Hypercalcaemia in rheumatoid arthritis revisited

Role of mitochondrial dysfunction in the pathogenesis of rheumatoid arthritis: Looking closely at fibroblast- like synoviocytes

Rheumatoid arthritis (RA) is a chronic, autoimmune, and inflammatory disease that primarily targets the joints, leading to cartilage and bone destruction.Fibroblast-like synoviocytes (FLS) are specialized cells of the synovial lining in the joint that plays a fundamental role in the development of RA. Particularly, FLS of RA patients (RA-FLS) in the joint exhibit specific characteristics like higher invading and immunogenic properties, hyperproliferation, and reduced apoptotic capacity, suggesting a dysfunctional mitochondrial pool in these cells. Mitochondria are emerging as a potential organelle that can decide cellular immunometabolism, invasion properties, and cell death. Accordingly, multiplestudies established that mitochondria are crucial in establishing RA. However, the underlying mechanism of impaired mitochondrial function in RA remains poorly understood. This review will provide an overview of the mitochondrial role in the progression of RA, specifically in the context of FLS biology. We will also outline how mitochondria-centric therapeutics can be achieved that would yield novel avenues of research in pathological mediation and prevention.

The influence of thyroid diseases, diabetes mellitus, primary hyperparathyroidism, vitamin B12 deficiency and other comorbid autoimmune diseases on treatment outcome in patients with rheumatoid arthritis: An exploratory cohort study

To investigate the impact of comorbid diseases on rheumatoid arthritis (RA) outcome.All patients diagnosed with RA since 2006, who were registered in our local Danbio registry, were included in this cohort study. Patients' demographics, serology results, and Disease Activity Score in 28 joints-C-reactive protein (DAS28-CRP) at the time of diagnosis and after 4 months of treatment initiation were collected. Patients' electronic hospital records were evaluated for a positive history of thyroid diseases, diabetes mellitus, primary hyperparathyroidism, vitamin B12 deficiency, and the presence of other diagnosed autoimmune diseases.1035 RA patients were included. The observed prevalence of thyroid diseases was 11.8%, DM 10.4%, primary hyperparathyroidism 2.8%, vitamin B12 deficiency 5.8%, and other diagnosed autoimmune diseases 1.6%. There were significant associations between presence of thyroid diseases and female gender (P < .001); DM and greater age (P < .001); primary hyperparathyroidism and longer disease duration (P = .002); other diagnosed autoimmune diseases and antinuclear antibody positivity (P < .001). RA patients with thyroid diseases (P = .001) and other comorbid autoimmune diseases (P < .001) had significantly poorer initial response to the RA treatment compared to patients with isolated RA.Univariate analyses revealed that age, the presence of thyroid diseases, the presence of other diagnosed autoimmune diseases and DAS28-CRP at the time of diagnosis were significantly associated with ΔDAS28-CRP. Additionally, multivariate analysis demonstrated that ΔDAS28-CRP deterioration was significantly correlated to the presence of thyroid diseases (unstandardized regression coefficient (standard error); -0.188 (0.088), P = .030) and the presence of other diagnosed autoimmune diseases (-0.537 (0.208), P = .010).RA patients are at increased risk of specific comorbidities with possible impact on the treatment outcome. To improve this situation, periodic assessment of comorbidities should be considered.

High incidence of nephrocalcinosis in extremely preterm infants treated with dexamethasone

BACKGROUND

The use of postnatal corticosteroids to treat or prevent chronic lung disease is common in very preterm infants. Medullary nephrocalcinosis has been noted as a possible side effect.

OBJECTIVE

This prospective study was designed to assess the incidence of nephrocalcinosis in extremely preterm infants exposed to dexamethasone.

PATIENTS AND METHODS

A prospective study of extremely preterm infants, recruited to a randomized trial of dexamethasone treatment for chronic lung disease, was initiated. Infants had US of the renal tract scheduled on entry into the study, at day 28 and at discharge or at the corrected gestational age of 36 weeks.

RESULTS

Thirty-three infants were enrolled in the study. Birth weight ranged between 440 and 990 g and gestation between 24 and 28 weeks. Nine infants died and six had incomplete data. Because there was no difference in incidence of calcification between those on the short course and those on the long course of dexamethasone, analysis was made on the entire cohort. One infant had nephrocalcinosis at the time of the initial US examination on day 26 of life. By day 28, nephrocalcinosis was present in 31% of those with complete data. By discharge, or corrected gestational age of 36 weeks, US evidence of nephrocalcinosis was present in 15 (83%) of 18 infants. All infants had at least one course of an aminoglycoside antibiotic during the study. All infants had parenteral nutrition. Only four infants received furosemide more regularly than single doses. The longest course was 10 days, received by an infant who did not develop nephrocalcinosis.

CONCLUSION

The incidence of nephrocalcinosis is high in this group of sick, extremely preterm infants. Dexamethasone may be a factor in the development of nephrocalcinosis. Future research should focus on the natural history of nephrocalcinosis in extremely preterm infants.

Changes of mineral metabolism in juvenile chronic arthritis

Thirty five children with ambulant JCA were studied to assess the biochemical parameters of bone metabolism. The mean age of the study group was 8.8 +/- 4.1 years and the mean duration of active disease 3.8 +/- 1.3 years. According to the onset of the disease the children belonged to the systemic (7), polyarticular (12) and pauciarticular type (16). All the patients were treated with NSAIDs. In addition the polyarticular group received either gold injections or D-penicillamine and the systemic group, steroids for at least 3 months. Two groups of controls were studied. The first one included fifteen children without chronic arthritis or bone disease and the second, four children who were treated with corticosteroids for a variety of reasons. In the group with systemic JCA Se Pi (1.28 +/- 0.29 mmol/l) and renal phosphate reabsorption (TmP/GFR = 1.07 +/- 0.18) were significantly lower than in the control groups (1.50 +/- 0.19; 1.54 +/- 0.25 mmol/l, p < 0.01 and 1.35 +/- 0.18; 1.29 +/- 0.23 mmol/l GF, p < 0.05). Also lower were serum alkaline phosphatase (58 +/- 16.4 versus 83 /- 24.2 and 80 +/- 15.6 IU/l, p < 0.05), osteocalcin (5.5 +/- 4.7 versus 11.0 +/- 4.5 and 10.0 +/- 5.7 ng/ml, p < 0.05), 25OHD (15.6 +/- 4.9 versus 27.3 +/- 6.2 and 20.6 +/- 9.8 ng/ml, p < 0.001) and 1,25(OH)2D (12.1 +/- 6.0 versus 20.9 +/- 11.0 and 27.6 +/- 3.2 pg/ml, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)