Polyethylene Glycol Precipitation Research Articles

The Clinical Significance and Utility of Routine Screening for Macroprolactin in Patients With Hyperprolactinemia

Background: Macroprolactin is a complex of monomeric prolactin (PRL) molecules with immunoglobulin G (IgG) that can result in the elevation of serum prolactin level. Macroprolactin is biologically less active and failure to screen for macroprolactin may lead to unnecessary investigations and treatments in patients with hyperprolactinaemia. Aim: We sought to evaluate the clinical significance and clinical utility of routine screening of macroprolactin in patients with hyperprolactinemia. Methods: We analysed 141 patients from a retrospective database of patients with elevated serum prolactin in Changi General Hospital from Jan 2017 to Dec 2019 with routine screening of macroprolactin with polyethylene glycol (PEG) precipitation using Abbott Architect Prolactin assay. Clinical, biochemical, radiological data and medication usage were extracted from electronic medical records. Macroprolactinaemia was defined as a PRL recovery of < 60%. Approval was obtained from the local research ethics committee. Results: Thirty-six (26%) patients had macroprolactinaemia with a male predominance (72%). There were no significant differences in the presence of symptoms, the percentages of medication-induced hyperprolactinemia, and magnetic resonance imaging (MRI) pituitary scans done between patients with macroprolactinaemia and those with truly elevated serum prolactin. As such clinical features might not be useful to differentiate patients with macroprolactinaemia. Eight MRI pituitary scans were performed in patients with macroprolactinaemia and pituitary abnormalities were detected in 4 of the patients which are likely non-functioning pituitary lesions. As such, not only were unnecessary scans done but it also led to a cascade of further investigations. Eight patients had simultaneous macroprolactinaemia and elevated bioactive serum prolactin, as such post-PEG prolactin level with corresponding reference ranges rather than the percentage recovery should be use as the threshold for defining macroprolactinaemia to avoid misdiagnosis. Conclusion: Macroprolactinaemia is common and routine screening may avert unnecessary investigations. Post-PEG prolactin level with corresponding reference ranges should be used as diagnostic threshold.

8 Suspected presence of macroprolactin in the plasma of horses and ponies

Prolactin is a peptide hormone that plays a role in various physiological functions and its production is influenced by several factors (thyrotropin-releasing hormone, dopamine, season, meal feeding or physiological state such as lactation). Plasma levels help understand reproductive physiology; but may also be a useful indicator of dopamine production at a central level (connection between the hypothalamus and pituitary gland). In human medicine, when prolactin is measured using sandwich immunometric methodologies in automated analysers, hyperprolactinemia diagnosis may be confounded by the presence of a high molecular mass prolactin/IgG autoantibody complex termed macroprolactin, which does not have biological effects. Macroprolactinaemia has not previously been described in horses. Previously equine prolactin has been measured by radioimmunoassay (RIA) analysis; however, more rapid ELISA assays are now available without the radioactive tracer health and safety considerations. In this study, prolactin was measured in plasma from 20 normal horses and 20 horses with pituitary pars intermedia dysfunction, using a commercial ELISA assay (Biorbyt, UK). Surprisingly, while most showed values below 100 ng/mL, 13 appeared to have extremely high concentrations, well in excess of the upper limit of the standard curve at 1000 ng/mL. There was no significant association of this finding with disease category, breed, sex or age. To determine whether the presence of macroprolactin could be causing these aberrant values, a polyethyleneglycol (PEG) precipitation step was introduced, as previously shown in humans, to remove the macroprolactin while leaving the monomeric form in solution. After the addition of PEG and centrifugation to precipitate out macroprolactin, the supernatant with the unprecipitated prolactin was tested and compared with unprecipitated samples from the same individuals. PEG precipitation resulted in a reduction in prolactin values by more than 99% in those with apparent hyperprolactinaemia (to below 200 ng/mL in all cases except one at 243 ng/mL). In the other samples the values were reduced from 67.4 ± 9.9ng/ml to 10.6 ± 0.7ng/ml (approximately 75% reduction). Although this data is preliminary and more validation work is necessary, these findings are consistent with macroprolactin being detected by the ELISA assay in these individual horses. While it may be possible to validate the ELISA assay for measuring prolactin in equine plasma, a PEG precipitation step is required to remove this interfering substance. Further research is needed to confirm the presence and size characteristics of this macroprolactin complex in equine plasma.

An optimized and robust PEG precipitation method for detection of SARS-CoV-2 in wastewater

Wastewater-based epidemiology is currently being utilized to monitor the dissemination of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), on a population scale. The detection of SARS-CoV-2 in wastewater is highly influenced by methodologies used for its isolation, concentration and RNA extraction. Although various viral concentration methods are currently employed, including polyethylene glycol (PEG) precipitation, adsorption-extraction, ultracentrifugation and ultrafiltration, to our knowledge, none of these methods have been standardized for use with a variety of wastewater matrices and/or different kits for RNA extraction and quantification. To address this, wastewater with different physical characteristics was seeded with gamma-irradiated SARS-CoV-2 and used to test the efficiency of PEG precipitation and adsorption-extraction to concentrate the virus from three physiochemically different wastewater samples, sourced from three distinct wastewater plants. Efficiency of viral concentration and RNA extraction was assessed by reverse-transcriptase polymerase chain reaction and the recovery yields calculated. As co-purification of inhibitors can be problematic for subsequent detection, two commonly used commercial master mixes were assessed for their sensitivity and efficiency to detect two SARS-CoV-2 target nucleocapsid (N) gene sequences. Recovery rates varied greatly between wastewater matrices and concentration methods, with the highest and most reproducible recovery rates (46.6–56.7%) observed when SARS-CoV-2 was precipitated with PEG and detected by the Luna® Universal master mix. The adsorption-extraction method was less effective (0–21.7%). This study demonstrates that PEG precipitation is the more robust method, which translates well to varying wastewater matrices, producing consistent and reproducible recovery rates. Furthermore, it is compatible with different kits for RNA extraction and quantitation.

Luteinizing hormone (LH) formed a complex with an immunoglobulin G caused abnormally high levels of LH: A case report

We encountered a 30-year-old woman with remarkably elevated luteinizing hormone (LH) levels, as measured by electrochemiluminescent immunoassay (ECLIA), and no specific symptoms. We performed the following investigations: dilution linearity test, polyethylene glycol (PEG) precipitation test, immunoprecipitation test, protein G addition test, and high-performance liquid chromatography (HPLC) analysis. The linearity of patient’s serum was similar to that of a standard LH preparation, and non-specific reactions were not observed. The recovery rate of LH shown by the PEG precipitation test, immunoprecipitation test, and protein G addition test was low. Moreover, an abnormal peak in HPLC was located at a slightly larger molecular weight position than that of IgG. These results showed the presence of macro-LH, LH, and anti-LH-IgG autoantibody complex and suggested that the clearance of LH from the blood was delayed due to IgG binding, and therefore, the LH value was falsely high. We should keep the possibility of macro-LH in mind in cases of unexpectedly high LH values.

An IgG/IgY sandwich-ELISA for the detection of heat-labile enterotoxin B subunit of enterotoxigenic Escherichia coli

ObjectiveEnterotoxinogenic Escherichia coli is a health-threatening pathogen, especially in children. LT toxin this bacterium causes diarrhea and loss of body fluids. The development of rapid and cost-effective methods for diagnosis will help the patient survive and prevent the spread of this bacterium. The aim of this study was to design and set up the double sandwich ELISA diagnostic method for the detection of LT toxin using egg yolk (IgY) and rabbit antibody (IgG). MethodsRecombinant LTB protein was expressed in E coli BL21 (DE3) and purified using a Ni-NTA column. Chickens and rabbits were immunized subcutaneously and the generated antibodies were purified from egg yolks by polyethylene glycol (PEG) precipitation and from the rabbits' sera by protein G column. These antibodies were used to set up the ELISA method. The sensitivity of the designed ELISA method was evaluated using serial dilutions of the protein. ResultsExpression of recombinant protein led to the production of LTB with molecular weight of 15 kDa. Yield of protein was 6 mg/L. ELISA assay results showed, increased serum antibody levels against the protein in chickens and rabbits sera after each injection. The yield of purified IgG was 2/5 mg/mL. The yield of purified IgY was 27 mg per egg. The sensitivity of the ELISA method was about 39 ng for recombinant LTB. The results showed the high specificity of this technique. ConclusionResults suggest that IgY/IgG-based sandwich ELISA in this study provides a convenient preparation for the development of immune-based method for the detection of LTB.

Unexpected Vancomycin Pharmacokinetic Profile Secondary to Macromolecular Complexing: A Case Series.

The optimal dosing and monitoring of vancomycin has been largely debated for decades, with key guideline changes for recommended monitoring in 2009 and 2020. Current and past practices for pharmacokinetic dose optimization use serum drug assays to guide dose adjustment to effectively balance efficacy and the risks of toxicity. These assays detect both bound and unbound serum concentrations. Vancomycin is believed to be 50%-55% protein bound in most cases; however, some variability in this parameter has been previously published. The authors report 2 cases of abnormal vancomycin pharmacokinetics discovered based on unexpected serum levels during routine clinical care. Unexpected vancomycin levels, observed during clinical care for 2 separate patients, were further evaluated to determine the source of the abnormal pharmacokinetics. In case 1, serial dilution was performed to assure that assay interference was not associated with the significant elevation (>100 mg/L). In both cases, samples were filtered using a Millipore Centrifree 30 KDa centrifugal filter to separate bound vancomycin, with a Protein G spin kit used to bind IgG and remove IgG complexes from the patient sample. In case 2, a polyethylene glycol precipitation was also performed to precipitate large-molecular-weight complexes. In both cases, laboratory analysis revealed abnormal vancomycin protein-binding profiles with macromolecular complex formation. Immunoglobulin G played a role in the macrocomplex in both patients. In cases of unusual or unexpected vancomycin pharmacokinetics in the absence of renal dysfunction, an abnormal protein-binding profile should be considered. Bound vancomycin may yield elevated serum levels, leading to poorly informed dose adjustments and risk for treatment failure. Given implications for therapeutic drug monitoring and unknown impacts on efficacy and toxicity, further investigations into population incidence and risk factors for abnormal protein binding of vancomycin are warranted.

Time Evolution of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Wastewater during the First Pandemic Wave of COVID-19 in the Metropolitan Area of Barcelona, Spain.

Two large wastewater treatment plants (WWTP), covering around 2.7 million inhabitants, which represents around 85% of the metropolitan area of Barcelona, were sampled before, during, and after the implementation of a complete lockdown. Five one-step reverse transcriptase quantitative PCR (RT-qPCR) assays, targeting the polymerase (IP2 and IP4), the envelope (E), and the nucleoprotein (N1 and N2) genome regions, were employed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA detection in 24-h composite wastewater samples concentrated by polyethylene glycol (PEG) precipitation. SARS-CoV-2 was detected in a sewage sample collected 41 days ahead of the declaration of the first COVID-19 case. The evolution of SARS-CoV-2 genome copies in wastewater evidenced the validity of water-based epidemiology (WBE) to anticipate COVID-19 outbreaks, to evaluate the impact of control measures, and even to estimate the burden of shedders, including presymptomatic, asymptomatic, symptomatic, and undiagnosed cases. For the latter objective, a model was applied for the estimation of the total number of shedders, evidencing a high proportion of asymptomatic infected individuals. In this way, an infection prevalence of 2.0 to 6.5% was figured. On the other hand, proportions of around 0.12% and 0.09% of the total population were determined to be required for positive detection in the two WWTPs. At the end of the lockdown, SARS-CoV-2 RNA apparently disappeared in the WWTPs but could still be detected in grab samples from four urban sewers. Sewer monitoring allowed for location of specific hot spots of COVID-19, enabling the rapid adoption of appropriate mitigation measures.IMPORTANCE Water-based epidemiology (WBE) is a valuable early warning tool for tracking the circulation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among the population, including not only symptomatic patients but also asymptomatic, presymptomatic, and misdiagnosed carriers, which represent a high proportion of the infected population. In the specific case of Barcelona, wastewater surveillance anticipated by several weeks not only the original COVID-19 pandemic wave but also the onset of the second wave. In addition, SARS-CoV-2 occurrence in wastewater evidenced the efficacy of the adopted lockdown measures on the circulation of the virus. Health authorities profited from WBE to complement other inputs and adopt rapid and adequate measures to mitigate the effects of the pandemic. For example, sentinel surveillance of specific sewers helped to locate COVID-19 hot spots and to conduct massive numbers of RT-PCR tests among the population.

The presence of SARS-CoV-2 RNA in human sewage in Santa Catarina, Brazil, November 2019.

Human sewage from Florianopolis (Santa Catarina, Brazil) was analyzed for severe acute respiratory syndrome coronavirus-2 (SARS-CoV2) from October 2019 until March 2020. Twenty five ml of sewage samples were clarified and viruses concentrated using a glycine buffer method coupled with polyethylene glycol precipitation, and viral RNA extracted using a commercial kit. SARS-CoV-2 RNA was detected by RT-qPCR using oligonucleotides targeting N1, S and two RdRp regions. The results of all positive samples were further confirmed by a different RT-qPCR system in an independent laboratory. S and RdRp amplicons were sequenced to confirm identity with SARS-CoV-2. Genome sequencing was performed using two strategies; a sequence-independent single-primer amplification (SISPA) approach, and by direct metagenomics using Illumina's NGS. SARS-CoV-2 RNA was detected on 27th November 2019 (5.49 ± 0.02 log10 SARS-CoV-2 genome copies (GC) L−1), detection being confirmed by an independent laboratory and genome sequencing analysis. The samples in the subsequent three events were positive by all RT-qPCR assays; these positive results were also confirmed by an independent laboratory. The average load was 5.83 ± 0.12 log10 SARS-CoV-2 GC L−1, ranging from 5.49 ± 0.02 log10 GC L−1 (27th November 2019) to 6.68 ± 0.02 log10 GC L−1 (4th March 2020). Our findings demonstrate that SARS-CoV-2 was likely circulating undetected in the community in Brazil since November 2019, earlier than the first reported case in the Americas (21st January 2020).

Enteric virus presence in green vegetables and associated irrigation waters in a rural area from Argentina. A quantitative microbial risk assessment

The aim of this study was to assess the presence of norovirus, rotavirus and infective enterovirus in leafy green vegetables and irrigation waters collected from a farm located at the province of Córdoba, Argentina, and to estimate the quantitative risk of infection by consuming these vegetables. During June 2014–July 2015, vegetables (n = 101) and their corresponding irrigation waters (n = 24) were collected. Viruses were concentrated in both matrices by polyethylene glycol precipitation and then were subjected to RT-PCR to assess the presence of norovirus and rotavirus. The concentrates were also inoculated in CaCo-2 cells to monitor the occurrence of infective enterovirus. The frequency of detection of norovirus, rotavirus and infective enterovirus in irrigation waters was 37.5%, 20.8% and 37.5% and in crops 60.4%, 22.7% and 35.6% respectively. Similar profiles of norovirus genogroups and rotavirus G-types distribution were observed in green vegetables and irrigation waters. The estimated risk of rotavirus infection associated with raw consumption of the vegetables harvested in that rural farm was 0.2 per person per day. This study demonstrates a wide distribution of human pathogenic viruses in irrigation waters and green leafy vegetables, which is of concern when, as in this case, the vegetables are eaten raw.

Concentration and Quantification of SARS-CoV-2 RNA in Wastewater Using Polyethylene Glycol-Based Concentration and qRT-PCR.

Wastewater-based epidemiology has become an important tool for the surveillance of SARS-CoV-2 outbreaks. However, the detection of viruses in sewage is challenging and to date there is no standard method available which has been validated for the sensitive detection of SARS-CoV-2. In this paper, we describe a simple concentration method based on polyethylene glycol (PEG) precipitation, followed by RNA extraction and a one-step quantitative reverse transcription PCR (qRT-PCR) for viral detection in wastewater. PEG-based concentration of viruses is a simple procedure which is not limited by the availability of expensive equipment and has reduced risk of disruption to consumable supply chains. The concentration and RNA extraction steps enable 900–1500× concentration of wastewater samples and sufficiently eliminates the majority of organic matter, which could inhibit the subsequent qRT-PCR assay. Due to the high variation in the physico-chemical properties of wastewater samples, we recommend the use of process control viruses to determine the efficiency of each step. This procedure enables the concentration and the extraction the DNA/RNA of different viruses and hence can be used for the surveillance of different viral targets for the comprehensive assessment of viral diseases in a community.

Detection and disinfection of COVID-19 virus in wastewater.

The coronavirus disease 2019, COVID-19, caused by the severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, appears as a major pandemic having adverse impact on public health and economic activities. Since viral replication in human enterocytes results in its faecal shedding, wastewater surveillance is an ideal, non-invasive, cost-effective and an early warning epidemiological approach to detect the genetic material of SARS-CoV-2. Here, we review techniques for the detection of SARS-CoV-2 in municipal wastewater, and disinfectants used to control viral spread. For detection, concentration of ribonucleic acid involves ultrafiltration, ultracentrifugation and polyethylene glycol precipitation. Identification is done by reverse transcriptase amplification, nucleic acid sequence-based amplification, helicase dependent amplification, loop-mediated isothermal amplification, recombinase polymerase amplification, high throughput screening and biosensor assays. Disinfectants include ultraviolet radiations, ozone, chlorine dioxide, hypochlorites and hydrogen peroxide. Wastewater surveillance data indicates viral presence within longer detection window, and provides transmission dynamics earlier than classical methods. This is particularly relevant for pre-symptomatic and asymptomatic COVID-19 cases.

Standard Bacteriophage Purification Procedures Cause Loss in Numbers and Activity.

For decades, bacteriophage purification has followed structured protocols focused on generating high concentrations of phage in manageable volumes. As research moves toward understanding complex phage populations, purification needs have shifted to maximize the amount of phage while maintaining diversity and activity. The effects of standard phage purification procedures such as polyethylene glycol (PEG) precipitation and cesium chloride (CsCl) density gradients on both diversity and activity of a phage population are not known. We have examined the effects of PEG precipitation and CsCl density gradients on a number of known phage (M13, T4, and ΦX 174) of varying structure and size, individually and as mixed sample. Measurement of phage numbers and activity throughout the purification process was performed. We demonstrate that these methods, used routinely to generate “pure” phage samples, are in fact detrimental to retention of phage number and activity; even more so in mixed phage samples. As such, minimal amounts of processing are recommended to introduce less bias and maintain more of a phage population.

Evaluation of Two Methods to Concentrate SARS-CoV-2 from Untreated Wastewater.

Use of wastewater-based epidemiology as a tool to record and manage the course of SARS-CoV-2 infections in human populations requires information about the efficiency of methods to concentrate the virus from wastewater. In the present study, we spiked untreated wastewater with quantified SARS-CoV-2 positive clinical material and enriched the virus by polyethylene glycol precipitation and ultrafiltration with Vivaspin 10 kDa MWCO columns. SARS-CoV-2 was detected and quantified by reverse transcription quantitative PCR (E- and S-gene) and droplet digital PCR. The concentration of virus with precipitation resulted in mean recoveries between 59.4% and 63.7% whereas rates from 33.0% to 42.6% after ultrafiltration of samples were demonstrated. The results suggest that the use of both methods allows an effective and practicable enrichment of SARS-CoV-2 from raw wastewater.

Survey of rapid development of environmental surveillance methods for SARS-CoV-2 detection in wastewater

Environmental surveillance as a part of wastewater-based epidemiology (WBE) of SARS-CoV-2 can provide an early, cost-effective, unbiased community-level indicator of circulating COVID-19 in a population. The objective of this study was to determine how widely SARS-CoV-2 detection in wastewater is being investigated and what methods are used. A survey was developed and distributed, with results showing that methods were rapidly applied to conduct SARS-CoV-2 WBE, primarily to test wastewater influent from large urban wastewater treatment plants. Additionally, most methods utilized small wastewater volumes and the primary concentration methods used were polyethylene glycol precipitation, membrane filtration and centrifugal ultrafiltration followed by nucleic acid extraction and assay for primarily nucleocapsid gene targets (N1, N2, and/or N3). Since this survey was performed, many laboratories have continued to optimize and implement a variety of methods for SARS-CoV-2 WBE. Method comparison studies completed since this survey was conducted will assist in developing WBE as a supplemental tool to support public health and policy decision making responses.

Prolactin Level in Polycystic Ovary Syndrome (PCOS): An approach to the diagnosis and management.

Introduction:In spite of the increasing prevalence of polycystic ovary syndrome, there are restricted studies about different features of PCOS. In this study, we evaluate serum prolactin levels in PCOS patients and compare clinical features and hormone levels between patients with hyperprolactinemia and normal levels of prolactin.Methods:Serum prolactin level in 330 PCOS patients were evaluated. If the prolactin levels were normal (equal to or less than 25 ng/ml) the patient was considered normal. If the prolactin levels were >25 ng/ml, then the level was measured by Polyethylene glycol (PEG) precipitation method to detect macroprolactinemia. Furthermore, brain MRI was done in case of hyperprolactinemia to discover pituitary adenoma.Results:Among 330 patients with PCOS, 208 (63.4%) had normal prolactin levels and 122 (37%) patients had hyperprolactinemia. Among hyperprolactinemic patients, 72 (59%) had normal prolactin levels after PEG precipitation and 33 (27%) patients had pituitary adenoma in their brain MRI and 17 (13%) patients were considered as idiopathic hyperprolactinemia with normal MRI. Further, higher levels of LH and LH/FSH ratio and lower estradiol levels were observed in patients with normal prolactin levels. Also, menstrual disorders were more prevalent among patients with pituitary adenoma.Conclusions:Investigating increased level of prolactin in PCOS patients is recommended to detect the causes of hyperprolactinemia, especially macroprolactinemia. (www.actabiomedica.it)

Persistent idiopathic prolactin elevation merits macroprolactin estimation: A case report and review of literature

The prevalence of hyperprolactinemia ranges from about 0.4% in an unselected adult population to as high as 9%–17% in women with reproductive disorders. It may cause infertility in about 11% of the oligospermic males. Rarely, the cause of persistently elevated prolactin remains obscure even after thorough work up. Macroprolactinemia is biologically inactive, high-molecular-weight form of prolactin resulting from its binding to immunoglobulin G, causing a decrease in its clearance. We report the case of a 35-year-old female, detected to have hyperprolactinemia on multiple tests, during routine work up for primary infertility. Secondary causes for the same were ruled out. A magnetic resonance imaging (MRI) of the brain excluded a prolactinoma. This prompted an estimation of prolactin levels after polyethylene glycol precipitation which showed a decrease to 5.58 ng/mL, with <40% recovery, confirming the presence of macroprolactin. Thus, persistently elevated prolactin levels in the background of negative neurological imaging necessitate the estimation of macroprolactin.

Changes in phospholipid metabolism in exosomes of hormone-sensitive and hormone-resistant prostate cancer cells.

Background: To explore the changes in lipids in exosomes of hormone-sensitive and hormone-resistant prostate cancer cells and develop an inexpensive and rapid technique for screening lipid-based biomarkers of prostate cancer.Methods: Exosomes were extracted from LnCap, PC3 and DU-145 cells, and their lipid composition was analyzed quantitatively using high-throughput mass spectrometry. Exosomes released by LnCap prostate cancer cells were also purified using a modified procedure based on polyethylene glycol (PEG) precipitation.Results: Exosomes extracted from LnCap cells contained higher proportions of phosphatidyl choline, phosphatidyl ethanolamine and phosphatidyl inositol lipids than whole LnCap cells. Lysophosphatidylcholine, a harmful intermediate product of phosphatidylcholine metabolism in vivo, was not found in LnCap cells but in exosomes. Phospholipids were different in exosomes from LnCap, PC3 and DU-145 prostate cancer cells. The main lipid pathways involved, i.e., glycerophospholipid metabolism, autophagy, and ferroptosis pathways, were also different in these cells. Exosomes isolated by this modified PEG precipitation technique were similar in purity to those obtained using a commercial kit.Conclusions: This study demonstrates that phosphatidylcholine and its harmful product lysophosphatidylcholine may play important roles in hormone-sensitive prostate cancer. Phospholipid exosome metabolism was changed in hormone-sensitive and hormone-resistant prostate cancer cells. The LPC, lipid pathway of autophagy and ferroptosis may act as therapeutic targets. The possibility of purifying prostate cancer cell exosomes using modified PEG precipitation is suitable for cancer screening.

Prevalence of Macroprolactinemia in Patients with Hyperprolactinemia Using Roche Elecsys Platform in a Large Tertiary Referral Center in UAE

Objectives: Macroprolactin (macroPRL) excess is an important cause of hyperprolactinemia. Several prolactin assays have high reactivity to macroPRL. However, macroPRL screening is not routinely performed in many labs. This study aimed to evaluate the prevalence of macroprolactinemia (MP) in patients with elevated prolactin using the Roche Elecsys assay in a large tertiary center in UAE. Materials and Methods: Consecutive samples of patients with elevated prolactin presenting to Tawam Hospital from June to August 2018 were evaluated for MP. Polyethylene glycol (PEG) was used to precipitate macroPRL. Monomeric prolactin recovery cutoff ≤50% was used to determine the prevalence of MP. Results: A total of 180 patients with elevated prolactin were included in the study with a mean age of 33.1 ± 11.9 years. The majority were women (87.2%), and about 77.8% were newly diagnosed patients with hyperprolactinemia. The main indications for prolactin testing were menstrual irregularity (n = 121), infertility (n = 11), galactorrhea (n = 11), and sellar masses (n = 12). MP was present in 8.3% of the patients. The median (IQR) of total prolactin level was 740.5 (579–1,085) IU/m before PEG precipitation and was not significantly different between MP and true hyperprolactinemia cases. Three patients with MP had pituitary MRI evaluation, which was normal. Eight patients with MP were treated with cabergoline. Conclusion: One in 12 patients with hyperprolactinemia had MP on the Roche Elecsys assay defined as the cutoff recovery of ≤50% post-PEG precipitation. Physicians should be aware of the prolactin assay used in their labs, and we recommend routine macroPRL assessment in mild hyperprolactinemia samples in labs using the Roche Elecsys platform.

Prevalence of Macroprolactinaemia by Polyethylene Glycol Precipitation Method: A Cross-sectional Study

Introduction: Macroprolactin, an immunoreactive molecule resulting from association of monomeric Prolactin (mPRL) and immunoglobulin G is a significant cause of misdiagnosis, unnecessary radiological investigation and treatment for hyperprolactinaemia. Data on its prevalence and clinical manifestation varies regionally. Case presentation can vary with assymptomatic cases to those with galactorrhea and irregular menses. Aim: To find the prevalence and clinical features associated with macroprolactin in cases of hyperprolactinaemia in hospital patients. Materials and Methods: A cross-sectional study was conducted in the Department of Biochemistry, Institute of Postgraduate Medical Education and Research and SSKM hospital, Kolkata, India, from November 2018 to April 2019. Serum samples were assayed for serum PRL levels in 1400 subjects by Chemiluminescence immunoassay (Immulite 1000 siemens) based on presenting symptoms of galactorrhoea, amenorrhoea and infertility. Serum PRL samples (n=240) above the manufacturer’s reference cut-off level (PRL ≥30 ng/mL) were obtained from patients with or without symptoms of hyperprolactinaemia. Retesting for PRL levels were done following precipitation of macroprolactin using Polyethylene Glycol (PEG, MW: 6000). Fourty cases with physiological causes of PRL excess, hypothyroidism, polycystic ovary syndrome, antidopaminergic drug intake, hepatorenal diseases and chest wall disorders were excluded. The results were expressed in terms of Mean±Standard Deviation (SD) and compared using student t-test. Results: Prevalence of macroprolactin was 16 (13.3%) out of 120 among true hyperprolactaemic cases (male=2; female, n=14) based on percentage recovery of PRL in post-PEG cases (Recovery Rate (RR) &lt;40%). The mean pre-PEG and post-PEG values were 52.5 ng/mL and 19.2 ng/mL (RR: 36.5%; p-value &lt;0.05), respectively. The mean pre PEG, PRL values were significantly lower in macroprolactaemic cases than those with true hyperprolactinaemia (52.5 ng/mL versus 74.57 ng/mL; p-value 0.038). Some of the Macro-PRL cases reported with complaints of galactorrhoea, menstrual irregularities and infertility. Conclusion: The results revealed a prevalence rate similar to those reported in other studies worldwide. Clinical features alone are an unreliable tool to distinguish between cases with true high PRL levels and macroprolactinaemia. Macro-PRL cases once diagnosed requires no extended endocrine review and long term management. Hence, in cases with high PRL levels discordant with clinical symptoms/radiological data routine PEG precipitation test is an inexpensive assay for initial screening for presence of macroprolactin and also monitoring of patients already started on dopamine agonists for hyperprolactinaemia of unknown aetiology.

Immunocomplex changes in the lacrimal fluid and in the blood serum of patients with herpesvirus keratoconjunctivitis and their correction

The quantitative and qualitative composition of circulating immune complexes (CIC) in the lacrimal fluid and blood serum of patients with herpesvirus keratoconjunctivitis (ИКС) caused by herpes simplex virus type 1 (HSV-1) were studied. The effectiveness of the treatment by gammalin and nimesil was evaluated. 65 patients with ИКС from 24 to 54 years of age of both sexes were examined. Polymerase chain reaction for HSV-1 was positive in all patients. The control group consisted of 32 patients who received basic treatment with Zovirax ointment and Interferon. The main group consisted of 33 patients who received Gammalin and Nimesil in addition to basic therapy. The reference norm group consisted of 38 healthy donors. Tear fluid and venous blood serum were examined. The CIC was studied by precipitation in polyethylene glycol. Statistical processing was performed using the Student and Mann-Whitney tests. It has been established that in ИКС HSV-1 etiology in the lacrimal fluid of the affected eye and in the blood serum of patients the levels of total CIC increase, mainly due to medium and small fractions, which were the largest in the lacrimal fluid. In the convalescence phase violations of the quantitative and fractional composition of the CIC in the blood serum disappeared, while in the lacrimal fluid they decreased without normalization. The use of Gammalin and Nimesil in the treatment of patients with ИКС HSV-1 etiology improves the quantitative and fractional composition of CIC, both in the lacrimal fluid of the causal eye and in the blood serum of patients, which is manifested in a decrease in the number of total CIC, mainly due to a decrease in the concentrations of medium and small fractions. Keywords: keratoconjunctivitis, herpesviruses, immune complexes, Gammalin, Nimesil.