Novel biomarkers of diabetic kidney disease: current status and potential clinical application

Diabetic kidney disease (DKD) is a leading cause of end-stage renal disease (ESRD). Although both albuminuria and glomerular filtration rate (GFR) are well-established diagnostic/prognostic biomarkers of DKD, they have important limitations. There is, thus, increasing quest to find novel biomarkers to identify the disease in an early stage and to improve risk stratification. In this review, we will outline the major pitfalls of currently available markers, describe promising novel biomarkers, and discuss their potential clinical relevance. In particular, we will focus on the importance of recent advancements in multi-omic technologies in the discovery of new DKD biomarkers. In addition, we will provide an update on new emerging approaches to explore renal function and structure, using functional tests and imaging.

Treatment with eltrombopag of severe immune thrombocytopenia and hemolytic anemia associated with COVID-19 pneumonia: a case report

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). Whether SARS-CoV-2 can trigger an autoimmune reaction against platelets and red blood cells remains unclear. Herein, we report a case of COVID-19 pneumonia associated with severe immune thrombocytopenia and hemolytic anemia. An 83-year-old woman was admitted to the hospital because of both dyspnea and diffuse mucocutaneous bleeding. Exams revealed hemolytic anemia (HA), severe immune thrombocytopenia (ITP), and bilateral pneumonia. Molecular testing confirmed a diagnosis of COVID-19 pneumonia. Thrombocytopenia did not respond to first-line treatment with immunoglobulin, corticosteroids, and platelet transfusions. Addition to therapy of the thrombopoietin receptor agonist, eltrombopag, resulted in full recovery. COVID-19 can be associated with ITP and HA. There are neither guidelines nor clinical experience on the treatment of COVID-19-associated ITP and our case, showing complete response to eltrombopag, may help clinicians in their practice during the COVID-19 pandemic.

PLAIN LANGUAGE SUMMARY

The case of an 83-year-old woman with COVID-19 pneumonia associated with two severe blood diseases that cause platelet and red cell destruction Coronavirus disease 2019 (COVID-19) is caused by a virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We do not know exactly whether this virus can stimulate our immune system to react against platelets and red blood cells. Herein, we report a case of COVID-19 pneumonia associated with two severe blood diseases, immune thrombocytopenia, which causes platelet destruction, and hemolytic anemia, which causes red cell destruction. An 83-year-old woman was admitted to the hospital because of both difficulty in breathing and diffuse bleeding in mucosae and skin. Exams revealed hemolytic anemia, severe immune thrombocytopenia, and pneumonia in both lungs. Molecular testing confirmed a diagnosis of COVID-19 pneumonia. The first treatment with immunoglobulin, corticosteroids, and platelet transfusions was not enough to cure thrombocytopenia; the addition of eltrombopag which acts on the thrombopoietin receptor agonist resulted in full recovery. COVID-19 can be present together with immune thrombocytopenia and hemolytic anemia. As there are no guidelines on the treatment of immune thrombocytopenia in patients with COVID-19 and the clinical experience is limited, the complete response achieved with eltrombopag may help clinicians in their practice during the COVID-19 pandemic.

Adaptation of the fish juvenile growth test (OECD TG 215, 2000) to the marine species Dicentrarchus labrax

The OECD TG 215 method (2000) (C.14 method of EC Regulation 440/2008) was developed on the rainbow trout (Oncorynchus mykiss) to assess chronic toxicity (28d) of chemicals on fish juveniles. It contemplates to use other well documented species identifying suitable conditions to evaluate their growth. OECD proposes the European sea bass (Dicentrarchus labrax, L. 1758) as Mediterranean species among vertebrates recommended in the OECD guidelines for the toxicity testing of chemicals. In this context, our study is aimed to proposing the adaptation of the growth test (OECD TG 215, 2000) to D. labrax. For this purpose toxicity tests were performed with sodium dodecyl sulfate, a reference toxicant commonly used in fish toxicity assays. The main aspects of the testing procedure were reviewed: fish size (weight), environmental conditions, dilution water type, experimental design, loading rate and stocking density, feeding (food type and ration), test validity criteria. The experience gained from growth tests with the sea bass allows to promote its inclusion among the species to be used for the C.14 method.

Fitness Evaluation of Ruditapes philippinarum Exposed to Ni

In this study, long-term effects of Ni, a widespread heavy metal in the aquatic ecosystems, have been determined on growth and lethality of the clam Ruditapes philippinarum, a known bioindicator of the marine environment. Three/four-month-old bivalves have been exposed to different concentrations of Ni dissolved in synthetic seawater. Growth and lethality as endpoints after 28 days of treatment have been observed. Obtained results are the following: EC₂₅ = 3.97 ± 0.94 and 9.45 ± 1.59 mg/L and NOEC = 1.56 and 6.25 mg/L for growth and mortality, respectively. Moreover, this study can be considered a new tool for the evaluation of fitness of bivalve clam, together with other biological responses following to the biological impacts of metal pollution.

Can Artemia Hatching Assay Be a (Sensitive) Alternative Tool to Acute Toxicity Test?

Artemia sp. is extensively used in ecotoxicity testing, despite criticisms inherent to both acute and long-term tests. Alternative endpoints and procedures should be considered to support the use of this biological model. The hatching process comprises several developmental steps and the cyst hatchability seems acceptable as endpoint criterion. In this study, we assessed the reliability of the hatching assay on A. franciscana by comparing with acute and long-term mortality tests, using two chemicals: Diethylene Glycol (DEG), Sodium Dodecyl Sulphate (SDS). Both DEG and SDS tests demonstrated a dose dependent hatching inhibition. The hatching test resulted more sensitive than acute mortality test and less sensitive than the long-term one. Results demonstrate the reliability and high sensitivity of this hatching assay on a short time lag and support its useful application in first-tier risk assessment procedures.

Interdependence of initial cell density, drug concentration and exposure time revealed by real-time impedance spectroscopic cytotoxicity assay

We investigated the combined effect of the initial cell density (12,500, 35,000, 75,000, and 100,000 cells cm(-2)) and concentration of the anti-cancer drug doxorubicin on HeLa cells by performing time-dependent cytotoxicity assays using real-time electrochemical impedance spectroscopy. A correlation between the rate of cell death and the initial cell seeding density was found at 2.5 μM doxorubicin concentration, whereas this was not observed at 5 or 100 μM. By sensing the changes in the cell-substrate interaction using impedance spectroscopy under static conditions, the onset of cytotoxicity was observed 5 h earlier than when using a standard colorimetric end-point assay (MTS) which measures changes in the mitochondrial metabolism. Furthermore, with the MTS assay no cytotoxicity was observed after 15 h of incubation with 2.5 μM doxorubicin, whereas the impedance showed at this time point cell viability that was below 25%. These results indicate that impedance detection reveals cytotoxic events undetectable when using the MTS assay, highlighting the importance of combining impedance detection with traditional drug toxicity assays towards a more in depth understanding of the effect of anti-cancer drugs on in vitro assays. Moreover, the detection of doxorubicin induced toxicity determined with impedance under static conditions proved to be 6 times faster than in perfusion culture.

Ecotoxicity of diethylene glycol and risk assessment for marine environment

Diethylene glycol (DEG) is a chemical compound used during offshore oil activities to prevent hydrate formation, and it may be released into the sea. A full ecotoxicological characterization is required according to European and Italian regulations for chemical substances. We have evaluated long-term toxic effects of DEG on indicator species of the marine environment as algae (Phaeodactylum tricornutum), crustaceans (Artemia franciscana), molluscs (Tapes philippinarum) and fish (Dicentrarchus labrax). A range of no observed effect concentrations (365-25,000 mg/L) has been identified. Based on the toxicity results and the ratio between predicted environmental concentration and predicted no-effect concentration, we have estimated the maximum allowable value of DEG in the marine environment.

Impedimetric toxicity assay in microfluidics using free and liposome-encapsulated anticancer drugs

In this work, we have developed a microfluidic cytotoxicity assay for a cell culture and detection platform, which enables both fluid handling and electrochemical/optical detection. The cytotoxic effect of anticancer drugs doxorubicin (DOX), oxaliplatin (OX) as well as OX-loaded liposomes, developed for targeted drug delivery, was evaluated using real-time impedance monitoring. The time-dependent effect of DOX on HeLa cells was monitored and found to have a delayed onset of cytotoxicity in microfluidics compared with static culture conditions based on data obtained in our previous study. The result of a fluorescent microscopic annexin V/propidium iodide assay, performed in microfluidics, confirmed the outcome of the real-time impedance assay. In addition, the response of HeLa cells to OX-induced cytotoxicity proved to be slower than toxicity induced by DOX. A difference in the time-dependent cytotoxic response of fibrosarcoma cells (HT1080) to free OX and OX-loaded liposomes was observed and attributed to incomplete degradation of the liposomes, which results in lower drug availability. The matrix metalloproteinase (MMP)-dependent release of OX from OX-loaded liposomes was also confirmed using laryngopharynx carcinoma cells (FaDu). The comparison and the observed differences between the cytotoxic effects under microfluidic and static conditions highlight the importance of comparative studies as basis for implementation of microfluidic cytotoxic assays.

Evaluation of a peptide ELISA for the detection of rituximab in serum

Pharmacokinetic studies of therapeutic monoclonal antibodies necessitate the measurement of their biologically active fraction. The aim of this work was to develop an enzyme-linked immunosorbent assay (ELISA) for rituximab, a chimeric anti-CD20 monoclonal antibody, based on its binding to a 20-mer peptide (P20) derived from the extracellular loop of human CD20 (residues 165-184). Derivatives of P20 were prepared by conjugation to bovine serum albumin (BSA-P20ACM) or biotin (Biot-P20ACM). Interactions of P20 and its derived peptides with rituximab were analyzed by surface plasmon resonance (SPR) and by ELISA. A monoclonal anti-idiotype antibody (MB2A4) was used as the reference in each case. SPR analysis showed that P20 (conjugated or unconjugated) had a lower affinity for rituximab than MB2A4. ELISA methods based on P20 or MB2A4 were both highly accurate and reproducible for rituximab measurement in spiked samples, but the MB2A4-based assay had a lower limit of quantification. Interestingly, discrepant results were obtained with the two ELISA methods when analyzing pharmacokinetic samples, with the rituximab concentrations obtained with the MB2A4-based method being systematically higher than those determined by the P20-based method. Possible interference of circulating CD20 with the P20-based method was supported by competition experiments. Rituximab aggregation in the bloodstream may also account for the bias observed in samples from healthy mice. The P20-based ELISA is far less sensitive than the MB2A-based ELISA, thus limiting its utility for pharmacokinetic studies. However, the discrepancy observed between two different approaches for rituximab measurement indicates that data from different studies should be interpreted with care.

Differential Estradiol Requirement for the Induction of Estrus Behavior and the Luteinizing Hormone Surge in Two Breeds of Sheep1

For a better understanding of the mechanisms that lead to the preovulatory GnRH/LH surge and estrus behavior, the minimum estradiol (E) requirements (dose and duration) to induce each of these events were determined and compared between two breeds of ewes having either single (Ile de France) or multiple (Romanov) ovulations. The ewes were initially studied during a natural estrus cycle, and were then ovariectomized and run through successive artificial estrus cycles. For these artificial cycles the duration and amplitude of the follucular phase E increase were manipulated by E implants. Under all conditions, the onset of estrus behavior was similar in the two breeds, although its duration was longer in Romanov ewes. While a moderate E signal (6 cm for 12 h) induced an LH surge in 10/10 Ile de France ewes, a larger E signal (12 cm for 12 h) was minimally effective in Romanov ewes (4/10). Additional studies revealed that a small E signal (3 cm for 6 h) induced full estrus behavior in all Romanov ewes but was completely ineffective in Ile de France animals (0/10). Higher doses and mostly longer durations of the E signal (12 cm for 24 h) were required to induce a surge in all the Romanov ewes. These results demonstrate a clear difference in the E requirement for the induction of estrus behavior and the LH surge between breeds of ewes that have different ovulation rates. These data provide compelling evidence that, in one breed, the neuronal systems that regulate both events require different estrogen signals.

Comparative assessment of methods for the reactivity measurement in subcritical systems by pulsed experiments

The determination of the subcriticality level for source-driven systems is an important problem that can be handled by several deterministic methods developed for the interpretation of flux signals in pulsed experiments. The paper compares the performance of several methods for different physical characteristics of the system considered and for different durations of the source pulse. The effects of the subcriticality level and of the experimental uncertainty are also investigated. Furthermore, an analysis of the influence of spatial effects is carried out. The study gives some indications on the most suitable method in a specific experimental configuration pointing out at the situations where non-conservative evaluations of the reactivity can be expected, i.e. when the system effective multiplication constant is underestimated.

Passage of progesterone into the brain changes with photoperiod in the ewe

In this study we tested the hypothesis that photoperiod can modulate steroid access to the brain in a seasonal breeder. To this goal, we compared the passage of exogenous progesterone to the brain of female sheep maintained under short (SD) or long (LD) daylengths. In the first experiment, we studied two groups of ovariectomized females maintained under SD or LD, for three artificial cycles, consisting of bearing a subcutaneous oestradiol implant (E2-treated) and an intravaginal device releasing progesterone (CIDR). During the third cycle, the concentrations of progesterone and of its metabolites 5alpha-dihydroprogesterone and 3alpha-hydroxy-5alpha-pregnan-20-one were measured in the preoptic area (POA). The levels of progesterone in the POA were higher in ewes under LD than under SD while the amounts of metabolites were unchanged. In the second experiment, we compared ovariectomized female sheep equipped with a cannula in the third ventricle to sample the cerebrospinal fluid (CSF) under LD vs. SD. After progesterone (1 mg and 10 mg) was injected into the carotid artery, it was only detectable in the cerebrospinal fluid in sheep under LD. In the third experiment, we compared progesterone concentration in plasma and CSF in two groups of SD vs. LD ovariectomized E2-treated ewes for 2 h under CIDR treatment. Despite similar progesterone plasma concentrations, concentration in the CSF was 2.5 times higher in SD than in LD. Our results suggest a physiological modulation of the passage of progesterone to the brain according to the photoperiod.

The xenotransplantation of goat and human hematopoietic cells to sheep fetuses

Hematopoietic xenografts were carried out in three experiments using goat fetal liver (44-48 days, experiments I and II) or purified human CD 34+ cells (experiment III) as the donor cells. Recipients were sheep fetuses at 41-47 days of gestation. Goat fetal liver cells were either injected without any pretreatment or stimulated by preincubation in a culturing in goat phytohemagglutinin-stimulated lymphocyte supernatant. Human CD 34+ myeloid progenitor cells were purified from bone marrow by minimacs immunomagnetic purification and cultured in medium supplemented with stem cell factor, IL3, and IL6. Goat-sheep chimerism was assessed by flow cytometry analysis (FCA) of peripheral blood and bone marrow cells using a mouse anti-goat CD 45 monoclonal antibody and by karyotype analysis of peripheral blood from goat/sheep chimeras. Human cell engraftment was assessed by polymerase chain reaction amplification of the human DAX1 gene in blood and bone marrow DNA from sheep which had received human cells. In the three experiments, a mean of 76% (26 of 34) of injected fetuses were born alive without any clinical evidence of graft-versus-host disease. Three lambs were found to be goat/sheep chimeric after flow cytometry analysis (peripheral blood and bone marrow) and karyotype (peripheral blood) analysis. Both tissues continued to express goat cells at 6 or 12 months (last assessment) depending on the experiment. No human chimerism was detected using polymerase chain reaction amplification in peripheral blood and bone marrow of any of the six sheep grafted with human cells. These data and those also obtained on other species (human, pig/sheep) show that it is possible to carry out hematopoietic xenografts using the sheep fetus as recipient provided both donor and recipient fetal cells are processed during the period of tolerance to foreign antigens.

Autologous lymphocytes prevent the death of monocytes in culture and promote, as do GM-CSF, IL-3 and M-CSF, their differentiation into macrophages

Blood monocytes collected by apheresis from healthy donors were differentiated in vitro to macrophages which were subsequently activated with recombinant human interferon-gamma. 7 day cultures were established by seeding Ficoll-separated mononuclear cells or elutriation-purified monocytes under different culture conditions. The best macrophage yields required the seeding of mononuclear cells (instead of purified monocytes) in teflon bags with a high air-liquid surface interface. The effects of GM-CSF, IL-3 and M-CSF on the macrophage yield were then evaluated. GM-CSF increased the average yield by 3.6- and 2.3-fold when purified monocytes or total mononuclear cells were seeded respectively. The corresponding increases with IL-3 were 2.5- and 2.1-fold respectively and with M-CSF 1.2- and 1.4-fold respectively. Macrophages matured under these various conditions displayed similar CD14, CD64, CD71, HLA-DR and Max 1 antigen expression and similar in vitro anti-tumoral activity against U937 cells. Culturing in the presence of cytokines permits the large scale production of activated macrophages for adoptive immunotherapy trials.

Production of human macrophages with potent antitumor properties (MAK) by culture of monocytes in the presence of GM-CSF and 1,25-dihydroxy vitamin D3

Antitumoral macrophages (MAK) were obtained by the culture of human mononuclear cells in hydrophobic bags. From one cytapheresis, up to 10(9) mature macrophages could be purified by elutriation after one week of culture in IMDM medium in the presence of 2% human AB serum. These MAK cells were used for adoptive treatment in metastatic cancer patient with no dose-limiting toxicity. The present study aimed to improve the average MAK yield by addition of GM-CSF and of dihydroxy-cholecalciferol. The differentiated macrophages obtained presented higher antitumoral functionality in response to rh-IFN gamma than in their absence. These MAK presented all the differentiation antigens of cytotoxic macrophages compared to MAK cells differentiated in standard medium. They killed human tumor targets effectively in vitro at a low (1/1) effector/tumor ratio; furthermore, the antitumoral activity reached by MAK cells after IFN gamma activation appeared to be stabilized for several days.

Adoptive immunotherapy with activated macrophages grown in vitro from blood monocytes in cancer patients: a pilot study

Ninety-three collections of leucocytes by cytapheresis followed by separation of monocytes by centrifugal elutriation were undertaken in twelve metastatic cancer patients (four melanomas, six colon carcinomas, one ovarian carcinoma, and one lung cancer). The leucaphereses were performed aiming to collect a product, ready for introduction into the elutriation chamber, i.e., with low contamination by erythrocytes and granulocytes. The median collection of leucocytes was 7.3 x 10(9). After elutriation, purified monocytes (mean: 0.91 x 10(9)) were cultured with 3-5% autologous serum for 7 days in the presence of 250 IU/ml of recombinant human gamma-interferon (Rh-IFN gamma) for the last 18 h of culture. The median number of activated macrophages (MAK) available for reinfusion was 2.4 x 10(8) for each culture. The phenotypes and the antitumoral potentiality of MAK cells were documented. Reinfusions performed i.v. or i.p. were well tolerated with no major side effects. No complete tumor response was obtained. One partial response and two stabilizations of the disease were observed in one melanoma and two colon carcinomas.

[HLA B27 phenotyping using flow cytometry]

Results of typing for HLA B27 antigens of 106 patients in whole blood with a FITC monoclonal anti HLA B27 antibody and analysis by flow cytometry are compared to the results obtained by the classical microlymphocytoxicity test. By flow cytometry analysis, there are not false negative result, but, because of cross reactions of the used monoclonal antibody with other specificities of the CREG B7 group, false positive result may be encountered. The flow cytometry analysis for typing HLA B27 antigens using a monoclonal antibody can be a good screening technique: so it's rapid and moreover the negative results can be accepted. The positive results must be confirmed.

Serial study of T-lymphocyte subsets in women during very early pregnancy

The aim of this serial study was to define variations in T-lymphocyte populations during the first weeks of pregnancy. Results obtained with 14 women pregnant after artificial insemination show that the CD4+ population decreased significantly as soon as the fourth week. This decrease was concomitant with the HCG peak and could be compatible with certain immunological mechanisms participating in tolerance to the fetal graft.

Correlation of plasma hormone levels and peripheral circulating lymphocyte subpopulations during human pregnancy

Using monoclonal antibodies (OKT3, OKT4, OKT8) peripheral blood lymphocyte subsets were determined in 40 normal primiparous pregnant women and compared with those of 31 nonpregnant controls. In pregnant women plasma concentrations of estradiol, progesterone, human placental lactogen (HPL), beta subunit of human chorionic gonadotropin (beta HCG), and alpha-fetoprotein were measured by means of radioimmunoassay. We studied if correlations between peripheral lymphocyte subsets and plasma hormone levels might exist. We observed in pregnant women from 10 to 40 wk of amenorrhea a decrease in the percentage of OKT3 and OKT8 cells, and during the course of pregnancy an increase in the percentage of OKT4 cells. This increase inversely correlated with plasma beta HCG levels and directly correlated with plasma HPL levels.