Incidence of healthcare-associated infections in patients with fever during the first 48 hours after decannulation from veno-venous extracorporeal membrane oxygenation.

INTRODUCTION: Fevers following decannulation from veno-venous extracorporeal membrane oxygenation often trigger an infectious workup; however, the yield of this workup is unknown. We investigated the incidence of post-veno-venous extracorporeal membrane oxygenation decannulation fever as well as the incidence and nature of healthcare-associated infections in this population within 48 hours of decannulation. METHODS: All patients treated with veno-venous extracorporeal membrane oxygenation for acute respiratory failure who survived to decannulation between August 2014 and November 2018 were retrospectively reviewed. Trauma patients and bridge to lung transplant patients were excluded. The highest temperature and maximum white blood cell count in the 24 hours preceding and the 48 hours following decannulation were obtained. All culture data obtained in the 48 hours following decannulation were reviewed. Healthcare-associated infections included blood stream infections, ventilator-associated pneumonia, and urinary tract infections. RESULTS: A total of 143 patients survived to decannulation from veno-venous extracorporeal membrane oxygenation and were included in the study. In total, 73 patients (51%) were febrile in the 48 hours following decannulation. Among this cohort, seven healthcare-associated infections were found, including five urinary tract infections, one blood stream infection, and one ventilator-associated pneumonia. In the afebrile cohort (70 patients), four healthcare-associated infections were found, including one catheter-associated urinary tract infection, two blood stream infections, and one ventilator-associated pneumonia. In all decannulated patients, the majority of healthcare-associated infections were urinary tract infections (55%). No central line-associated blood stream infections were identified in either cohort. When comparing febrile to non-febrile cohorts, there was a significant difference between pre- and post-decannulation highest temperature (p < 0.001) but not maximum white blood cell count (p = 0.66 and p = 0.714) between the two groups. Among all positive culture data, the most commonly isolated organism was Klebsiella pneumoniae (41.7%) followed by Escherichia coli (33%). Median hospital length of stay and time on extracorporeal membrane oxygenation were shorter in the afebrile group compared to the febrile group; however, this did not reach a statistical difference. CONCLUSION: Fever is common in the 48 hours following decannulation from veno-venous extracorporeal membrane oxygenation. Differentiating infection from non-infectious fever in the post-decannulation veno-venous extracorporeal membrane oxygenation population remains challenging. In our febrile post-decannulation cohort, the incidence of healthcare-associated infections was low. The majority were diagnosed with a urinary tract infection. We believe obtaining cultures in febrile patients in the immediate decannulation period from veno-venous extracorporeal membrane oxygenation has utility, and even in the absence of other clinical suspicion, should be considered. However, based on our data, a urinalysis and urine culture may be sufficient as an initial work up to identify the source of infection.

Prenatal diagnosis of biliary atresia: A case series.

BACKGROUND: Biliary atresia is a progressive disease presenting with jaundice, and is the most common indication for liver transplantation in the pediatric population. Prenatal series have yielded conflicting results concerning a possible association between BA and prenatal nonvisualization of the gallbladder. AIMS: This retrospective case series was performed to assess the association between biliary atresia, prenatal nonvisualization of the gallbladder and other sonographic signs. STUDY DESIGN/SUBJECTS: We identified biliary atresia patients who underwent a Kasai procedure by a single pediatric surgeon and/or follow up by a single pediatric gastroenterologist. Axial plane images and/or video recordings were scrutinized for sonographic signs of biliary atresia on the second trimester anomaly scan. OUTCOME MEASURES: Proportion of biliary atresia cases with prenatal sonographic signs. RESULTS: Twenty five charts of children with biliary and high quality prenatal images were retrieved. 6/25 (24%) of cases analyzed had prenatal nonvisualization of the gallbladder or a small gallbladder on the prenatal scan. Two cases had biliary atresia splenic malformation syndrome. None of the cases had additional sonographic markers of biliary atresia. CONCLUSIONS: Our study suggests that in addition to the well-established embryonic and cystic forms, an additional type can be suspected prenatally, which is characterized by prenatal nonvisualization of the gallbladder in the second trimester. This provides additional evidence that some cases of BA are of fetal rather than perinatal onset and may have important implications for prenatal diagnosis, for counseling and for research of the disease's etiology and pathophysiology.

An 11,000-isolate same plate/same day comparison of the 3 most widely used platforms for analyzing multidrug-resistant clinical pathogens.

Stewardship of the dwindling number of effective antibiotics relies on accurate phenotyping. We sought to conduct the first large-scale, same plate and day comparison of the 3 most widely used bacterial analyzers. A total of 11,020 multidrug-resistant clinical isolates corresponding to more than 485,000 data points were used to compare the 3 major identification and antibiotic susceptibility testing (AST) platforms. Bacterial suspensions, prepared from a single plate, were simultaneously tested on all platforms in the same laboratory. Discrepancies were derived from MIC values using 2014 interpretive guidelines. Molecular methods and manual microbroth dilution were reference standards. Most discrepancies were due to drug-organism-AST platform combination instead of individual factors. MicroScan misidentified Acinetobacter baumannii (P<0.001) and underestimated carbapenem susceptibility in Klebsiella pneumoniae. Vitek-2 and Phoenix had higher discrepancies for blaKPC-containing Enterobacteriaceae (P<0.05) and reported false susceptibilities more often. While all platforms performed according to standards, each had strengths and weaknesses for organism identification, assaying specific drug-organism combinations and inferring carbapenemase production.

Early second trimester transvaginal ultrasound anomaly scan does not cause adverse perinatal outcome.

OBJECTIVE: During an early second-trimester transvaginal ultrasound anomaly scan, pressure is applied to the uterus, and the fetus is often rotated manually to allow scanning of its various organs. This study was designed to determine if performing a transvaginal ultrasound anomaly scan during the early second trimester of pregnancy is associated with adverse perinatal outcome or cord entanglement. METHODS: During the 4.5year study period we prospectively collected cases of routine ultrasound scans at 14-17weeks gestation performed as anomaly screening, together with perinatal outcome. The study population consisted of 164 women who underwent a transvaginal approach, and the control population consisted of 224 women in which a transabdominal approach was used. Data on perinatal parameters was collected from delivery charts from the four local hospitals. RESULTS: There were more operative deliveries (vaginal or Cesarean) in the transvaginal scan group (32% vs. 23%, p=0.05). However, on multiple logistic regression analysis vaginal scans were not associated with increased operative delivery rates with an adjusted odds ratio of 1.47 and a 95% confidence interval of 0.85-2.54. There were no other clinically significant differences in perinatal outcomes, or in cord entanglement. CONCLUSIONS: Transvaginal ultrasound anomaly scan conducted in the early second trimester of pregnancy is a safe procedure for the fetus.

Ovarian reserve and PGD treatment outcome in women with myotonic dystrophy.

Myotonic dystrophy (DM) is the most common form of muscular dystrophy in adults. There are conflicting reports about its effect on female fertility. This study investigated ovarian reserve and IVF-preimplantation genetic diagnosis (PGD) outcome in women with DM1. A total of 21 women undergoing PGD for DM1 were compared with 21 age- and body mass index-matched women undergoing PGD for other diseases. Ovarian reserve markers, response to stimulation, embryo quality and clinical pregnancy and live birth rates were compared. Day-3 FSH concentration was higher, while anti-Müllerian hormone concentration and antral follicle count were lower in the DM1 group (median, range: 6.9 (1.8-11.3) versus 5.7 (1.5-10.7)IU/l; 0.9 (0.17-5.96) versus 2.68 (0.5-9.1)ng/ml; and 13 (0-63) versus 23 (8-40) follicles, respectively, all P < 0.05). Total FSH dose was higher (5200 versus 2250 IU, P = 0.004), while the numbers of oocytes retrieved (10 versus 16, P < 0.04) and metaphase-II oocytes (9 versus 12, P < 0.03) were lower in the DM1 group. The number of cycles with top-quality embryos and the clinical pregnancy rate were lower in the DM1 group. In conclusion, there is evidence of diminished ovarian reserve and less favourable IVF-PGD outcome in women with DM1. Myotonic Dystrophy (DM) is the most common form of muscular dystrophy in adults. There is evidence of subfertility in males affected with the disease but conflicting reports about the effect of the disease on female fertility. The aim of our study was to investigate ovarian reserve and IVF-PGD results in women with DM. Twenty-one women undergoing preimplantation genetic diagnosis (PGD) treatment for DM were compared to 21 age- and BMI matched women undergoing PGD treatment for other diseases. The two groups were compared for antral follicle count (AFC) and serum anti-Mullerian hormone (AMH) levels (the best known markers of ovarian reserve and fertility potential), ovarian response, embryo quality and pregnancy and live birth rates. AFC and the AMH levels were statistically significant lower in the DM group. Total medication dose needed for ovarian stimulation was higher, the number of oocytes and mature oocytes retrieved, and the number of cycles with top quality embryos were lower in the DM group compared to the controls. In conclusion, there is evidence of diminished ovarian reserve, and less favorable IVF-PGD outcome in women with DM. Therefore, we recommend advising these women about the possibility of early decreasing ovarian function in order to prevent any delay in reproductive planning.

Absent gallbladder on fetal ultrasound: prenatal findings and postnatal outcome.

OBJECTIVES: Fetal gallbladder non-visualization on prenatal ultrasound in the second trimester is uncommon and in most cases the gallbladder is detected eventually. Associations of gallbladder non-visualization with cystic fibrosis, aneuploidy, agenesis of the gallbladder and biliary atresia have been reported. We present our experience and review the literature. METHODS: During the study period from January 2004 to June 2009 we collected prospectively cases of non-visualization of the fetal gallbladder in the second trimester. In each case the fetus was evaluated by two examiners on at least two occasions, at least a week apart. Cases with no additional sonographic malformations were designated as isolated. Further evaluation included follow-up scans and a meticulous search for fetal anomalies. All patients were offered genetic consultation. Cystic fibrosis testing, amniocentesis for karyotyping and analysis of fetal digestive enzymes in the amniotic fluid were offered. RESULTS: We collected 21 cases of non-visualization of the fetal gallbladder, 16 of which were isolated and five of which had additional malformations. In four of these five, the associated anomalies were severe and the pregnancies were terminated for aneuploidy (two cases of trisomy 18 and one triploidy) or for the severity of the associated anomalies. Associated anomalies included left isomerism with complex cardiac anomaly and intrauterine growth restriction with multisystem anomalies. The fifth fetus had interrupted inferior vena cava with azygos continuation without other anomalies and the child was alive and well at the age of 4 years. In 15 of the 16 isolated cases, antenatal and postnatal development were normal at the last follow-up, ranging from 4 months to 2.5 years. One case of cystic fibrosis was diagnosed prenatally and this pregnancy was terminated. There were no diagnoses of abnormal karyotype or biliary atresia among cases of isolated non-visualization of the gallbladder. CONCLUSIONS: When prenatal non-visualization of the fetal gallbladder is associated with other severe malformation, aneuploidy should be suspected. When it is isolated, if cystic fibrosis is ruled out, the outcome is good.

Congenital diaphragmatic hernia: review of the literature in reflection of unresolved dilemmas.

BACKGROUND: Congenital diaphragmatic hernia (CDH) is a rare but clinically and scientifically challenging condition. The introduction of ultrasound has enabled early prenatal detection and consequently, hope of early therapeutic intervention. AIM: We undertook the task to review the recent developments in understanding the pathology of CDH as well as the history and current management strategies to aid perinatologists in consultations with parents of CDH-affected foetuses. STUDY DESIGN: A Medline search was undertaken of all reports and reviews published between 1980 and 2008 using MeSH search terms 'diaphragmatic hernia', 'congenital' and 'newborn'. RESULTS: The true incidence of CDH is still difficult to estimate because of the high incidence of hidden mortality of CDH. Complete case ascertainment also poses difficulties in assessment of the impact of new therapeutic modalities on overall survival. Recent improvements in prenatal detection are a milestone in affording time for re-assessments and parental counselling. The true benefit of antenatal therapy is circumscribed and should be offered only in selected cases of isolated severe CDH as defined by existing guidelines. Postnatal intensive respiratory supportive therapy and innovative surgical techniques within specialized tertiary centres has had a major impact on survival of babies with CDH. CONCLUSION: The high survival of 'selected cases' that are live births and benefit from optimal care will be difficult to improve by antenatal interventions. The multidisciplinary approach to basic research and randomized clinical trials will further define the best approach to the foetus and neonate with CDH.

Effects of a copper-medicated intrauterine device on ovarian artery, uterine artery, and intrauterine blood flow.

AIM: To determine the effect of a copper-medicated intrauterine device (IUD) on ovarian, uterine, arcuate, radial and subendometrial Doppler-derived indices of blood flow. METHOD: 23 regularly menstruating patients requested insertion of an IUD. All patients had a copper T (Nova T) IUD inserted between days 8 and 11 of the menstrual cycle. Ovarian, uterine, arcuate, radial and subendometrial artery pulsatility indices (PIs) were assessed by transvaginal color Doppler prior to insertion between days 8 and 11 of the menstrual cycle, and after 2 months in the same period of the cycle. Ovarian, uterine, arcuate, radial and subendometrial artery PIs were considered prior to and following IUD insertion. RESULTS: No differences were recorded in any of the blood vessels sampled between pre- and post-insertion PIs. CONCLUSION: No significant change in ovarian or in uterine system vascular impedance is associated with the presence of a copper-medicated IUD.

Prenatal diagnosis of intestinal pseudo-obstruction.

The appearance of polyhydramnios and dilated bowel loops on prenatal sonographic examination usually implies mechanical obstruction. The prognosis is variable, depending on the etiology. Congenital pseudo-obstruction, a potentially lethal disease, comprises a group of disorders characterized by intestinal obstruction in the absence of an anatomic lesion. This report focuses on the prenatal diagnosis of intestinal pseudo-obstruction, and two cases of transient congenital intestinal pseudo-obstruction in one family are described. In both, the prenatal sonographic presentation was of small bowel obstruction. In one case there was postnatal suspicion of neurogenic bladder, and in the other there was unilateral hydronephrosis. The sonographic appearance of intestinal pseudo-obstruction is similar to that of mechanical obstruction. The clues to the prenatal diagnosis of pseudo-obstruction include associated urinary tract abnormalities and a family history of pseudo-obstruction.

Placental shelf - a common, typically transient and benign finding on early second-trimester sonography.

OBJECTIVE: Placental shelves are believed to represent circumvallate placentae. It is thought that circumvallate placenta may be associated with adverse perinatal outcome when present at delivery. The objective of this study was to determine the prevalence, persistence and significance of placental shelves detected in the early second trimester. METHODS: In 152 consecutive anomaly scans performed between 13 and 16 weeks of gestation, special attention was directed to placental structure and the presence of a placental shelf. When present, a mid-gestation scan was performed to verify if the finding persisted. If so, a third-trimester scan was performed. Delivery charts were reviewed for all cases initially diagnosed with a placental shelf, recording any placenta-related complications. RESULTS: In 17 of 152 (11.2%) early second-trimester scans a placental shelf was detected. In three of these 17 cases the shelf persisted to the 20-22-week scan. In the two cases that presented for the third-trimester scan the shelf was no longer present. In all 17 cases the perinatal outcome was good. CONCLUSIONS: In our study group early second-trimester placental shelves rarely persisted to mid-gestation and never to the third trimester. There were no placenta-related perinatal problems. Early second-trimester placental shelf appears to be a common, benign and transient sonographic finding.

Number of yolk sacs does not predict amnionicity in early first-trimester monochorionic multiple gestations.

OBJECTIVE: To determine the relationship between amnionicity and number of yolk sacs before 11 weeks of gestation. METHODS: Twenty-two cases of monochorionic multiple pregnancy were scanned before 11 weeks of gestation. There were 21 sets of twins and one of triplets. Amnionicity was determined by visualization of a dividing amniotic membrane between the gestational sacs. The number of yolk sacs was recorded and compared with the presence or absence of a dividing membrane for all fetuses. RESULTS: In 17/20 (85%) cases of monochorionic diamniotic twins, two yolk sacs were seen. In 3/20 (15%) cases of monochorionic diamniotic twins, a single yolk sac was seen. In the one case of monochorionic diamniotic triplets, two yolk sacs were visualized. In one case of monoamniotic twins, a single yolk sac was observed. CONCLUSIONS: In monochorionic pregnancies, the presence of two yolk sacs predicts diamnionicity. However, the use of the number of yolk sacs as a predictor of amnionicity may not be accurate in a small proportion of patients. The diagnosis of monoamnionicity can be made only following a careful search for a dividing amniotic membrane.

Does prenatal diagnosis influence the morbidity associated with left in situ nonfunctioning or poorly functioning renal moiety after endoscopic puncture of ureterocele?

PURPOSE: We compared long-term morbidity associated with left in situ nonfunctioning or poorly functioning renal moiety of a duplex system in children with prenatal vs postnatal diagnosis of ureterocele who underwent endoscopic puncture. MATERIALS AND METHODS: A total of 48 children underwent primary endoscopic puncture of duplex system ureterocele. Of the cases 35 (73%) were diagnosed prenatally (group 1) and 13 (27%) postnatally (group 2). Median age at time of puncture was 4 months in group 1 and 3.5 years in group 2. A total of 20 patients in group 1 (57%) and 8 in group 2 (62%) presented with intravesical ureterocele, while 15 in group 1 (43%) and 5 in group 2 (38%) had ectopic ureterocele. A total of 20 children in group 1 (57%) and 7 in group 2 (54%) had a nonfunctioning renal moiety, and 15 in group 1 (43%) and 6 in group 2 (46%) had a poorly functioning ureterocele moiety. Vesicoureteral reflux (VUR) was present in 23 children in group 1 (66%) comprising 30 renal refluxing units (RRUs), and in 12 in group 2 (92%) comprising 14 RRUs. Median followup was 9 years (range 1 to 15) for both groups. RESULTS: Preoperative urinary tract infection (UTI) was common in group 2 (92%) vs group 1 (20%). No patient in group 1 had development of UTI after puncture, while 23% of the children in group 2 presented with UTI. Four children (2 from each group) with ectopic ureterocele required secondary puncture resulting in satisfactory drainage. A total of 14 RRUs (47%) showed spontaneous resolution of VUR in group 1 compared to 3 (21%) in group 2. Four RRUs (13%) required endoscopic correction due to high grade VUR in group 1. Two RRUs (17%) were treated with endoscopic correction and 2 (17%) with ureteral reimplantation due to UTI in group 2. Only 1 patient in group 1 underwent nephrectomy due to nonfunctioning kidney, while 2 patients in group 2 required partial nephrectomy due to UTI. CONCLUSIONS: Our data reveal that prenatal diagnosis of duplex system ureterocele is associated with fewer UTIs, and early endoscopic management may decrease UTI and the need for additional surgery. Nonfunctioning or poorly functioning renal moieties left in situ following successful endoscopic decompression of ureterocele are not associated with additional morbidity and do not require partial nephrectomy in the majority of the cases.

An increase in superoxide dismutase ameliorates oxygen-induced retinopathy in transgenic mice.

PURPOSE: Oxygen therapy is a well-recognized risk factor for retinopathy of prematurity. We examined whether an increase in the naturally occurring enzyme copper-zinc superoxide dismutase (CuZnSOD), which controls oxygen, can reduce the severity of oxygen-induced retinopathy in a mouse model. METHODS: Seven transgenic mice overexpressing CuZnSOD and six wild-type mice were exposed to 75% oxygen from postnatal day 7 to 12. Seven transgenic mice and five mice of the wild type were kept in room air and served as controls. Fluorescein-conjugated dextran angiography of retinal vasculature was performed and flat-mounted preparations were evaluated by scoring blood vessel growth, blood vessel tuft formation, extraretinal neovascularization, degree of central constriction, and tortuosity of vessels. In addition, quantification of the number of blood vessel tufts was performed in a masked fashion with haematoxylin and eosin staining of paraffin-embedded eye sections. RESULTS: The mean retinal score+/-SD obtained by the wild-type mice was 9.4+/-2.0, whereas the transgenic mice overexpressing CuZnSOD obtained a value of 2.4+/-1.6 (P=0). The two control groups (wild type and transgenic) that were kept in room air, each obtained a score of 0. Significantly fewer extraretinal vascular tufts were seen in the transgenic mice (0.26+/-0.34) than in the wild-type mice (4.27+/-1.6) after both groups were exposed to oxygen (P<0.001). CONCLUSIONS: The results suggest that high SOD activity protects neonatal mice against oxygen-induced retinopathy, and support the assumption that oxygen radicals are a major causative factor in oxygen-induced retinopathy.

Transvaginal sonographic diagnosis of a tumor fistula.

We report on two cases of advanced pelvic cancer in women who presented with profuse vaginal watery discharge. In both cases, transvaginal ultrasound revealed a fistulous tract connecting the tumor to the apex of the vaginal vault. The differential diagnoses and a review of the literature are discussed.

The ocular manifestations of Weissenbacher-Zweymuller syndrome.

PURPOSE: Weissenbacher-Zweymuller syndrome (WZS) is an autosomal recessive disorder of delayed skeletal maturation. Its characteristic features include rhizomelic dwarfism with metaphyseal and vertebral changes. It has been challenged whether WZS is a part of the spectrum of Stickler syndrome. We report ocular findings in the largest ever-presented series of patients with WZS. METHODS: Patients underwent a paediatric examination, including assessment of growth and development, genetic work-up and X-ray of vertebra and long bones. All had a complete ophthalmic examination, cycloplegic refraction, and face and body photography. RESULTS: All patients had hypertelorism and protruding eyes. Four patients had refractive errors necessitating optical correction ranging from +3 to -8 D. Two patients had strabismus. None had vitreoretinal degeneration, glaucoma, or cataract. CONCLUSIONS: Ocular manifestations of WZS differ from those in Stickler syndrome, indicating that the two likely represent distinct clinical entities. Strabismus and various refractive errors often accompany WZS. An ophthalmologist should follow children with this disorder from an early age to prevent amblyopia.

Comparison between clinical and ultrasound findings in patients with vitreous hemorrhage.

PURPOSE: To ascertain the causes of vitreous hemorrhage and to determine the accuracy of ultrasound (U/S) in these cases, based on the degree of agreement between ultrasound and clinical findings. METHODS: A chart review of 96 consecutive patients (106 eyes) with dense vitreous hemorrhage who underwent A- and B-scan U/S by one examiner between June 1996 and June 1999. U/S records were evaluated to determine the presence and exact distribution of areas of retinal detachment and the presence of posterior vitreous detachment, retinal tear, intraocular foreign body, or choroidal detachment. Clinical information was obtained from the medical records after the vitreous hemorrhage was reabsorbed or following vitreous surgery. Clinical and U/S findings were compared. False-positive and False-negative rates for U/S were calculated based on clinical findings. RESULTS: In 37 eyes (35%) the vitreous hemorrhage was because of proliferative diabetic retinopathy and in 33 eyes (31%) because of ocular trauma. The false-positive rate for retinal detachment (retinal detachment by U/S without clinical confirmation) was 18.9% (seven of 37 eyes). Retinal tears were diagnosed and localized accurately in only four of nine eyes (44%). CONCLUSIONS: The most common cause of vitreous hemorrhage was proliferative diabetic retinopathy, followed by ocular trauma. U/S correctly diagnosed all cases of retinal detachment, but less than 50% of retinal tears. A total of 18.9% of the eyes were falsely diagnosed as having retinal detachment. U/S is an effective diagnostic tool in patients with vitreous hemorrhage.

Neuronal-binding antibodies from patients with antiphospholipid syndrome induce cognitive deficits following intrathecal passive transfer.

Antiphospholipid antibodies (aPL) have been suggested to play a role in causing cognitive and behavioral impairments. In the present study we investigated the pathogenic potential of aPL by intracerebro-ventricular (ICV) administration of immunoglobulins (IgG) from patients with antiphospholipid syndrome (APS). IgG, purified from the sera of four APS patients, was tested for binding to normal mouse brain by immunohistological staining. These IgG (7.5 microg) were injected ICV unilaterally to male C3H mice. Mice injected with IgG purified from pooled sera derived from healthy subjects served as controls. The mice were examined neurologically for motor function and coordination, and cognitively in a Morris water maze. The cognitive tests were performed with the experimenter blinded to the treatment. The performance of the mice in four separate experiments was compared by analysis of variance with repeated measures. IgG from one APS patient was found to bind best to neuronal structures in the hippocampus and cerebral cortex. Mice (n = 43) injected with this IgG performed worse in the water maze compared to the controls (n = 45) with significant effects of the aPL IgG on the overall performance of the mice (treatment, P < 0.03), on learning throughout the experiment (treatment x day, P < 0.02) and on short term memory (treatment x day xtrial, P < 0.002). IgG injected from two of the three other patients also bound specifically to mouse brain neurons and produced an impairment in performance of the water maze. These results support the hypothesis that aPL that gain access to the central nervous system may play a direct role in the pathogenesis of neurological manifestations of APS.

Hyposialated 185 kDa CD45RA+ molecules attain a high concentration in B lymphoma cells and in activated human B cells.

Alternate splicing of exons of the CD45 molecule generates multiple isoforms differing in their molecular weights (MWs). In B-lymphocytes the CD45RA isoform was previously shown to be expressed on glycoproteins with MWs of 220 and 205 kDa, while the CD45RO isoform was expressed on glycoproteins with MW of 180 kDa. The present study demonstrated that B cell lymphomas and activated B-cells contain CD45 molecules with a MW of 185 kDa that express the CD45RA and CD45RC specificities but neither the CD45RB nor the CD45RO specificities. 185 kDa CD45RA+ molecules were detected in B cell lymphoma B lines, in Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines, and in tonsillar B cells, but not in normal, unstimulated peripheral blood B cells. These molecules were not detected in neoplastic and normal T cells. CD45RA+ 185 kDa molecules were present in B cells from three non-Hodgkin's patients in leukemic phase were not detected in B lymphocytes of seven of nine CLL patients tested. Trypsin treatment eliminated only 220 kDa CD45RA+ molecules but not 185 kDa CD45RA+ molecules, indicating that the 185 kDa CD45RA+ molecules are not expressed on the cell surface. Pulse-chase experiments, and studies on the effects of tunicamycin, neuraminidase and O-glycosidase, indicated that the 185 kDa molecules are partially glycosylated CD45RABC molecules that constitute precursors of the 220 kDa molecules. The high concentration of 185 kDa CD45RA+ molecules in B lymphoma cells and in activated B cells seems to reflect a high turnover of CD45RA+ molecules characteristic for these cells.