RESUMEN
OBJECTIVES: Tubular maximum phosphate reabsorption per glomerular filtration rate (TmP/GFR) is used to evaluate renal phosphate reabsorption and it is a useful tool for the differential diagnosis of hypophosphatemic syndromes. TmP/GFR is typically calculated from fasting plasma and second morning void urine samples, obtained 2â¯h after the first void (TmP/GFR 2â¯h). The purpose of this study was to evaluate if TmP/GFR calculated from 24â¯h urine collection (TmP/GFR 24â¯h) can be used as an alternative for TmP/GFR 2â¯h in patients with urine phosphate wasting. METHODS: We enrolled adult patients with X-linked hypophosphatemia (XLH) or tumor-induced osteomalacia (TIO). All patients underwent blood and urine sample collections, to calculate TmP/GFR 24â¯h and TmP/GFR 2â¯h. RESULTS: Twenty patients (17 XLH and 3 TIO), aged 24-78 years, were included. All patients had low TmP/GFR 2â¯h (0.35â¯mmol/L, IQR 0.24-0.47â¯mmol/L) and TmP/GFR 24â¯h (0.31â¯mmol/L, IQR 0.22-0.43â¯mmol/L). The concordance correlation coefficient between TmP/GFR 2â¯h and TmP/GFR 24â¯h was 0.86 (95â¯% CI: 0.69-0.93), with a systematic bias of 0.05â¯mmol/L (95â¯% limits of agreement: -0.10 to 0.20). Furthermore, in 70â¯% (i.e., 14 patients out of 20) and 80â¯% (i.e., 16 patients out of 20) of cases the difference between TmP/GFR 2â¯h and TmP/GFR 24â¯h was within ±30â¯% and ±35â¯%, respectively. CONCLUSIONS: Despite TmP/GFR 2 and 24â¯h show a relatively suboptimal agreement, the difference between the two parameters appears to be small and not clinically significant in the setting of adult patients with FGF23-dependent urine phosphate wasting and secondary hypophosphatemia.
Asunto(s)
Factor-23 de Crecimiento de Fibroblastos , Osteomalacia , Fosfatos , Toma de Muestras de Orina , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Raquitismo Hipofosfatémico Familiar/orina , Raquitismo Hipofosfatémico Familiar/diagnóstico , Tasa de Filtración Glomerular , Hipofosfatemia/orina , Hipofosfatemia/diagnóstico , Túbulos Renales/metabolismo , Osteomalacia/orina , Osteomalacia/diagnóstico , Síndromes Paraneoplásicos/orina , Síndromes Paraneoplásicos/diagnóstico , Fosfatos/orina , Toma de Muestras de Orina/métodosRESUMEN
Hepatitis C-associated osteosclerosis (HCAO) is a very rare condition that can be observed in a small number of patients with Hepatitis C Virus (HCV) infection. HCAO is usually characterized by widespread bone sclerosis, associated with severe bone pain, and increased levels of bone turnover markers, especially alkaline phosphatase (ALP). In this report, we present the case of a 55-year-old woman who was affected by HCV and came to our attention for severe and diffuse bone pain. Radiological studies showed bone sclerosis, and bone mineral density (BMD) was markedly increased, as well as serum ALP levels. The patient was initially treated with intravenous pamidronate, which provided only a transient benefit on clinical symptoms. Then antiviral therapy for HCV (interferon-alfa and ribavirin) was started and it was effective in making the viral load undetectable. After a long follow-up period, we observed a persistent remission of bone pain, a reduction in BMD together with a progressive trend toward the normalization of bone turnover markers. In conclusion, HCAO, although rare, should be considered among the potential causes of increased bone mass in patients with HCV infection, and treatment for the underlying infection may be effective in controlling the manifestations of this disease.
Asunto(s)
Hepatitis C , Osteosclerosis , Femenino , Humanos , Persona de Mediana Edad , Antivirales/uso terapéutico , Estudios de Seguimiento , Hepacivirus , Hepatitis C/complicaciones , Hepatitis C/tratamiento farmacológico , Osteosclerosis/etiología , Osteosclerosis/complicaciones , Dolor/complicaciones , Esclerosis/complicaciones , Esclerosis/tratamiento farmacológicoRESUMEN
Little information is available on the beneficial effects of cholecalciferol treatment in comorbid patients hospitalized for COVID-19. The aim of this study was to retrospectively examine the clinical outcome of patients receiving in-hospital high-dose bolus cholecalciferol. Patients with a positive diagnosis of SARS-CoV-2 and overt COVID-19, hospitalized from 15 March to 20 April 2020, were considered. Based on clinical characteristics, they were supplemented (or not) with 400,000 IU bolus oral cholecalciferol (200,000 IU administered in two consecutive days) and the composite outcome (transfer to intensive care unit; ICU and/or death) was recorded. Ninety-one patients (aged 74 ± 13 years) with COVID-19 were included in this retrospective study. Fifty (54.9%) patients presented with two or more comorbid diseases. Based on the decision of the referring physician, 36 (39.6%) patients were treated with vitamin D. Receiver operating characteristic curve analysis revealed a significant predictive power of the four variables: (a) low (<50 nmol/L) 25(OH) vitamin D levels, (b) current cigarette smoking, (c) elevated D-dimer levels (d) and the presence of comorbid diseases, to explain the decision to administer vitamin D (area under the curve = 0.77, 95% CI: 0.67-0.87, p < 0.0001). Over the follow-up period (14 ± 10 days), 27 (29.7%) patients were transferred to the ICU and 22 (24.2%) died (16 prior to ICU and six in ICU). Overall, 43 (47.3%) patients experienced the combined endpoint of transfer to ICU and/or death. Logistic regression analyses revealed that the comorbidity burden significantly modified the effect of vitamin D treatment on the study outcome, both in crude (p = 0.033) and propensity score-adjusted analyses (p = 0.039), so the positive effect of high-dose cholecalciferol on the combined endpoint was significantly amplified with increasing comorbidity burden. This hypothesis-generating study warrants the formal evaluation (i.e., clinical trial) of the potential benefit that cholecalciferol can offer in these comorbid COVID-19 patients.