Interferences in the measurement of circulating phosphate: a literature review.

Background Inorganic phosphate in blood is currently determined by the reaction with molybdate. This report aims at reviewing conditions underlying spuriously altered levels of circulating inorganic phosphate. Content A systematic search of the Excerpta Medica, the National Library Database and the Web of Science database was conducted without language restriction from the earliest publication date available through January 31, 2020. Summary For the analysis, 80 reports published in English (n = 77), French (n = 1), German (n = 1) and Spanish (n = 1) were retained. Well-documented pseudohyperphosphatemia was observed in individuals exposed to liposomal amphotericin, in patients affected by a gammopathy, in patients with hyperlipidemia and in patients with hyperbilirubinemia. An unexplained elevated inorganic phosphate level sometimes provided a clue to the diagnosis of a gammopathy. Well-documented cases of pseudohypophosphatemia were observed in patients on large amounts of intravenous mannitol. Finally, pseudohypophosphatemia was occasionally observed on treatment with liposomal amphotericin and in patients with a gammopathy. Outlook In order to avoid unnecessary testing and treatment, the phenomenon of spuriously altered inorganic phosphate should be recognized. An unexplained hyperphosphatemia may provide a clue to the diagnosis of a gammopathy or a severe hyperlipidemia.

Association among myocardial injury and mortality in Influenza: A prospective cohort study.

BACKGROUND: Myocardial injury (MINJ) is a well-recognized prognostic marker in different acute cardio-respiratory illnesses, nonetheless, its relevance in Influenza remains poorly defined. Our aim was to assess incidence, correlates, short and mid-term prognostic role of MINJ in Influenza. METHODS: Hospitalized patients (pts) with laboratory confirmed Influenza A or B underwent highly sensitive cardiac T Troponin (hs-cTnT) measurement at admission in four regional Swiss hospitals during the 2018-2019 epidemic. MINJ was defined as hs-cTnT >14 ng/L. Clinical, laboratory and outcome data were prospectively collected. The primary endpoint was mortality at 28 days while the composite of mortality, admission to intensive care unit (ICU) or need for mechanical ventilation at 28-days and mortality at 30-months were set as secondary endpoints. RESULTS: The presence of MINJ was assessed within 48 h from admission in 145 consecutive hospitalized pts, being evident in 94 (65.5%) pts and associated with older age, higher C-reactive protein levels, renal impairment or chronic obstructive pulmonary disease. At a 28-days follow-up, 7 deaths (4.8%) occurred, all in patients with MINJ at admission (log-rank p = 0.048). MINJ was strongly associated with occurrence of death, ICU admission or mechanical ventilation (OR 5.74, 95% CI 1.28-53.29; p = 0.015). After a median follow-up of 32.7 months (IQR 32.2-33.4), 15 (10.3%) deaths occurred, all among pts with MINJ at index hospitalization leading to a higher mortality at follow-up among patients with MINJ (log-rank p = 0.003). CONCLUSIONS: MINJ is common in patients hospitalized for Influenza and is able to stratify the risk of short-term adverse events and mid-term mortality.

Comparative frequency and prognostic impact of myocardial injury in hospitalized patients with COVID-19 and Influenza.

Aims: Myocardial injury (MINJ) in Coronavirus disease 2019 (COVID-19) identifies individuals at high mortality risk but its clinical relevance is less well established for Influenza and no comparative analyses evaluating frequency and clinical implications of MINJ among hospitalized patients with Influenza or COVID-19 are available. Methods and results: Hospitalized adults with laboratory confirmed Influenza A or B or COVID-19 underwent highly sensitive cardiac T Troponin (hs-cTnT) measurement at admission in four regional hospitals in Canton Ticino, Switzerland. MINJ was defined as hs-cTnT >14 ng/L. Clinical, laboratory and outcome data were retrospectively collected. The primary outcome was mortality up to 28 days. Cox regression models were used to assess correlations between admission diagnosis, MINJ, and mortality. Clinical correlates of MINJ in both viral diseases were also identified. MINJ occurred in 94 (65.5%) out of 145 patients hospitalized for Influenza and 216 (47.8%) out of 452 patients hospitalized for COVID-19. Advanced age and renal impairment were factors associated with MINJ in both diseases. At 28 days, 7 (4.8%) deaths occurred among Influenza and 76 deaths (16.8%) among COVID-19 patients with a hazard ratio (HR) of 3.69 [95% confidence interval (CI) 1.70-8.00]. Adjusted Cox regression models showed admission diagnosis of COVID-19 [HR 6.41 (95% CI 4.05-10.14)] and MINJ [HR 8.01 (95% CI 4.64-13.82)] to be associated with mortality. Conclusions: Myocardial injury is frequent among both viral diseases and increases the risk of death in both COVID-19 and Influenza. The absolute risk of death is considerably higher in patients admitted for COVID-19 when compared with Influenza.