How useful is an oral calcium load test for diagnosing recurrent calcium stone formers?

Hypercalciuria is the main risk factor for recurrent calcium urolithiasis. The goal of our study is to determinate how useful an oral calcium load test is for stone formers to classify different forms of hypercalciuria in pathogenetic categories defined as renal or absorptive according to the current knowledge. Between June 2013 and February 2016, a prospective study was carried out on 117 documented recurrent hypercalciuric stone formers undergoing an oral calcium load test modified from the original description by Pak. After 2 days of calcium-restricted diet, urine and blood were analyzed at baseline and 120 min after receiving orally 1 g of calcium. Total and ionized calcium, parathyroid hormone from serum and urine calcium and creatinine were assessed in order to divide patients in three groups as previously described: resorptive, absorptive, and renal hypercalciuria. This allowed the identification of 19, 39, 34 and 33 patients with normocalcemic primary hyperparathyroidism (NPHPT), renal hypercalciuria aka renal calcium leak (RCL), absorptive hypercalciuria (AH) and unidentified cause, respectively. Patients with NPHPT (who required parathyroidectomy) experienced a lower PTH decrease (41.41 ± 12.82 vs. 54.06 ± 13.84% p < 0.01), higher beta-crosslaps, as well as lower TmP/GFR and distal third radius bone mineral density. RCL resulted in increased fasting urine calcium-to-creatinine ratio (Uca/Cr), i.e., > 0.37 mmol/mmol), without hyperparathyroidism. AH was diagnosed by the presence of ΔUCa/Cr > 0.60 mmol/mmol between baseline and 120 min without any other anomaly. For all remaining patients, results were inconclusive due to the lack of sufficient increase in serum calcium or because the cause of lithogenesis could not be clearly identified. The oral calcium load test is useful in nearly 80% of patients by identifying the different forms of hypercalciuria causing urolithiasis and by guiding treatment, including parathyroid surgery.

How the diagnosis and the management of genetic renal phosphate leak impact the life of kidney stone formers?

Genetic renal phosphate leak is one of the rare disorders in recurrent stone formers with absorptive hypercalciuria. Diagnosis and appropriate management may change the life of patients. To provide answers on how and when to make the diagnosis of genetic renal phosphate leak and how medical management prevents the recurrences and changes patients' life, we conducted a retrospective study including nine patients with recurrent nephrolithiasis and a confirmed genetic mutation of a phosphate transporter between 2008 and 2019 in our multidisciplinary center at the Pitié Salpetriere Hospital, Paris, France. We compared the number and the annual rate of urological intervention before and after the diagnosis and management using the Wilcoxon test. A qualitative survey was done to evaluate the quality of life of patients. A total of 9 patients were included in this study. Patient baseline characteristics and elements supporting the diagnosis are described. We showed an effective decrease in urological intervention number (p = 0.0078) and annual rate (p = 0.0117) after the diagnosis and the appropriate management, and an improvement in the patients' quality of life. The diagnosis and the appropriate management of genetic renal phosphate leak disorder improve the quality of life by preventing stone recurrence and decreasing the number of surgical intervention.

Impact of lean mass and bone density on glomerular filtration rate estimation in people living with HIV/AIDS.

CONTEXT: Chronic kidney disease is a frequent complication in persons living with HIV/AIDS. Although previous studies have suggested that the CKD-EPI formula is appropriate to estimate glomerular filtration rate (GFR) in HIV-positive adults with normal kidney function, the optimal way to estimate GFR in those with Stage 3 chronic kidney disease is not known. Moreover, the impact of muscle mass on creatinine level and GFR estimation is unknown. AIM AND METHODS: Our study aimed to evaluate the accuracy of different diagnostic tests available compared to the gold standard measurement of GFR. A group of 44 HIV-1 patients with an estimated GFR between 60 and 30 ml/min/1.73 m2 were included in a single-center cross-sectional study. Serum creatinine and cystatin C were measured. GFR was estimated using Cockcroft-Gault, MDRD, sMDRD, CKD-EPI, CKD-EPIcyst, and CKD-EPIcyst/creat formulae and was measured using isotopic Chrome51 EDTA clearance. Bone density and muscle mass were measured by DXA scan. RESULTS: Mean age was 62±10 years. Mean BMI was 23±4 kg/m2. Prevalence of diabetes was 30% and of hypertension was 47%. Viral load was <40 copies/ml for 90% of the patients, and mean CD4 count was 446±191 cells/mm3. Mean measured GFR was 63.4±16.5 ml/min/1.73 m2. All formulae under-estimated GFR. The best relative precision and accuracy were provided by the CKP-EPI formula. sMDRD, CKD-EPIcyst, and CKD-EPIcyst/creat performed worse than the CKD-EPI formula. Body composition did not significantly influence accuracy or precision of GFR estimation. CONCLUSION: In HIV-infected patients in stable immunovirologic conditions with CKD stage 3 and high prevalence of metabolic associated conditions, the CKD-EPI formula performed best, although all formulae under estimate GFR.

Dermatitis herpetiformis and bone mineral density: analysis of a French cohort of 53 patients.

The characteristics of patients with dermatitis herpetiformis (DH) in France is poorly documented. Furthermore, the risk of fractures and bone mineral density (BMD) in DH remain under-described, and recommendations for systematic screening for osteoporosis in DH are lacking. To describe the characteristics of DH in a large French cohort and evaluate the association between BMD and features of osteoporosis. Patients were recruited from the French Association of Gluten Intolerants (AFDIAG) and a single university dermatology department. A telephone questionnaire was used to record features of DH, history of fractures, calcium intake, treatment, and the gluten-free diet (GFD). Serum calcium and 25(OH) vitamin D3+D2 levels, as well as BMD, were measured. We included 53 patients (27 men) with a median age of 49 years (range: 23-86). Median disease duration before inclusion was 14 years (range: 2-55); 51 patients (96%) were adherent to a GFD and had no digestive symptoms. Overall, 18 (34%) had a history of fractures; 16 high-velocity (traumatic) and two low-velocity (non-traumatic). Mean BMD, measured in 48 patients, was normal (femoral neck: 0.956 ± 0.210 g/cm2; lumbar spine: 1.091 ± 1.199 g/cm2). In all, 18 patients (38%) had osteopenia and one (2%) osteoporosis. T-score for bone density did not differ with and without fractures. Calcium intake and serum calcium level were normal in all patients. Screening for osteoporosis does not appear to be mandatory for DH patients with good adherence to a GFD and without digestive symptoms or additional risk factors of osteoporosis.

Children and adolescents with severe mental illness need vitamin D supplementation regardless of disease or treatment.

BACKGROUND: To protect against osteoporosis, keeping the vitamin D blood level (25[OH]D; VDBL) above 30 ng/mL is recommended. It is established that regular intake of vitamin D, calcium intake, and physical exercise contribute to maximizing bone mineral mass during childhood and adolescence. Recent articles suggest that patients with schizophrenia treated with antipsychotics have low VDBL and may have a higher risk of hip fractures in their later years than the general population. OBJECTIVES: To evaluate whether adolescent psychiatric inpatient VDBL is lower than the 30-ng/mL optimal threshold and to document low-VDBL risk factors. METHOD: We determined the VDBL of all consecutive inpatients from three adolescents units in 2009 (N = 136). Univariate analyses explored the influence on VDBL of (1) well-documented risk factors (e.g., age, gender, ethnic origin, body mass index, or season) and (2) suspected risk factors (e.g., disease type or antipsychotic treatment). RESULTS: All but six patients had a VDBL <30 ng/mL (mean [ ± SD]: 15.9 [ ± 8.4] ng/mL). VDBL was significantly lower for all patients during the first quarter of the year compared to the other three (all p < 0.01). VDBL was also lower for blacks/North Africans 12.8 (±7.0) than for Caucasians/Europeans 17.2 (±8.5): t = 2.62, p = 0.009. We found no differences between patients regarding disease category (K = 3.75, p = 0.154) or antipsychotic treatment (t = 0.127, df = 124, p = 0.89). CONCLUSION: VDBL in an adolescent population with severe mental illness is lower than current recommendations of optimal level for bone health regardless of treatment or disease type. Because adolescence is a period of bone construction and could represent a critical window of opportunity for maximizing bone mass, especially among patients with severe mental illness, we recommend vitamin D supplementation.

Outcome of patients with undifferentiated chronic monoarthritis: retrospective study of 46 cases.

OBJECTIVE: To determine the natural history of undifferentiated monoarthritis of more than 3 months' duration and to evaluate the usefulness of classic diagnostic tools for identifying factors associated with outcomes. METHOD: Retrospective study of 46 patients with undifferentiated monoarthritis of more than 3 months' duration. RESULTS: Full resolution was the outcome in 50% of cases. Rheumatoid arthritis and spondyloarthropathy were the most common diagnoses in the remaining patients. HLA-B27 status was the only significant predictor of outcome: progression to spondyloarthropathy was significantly more common (P = 0.05) among HLA-B27-positive patients. Mean time to full recovery was significantly shorter than mean time to disease progression (12 vs. 45 months, P = 0.0015). Intraarticular glucocorticoid injections were effective in over 50% of patients. Arthritis relief during the month following the injection was associated with self-limited disease. The role for magnetic resonance imaging in managing patients with undifferentiated monoarthritis remains unclear. CONCLUSION: In patients with undifferentiated monoarthritis, the likelihood of a full recovery is 50%. The only significant predictor of outcome was positive HLA-B27 status, which was associated with progression to spondyloarthropathy.

Aggressive systemic mastocytosis.

Systemic mastocytosis is a rare and occasionally aggressive condition that raises major diagnostic challenges. We report a case in a 72-year-old patient in whom the diagnosis of malignant mastocytosis required two bone marrow smears and three bone marrow biopsies examined using specific staining techniques. Despite interferon therapy, a mast-cell sarcoma of the sternum developed 1 year after symptom onset, followed 1 year later by acute myeloblastic leukemia, which was rapidly fatal.