Drugs associated with epidermal necrolysis in children: A World Health Organization pharmacovigilance database analysis

BACKGROUND

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare life-threatening mucocutaneous reactions most often induced by drugs. To date, no large pharmacovigilance study has been conducted in the paediatric population.

OBJECTIVES

To describe the spectrum of drugs associated with SJS-TEN in children through the analysis of cases reported in the WHO pharmacovigilance database (VigiBase).

METHODS

Disproportionality study using data from VigiBase. All paediatric (age under 18 years) cases reported between January 1, 1967, and July 6, 2022, were included. For each molecule, a case-non-case study was performed to assess a potential pharmacovigilance signal by computing the lower end of the 95% credibility interval for the information component (IC025). We performed sensitivity analyses, (i) taking into account only cases reported by physicians and (ii) taking into account only cases reported in the last 10 years.

RESULTS

Among 31,376,783 adverse drug reactions reported in VigiBase, 2,248,727 were paediatric cases and 7342 were encoded as paediatric SJS-TEN. Significant statistical pharmacovigilance signals were observed for 165 drugs. The two most represented drug classes were antiepileptics and anti-infectious drugs. The five drugs with the highest IC025 were lamotrigine (IC025 4.99), carbamazepine (IC025 4.88), phenobarbital (IC025 4.67), phenytoin (IC025 4.52) and nimesulide (IC025 4.23). Acetaminophen was significantly associated with paediatric SJS-TEN (IC025 2.85) and we also described various new suspected drugs. Vaccines had no significant pharmacovigilance signal. These results were confirmed with the sensitivity analyses.

CONCLUSIONS

This study updates the spectrum of drugs potentially associated with paediatric SJS-TEN.

Comparison of idiopathic and drug-induced epidermal necrolysis in children

In this monocentric retrospective study in a French paediatric reference centre, children with idiopathic epidermal necrolysis (EN) had more severe disease than those with drug-induced EN during the acute stage. In our study, no EN was attributed to infection.

Proton Pump Inhibitors Associated With Drug-Induced Lupus Erythematosus

This descriptive case series investigates the potential association between the use of proton pump inhibitors and drug-induced lupus erythematosus in cases reported in 2 large pharmacovigilance databases.

Two pediatric cases of multisystem inflammatory-like syndrome following COVID-19 vaccination

Multisystem inflammatory syndrome in children (MIS-C) is a novel post-infectious disease occurring in the context of SARS-CoV2 infection. COVID-19 vaccines have been authorized since December 2020, and adverse events including myocarditis have been reported following vaccination. We describe the cases of two pediatric patients presenting with clinical and laboratory features suggestive of MIS-C a few days after receiving their first dose of the Pfizer BNT162b2 vaccine. The outcome was favorable for both patients (after corticosteroid and immunoglobulin administration for one patient). These cases suggest an association between the COVID-19 vaccine and the occurrence of MIS-C.

Paradoxical reactions and biologic agents: a French cohort study of 9,303 patients

BACKGROUND

Paradoxical reactions (PRs) are defined as the occurrence during biologic therapy of a pathological condition that usually responds to these drugs.

OBJECTIVE

To estimate the incidence of PRs and identify risk factors.

METHODS

Multicenter study of the database for the Greater Paris University Hospitals including biological-naïve patients receiving anti-tumor necrosis factor-α, anti-interleukin-12/23, anti-interleukin-17 or anti-α4ß7-integrin agents for psoriasis, inflammatory rheumatism or inflammatory bowel disease (IBD). We used natural language processing algorithms to extract data. A cohort and a case-control study nested in the cohort with controls selected by incidence density sampling was used to identify risk factors.

RESULTS

Most of the 9,303 included patients (median age 43.0; 53.8% women) presented an IBD (3,773 [40.6%]) or a chronic inflammatory rheumatic disease (3,708 [39.9%]), and 8,487 (91.2%) received anti-TNF-α agents. A total of 293 (3.1%) had a PR. The global incidence rate was 7.6 per 1,000 person-years (95%CI 6.7-8.4). Likelihood of PR was associated with IBD (adjusted OR [aOR] 1.9, 95%CI 1.1-3.2, p=0.021) and a combination of two inflammatory diseases (aOR 6.1, 95%CI 3.6-10.6, p<0.001) and was reduced with conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) and corticosteroids (aOR 0.6, 95%CI 0.4-0.8, p=0.003; 0.4, 0.2-0.7, p<0.001).

CONCLUSION

Likelihood of PRs was associated with IBD or a combination of a least two inflammatory diseases. More studies are needed to assess the benefit of systematically adding csDMARDs for such high-risk patients.

Infection à SARS-CoV-2 et biomédicaments : une étude multicentrique française de 7808 patients

Introduction

Les formes sévères d’infection à COVID-19 sont liées à une importante réponse inflammatoire. Certains biomédicaments (BM) sont en cours d’évaluation dans des essais thérapeutiques avec pour rationnel cet orage cytokinique. À l’inverse, nous pouvons nous interroger sur le risque d’infections à COVID-19 chez les patients sous BM au long cours. L’objectif principal de notre étude était de déterminer l’impact de la prise d’un BM sur le taux d’hospitalisation, de passage en réanimation (ICU) et de décès chez les patients sous BM atteints d’une infection à COVID-19.

Matériels et méthodes

Étude de cohorte rétrospective multicentrique à partir des données médico-administratives de l’Entrepôt de Données de Santé (EDS) de l’APHP. L’ensemble des patients recevant un BM (anti-TNF, anti-IL-12/23, anti-IL-17 ou anti-intégrine) étaient inclus. Les événements d’intérêt étaient la survenue d’une hospitalisation, d’un séjour en ICU ou d’un décès dans le cadre d’une infection à COVID-19 (confirmée par RT-PCR ou TDM thoracique) entre le 01/02 et le 22/04/20. Le risque d’hospitalisation/ICU/décès était évalué selon la méthodologie du Ratio de Morbidité/Mortalité Standardisé (SMR) en calculant le rapport entre le nombre observé et le nombre attendu. Le nombre attendu d’hospitalisation/ICU/décès était calculé en appliquant le taux d’hospitalisation/ICU/décès à COVID-19 de la population d’Ile-de-France (par tranche d’âge de 20 ans et par sexe) au nombre de personnes sous BM dans la sous-classe correspondante de la même source de données (données EDS de l’APHP).

Résultats

Un total de7808 patients (âge médian 45 ans, 51 % de femmes) étaient inclus ; dont 48 avec un diagnostic d’infection à COVID-19 : 19 (40 %) hospitalisés, 4 (8 %) en ICU et 1 décès. En comparaison avec la population d’Ile-de-France, les taux d’hospitalisation et d’ICU étaient significativement élevés chez les patients sous BM avec SMR 2,19, IC95 % 1,32-3,42, p < 0,001 et SMR 6,04, IC95 % 1,62-15,45, p < 0,001 respectivement, significativement observés chez les [20-40[. Cependant, une analyse post-hoc suggérait que les SMR d’hospitalisation et d’ICU étaient surestimés, un retour aux compte-rendus mettant en évidence une poussée de la pathologie sous-jacente comme principal motif d’hospitalisation chez les [20-40[et non une infection à COVID-19 nécessitant une hospitalisation ou un passage en ICU. Aucun sur-risque de mortalité était mis en évidence.

Discussion

À partir d’une large base de données, notre étude a permis de confirmer que les taux d’hospitalisation, de passage en réanimation et de mortalité n’étaient pas augmentés chez les patients sous BM. Nos résultats sont concordants avec les différentes études publiées dans la littérature (Haberman et al., Favalli et al. ou Sanchez-Piedra et al.).

Conclusion

Ces résultats plaident pour un maintien des BM en période d’épidémie du virus COVID-19 pour éviter la rechute des pathologies inflammatoires de fond.

Performance of the Kleihauer Betke test in the prediction of neonatal anemia

OBJECTIVES

The aim of this study was to correlate antenatal Kleihauer (KT) test results with fetal hemoglobin at birth to find a threshold for predicting severe fetal anemia. The secondary objectives were to assess the impact of KT on obstetric management and to study the correlation between the middle cerebral artery peack systolic velocity and fetal anemia.

RESULTS

One thousand forty-six KT were positive over the 10-year period, but only 147 were included from 88 patients, of which 17 fetuses were anemic. Demographic and obstetric characteristics were similar between anemic and non-anemic groups. As regards new-born, there was a higher risk of prematurity among anemic as long as a lower birth rate in accordance. While a negative correlation was observed between KT and hemoglobin at birth, no KT upper threshold could be found that was both sensitive and specific. In addition, there was no case of fetal anemia when KT was repeated, even though it increased. KT showed little usefulness in obstetrics management to help improving neonatal care for anemia. Conversely, the MCA PSV demonstrated good performance in this matter and the ROC curve area was 0.91 (figure).

DISCUSSION

Feto-maternal hemorrhage is a rare but grave pathology which could lead to anemia. The most common clinical sign is reduced fetal movement and it was the main indication to perform a KT. Cardiotocography patterns suggestive of anemia are sinusoidal, micro-oscillatory and non-reactive monitoring. Ultrasound features were polyhydramnios, hydrop fetalis and increased MCA peack systolic velocity. KT was correlated with MCA PSV and with hemoglobin level at birth. However, the latter showed a better diagnostic performance. MCA PSV measurement is a powerful test to screen for fetal anemia, and should be part of the regular training of obstetricians. Indeed, this technic gives immediate and reliable results, while those of KT are delayed.

CONCLUSION

The KT should not be used as a tool to screen for fetal anemia but rather as a test to explain a fetal anemia. However, the MCA PSV is reliable in this matter and give immediate result, thus obstetrician should be trained to routinely perform it.

Spontaneous heterotopic triplets - A review of literature

OBJECTIVE

Spontaneous heterotopic triplets, a tubal ectopic pregnancy and a twin pregnancy, are rare disorders. The study aimed to examine all available evidence regarding signs and symptoms, imaging findings, management and newborn outcome of spontaneous heterotopic triplets.

DESIGN

A literature search in Medline and EMBASE databases from 2000 to 2016 was conducted. The following key words were employed: 'spontaneous heterotopic pregnancy', OR 'heterotopic triplets'. Only cases of spontaneous heterotopic triplets without assisted reproduction techniques were included.

RESULTS

Six cases were identified and included in the present review. All cases presented with abdominal pain and one case presented in shock. Hemoperitoneum was present in five cases. Laterouterine mass with adnexal gestational sac is not systematically described (3 cases/6), but was a good ultrasonographic sign of heterotopic pregnancy. All patients had tubal rupture, but anyone had vaginal bleeding. The surgical treatment was made by salpingectomy in five cases to ensure successful treatment. The mean and median gestational age at delivery were 29.9 and 37.54 weeks, respectively (range 6-41 weeks). The neonatal outcome was good for 6 newborns.

CONCLUSION

Spontaneous heterotopic triplets are rare. Early surgical intervention is the key to successful treatment of heterotopic triplet pregnancy and allows good neonatal outcome.

Phenotype-genotype correlation and follow-up in adult patients with hypokalaemia of renal origin suggesting Gitelman syndrome

INTRODUCTION

Gitelman syndrome (GS) is a tubulopathy caused by SLC12A3 gene mutations, which lead to hypokalaemic alkalosis, secondary hyperaldosteronism, hypomagnesaemia and hypocalciuria.

AIM

The aim of this study was to assess the prevalence of SLC12A3 gene mutations in adult hypokalaemic patients; to compare the phenotype of homozygous, heterozygous and non-mutated patients; and to determine the efficiency of treatment.

METHODS

Clinical, biological and genetic data were recorded in 26 patients.

RESULTS

Screening for the SLC12A3 gene detected two mutations in 15 patients (six homozygous and nine compound heterozygous), one mutation in six patients and no mutation in five patients. There was no statistical difference in clinical symptoms at diagnosis between the three groups. Systolic blood pressure tended to be lower in patients with two mutations (P=0.16). Hypertension was unexpectedly detected in four patients. Five patients with two mutated alleles and two with heterozygosity had severe manifestations of GS. Significant differences were observed between the three groups in blood potassium, chloride, magnesium, supine aldosterone, 24 h urine chloride and magnesium levels and in modification of the diet in renal disease. Mean blood potassium levels increased from 2.8 ± 0.3, 3.5 ± 0.5 and 3.2 ± 0.3 before treatment to 3.2 ± 0.5, 3.7 ± 0.6 and 3.7 ± 0.3 mmol/l with treatment in groups with two (P=0.003), one and no mutated alleles respectively.

CONCLUSION

In adult patients referred for renal hypokalaemia, we confirmed the presence of mutations of the SLC12A3 gene in 80% of cases. GS was more severe in patients with two mutated alleles than in those with one or no mutated alleles. High blood pressure should not rule out the diagnosis, especially in older patients.

Traitement de la rectocèle par voie périnéale avec prothèse. Une étude prospective

PURPOSE

To assess the long term results of a transperineal repair of rectocele with a prosthetic mesh and the criteria for selecting the patients.

METHODS

Twenty-five consecutive patients (median age: 60 years) with a symptom-giving rectocele have been operated upon. Indication for surgery was: an obstructed defecation (N = 22); a fecal incontinence (N = 1); a pelvic heaviness with dyspareunia (N = 1) or a severe rectal syndrome (N = 1). Patients were evaluated by physical examination and, preoperatively, by defecography and anorectal manometry. The rectovaginal septum was repaired, through a perineal approach, with an absorbable (N = 5) or non absorbable (N = 20) prosthetic mesh. Long term results were assessed after a median follow-up of 45 (range 12-120) months by physical examination and a standardized questionnaire. The presence of the following three symptoms was evaluated: feeling of incomplete emptying, prolonged and unsuccessful straining at stool, digital assistance. Outcome was considered as successful when none of these symptoms were present, as good when minor emptying difficulties persisted, as moderate when emptying difficulties were associated with straining, as a failure when the symptomatic triad was unchanged. A general satisfaction score was established.

RESULTS

All the patients had the defect of the rectovaginal septum corrected. Four patients had a low residual rectocele associated, in two cases, with a rectal prolapse subsequently treated by a Delorme's operation. Outcome in patients complaining of obstructed defecation was considered excellent or good in 80% of patients, moderate in 9% and poor in 9%. Subjective scoring showed a significantly better result in cases of success. Among 11 incontinent patients, seven (63.5%) improved or regained full continence. Dyspareunia in three cases was corrected. Age, parity, digital assistance, previous gynecologic surgery, use of laxatives, size of rectocele, type of mesh, anatomical result of repair had no significant prognostic value. On the other hand, in patients with obstructed defecation, clinical and manometric signs of anal hyperactivity of the pelvic floor or anismus (N = 4) were significantly related to a poor result (P < 0.001).

CONCLUSION

Surgical repair with a prosthetic mesh is an efficient therapy in patients with obstructed defecation and/or incontinence caused by a rectocele. Clinical and defecographic parameters have no influence on outcome. Preoperative manometric data may help in selecting patients. In case of anal hyperactivity or anismus, given the risk of functional failure, behavioral retraining must be considered as first-line treatment.

Triple Nucleoside Combination Zidovudine/Lamivudine/Abacavir versus Zidovudine/Lamivudine/Nelfinavir as First-Line Therapy in HIV-1-Infected Adults: A Randomized Trial

Objective

To compare the efficacy and safety of a triple nucleoside combination to a protease inhibitor-containing triple regimen as first-line antiretroviral therapy (ART) in HIV-1-infected patients.

Design

Open-label study in HIV-1-infected ART-naive adults, randomized to receive either Combivir® (lamivudine 150 mg/zidovudine 300 mg twice daily) + abacavir (300 mg twice daily), or Combivir® + nelfinavir (750 mg every 8 h) for 48 weeks. Plasma HIV-1 RNA, CD4 cell count and adverse events were assessed at baseline and weeks 4, 8, 16, 24, 32, 40 and 48.

Results

195 subjects (131 men, 64 women), median age 34 years, were randomized: 98 received combivir/abacavir and 97 combivir/nelfinavir. Baseline median plasma HIV-1 RNA was 4.2 log10 copies/ml [Interquartile range (IQR): 3.7-4.5.2] and 4.1 log10 copies/ml (IQR: 3.8–4.6), respectively. Baseline median CD4 cell count was 387 cells/mm3 (IQR: 194–501) and 449 cells/mm3 (IQR: 334–605), respectively. Nine patients (3 vs 6, respectively) did not start treatment or did not have any available efficacy data. At week 48, using the intent to treat analysis (switch/missing equals failure), plasma HIV-1 RNA was <50 copies/ml in 54/95 (57%) and 53/91 (58%) of subjects, respectively. Median CD4 increase was +110 and +120 cells/mm3, respectively. Possible hypersensitivity reactions to abacavir were reported in four subjects (4%).

Conclusion

The triple nucleoside combination combivir/abacavir is well tolerated as a first-line ART regimen in HIV-1-infected adults, with comparable antiviral activity to a nelfinavir-containing regimen at week 48.

[Randomized trials in the prevention of recurrent calcium oxalate stones]

Kidney stone, with or without lumbar pain, is a major health care problem because of its prevalence and cost for both the patient and the society. Although, surgical procedures are well known, medical treatment and recurrences prophylaxis are uncodified. Fifteen stone recurrence prevention studies have been reviewed, evaluating dietary intake and drugs. The most important factor is a daily diuresis of at least 2 liters. Calcium intake shouldn't be restricted, whereas oxalate, sodium, and protein intakes have to be limited. Hyper and normocalciuretic kidney stone formers improve their outcome with thiazide or indapamide treatment. Hyperuricosuria justifies allopurinol. Potassium citrate (without sodium) may decrease recurrence risk, even in patients without hypocitraturia.

[Factors determining the choice of a modality of treatment by dialysis: a study of nine dialysis centers]

BACKGROUND

The objective of this cross-sectional study in a population of 1472 dialysis patients was to identify the main factors involved in the choice of a specific option for dialysis therapy, taking into account three different types of criteria such as medical dependence (DM), nurse care requirement (SI) and independence for dialysis therapy (CA).

METHODS

Each patient has been analysed, independently of present treatment modality, according to the above three criteria, namely DM, SI and CA. For each type of parameter, patients have been allocated to one of three levels, each level being established to evaluate whether dialytic treatment should be undertaken as hospital centre dialysis (HDC) or in a facility off the hospital. Level 3 of any one category corresponded to the inability of doing haemodialysis at home (HHD) or in self-care unit (AD). Level 2 included patients who could be treated in AD or by peritoneal dialysis (PD) with the assistance of a nurse. CAPD or HHD were considered as potential treatment modalities only in patients qualifying for level 1 of each criterion.

RESULTS

In the patient population as a whole, the following treatment options were observed: HHD 3.6%, CAPD 6%, PD 1.8%, AD 16.3% and HDC 72.2%. For medical dependence (DM) there was a relatively even distribution for the three levels in six centres. In contrast, two centres were characterized by a predominance of DM level 3. Differences in DM levels between centres were greatly reduced when considering separately only those patients who were actually treated by CAPD, HDC and AD. SI levels were more uniformly distributed within all centres, and this was true for HCD and AD patients. When considering CA levels in HDC patients, a large predominance of CA level 3 was observed in all centres whereas CA level 1 was nearly in existent.

CONCLUSION

The major finding of this study was that the inability or the refusal of dialysis patients to participate at treatment, independently of medical condition and nurse care requirement, was the main factor in the choice of hospital centre dialysis.

Renal and hypertensive complications of extracorporeal shock wave lithotripsy: who is at risk?

Extracorporeal shock wave lithotripsy (ESWL) is now used in the treatment of about 90% of renal and ureteral stones. Because of the non-punctual delivery of energy to the stone, a small volume of renal parenchyma is injured giving place to a fibrous scar which can be shown by highly resolutive imaging techniques like magnetic nuclear resonance. Isotopic clearances point to a reduction of 15% in the renal plasma flow on the side of the lithotripsy, but this alteration appears to be transient in nature. In a few cases an abrupt onset of transient hypertension has been reported in clear relation to a compressive perirenal hematoma. The responsibility of ESWL in the late occurrence of permanent hypertension is, however, still uncertain, probably because of the difficulty in showing that this occurrence is not only related to the older age of the patient. The American Food and Drug Administration-sponsored multicentric study begun in 1992 should solve this issue in the future. Recent articles suggest that altered renal function prior to ESWL would predict the late occurrence of hypertension and worsening of renal failure. Furthermore, age and the resistance index of arcuate or interlobar renal arteries (measured by Doppler) could help to screen patients at risk of developing hypertension. In practice in patients over 60 years of age and/or with a plasma creatinine of >to 300 micromol/l, ESWL should be performed with caution, and renal function and blood pressure should be carefully monitored.

[Renal and hypertensive complications of extracorporeal lithotripsy]

HISTOLOGICAL AND FUNCTIONAL CONSEQUENCES OF ESWL: Extracorporeal shock wave litotripsy is now used for the treatment of about 90% of stones. Because of the nonpunctual delivery of energy into the stone, a small volume of renal parenchyma is injured, giving rise to a fibrous scar which can be visualized by morphological techniques such as magnetic nuclear resonance. Isotopic techniques point out a 15% reduction of renal plasma flow on the side of the litotripsy. For a majority of patients, this alteration is transient.

HYPERTENSION

In a few cases, abrupt onset of transient hypertension has been reported in clear relation with a compressive perirenal hematoma. The causal effect of ESWL on late occurrence of permanent hypertension is however still uncertain, probably because of the difficulty to show that this occurrence is not related to the older age of the patient alone. The FDA sponsored multicentric study begun in 1993 should solve this issue in the future.

PATIENTS AT RISK

Recent articles suggest that altered renal function prior to ESWL would predict late occurrence of hypertension and worsening of renal failure. Furthermore, age and the resistance index of arcuate or interlobular renal arteries (measured by Doppler) could help to screen the patients at risk of developing hypertension. Practical attitude: In practice, renal function and blood pressure should be carefully monitored in patients aged over 60 and/or who have a serum creatinine > 300 mumol/l.

Serial measurements of antineutrophil cytoplasmic autoantibodies in patients with systemic vasculitis

PURPOSE

To assess the value of serial determinations of antineutrophil cytoplasmic autoantibodies (ANCA) for monitoring disease activity in patients with systemic vasculitis.

PATIENTS AND METHODS

Forty-three patients with histologically proven vasculitis (21 with Wegener's granulomatosis, 17 with microscopic polyangiitis, and 5 with renal-limited vasculitis) were studied for a median follow-up of 22 months. Disease activity was prospectively assessed and quantified by the Birmingham Vasculitis Activity Score. A total of 347 sera were analyzed for ANCA determination.

RESULTS

Relapses occurred in 23 (54%) of 43 patients. Diagnostic category (Wegener's granulomatosis vs micropolyangiitis and renal-limited vasculitis), severity of initial symptoms (mean vasculitis activity score, mean number of organs involved), and ANCA pattern [cytoplasmic-ANCA (c-ANCA) vs perinuclear-ANCA (p-ANCA)] did not significantly differ between relapsers and nonrelapsers. Lung involvement was more frequent at onset among relapsers [16 of 23 (70%) vs 6 of 20 (30%); P = 0.02]. Relapses were slightly, but not significantly, more frequent in patients with Wegener's granulomatosis or a c-ANCA pattern. The percentage of relapsers was greater in patients with persistently positive ANCA than in patients with negative or decreasing ANCA titers (86% vs 20%, P = 0.0001). However, the predictive value of an increase in ANCA titers for the occurrence of a subsequent relapse was only 28% (4 of 14) for c-ANCA, 12% (2 of 17) for anti-proteinase 3-ANCA, and 43% (6 of 14) for anti-myeloperoxidase-ANCA. An increase in ANCA occurred before or during relapse in 33% (10 of 30) of cases for c-ANCA/anti-proteinase 3 antibodies, and 73% (11 of 15) of cases for anti-myeloperoxidase antibodies.

CONCLUSION

The persistence of ANCA positivity is strongly associated with relapses. However, an increase in ANCA titers has a poor value for the early prediction of a subsequent relapse and should not be used as a sole parameter for therapeutic intervention. In addition, our results suggest that serial anti-myeloperoxidase determination may be useful as a prognostic marker in patients who are p-ANCA positive.

Pathophysiology and treatment of idiopathic hypercalciuria

Nearly 50 years after its initial description by Dr. F. Albright, the term idiopathic hypercalciuria (IH) is still in use. The exact mechanism of hypercalciuria is still unknown despite extensive pathophysiologic investigations; recent advances represent the focus of this review. A precise definition of true IH is proposed, taking into account the various nutritional conditions influencing calcium excretion. The potential pathogenic mechanisms are discussed, and the limits of the classical Pak's pathophysiological classification are recalled. The evidence supporting the role of an increased intestinal calcium absorption, a defect in renal tubular calcium reabsorption, or an increased bone loss as a primary mechanism in IH are successively examined. Since overall available human data indicates that all three mechanisms may be found in IH, the hypothesis that a broader disorder encompassing all these various abnormalities may be involved in IH is discussed. Three global hypotheses to account for IH physiopathology are examined: a diffuse defect in fatty acid content of cell membranes, an increased expression of the vitamin D receptor of the 25(OH) vitamin D 1 alpha-hydroxylase, or of the calcium sensor receptor and a monocyte disease. Finally, the available clinical data justifying the therapeutic approaches are reviewed, and guidelines for dietary recommendations regarding calcium and also animal protein, sodium chloride, alcohol, carbohydrate, phosphate, and potassium intakes are proposed, and drug therapy indications are discussed.

Low bone mineral density and peripheral blood monocyte activation profile in calcium stone formers with idiopathic hypercalciuria

Calcium stone formers (CaSF) with idiopathic hypercalciuria (IH) have been shown to have decreased bone mineral density (BMD). The mechanism of their bone loss remains obscure. Monokines like interleukin-1 beta (IL-1 beta), IL-6, tumor necrosis factor-alpha (TNF-alpha), and granulocyte macrophage stimulating factor (GM-CSF) are involved in bone remodeling, but only IL-1 excess has been incriminated in the bone loss of CaSF with IH. Therefore, to more precisely delineate the role of monocyte activation in the pathogenesis of bone loss in these patients, we studied the production of IL-1 beta, IL-6, TNF-alpha, and GM-CSF by unstimulated or lipopolysaccharide (LPS)-stimulated cultured peripheral blood monocytes in 15 CaSF with IH, in 10 CaSF with dietary calcium-dependent hypercalciuria (DH), and in 10 healthy controls (C). Cytokines were measured in the culture medium by sensitive enzyme-linked immunosorbent assay and vertebral BMD by single energy computed tomography. The decrease of vertebral BMD in IH compared with DH, was confirmed (Z score: -1.2 +/- 0.2 vs. -0.5 +/- 0.2; P = 0.04; Mann-Whitney). In the supernatant of unstimulated peripheral blood monocytes, IL-1 beta and TNF-alpha levels were higher in IH than in C (respectively, 40 +/- 21 vs. 7 +/- 1 pg/mL, P = 0.008 and 236 +/- 136 vs. 39 +/- 23 pg/mL, P = 0.03); those of GM-CSF were greater in IH than in DH and C (respectively, 52 +/- 27 vs. 6 +/- 2, P = 0.04 and 6 +/- 2 pg/mL, P = 0.01) and those of IL-6 were not significantly different among the groups. After in vitro stimulation by LPS (10 micrograms/mL), the levels of the various monokines were not significantly different. In IH patients, the post-LPS levels of IL-6 were negatively correlated to vertebral BMD (n = 15, Z = -1.97, P = 0.04; Spearman), whereas those of GM-CSF were positively related to vertebral BMD (n = 15, Z = 2.01, P = 0.04). In this study, calcium stone formers with IH have bone mineral decrease and a particular profile of peripheral blood monocytes activation. This latter is characterized by a spontaneously increased synthesis of IL-1 beta, TNF-alpha, and GM-CSF. Furthermore, post-LPS levels of IL-6 and GM-CSF are correlated with vertebral BMD. These results suggest that monocyte activation may be involved in the bone loss of calcium stone formers with IH.