for nongenomic effects leading to rapid influx of calcium within muscle cells. Hypovitaminosis D is consistently associated with decrease in muscle function and performance and increase in disability. On the contrary, vitamin D supplementation has been shown to improve muscle strength and gait in different settings, especially in elderly patients. Despite some controversies in the interpretation of meta-analysis, a reduced risk of falls has been attributed to vitamin D supplementation due to direct effects on muscle cells. Finally, a low vitamin D status is consistently associated with the frail phenotype. This is why many authorities recommend vitamin D supplementation in the frail patient.

Systemic lupus erythematosus (SLE) is an autoimmune disease affecting mostly women of child-bearing age. Immune dysfunction in SLE results from disrupted apoptosis which lead to an unregulated interferon (IFN) stimulation and the production of autoantibodies, leading to immune complex formation, complement activation, and organ damage. Lupus nephritis (LN) is a common and severe complication of SLE, impacting approximately 30% to 40% of SLE patients. Recent studies have demonstrated an alteration in mitochondrial homeostasis in SLE patients. Mitochondrial dysfunction contributes significantly to SLE pathogenesis by enhancing type 1 IFN production through various pathways involving neutrophils, platelets, and T cells. Defective mitophagy, the process of clearing damaged mitochondria, exacerbates this cycle, leading to increased immune dysregulation. In this review, we aim to detail the physiopathological link between mitochondrial dysfunction and disease activity in SLE. Additionally, we will explore the potential role of mitochondria as biomarkers and therapeutic targets in SLE, with a specific focus on LN. In LN, mitochondrial abnormalities are observed in renal cells, correlating with disease progression and renal fibrosis. Studies exploring cell-free mitochondrial DNA as a biomarker in SLE and LN have shown promising but preliminary results, necessitating further validation and standardization. Therapeutically targeting mitochondrial dysfunction in SLE, using drugs like metformin or mTOR inhibitors, shows potential in modulating immune responses and improving clinical outcomes. The interplay between mitochondria, immune dysregulation, and renal involvement in SLE and LN underscores the need for comprehensive research and innovative therapeutic strategies. Understanding mitochondrial dynamics and their impact on immune responses offers promising avenues for developing personalized treatments and non-invasive biomarkers, ultimately improving outcomes for LN patients.

Background: The use of automated (oscillometric) blood pressure (BP) devices is not validated in atrial fibrillation (AF) patients. Objectives: To assess the reliability of three oscillometric BP devices, and the agreement with invasive arterial blood pressure(IBP) in AF patients. Methods: 48 AF patients with randomized sequences of 10 consecutive BP measurements with two pairs of devices: (1) OmronR7™(wrist) and OmronHEM907™(arm); (2) OmronR7™ and Microlife WatchBPhome(arm). Reliability and agreement of each device were assessed by the intra-class correlation coefficient (ICC) for the continuous BP measurements and Bland & Altman methodology, respectively. In 10 additional AF patients, 10 consecutive measurements with IBP and OmronHEM907™, and IBP and Microlife WatchBPhome were performed. Results: The OmronR7™ was not able to obtain any BP Readings. Arm devices presented better ICC for systolicBP(SBP) than for diastolicBP(DBP) (Omron HEM907™:0.94 [0.90; 0.97] vs. 0.77 [0.67; 0.89]; Microlife WatchBPhome:0.92 [0.88; 0.96] vs.0.79 [0.69; 0.89]).The correlation coefficient between Microlife WatchBPhome and IBP computed using the average of repeated measurements from two to ten measurements improved up to the third and remained stable afterwards. The agreement between IBP and SBP, and IBP and DBP, was moderate as illustrated by a wide limit of agreement [−24; 26](SBP) and [−15;17](DBP) for Microlife WatchBPHome, respectively and [−30; 13](SBP) and [−7; 15](DBP) for OmronHEM907. Conclusions: BP measurement using the two arm oscillometric devices achieved a high reliability for SBP. The agreement between IBP and arm devices was low but using the average of three consecutive measurements improved the results substantially.

To describe the optical coherence tomography angiograhy (OCTA) of drusenoid pigment epithelial detachments (PEDs) in a woman affected by Complement 3 (C3) glomerulopathy, which represents a spectrum of glomerular diseases characterized on fluorescent microscopy by C3 accumulation with absent, or scanty, immunoglobulin deposits. It is due to acquired or genetically defective alternative pathway control and is generally associated with drusen-like deposits in Bruch’s membrane, as well as choriocapillaris. These retinal lesions can be associated with choroidal neovascularization and central serous chorioretinopathy (CSCR). OCTA is useful to detect neovascularization without injecting a contrast product, particularly in these patients who may have renal insufficiency. A 28-year-old woman affected by C3 glomerulpathy was diagnosed with asymptomatic multiple bilateral PEDs during a routine ophthalmologic consultation. To better characterize the lesions, multimodal imaging was performed and included: optic coherence tomography (OCT), en-face OCT, OCTA, fluorescence and indocyanine angiography. The OCTA clearly identified vascular network rarefaction with decreased choriocapillary vascularization. It confirmed that PEDs associated with C3 glomerulonephritis are not vascularized, but rather of serous type. Patients affected by C3 glomerulopathy can develop neovascular membranes as retinal complications of pigment epithelial detachments. Optical coherence angiography may be indicated to identify this complication, without injecting any contrast product that could produce further kidney damage.

Rationale: Syphilis can share clinical features with autoimmune diseases, such as cutaneous Lupus or rheumatoid arthritis. Moreover, secondary syphilis can have visceral involvement, thus affecting the kidney. Syphilitic nephropathy causes nephrotic syndrome with a classic membranous pattern. We present a unique presentation of a co-infection by syphilis and parvovirus B19 sharing all the biological and histological features of proliferative lupus nephritis (LN). Patient concerns: We present a case of a 71-year-old Caucasian male returning from a trip to Asia presenting with nephrotic syndrome with antinuclear antibodies (ANA) positivity. Diagnoses: Because of nephrotic syndrome a kidney biopsy was performed. It demonstrated a membranous nephropathy with extracapillary proliferation and a full house pattern (presence of IgA, IgG, IgM and C1Q deposits) on immunofluorescence (IF), highly suggestive of LN class III and V. However, several atypical clinical features notably the age, sex of the patient and the history of travel prompt us to search for another cause of nephropathy. Interventions: A serology was positive for syphilis and a PCR in the renal biopsy was also positive for parvovirus B19. Thus, a co-infection by syphilis and parvovirus B19 was funded to be the cause of the renal lesions. Outcomes: The proteinuria improved; a course of antibiotic was administrated because of neurologic syphilitic involvement (presence of headache with positive syphilis serology in the CSF). Lessons: A co-infection by syphilis and parvovirus B19 can share all the biological and histological features of proliferative LN and must be recognized as a cause of pseudo-lupus nephritis.

Objectives: CD11B/ITGAM (Integrin Subunit α M) mediates the adhesion of monocytes, macrophages, and granulocytes and promotes the phagocytosis of complement-coated particles. Variants of the ITGAM gene are candidates for genetic susceptibility to systemic lupus erythematosus (SLE). SNP rs1143679 (R77H) of CD11B particularly increases the risk of developing SLE. Deficiency of CD11B is linked to premature extra-osseous calcification, as seen in the cartilage of animals with osteoarthritis. Serum calcification propensity measured by the T50 test is a surrogate marker for systemic calcification and reflects increased cardiovascular (CV) risk. We aimed to assess whether the CD11B R77H gene variant is associated with a higher serum calcification propensity (i.e., a lower T50 value) in SLE patients compared to the wild-type allele (WT). Methods: Cross-sectional study incorporating adults with SLE genotyped for the CD11B variant R77H and assessed for serum calcification propensity with the T50 method. Participants were included in a multicenter trans-disciplinary cohort and fulfilled the 1997 revised American College of Rheumatology (ACR) criteria for SLE. We used descriptive statistics for comparing baseline characteristics and sequential T50 measurements in subjects with the R77H variant vs. WT CD11B. Results: Of the 167 patients, 108 (65%) were G/G (WT), 53 (32%) were G/A heterozygous, and 6 (3%) were A/A homozygous for the R77H variant. A/A patients cumulated more ACR criteria upon inclusion (7 ± 2 vs. 5 ± 1 in G/G and G/A; p = 0.02). There were no differences between the groups in terms of global disease activity, kidney involvement, and chronic renal failure. Complement C3 levels were lower in A/A individuals compared to others (0.6 ± 0.08 vs. 0.9 ± 0.25 g/L; p = 0.02). Baseline T50 did not differ between the groups (A/A 278 ± 42′ vs. 297 ± 50′ in G/G and G/A; p = 0.28). Considering all sequential T50 test results, serum calcification propensity was significantly increased in A/A individuals compared to others (253 ± 50 vs. 290 ± 54; p = 0.008). Conclusions: SLE patients with homozygosity for the R77H variant and repeated T50 assessment displayed an increased serum calcification propensity (i.e., a lower T50) and lower C3 levels compared to heterozygous and WT CD11B, without differing with respect to global disease activity and kidney involvement. This suggests an increased CV risk in SLE patients homozygous for the R77H variant of CD11B.