Positron emission tomography - computed tomography as a monitoring response tool in pre-fibrotic myelofibrosis: A case report.

Primary myelofibrosis is a haematopoietic stem cell neoplasm resulting in ineffective haematopoiesis and bone marrow fibrosis. We present a case of a 67-year-old male patient who came to the oncology/haematology department of Dr. Ziauddin Hospital, Karachi, in February 2020 with complaints of weight loss, gastroesophageal reflux and loss of appetite. Examination revealed splenomegaly and initial workup demonstrated bicytopenia on complete blood picture. Bone marrow biopsy was consistent with pre-fibrotic myelofibrosis (Janus kinase 2 (JAK-2) positive). He was categorized as intermediate-2 risk according to Dynamic International Prognostic Scoring System (DIPPS) with score of 3 and was advised to start JAK-1/JAK-2 inhibitors. Prior to therapy, he underwent positron emission tomography-computed tomography (PET/CT) scan which showed increased fluorodeoxyglucose (FDG) uptake in the spleen and bone marrow. Monitoring by the scan after initiating treatment demonstrated decreased FDG uptake in bone marrow and spleen, demonstrating that PET/CT is a non-invasive way to assess and monitor treatment response in pre-fibrotic myelofibrosis.

Diagnostic Accuracy of Serum Procalcitonin (PCT) as an Early Biomarker of Neonatal Sepsis using Blood Culture as Gold Standard.

OBJECTIVE: To ascertain the diagnostic accuracy of serum PCT as an early biomarker of neonatal sepsis using blood culture as gold standard, so that the condition could be diagnosed and managed early to prevent and reduce morbidity and mortality in neonates.  Study Design: Cross-sectional study. PLACE AND DURATION OF STUDY: Dr. Ziauddin University Hospital, Karachi, from March 2019 to December 2019. METHODOLOGY: A total of 171 neonates, 1-29 days of age, presented with clinical diagnosis of neonatal sepsis, were included in this study. Patients' data regarding age, gender, birth weight, prematurity and premature rupture of membranes (PROM) were collected. Blood cultures were performed in Microbiology Department; and Serum PCT was analyzed on Electrochemiluminescence Immunnoassay Analyzer (Cobas e601). Diagnostic accuracy, including sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of PCT were calculated with contingency tables using blood culture findings as gold standard. RESULTS: Out of 171 clinically diagnosed cases of neonatal sepsis, 86 (50.3%) were confirmed as having neonatal sepsis (blood culture positive). There was a significant difference in serum PCT levels in both the groups. The sensitivity of PCT was 97.7%; specificity 70.6%; PPV 77.1; NPV 96.8%; likelihood ratio of a positive test (LR+ve) 3.32; likelihood ratio of a negative test (LR -ve) 0.03, and cumulative diagnostic accuracy of PCT 84.2%. CONCLUSION: PCT is a very useful biomarker for the early diagnosis of neonatal sepsis, showing 84.2% diagnostic accuracy. Thus PCT can help in making early clinical decisions regarding management of patients. Key Words: Diagnostic accuracy, PCT, Neonatal sepsis.

Diagnostic Accuracy of Electro-Chemiluminescence Immunoassay Anti-SARS-CoV-2 Serological Test.

OBJECTIVE: To determine the diagnostic accuracy of fully automated electro-chemiluminescence immunoassay (ECLIA) anti-SARS-CoV-2 serological test for detection of past SARS-CoV-2 infection and to be used in seroprevalence surveys. METHOD:  A total of 426 patients who had tested for anti-SARS-CoV-2 from August 1 to 31, 2020 were selected for the study. Informed consent was obtained and a questionnaire including the patient's age, gender, symptoms, and past polymerase chain reaction (PCR) status was filled by the patient. Samples were analyzed for anti-SARS-CoV-2 antibodies on Roche Cobas e601. RESULTS: The mean age of the patients was 42.43±16.67 years. One hundred and five (24.6%) were PCR positive, while 321 (75.4%) were PCR negative. Most patients were males 241 (56.6%) while 185(43.3%) were females. Over 185(43.3%) patients presented with symptoms, and the rest of the patients 241 (56.6%) were asymptomatic. Anti-SARS-CoV-2 had sensitivity 89.5%, specificity 99.06%, positive predictive value (PPV) 96.90%, negative predictive value (NPV) 96.6%, and positive likelihood ratio 4.26, while negative likelihood ratio 0.1. Diagnostic accuracy of anti-SARS-CoV-2 was 96.7% based on receiver-operating characteristic (ROC) curve analysis. CONCLUSION: Anti-SARS-CoV-2 is very useful for the detection of past COVID-19 infection; it can be proved helpful in the identification of post-COVID complications and actual disease burden in a population.

Persistent DNA damage signalling triggers senescence-associated inflammatory cytokine secretion.

Cellular senescence suppresses cancer by stably arresting the proliferation of damaged cells. Paradoxically, senescent cells also secrete factors that alter tissue microenvironments. The pathways regulating this secretion are unknown. We show that damaged human cells develop persistent chromatin lesions bearing hallmarks of DNA double-strand breaks (DSBs), which initiate increased secretion of inflammatory cytokines such as interleukin-6 (IL-6). Cytokine secretion occurred only after establishment of persistent DNA damage signalling, usually associated with senescence, not after transient DNA damage responses (DDRs). Initiation and maintenance of this cytokine response required the DDR proteins ATM, NBS1 and CHK2, but not the cell-cycle arrest enforcers p53 and pRb. ATM was also essential for IL-6 secretion during oncogene-induced senescence and by damaged cells that bypass senescence. Furthermore, DDR activity and IL-6 were elevated in human cancers, and ATM-depletion suppressed the ability of senescent cells to stimulate IL-6-dependent cancer cell invasiveness. Thus, in addition to orchestrating cell-cycle checkpoints and DNA repair, a new and important role of the DDR is to allow damaged cells to communicate their compromised state to the surrounding tissue.

Neurotoxic and neurotrophic roles of proNGF and the receptor sortilin in the adult and ageing nervous system.

The precursor form of the nerve growth factor (proNGF), forms a heterotrimeric complex with the receptors p75 and sortilin; this complex has been implicated in neuron cell death. However, it is not known whether proNGF and the receptors p75 and sortilin contribute to age- and disease-related neurodegeneration. Here we show that proNGF induces cell death in subpopulations of basal forebrain and peripheral sympathetic neurons of old, but not of young, adult rodents. In contrast, proNGF appears to induce neurite outgrowth rather than cell death of young adult sympathetic neurons. We have examined the neurotoxic role of proNGF in old age, and find that proNGF protein is elevated during ageing in the projection areas of some populations of vulnerable central and peripheral neurons; caloric restriction, which has known neuroprotective effects, partially prevents these increases. Sortilin was found to play a significant part in the observed patterns of age-related proNGF-mediated neurotoxicity. In particular, survival of aged neurons was rescued by neurotensin, an alternative sortilin ligand that blocks the sortilin-mediated effects of proNGF. Furthermore, sortilin immunoreactivity increases markedly in ageing rodent basal forebrain and sympathetic neurons; in contrast, p75 levels are either unchanged or reduced. From these data we propose that selective age-related neuronal atrophy and neurodegeneration may be mediated by increased sortilin expression in neurons, together with elevated levels of proNGF expression in some targets.

ProNGF, sortilin, and age-related neurodegeneration.

Several studies have sought to demonstrate that neurodegeneration during disease and in old age is associated with reduced neurotrophic support. Little positive evidence has been forthcoming, either in relation to the availability of neurotrophins or to expression and function of the relevant receptors. Recently, a novel way in which neurotrophins could contribute to neurodegeneration has been suggested. In contrast to the well-known neurotrophic functions of the mature beta-form of nerve growth factor (mNGF), its precursor proNGF has recently been shown to be abundant in the adult brain and in the brains of patients with Alzheimer's disease. proNGF is synthesized as 25 and 32 kDa isoforms, which are glycosylated to form a principal 40 kDa species. Studies of the cortical targets of NGF-responsive basal forebrain neurons show that the 40 kDa form of proNGF is secreted in response to nerve stimulation, along with the proteases needed to generate the 13 kDa mNGF, or to degrade it. We have recently found that levels of 40 kDa proNGF are elevated in the aging brain and also in targets of peripheral NGF-responsive neurons. proNGF has been shown to be neurotoxic when bound in a heterotrimer with the p75 receptor and the receptor sortilin (identical to the neurotensin receptor NTS3). Interestingly, we find that sortilin levels increase in aged central and peripheral neurons, perhaps making these neurons more vulnerable to age-related increases in proNGF. Whether elevated levels of proNGF in targets or of sortilin in neurons contribute to known patterns of age- and disease-related neurodegeneration has not been previously investigated. Using in vitro models, our preliminary data now indicate that proNGF is indeed neurotoxic for aged, but not young, NGF-responsive basal forebrain and sympathetic neurons and that blockade of sortilin rescues proNGF-induced cell death. We therefore propose that increased proNGF in targets combined with increased sortilin expression in projecting neurons contributes to age-related neuronal atrophy and degeneration.