Blood Cells In Cerebrospinal Fluid Research Articles

A-140 Reducing cell count bias with the GloCyte® Automated Cell Counter for CSF: an observational study at Loyola University Medical Center

Abstract Background Accurate STAT cerebrospinal fluid (CSF) cell counts are critical in supporting diagnoses of meningitis, malignancy, demyelinating disease, and hemorrhage. Limitations of automated analyzers to achieve acceptable linearity for the clinically relevant range has maintained manual CSF cell counting as the preferred method. Manual cell counting, performed with a hemocytometer and bright field microscope, is time-consuming, requires specialized skills and depends on human interpretation. This subjectivity inherently introduces the potential for non-random error in the enumeration of both total nucleated cells (TNC) and red blood cells in CSF by manual methods. The purpose of this study was to evaluate and compare the level of bias inherent in manual determination (TNC) in CSF as compared to the GloCyte Automated Cell Counter. Methods Result bias data for CSF specimens processed in the hematology lab at Loyola University Medical Center, a quaternary care 547-bed academic medical center in Maywood, IL, was analyzed for manual cell counting using a Neubauer-improved hemocytometer and GloCyte, an FDA-cleared cell counting device employing fluorescence technology to automate RBC and TNC counts in under 5 minutes, with linearity down to 0 cells/µL. Result bias was determined by defining the “expected result” for both GloCyte and hemocytometer as the initial cell count determined at a 1:5 dilution of a freshly-collected CSF sample and calculating the expected cell count for subsequent serial dilutions of 1:10, 1:20, 1:50, 1:100 for each method. The actual TNC count and the disparity of the actual result from the expected result was recorded as bias. Results Data are summarized below in the Table, and indicate a lower bias for GloCyte compared to manual counts across the range of dilutions. Conclusions This study demonstrates that GloCyte can be implemented as a means of effectively mitigating the reporting bias of CSF TNC counts performed with a Neubauer-improved hemocytometer.

Red blood cell count in cerebrospinal fluid was correlated with inflammatory markers on the seventh postoperative day and all associated with the outcome of aneurysmal subarachnoid hemorrhage patients.

Exploring factors associated with the outcome of patients with aneurysmal subarachnoid hemorrhage (aSAH) has become a hot focus in research. We sought to investigate the associations of inflammatory markers and blood cell count in cerebrospinal fluid with the outcome of aSAH patients. We carried a retrospective study including 200 patients with aSAH and surgeries. The associations of neutrophil, lymphocyte, neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), systemic immune inflammation index (SII), system inflammation response index (SIRI), and blood cell count in cerebrospinal fluid on the 1st and 7th postoperative days with the outcome of aSAH patients were investigated by univariate analysis and multivariate logistic regression model. According to the modified Rankin scale (mRS) score, there were 147 patients with good outcome and 53 patients with poor outcome. The neutrophil, NLR, SIRI, and SII levels on the seventh postoperative day in patients with poor outcome were all significantly higher than patients with good outcome, P < 0.05. The multivariate logistic regression model including inflammatory markers and blood cell counts in cerebrospinal fluid on the 1st postoperative day confirmed that red blood cell count in cerebrospinal fluid (≥177 × 109/L; OR: 7.227, 95% CI: 1.160-45.050, P = 0.034) was possibly associated with poor outcome of aSAH patients, surgical duration (≥169 min), Fisher grade (III-IV), hypertension, and infections were also possibly associated with the poor outcome. The model including inflammatory markers and blood cell counts in cerebrospinal fluid on the 7th postoperative day confirmed that red blood cell count in cerebrospinal fluid (≥54 × 109/L; OR: 39.787, 95% CI: 6.799-232.836, P < 0.001) and neutrophil-lymphocyte ratio (≥8.16; OR: 6.362, 95% CI: 1.424-28.428, P = 0.015) were all possibly associated with poor outcome of aSAH patients. The NLR (r = 0.297, P = 0.007) and SIRI (r = 0.325, P = 0.003) levels were all correlated with the count of red blood cells in cerebrospinal fluid. Higher neutrophil-lymphocyte ratio and higher red blood cell count in cerebrospinal fluid were all possibly associated with poor outcome of patients with aneurysmal subarachnoid hemorrhage. However, we need a larger sample study.

Eosinophilic meningitis epidemiological data from a national database in Thailand’s Department of Disease Control: a pragmatic, retrospective analytical study

BackgroundEosinophilic meningitis (EOM) is a rare neurological disease that can be misdiagnosed or underdiagnosed. Based on reported cases in the literature, there have been 2,827 cases worldwide since 1945. There are limited data on the prevalence and trends of EOM in a real-world setting, even in Thailand, the country with the highest prevalence of EOM. Therefore, this study aimed to evaluate the prevalence of EOM and EOM epidemiological data in a real-world setting.MethodsThis was a pragmatic, retrospective analytical study using a national database. We retrieved EOM epidemiological data reported from government hospitals to Thailand’s Bureau of Epidemiology, within the Ministry of Public Health’s Department of Disease Control (DDC), between 2014 and 2019. The study was conducted by retrieving the data of all patients diagnosed with EOM and reported to the DDC. Diagnosis of EOM is made clinically by evidence of eosinophils of 10% or more of the total white blood cells in cerebrospinal fluid. Details of each patient were retrieved from the 506 Report Form, including age, month of reported case, zone of country, occupation, and mortality. Data regarding infection rate in each year and each zone were reported in rate/100,000 population, while data regarding age, month of reported case, and occupation were reported by year. Differences between means of age group, month of reported case, and occupation were tested by one-way analysis of variance (ANOVA). For those factors with significant differences among groups, Bonferroni method was used to compute pairwise differences.ResultsThere were 1,083 EOM cases reported in Thailand during the six-year study period. The average annual incidence of EOM was 180.5 cases, or 0.27 cases/100,000 population. The northeast zone had the highest rate, with 0.89/100,000 population. The common age groups were 25–54 years, with the highest rate among the 35–44 age group, with a mean of 38.3 persons/year. These age groups were significantly different from other age groups (F value 39.23; p < 0.001). A relatively high cumulative monthly incidence (> 100 cases) was seen in four months, including January (117 cases), September (103 cases), October (112 cases), and November (103 cases), though these rates were not significantly different from the other months’ rates. Regarding occupation, the top two occupations with EOM diagnoses were farmers and laborers, which were significantly different from other occupations (F value 99.95; p < 0.001). There was no reported case of death during the study period.ConclusionEOM is common in Northeast Thailand among people of working age. The disease can be found throughout the year but is more common in the last quarter of the year. Farmers and laborers have the highest infection rate. To better understand the burden and outcomes of EOM, a national EOM reporting system with a better reporting form is required in endemic countries. Such a report form should include more details on risk exposure, symptoms, signs, treatment, and outcomes.

Neurogenic shock due to transverse myelitis with Landry’s acute flaccid paralysis in a child

Neurogenic shock is a life-threatening condition mostly associated with cervical and high thoracic spine injury, whereas transverse myelitis leading to neurogenic shock is extremely rare. An 11-year-old boy was admitted to our center with Landry’s acute flaccid paralysis and urinary retention, which led the patient to severe respiratory distress. The test indicated a high level of protein and white blood cells in cerebrospinal fluid. He was diagnosed with transverse myelitis and then treated with methylprednisolone. The patient developed hypotension (63/45 mmHg), bradycardia (60 beats per minute), warm flushed skin, and decreased consciousness as a result of neurogenic shock. Fluid resuscitation, noradrenalin, and atropine were indicated, and the shock was well controlled. This is the first case of neurogenic shock due to transverse myelitis with Landry’s acute flaccid paralysis in a child we have experienced so far. It highlights that neurogenic shock should be considered in patients with acute transverse myelitis with Landry’s acute flaccid paralysis.

Prospective Implementation of the Ottawa Subarachnoid Hemorrhage Rule and 6-Hour Computed Tomography Rule.

Background and Purpose- The Ottawa subarachnoid hemorrhage (SAH) rule identifies patients with headache requiring no testing for SAH, while the 6-hour computed tomography (CT) rule guides when to forgo a lumbar puncture. Our objectives were to: (1) estimate the clinical impact of the Ottawa SAH rule and the 6-hour-CT rule on testing rates (ie, CT, lumbar puncture, CT angiography); (2) validate the 6-hour-CT rule for SAH when applied prospectively in a new cohort of patients. Methods- We conducted a multicenter prospective before/after implementation study from 2011 to 2016 with 6 months follow-up at 6 tertiary-care Canadian Academic Emergency Departments. Consecutive alert, neurologically intact adults with headache were included. For intervention period, physicians were given a 1-hour lecture, pocket cards, posters were installed, and physicians indicated Ottawa SAH rule criteria when ordering CTs. SAH was defined by blood on CT, xanthochromia in cerebrospinal fluid, or >1×106/L red blood cells in cerebrospinal fluid with aneurysm. Results- We enrolled 3672 patients, 1743 before and 1929 after implementation, including 188 with SAH. Proportions undergoing CT was unchanged (88.0% versus 87.5%; P=0.643). Lumbar puncture use decreased (38.9% versus 25.9%; P<0.0001). Additional testing following CT (ie, lumbar puncture or CT angiography) decreased (51.3% versus 42.2%; P<0.0001). Admissions declined (9.8% versus 7.4%; P=0.011). Mean emergency department stay was unchanged (6.3±4.0 versus 6.4±4.2 hours; P=0.685). The Ottawa SAH rule was 100% (95% CI, 98.1%-100%) sensitive, and the 6-hour-CT rule was 95.5% (95% CI, 89.8-98.5) sensitive for SAH. The 6-hour-CT rule missed 5 SAHs: 1 radiology misread, 2 incidental aneurysms, 1 nonaneurysmal cause, and 1 profoundly anemic patient. Conclusions- The Ottawa SAH rule and the 6-hour-CT rule are highly sensitive and can be used routinely when SAH is considered in patients with headache. Implementing both rules was associated with a meaningful decrease in testing and admissions to hospital.

Posterior Reversible Encephalopathy (PRES) in a Child with Severe Dengue.

Among neurological complications associated with dengue, posterior reversible encephalopathy syndrome (PRES) has not been reported in pediatric population. We report a 10-year-old girl with severe dengue who developed PRES. The patient presented with hemorrhagic shock that required fluid resuscitation and inotropic support. She developed seizures with encephalopathy 2 days after recovering from the shock. Cerebrospinal fluid (CSF) examination was negative for dengue (no white blood cells in CSF with negative polymerase chain reaction for dengue). Her clinical features and magnetic resonance imaging (MRI) findings showed typical changes associated with posterior encephalopathy that reverted after resolution of hypertension. Repeat MRI after a month was normal. PRES should be considered as a possible differential diagnoses of dengue associated encephalopathy, especially in cases with normal CSF examination and characteristic MRI changes.

On-Chip Cell Staining and Counting Platform for the Rapid Detection of Blood Cells in Cerebrospinal Fluid

Counting blood cells in cerebrospinal fluid (CSF) is indispensable for diagnosing several pathological conditions in the central nervous system, such as meningitis, even though collecting CSF samples is invasive. Cell counting methods, such as hemocytometer chambers and flow cytometers, have been used for CSF cell counting, but they often lack the sensitivity to detect low blood cell numbers. They also depend on off-chip, manual sample preparation or require bulky, costly equipment, thereby limiting their clinical utility. Here, we present a portable cell counting platform for simple, rapid CSF cell counting that integrates a microfluidic cell counting chamber with a miniaturized microscope. The microfluidic chamber is designed not only to be a reagent container for on-chip cell staining but also to have a large control volume for accurate cell counting. The proposed microscope miniaturizes both bright-field and fluorescence microscopy with a simple optical setup and a custom cell-counting program, thereby allowing rapid and automated cell counting of nucleated white blood cells and non-nucleated red blood cells in fluorescence and bright-field images. Using these unique features, we successfully demonstrate the ability of our counting platform to measure low CSF cell counts without sample preparation.

Clinical characteristics of cerebral syphilitic gumma

Objective To analyze the clinical characteristics of cerebral syphilitic gumma. Method The clinical characteristics, brain CT and MRI results and prognosis of 7 patients with cerebral syphilitic gumma admitted in Beijing Ditan Hospital from June 2012 to October 2016 were retrospectively analyzed. Results There were 5 females and 2 males in 7 patients. The symptoms or signs at onset were headache (n=5), increased white blood cells in cerebrospinal fluid (n=6) and increased protein contents in cerebrospinal fluid (n= 6). Total 10 lesions were detected in 7 cases, including 7 in cerebral lobe, and 3 in cerebellum, corpus callosum or intercrural space. The brain MRI showed nodular reinforcement in 5 cases, irregular circular reinforcement in 2 cases and obvious edema around the lesions in 6 cases. The patients were given intravenous infusion of 400 million units common penicillin, q. 4h for 2 wks, sequential intramuscular injection of 240 million units long-term penicillin q. w for 3 wks. Among 7 patients, 1 case died, 1 case showed symptomatic improvement and 5 cases obtained complete improvement with the significant imaging improvement. Conclusion Headache is the most common symptom at onset of cerebral syphilitic gumma, and the lesions mostly are located in the cerebral lobes with nodular enhancement in brain imaging, and the prognosis is generally good. Key words: Neurosyphilis; Pathological conditions, signs and symptoms; Magnetic resonance imaging

Red blood cells in cerebrospinal fluid as possible inhibitory factor for enterovirus RT-PCR.

The presence of hemoglobin in samples are considered an important inhibitory factor for polymerase chain reaction (PCR). The aim of this study was to examine the influence of red blood cells (RBC)s in cerebrospinal fluid (CSF) as an inhibitory factor to reverse transcription polymerase chain reaction (RT-PCR) for enteroviruses (EV). Forty-four CSF samples from patients showing characteristics of viral meningitis were assessed for EV by RT-PCR. Viral RNA extracted with guanidine isothyocianate buffer and virus detection was performed by in-house nested PCR. Positivity for EV RT-PCR was higher in CSF samples without RBCs than in samples with RBCs: 13(26%) and 36(9.2%), p = 0.001. In the group with positive EV RT-PCR, the mean + SD CSF RBC was 37 ± 183 cell/mm3; the group with negative results had 580 + 2,890 cell/mm3 (p = 0.007). The acceptable upper limit for CSF RBCs that could not influence RT-PCR was 108 cells/mm3. CSF samples with negative results for EV RT-PCR have more erythrocytes.

Laboratory diagnosis and genetic analysis of a family clustering outbreak of aseptic meningitis due to echovirus 30

Echovirus 30 (E30) is a major pathogen associated with aseptic meningitis. In the summer of 2014, a family clustering aseptic meningitis outbreak occurred in urban–rural fringe of Ningbo city in Zhejiang Province in China. To identify the etiologic agent, specimens were tested by cell culture and reverse transcriptase–polymerase chain reaction. Pathogenic examination confirmed that the outbreak is caused by E30. The first case is a 6-year-old child, who studied in kindergarten in local, suffered from headache and fever. Same symptoms appeared in his parents, aunts, and other six relatives continuously. Meanwhile, vomiting occurred in majority of the patients and diarrhea in parts of them. White blood cells in cerebrospinal fluid (CSF) exceeded normal range in all patients. Protein levels in CSF were above normal range in half of the patients. Glucose levels in CSF were within normal range in all patients. We isolated six strains E30 in the stool specimens of patients, and carried out sequencing analysis to VP1 region. Sequencing results showed that 100% sequence identity was seen in both nucleotide and amino acid levels. Phylogenetic analysis discovered that isolate in this study was grouped into sublineage D2 together with sequences isolated from other areas of China in the 2000s and 2010s. Our study is the first family clustering outbreak of aseptic meningitis caused by E30 in Zhejiang Province in China. It is essential to establish an enterovirus molecular surveillance system in China to prevent mass outbreaks in Zhejiang.

Effects of calcitonin gene related peptide in cisterna magna on cerebral vasospasm after experimental subarachnoid hemorrhage in rats

Objective To explore the effects of application calcitonin gene related peptide(CGRP)in cisterna magna on cerebral vasospasm after experimental subarachnoid hemorrhage (subarachnoid hemorrhage, SAH) in rat models. Methods 64 male Wistar rats were randomly divided into 4 groups. Group A was normal control group. After the subarachnoid hemorrhage models were established, group B, C, D were given normal saline, CGRP and adenovirus CGRP through cisterna magna respectively. White blood cells in cerebrospinal fluid were detected by automatic blood analyzer, CGRP activity was detected by enzyme linked immunosorbent assay, circulating endothelial cells were observed through laser scanning confocal microscope and parietal cortex regional cerebral blood flow were observed by laser doppler flowmeter. Basilar artery vasospasm and arterial blood gas analysis were detected by digital subtraction angiography and blood gas analyzer respectively. Results Before and after administration, there were no statistical differences in white blood cells and artery blood gas among the 4 groups (both P>0.05). After administration 48 h , compared with group A, concentrations of CGRP in cerebrospinal fluid group B(0.006±0.002) did not increase (P>0.05), but increased 200 times in Group C ((1.160±0.170)nmol/L, P 0.05). Conclusion Cerebral vasospasm after SAH can be effectively improved by administration CGRP in cisterna magna. Adenovirus CGRP effect is better than CGRP. Key words: Calcitonin gene related peptide; Rats; Subarachnoid hemorrhage; Cerebral vasospasm

Impact of Herpes simplex virus load and red blood cells in cerebrospinal fluid upon herpes simplex meningo-encephalitis outcome.

BackgroundHerpes simplex encephalitis (HSE) often leads to severe disability or death. Factors usually associated with outcome include Simplified Acute Physiology Score, age and delay of initiation of acyclovir treatment.Our aim was to determine the impact of Herpes simplex virus (HSV) load in cerebrospinal fluid (CSF) upon HSE outcome.MethodsWe retrospectively determined HSV load in the CSF of 43 patients with confirmed HSE, hospitalized in northern France from 1998 to 2005, using CSF samples collected the day of hospital admission and stored at −20°C. We analyzed the association between HSV load and mortality/morbidity by the Glasgow Outcome Scale. Fisher’s exact test and Wilcoxon’s test were used for statistical analysis.ResultsThe M/F sex ratio was 1.7 and median patient age was 61 years. Median HSV load in CSF was 2.0 log copies/μL (IQR 25-75=1.2-2.6). The mortality rate was 32.6% six months after HSE diagnosis. Higher age was associated with mortality (p=0.03). Longer delay in acyclovir initiation tended to be associated with higher mortality but did not reach statistical significance (p=0.08). Severe disability and death due to HSV were associated with a higher Knaus score (p=0.004), later acyclovir initiation (p=0.006), older age (p=0.04) and presence of red blood cells in CSF (p=0.05). HSV load in CSF was neither associated with mortality (p=1.00) nor with morbidity (p=0.90).ConclusionIn this study, HSV load in CSF was not found to be associated with poor outcome in patients with HSE. These data do not support measurement of HSV load at admission in patients with HSE.

Is this Subarachnoid Hemorrhage Significant? A National Survey of Neurosurgeons

Previously all subarachnoid hemorrhage (SAH) patients were admitted, whereas now patients with angiography may be discharged. To survey neurosurgeons to determine current practice and what constitutes a clinically significant subarachnoid hemorrhage. We surveyed all neurosurgeons listed in the Canadian Medical Directory. We used a modified Dillman technique with up to five mailed surveys plus a pre-notification letter. Neurosurgeons rated the significance of 13 scenarios of subarachnoid hemorrhage. Scenarios varied from aneurysmal subarachnoid hemorrhage to patients with isolated xanthochromia in cerebrospinal fluid. Each scenario was rated for clinical significance using a 5-point scale [1(always) to 5(never)]. Of the 224 surveyed, 115 neurosurgeons responded. Scenarios with aneurysms requiring intervention, arteriovenous malformations, death or any surgical intervention all had median responses of 1 (IQR 1, 1). Scenarios having xanthochromia and few red blood cells in cerebrospinal fluid with negative computerized tomogram (CT) and angiography had median responses of 3 (IQR 1, 4). Scenarios with perimesencephalic pattern on CT with negative angiography had median of 3 (IQR 2, 4). Scenarios where patient is discharged from the emergency department had median of 4 (IQR 3, 5). Subarachnoid hemorrhages due to aneurysms or arteriovenous malformations causing death or requiring surgical intervention are always clinically significant. Other types of nonaneurysmal subarachnoid hemorrhages had inconsistent ratings for clinical significance. These survey results highlight the need for further discussions to standardize the diagnosis of what constitutes a clinically significant subarachnoid hemorrhage and what care should be afforded to these patients.

Validation of the body fluid module on the new Sysmex XN-1000 for counting blood cells in cerebrospinal fluid and other body fluids

We evaluated the body fluid (BF) module on the new Sysmex XN-1000 for counting blood cells. One hundred and eighty-seven BF samples [73 cerebrospinal fluid (CSF), 48 continuous ambulatory peritoneal dialysis (CAPD), 46 ascites, and 20 pleural fluid] were used for method comparison between the XN-1000 and manual microscopy (Fuchs-Rosenthal chamber and stained cytospin slides) for counting red blood cells (RBCs) and white blood cells (WBCs) (differential). Good agreement was found for counting WBCs (y=1.06x+0.09, n=67, R2=0.96) and mononuclear cells (MNs) (y=1.04x-0.01, n=40, R2=0.93) in CSF. However, the XN-1000 systematically counted more polymorphonuclear cells (PMNs) (y=1.48x+0.18, n=40, R2=0.99) compared to manual microscopy. Excellent correlation for RBCs >1×109/L (y=0.99x+116.56, n=26, R2=0.99) in CSF was found. For other fluids (CAPD, ascites and pleural fluid) excellent agreement was found for counting WBCs (y=1.06x+0.26, n=109, R2=0.98), MNs (y=1.06x-0.41, n=93, R2=0.96), PMNs (y=1.06x+0.81, n=93, R2=0.98) and RBCs (y=1.04x+110.04, n=43, R2=0.98). By using BF XN-check, the lower limit of quantitation (LLoQ) for WBC was defined at 5×106/L. Linearity was excellent for both the WBCs (R2=0.99) and RBCs (R2=0.99) and carry-over never exceeded 0.05%. The BF module on the XN-1000 is a suitable tool for fast and accurate quantification of WBC (differential) and RBC counts in CSF and other BFs in a diagnostic setting.

Enterococcus gallinarum meningitis: a case report and literature review

We report a case of Enterococcus gallinarum meningitis in a 53-year-old female who was admitted to our hospital with a fever, headache, and consciousness disturbance one week after a life-saving craniotomy operation. There was obvious neck stiffness; lumber puncture was performed and cerebrospinal fluid parameters were consistent with bacterial meningitis. The patient was given ceftriaxone and vancomycin for bacterial meningitis. Cerebrospinal fluid culture yielded an isolate which was identified as Enterococcus gallinarum. The isolate was sensitive to ampicillin, ampicillin/clavulanate, linezolid, moxifloxacin and teicoplanin, but it showed intermediate sensitivity to vancomycin and quinoprism- dalfopristin. Intravenous linezolid, 600 mg every 12 hours, was started. Three days after starting treatment, the patient became afebrile; a repeat lumber puncture two week later showed no white blood cells in cerebrospinal fluid and no bacterial growth. Treatment with linezolid was continued for a total therapy duration of three weeks, after which the patient was discharged in a good condition.

Impact of Glutamine Transporters on Pneumococcal Fitness under Infection-Related Conditions

The genomic analysis of Streptococcus pneumoniae predicted six putative glutamine uptake systems, which are expressed under in vitro conditions, as shown here by reverse transcription-PCR. Four of these operons consist of glnHPQ, while two lack glnH, which encodes a soluble glutamine-binding protein. Here, we studied the impact of two of these glutamine ATP-binding cassette transporters on S. pneumoniae D39 virulence and phagocytosis, which consist of GlnQ and a translationally fused protein of GlnH and GlnP. Mice infected intranasally with D39Δgln0411/0412 showed significantly increased survival times and a significant delay in the development of pneumococcal pneumonia compared to those infected with D39, as observed in real time using bioluminescent pneumococci. In a mouse sepsis model, the mutant D39Δgln0411/0412 showed only moderate but significant attenuation. In contrast, the D39Δgln1098/1099 knockout strain was massively attenuated in the pneumonia and septicemia mouse infection model. To cause pneumonia or sepsis with D39Δgln1098/1099, infection doses 100- to 10,000-fold higher than those used for wild-type strain D39 were required. In an experimental mouse meningitis model, D39Δgln1098/1099 produced decreased levels of white blood cells in cerebrospinal fluid and showed decreased numbers of bacteria in the bloodstream compared to D39 and D39Δgln0411/0412. Phagocytosis experiments revealed significantly decreased intracellular survival rates of mutants D39Δgln1098/1099 and D39Δgln0411/0412 compared to wild-type D39, suggesting that the deficiency of Gln uptake systems impairs resistance to oxidative stress. Taken together, our results demonstrate that both glutamine uptake systems are required for full virulence of pneumococci but exhibit different impacts on the pathogenesis of pneumococci under in vivo conditions.

Evaluation of the XE-5000 for the automated analysis of blood cells in cerebrospinal fluid

Objectives Counting of cells in cerebrospinal fluid is an important clinical laboratory test and elevated white blood cell counts in cerebrospinal fluid are frequently seen in CNS disorders. Quantification of red blood cell concentrations in CSF may help to interpret certain diagnostic constellations and may result from subarachnoid haemorrhage, surgical procedures or contamination due to traumatic puncture. Table top analyser XE-5000 (Sysmex, Norderstedt, Germany) offers, beside its use as a haematology analyser, a protocol for the quantification of red and white blood cells in body fluids such as CSF including the differentiation between polymorphonuclear and mononuclear cells. A detection limit of 1 cell/mm 3 would render this device suitable for automated CSF analysis. Design and methods White blood cell counting was compared between Fuchs–Rosenthal counting chamber and XE-5000 in 273 routinely collected lumbar and ventricular CSF samples. Red blood cell counting was compared between UF-100 and XE-5000. Differentiation was performed on a slide stained after Pappenheim and compared to the differential count of the XE-5000. Results Linearity was established between 1 and 10,000 cells/mm 3 for white blood cells and between 1000 and 1 ⁎ 10 3 particles/mm 3 for red blood cells. Functional sensitivity was established at 20 cells/mm 3 for white blood cell counting and at 1000 particles/mm 3 (lowest reported concentration) for red blood cell counting. When comparing between microscopic and automatic white blood cell counts no statistically significant slope and offset were detected in lumbar CSF samples while a significant slope and offset were detected when comparing ventricular CSF samples. Most patients were classified correctly according to their WBC count (non-pathologic, mildly, moderately, and highly elevated) by both methods although more patients had pathologic white blood cell counts on XE-5000. A significant slope and offset were detected when comparing red blood cell counts between UF-100 and XE-5000. Conclusions In summary despite its high imprecision at low white blood cell counts (< 20 particles/mm 3) most patients were classified correctly and therefore XE-5000 is suitable for automated quantification of white blood cells in cerebrospinal fluid in a defined diagnostic setting. This could significantly improve automation in the relatively time- and manual work-intensive field of cerebrospinal fluid diagnostics. However, careful review of plausibility of the results continues to be compulsory.

Influence of the cerebrospinal fluid laboratory parameters in the ELISA test for neurocysticercosis using a total cysticerci antigen

To evaluate if the cerebrospinal fluid (CSF) parameters may influence the cysticercosis immunoreactivity response in the CSF. CSF samples of 109 patients were analyzed and classified in three groups, according to the neurological manifestations and the reactivity in antibody-enzyme linked immunosorbent assay (Ab-ELISA) testing in CSF for neurocysticercosis (NC): group A, 18 patients with neurological disorders compatible with NC and reactive Ab-ELISA in CSF for NC; group B, 50 patients with neurological disorders non-compatible with NC and reactive Ab-ELISA for NC; group C, 41 patients with neurological disorders non-compatible with NC and non-reactive Ab-ELISA in CSF for NC. The CSF analysis in group A was compatible with NC. The group B in comparison to the groups A and C presents higher frequency and intensity of hypercytosis, presence of red blood cells in CSF, protein concentration and immunological reactive test for other etiological agents (p<0.05). Based on the present data, we suggest that the inflammatory process and high protein concentration may determine false positive reactions in the Ab-ELISA test for NC in the CSF.

Automated Flow Cytometric Analysis of Blood Cells in Cerebrospinal Fluid

We compared the performance of an automated method for obtaining RBC and WBC counts and WBC differential counts in cerebrospinal fluid (CSF) samples with the reference manual method. Results from 325 samples from 10 worldwide clinical sites were used to demonstrate the accuracy, precision, and linearity of the method. Accuracy statistics for absolute cell counts showed a high correlation between methods, with correlation coefficients for all reportable absolute counts greater than 0.9. Linearity results demonstrated that the method provides accurate results throughout the reportable ranges, including clinical decision points for WBCs of 0 to 10/μL. Interassay precision and intra-assay precision for the ADVIA 120 (Bayer HealthCare, Tarrytown, NY) method were acceptable at all levels. The ADVIA 120 CSF Assay enumerates and differentiates cells via flow cytometry in a minimally diluted sample, improving the analysis of typically hypocellular CSF samples. Study results demonstrate that the automated ADVIA 120 CSF Assay is an acceptable alternative to the labor-intensive manual method.

Effect of methemoglobin formation on the MR appearance of subarachnoid hemorrhage.

Subarachnoid hemorrhage has a much higher intensity in magnetic resonance (MR) images with the passage of time. Acute subarachnoid hemorrhage is difficult to see; within 1 week its appearance has become intensified on T1-weighted images. Different concentrations of blood and lysed red blood cells in cerebrospinal fluid (CSF) were examined spectroscopically but did not significantly alter T1 and T2 relaxation of CSF acutely. Ultraviolet visible spectroscopy of bloody CSF stored hypoxically for 3 days showed the presence of methemoglobin. The iron in methemoglobin is paramagnetic; in combination with water this facilitates T1 relaxation. It is concluded that methemoglobin formation with T1 shortening at least partially accounts for the increasing intensity of the MR appearance of subarachnoid hemorrhage over time in the central nervous system and may also explain the intense appearance of subacute hemorrhage in MR images elsewhere in the body.