Letter to editor: is laboratory index really a practical and valid tool to predict mortality?

We carefully studied the article titled “A practical laboratory index to predict institutionalization and mortality – an 18-year population-based follow-up study” written by Heikkilä et al. and published in BMC Geriatrics on 25 February 2021 with great interest. We would like to make some comments regarding this article and tool. Laboratory Index (LI) has been executed with the data of 728 patients who had followed-up in our center, however the LI score was not able to predict the 10-year and 18-year mortality. Therefore, a question mark has been aroused in our minds at some points. Neither frailty nor comorbidities were considered in this index. For a geriatric patient, it would be inadequate to evaluate laboratory results regardless of the clinical status. Similarly, it would not be appropriate to predict mortality only on the basis of laboratory results without considering the clinical status of the patient.We think that although the recent study has a great impact, it can be improved by incorporating data on the comorbidities and frailty status of the patients into the analysis.

Monocyte to high density lipoprotein ratio in patients with acute kidney injury after cardiac surgery

Background: The Monocyte to high density lipoprotein ratio (MHR) has been postulated as a novel parameter associated with adverse renal and cardiovascular outcomes. In this study we investigated the association of MHR with cardiac surgery-associated acute kidney injury (CSA-AKI). Methods: In this retrospective study, we analyzed the data pertaining to 1505 patients undergoing cardiopulmonary bypass (CPB) surgery. The CSA-AKI, which was defined using Kidney Disease Improving Global Outcomes criteria. Concurrently, a retrospective scan of patient files was conducted and information relevant to nephropathy such as the level of their serum creatinine (SCr), Blood urea nitrogen (BUN), uric acid (UA), serum cystatin C (Cys-C), total cholesterol (TC), triglycerides (TG), glucose and MHR, ejection fraction, CPB duration time, and other indicators. Results: About 1505 patients were studied of whom 195 developed AKI. MHR was significantly higher in the AKI patients (p = 0.001). In multivariate logistic regression analysis, MHR, UA, Cys-C, age, glucose, and history of chronic kidney disease or hypertension were independently correlated with CSA-AKI. Conclusions: As a laboratory index, the elevated MHR is convenient, independent, and a useful predictor for CSA-AKI.

Novel laboratory index, based on fasting blood parameters, accurately reflects insulin sensitivity

Context Simple and reliable measurement of insulin sensitivity may be important for the prevention of insulin-resistance related diseases. Surrogate indices of insulin sensitivity are of limited utility in population without signs of metabolic syndrome. Objective The aim of our study was to provide simple and accurate index of insulin sensitivity. Design The study group comprised 150 young healthy participants. Hyperinsulinemic-euglycemic clamp was performed. Regression models with different laboratory parameters were constructed. Validation cohort 1 comprised independent group of 110 subjects, including individuals with prediabetes and newly diagnosed type 2 diabetes. Validation cohort 2 comprised 38 obese subjects before and after diet-induced weight loss. Validation cohort 3 comprised 60 nondiabetic subjects from an independent center. Results The supervised principal component model established optimal set of variables correlated with insulin sensitivity. This model (Fasting Laboratory Assessment of Insulin Sensitivity, FLAIS) used red blood cell count, alanine aminotransferase activity, serum C-peptide, SHBG, IGF-binding protein 1 and adiponectin concentrations. FLAIS exhibited strong correlation with clamp-derived insulin sensitivity. The sensitivity of the model was 90% and the specificity was 68%. In the validation cohort 1, differences in FLAIS among the groups paralleled those observed with the clamp, with the lowest values in prediabetes and diabetes. In the validation cohort 2, FLAIS reflected the change in insulin sensitivity after weight loss. The main findings were confirmed in the validation cohort 3. Conclusion We provide simple and accurate method of assessing insulin sensitivity, which allows to identify insulin resistance even in the population without overt metabolic disturbances.

Abundance alteration of nondominant species in fecal-associated microbiome of patients with SAPHO syndrome

Background SAPHO syndrome is a group of symptoms consisting of synovitis, acne, pustulosis, hyperostosis and osteosis. There is no specific laboratory index assist in the diagnosis of SAPHO because of its highly heterogeneous clinical manifestations. Pathogenic microorganisms had been identified in biopsies of some SAPHO cases and particular gene mutations were also linked to the occurrence of SAPHO. It is largely unknown whether intestinal microbiome plays a role in pathogenesis of SAPHO. To explore the intestinal microbiome structure of SAPHO syndrome, fecal samples from 17 SAPHO patients and 14 healthy controls (HC) were collected for 16S rDNA sequencing. Results Our results showed that there was no significant difference in alpha indexes and beta diversity between SAPHO and HC samples, while there were 14 operational taxonomic units (OTUs) in the Wilcoxon rank-sum test and 42 OTUs in the MetagenomeSeq analysis showed significant difference in distribution between the SAPHO and HC groups, 3 of which in Firmicutes were also observed in the random forest analysis and used to construct a receiver operating characteristic curve to evaluate the diagnostic value, the area under the curve was 0.86. Conclusion Fecal-associated microbiome in the SAPHO samples was characterized by the alteration in abundance of some nondominant species, and the 3 selected OTUs in Firmicutes could serve as candidate biomarkers for SAPHO syndrome diagnosis.

A Method for Assessing the Severity of Obstructive Jaundice of Non-Neoplastic Origin

AIM OF STUDY To develop a method for assessing the severity of obstructive jaundice (OJ) of non-neoplastic orogin on the basis of functional parameters of the liver and the activity of pathogenetic agents of hepatodepression.MATERIAL AND METHODS Clinical and laboratory studies of 142 patients with breast cancer of non-tumor origin. The indicators of the functional state of the liver, the index of plasma toxicity for albumin, and the content of malondialdehyde (MDA) were evaluated.RESUlTS Based on the assessment of a number of blood parameters - the content of total bilirubin (TB), the plasma toxicity index for albumin, the MDA level — the severity index of obstructive jaundice of non-neoplastic origin (SIOJ) was developed:SIOJ = IT1/ITn + TB1/TB + 5(MDA1/MDAn)where IT 1 is the plasma albumin toxicity index at the current moment, ITn is the normal albumin plasma toxicity index, TB1 is the current bilirubin content, TBn is the normal bilirubin content, MDA1 is the current malondialdehyde content, MDAn is the normal value. The index less than 13 indicates a mild severity, 14–21 is moderate severity, 22 and higher indicates a severe degree of OJ. The method increases the objectivity of determining the severity of non-neoplastic origin by establishing the severity of liver damage and the processes underlying it.CONClUSiON The suggested clinical and laboratory index allows the severity of obstructive jaundice to be objectively and quickly determined upon admission of a patient to the hospital and also adequate therapy to be initiated in case of severe degree for anticipation of possible post-operative complications, so the treatment should be focused on managing triggers of hepatodepression. The method is simple and available in medical institutions of various levels. The method is especially valuable when used in the dynamics of the early postoperative period.

A practical laboratory index to predict institutionalization and mortality – an 18-year population-based follow-up study

Background Previously, several indexes based on a large number of clinical and laboratory tests to predict mortality and frailty have been produced. However, there is still a need for an easily applicable screening tool for every-day clinical practice. Methods A prospective study with 10- and 18-year follow-ups. Fourteen common laboratory tests were combined to an index. Cox regression model was used to analyse the association of the laboratory index with institutionalization and mortality. Results The mean age of the participants (n = 1153) was 73.6 (SD 6.8, range 64.0–100.0) years. Altogether, 151 (14.8%) and 305 (29.9%) subjects were institutionalized and 422 (36.6%) and 806 (69.9%) subjects deceased during the 10- and 18-year follow-ups, respectively. Higher LI (laboratory index) scores predicted increased mortality. Mortality rates increased as LI scores increased both in unadjusted and in age- and gender-adjusted models during both follow-ups. The LI did not significantly predict institutionalization either during the 10- or 18-year follow-ups. Conclusions A practical index based on routine laboratory tests can be used to predict mortality among older people. An LI could be automatically counted from routine laboratory results and thus an easily applicable screening instrument in clinical settings.

Knee alterations in rheumatoid arthritis: Comparison of US and MRI

Objective This study was designed to compare the diagnostic efficacy of ultrasonography (US) and magnetic resonance imaging (MRI) in detecting changes in the knee of patients with rheumatoid arthritis (RA) and discover the possible association between the serological index and bone erosion detected by US. Patients and methods In this retrospective study, the US images and MRI findings of the knee in patients with RA from December 2017 to January 2020 were evaluated. Diagnostic outcomes were compared. The rheumatoid factor, C-reactive protein, erythrocyte sedimentation rate, and anti-cyclic citrullinated peptide antibody (ACPA) levels of the patients were recorded. The relation between laboratory index and US findings was analyzed by multivariable logistic regression. Results US showed remarkable accuracy, sensitivity, and specificity in diagnosing synovitis, bone erosion, and soft tissue swelling. In terms of reliability, the agreement between US and MRI was moderate to almost perfect. Meanwhile, a positive association between ACPA level and bone erosion was observed in patients with RA. Conclusions US may have a role as the initial imaging modality in patients with RA. Patients with higher ACPA levels may need more active treatment because they are more likely to have bone erosion detected by US.

Sensitivity of Multispectral Imager Liquid Water Cloud Microphysical Retrievals to the Index of Refraction

A cloud property retrieved from multispectral imagers having spectral channels in the shortwave infrared (SWIR) and/or midwave infrared (MWIR) is the cloud effective particle radius (CER), a radiatively relevant weighting of the cloud particle size distribution. The physical basis of the CER retrieval is the dependence of SWIR/MWIR cloud reflectance on the cloud particle single scattering albedo, which in turn depends on the complex index of refraction of bulk liquid water (or ice) in addition to the cloud particle size. There is a general consistency in the choice of the liquid water index of refraction by the cloud remote sensing community, largely due to the few available independent datasets and compilations. Here we examine the sensitivity of CER retrievals to the available laboratory index of refraction datasets in the SWIR and MWIR using the retrieval software package that produces NASA’s standard Moderate Resolution Imaging Spectroradiometer (MODIS)/Visible Infrared Imaging Radiometer suite (VIIRS) continuity cloud products. The sensitivity study incorporates two laboratory index of refraction datasets that include measurements at supercooled water temperatures, one in the SWIR and one in the MWIR. Neither has been broadly utilized in the cloud remote sensing community. It is shown that these two new datasets can significantly change CER retrievals (e.g., 1–2 µm) relative to common datasets used by the community. Further, index of refraction data for a 265 K water temperature gives more consistent retrievals between the two spectrally distinct 2.2 µm atmospheric window channels on MODIS and VIIRS. As a result, 265 K values from the SWIR and MWIR index of refraction datasets were adopted for use in the production version of the continuity cloud product. The results indicate the need to better understand temperature-dependent bulk water absorption and uncertainties in these spectral regions.