Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Abnormal expression of wild type p53 protein in normal cells of a cancer family patient

Mutations in the p53 gene are the commonest specific genetic change in human cancer. In normal tissues, p53 protein is present in such low quantities that it is not readily detectable by immunochemical techniques. However, in many tumour cells large amounts of p53 protein accumulate and can be seen by simple immunohistochemical staining; this is generally attributed to the accumulation of stabilised, mutant protein. We have found a mother and daughter, who both have a history of breast cancer, who show strong immunohistochemical staining of p53 in most of their normal epithelial and mesenchymal cells. Their family has a history of multiple cancers developing at an early age. Detailed protein analysis and gene sequencing of material obtained from cultured cells, grown from a skin biopsy taken from the daughter, suggest that her cells contained large quantities of normal (unmutated) p53. We suggest that this phenotype defines a new inherited cancer susceptibility syndrome that is distinct from the germ-line mutations in p53 found in some Li-Fraumeni families. This new syndrome affects p53 tumour suppressor function through an indirect mechanism that stabilises normal p53. It remains to be established whether this mechanism also contributes to the accumulation of p53 in sporadic cancers.

Mutations in RYR1 are a common cause of exertional myalgia and rhabdomyolysis

Mutations in the skeletal muscle ryanodine receptor (RYR1) gene are a common cause of neuromuscular disease, ranging from various congenital myopathies to the malignant hyperthermia (MH) susceptibility trait without associated weakness. We sequenced RYR1 in 39 unrelated families with rhabdomyolysis and/or exertional myalgia, frequent presentations in the neuromuscular clinic that often remain unexplained despite extensive investigations. We identified 9 heterozygous RYR1 mutations/variants in 14 families, 5 of them (p.Lys1393Arg; p.Gly2434Arg; p.Thr4288_Ala4290dup; p.Ala4295Val; and p.Arg4737Gln) previously associated with MH. Index cases presented from 3 to 45 years with rhabdomyolysis, with or without exertional myalgia (n=12), or isolated exertional myalgia (n=2). Rhabdomyolysis was commonly triggered by exercise and heat and, less frequently, viral infections, alcohol and drugs. Most cases were normally strong and had no personal MH history. Inconsistent additional features included heat intolerance, and cold-induced muscle stiffness. Muscle biopsies showed mainly subtle changes. Familial RYR1 mutations were confirmed in relatives with similar or no symptoms. These findings suggest that RYR1 mutations may account for a substantial proportion of patients presenting with unexplained rhabdomyolysis and/or exertional myalgia. Associated clinico-pathological features may be subtle and require a high degree of suspicion. Additional family studies are paramount in order to identify potentially MH susceptible relatives.

Intravenous and nebulised magnesium sulphate for acute asthma: systematic review and meta-analysis

OBJECTIVES

To estimate the effect of intravenous and nebulised magnesium sulphate upon hospital admissions and pulmonary function in adults and children with acute asthma.

METHODS

We undertook a systematic review and meta-analysis of randomised and quasi-randomised trials of intravenous or nebulised magnesium sulphate in acute asthma. Trials were identified by searches of the electronic literature, relevant journal websites and conference proceedings, and contact with authors and experts. Data were pooled using random effects meta-analysis of the relative risk (RR) of hospital admission and the standardised mean difference (SMD) in pulmonary function.

RESULTS

24 studies (15 intravenous, 9 nebulised) incorporating 1669 patients were included. Intravenous treatment was associated in adults with weak evidence of an effect upon respiratory function (SMD 0.25, 95% confidence interval (CI) -0.01 to 0.51; p = 0.05), but no significant effect upon hospital admission (RR 0.87, 95% CI 0.70 to 1.08; p = 0.22), and in children with a significant effect upon respiratory function (SMD 1.94, 95% CI 0.80 to 3.08; p<0.001) and hospital admission (RR 0.70, 95% CI 0.54 to 0.90; p = 0.005). Nebulised treatment was associated in adults with weak evidence of an effect upon respiratory function (SMD 0.17, 95% CI -0.02 to 0.36; p = 0.09), and hospital admission (RR 0.68, 95% CI 0.46 to 1.02; p = 0.06), and in children with no significant effect upon respiratory function (SMD -0.26, 95% CI -1.49 to 0.98; p = 0.69) or hospital admission (RR 2.0, 95% CI 0.19 to 20.93; p = 0.56).

CONCLUSION

Intravenous magnesium sulphate appears to be an effective treatment in children. Further trials are needed of intravenous and nebulised magnesium sulphate in adults and nebulised magnesium sulphate in children.

Cowden syndrome and Lhermitte-Duclos disease in a family: a single genetic syndrome with pleiotropy?

Cowden syndrome is an autosomal dominant condition of multiple hamartomas. Patients with this phakomatosis have an increased risk of breast cancer and thyroid tumours. Lhermitte-Duclos disease is usually a sporadic condition of cerebellar ganglion cell hypertrophy, ataxia, mental retardation, and self-limited seizure disorder. We describe a three generation family with Cowden syndrome and Lhermitte-Duclos disease. Karyotyping performed on the peripheral lymphocytes of the proband and her affected mother showed a 46,XX complement. Single strand conformational polymorphism analysis failed to show any germline p53 mutations as a cause of the syndrome in this family.

Causes and outcome of young infant admissions to a Kenyan district hospital

AIMS

To provide a comprehensive description of young infant admissions to a first referral level health facility in Kenya. These data, currently lacking, are important given present efforts to standardise their care through the integrated management of childhood illness (IMCI) and for prioritising both health care provision and disease prevention strategies.

METHODS

Prospective, 18 month observational study in a Kenyan district hospital of all admissions less than 3 months of age to the paediatric ward.

RESULTS

A total of 1080 infants were studied. Mortality was 18% overall, though in those aged 0-7 days it was 34%. Within two months of discharge a further 5% of infants aged <60 days on admission had died. Severe infection and prematurity together accounted for 57% of inpatient deaths in those aged <60 days, while jaundice and tetanus accounted for another 27%. S pneumoniae, group B streptococcus, E coli, and Klebsiella spp. were the most common causes of invasive bacterial disease. Hypoxaemia, hypoglycaemia, and an inability to feed were each present in more than 20% of infants aged 0-7 days. Both hypoxaemia and the inability to feed were associated with inpatient death (OR 3.8 (95% CI 2.5 to 5.8) and 7.4 (95% CI 4.8 to 11.2) respectively).

CONCLUSIONS

Young infants contribute substantially to paediatric inpatient mortality at the first referral level, highlighting the need both for basic supportive care facilities and improved disease prevention strategies.

The potential of health sector non-governmental organizations: policy options

Non-governmental organizations (NGOs) have increasingly been promoted as alternative health care providers to the state, furthering the same goals but less hampered by government inefficiencies and resource constraints. However, the reality of NGO health care provision is more complex. Not only is the distinction between government and NGO providers sometimes difficult to determine because of their operational integration, but NGOs may also suffer from resource constraionts and management inefficiencies similar to those of government providers. Some registered NGOs operate as for-profit providers in practice. Policy development must reflect the strengths and weaknesses of NGOs in particular settings and should be built on NGO advantages over government in terms of resource mobilization, efficiency and/or quality. Policy development will always require a strong government presence in co-ordinating and regulating health care provision, and an NGO sector responsive to the policy goals of government.

Male and female salivary testosterone concentrations before and after sexual activity

Salivary testosterone concentrations were measured in male and female members of four heterosexual couples on a total of 11 evenings before and after sexual intercourse and 11 evenings on which there was no intercourse. Testosterone increased across the evening when there was intercourse and decreased when there was none. The pattern was the same for males and females. Early evening measured did not differ on the two kinds of days, suggesting that sexual activity affects testosterone more than initial testosterone affects sexual activity.

Effect of methyldopa on plasma renin activity in man

The effect of methyldopa on plasma renin activity was studied in one hypertensive and four normotensive human volunteers. Peripheral venous blood for the estimation of plasma renin activity was obtained with the subjects supine and in a 70° head-up tilted position before, during and, in two subjects, after treatment with oral methyldopa. Despite a reduction in mean arterial pressure, the plasma renin activity was decreased by methyldopa in each subject. The increase in plasma renin activity associated with tilting, however, was not significantly suppressed by methyldopa. These results indicate that treatment with methyldopa can simultaneously decrease mean arterial pressure and plasma renin activity and it is possible that these effects may be causally related.

Abnormal blood glucose concentrations on admission to a rural Kenyan district hospital: prevalence and outcome

AIMS

To determine the prevalence, clinical characteristics, and outcome of hypoglycaemia on admission in children at a rural Kenyan district hospital.

METHODS

Observational study of 3742 children (including 280 neonates) in Kilifi District Hospital, Kenya.

MAIN OUTCOME MEASURES

hypoglycaemia (blood glucose <2.2 mmol/l) and hyperglycaemia (blood glucose >10.0 mmol/l).

RESULTS

Non-neonates: the prevalence of hypoglycaemia on admission was 7.3%. Severe illness, malnutrition, last meal >12 hours ago, and a positive malaria slide were independently associated with hypoglycaemia. Overall, mortality in hypoglycaemic children was 20.2% compared to 3.8% in normoglycaemic children (p < 0.001). The brunt of mortality in hypoglycaemic children was borne by those who were severely ill or malnourished (31.8%) as opposed to those who were neither severely ill nor malnourished (9.0%). Neonates: 23.0% of neonates were hypoglycaemic on admission. Inability to breast feed and weight <2500 g were independently associated with hypoglycaemia. Mortality was 45.2% compared to 19.6% in normoglycaemic neonates (p < 0.001). Hyperglycaemia was present in 2.7% of children and was associated with a higher mortality than normoglycaemia, 14.0% versus 3.8% respectively (p < 0.001).

CONCLUSIONS

Hypoglycaemia is common in children admitted to a rural Kenyan district hospital and is associated with an increased mortality. Apart from features of severe illness and poor feeding, clinical signs have a low sensitivity and specificity for hypoglycaemia. Where diagnostic facilities are lacking, presumptive treatment of severely ill children is recommended. For other children, the continuation of feeding (by nasogastric tube if necessary) should be part of standard management.

A precursor of the nitric oxide donor SIN-1 modulates the stress protein heme oxygenase-1 in rat liver

In this study the effect of increased nitric oxide (NO) production on the expression of rat liver heme oxygenase-1, an inducible stress protein responsible for the catalysis of heme to biliverdin and carbon monoxide, was investigated. Rats were injected intraperitoneally with molsidomine (SIN-10), a long acting drug that is enzymatically converted in the liver to yield the active NO-releasing agent 3-morpholinosydnonimine (SIN-1). Administration of SIN-10 resulted in a significant time- and dose-dependent increase in plasma levels of nitrite/nitrate, an index of NO release. A time course of heme oxygenase-1 mRNA levels in liver showed a gradual increase in the expression of the gene encoding for this protein, which was maximal at 4 hours and returned to normal levels by 6 hours after SIN-10 treatment. Heme oxygenase activity also increased by 50% at 4 hours and was maximal 12 hours after SIN-10 administration (63% increase over baseline). These results indicate a possible role for locally generated NO in the modulation of hepatic stress response in vivo suggesting that NO mediates cell adaptation to stress by activation of endogenous defensive mechanisms.

The Viking viewer for connectomics: scalable multi-user annotation and summarization of large volume data sets

Modern microscope automation permits the collection of vast amounts of continuous anatomical imagery in both two and three dimensions. These large data sets present significant challenges for data storage, access, viewing, annotation and analysis. The cost and overhead of collecting and storing the data can be extremely high. Large data sets quickly exceed an individual's capability for timely analysis and present challenges in efficiently applying transforms, if needed. Finally annotated anatomical data sets can represent a significant investment of resources and should be easily accessible to the scientific community. The Viking application was our solution created to view and annotate a 16.5 TB ultrastructural retinal connectome volume and we demonstrate its utility in reconstructing neural networks for a distinctive retinal amacrine cell class. Viking has several key features. (1) It works over the internet using HTTP and supports many concurrent users limited only by hardware. (2) It supports a multi-user, collaborative annotation strategy. (3) It cleanly demarcates viewing and analysis from data collection and hosting. (4) It is capable of applying transformations in real-time. (5) It has an easily extensible user interface, allowing addition of specialized modules without rewriting the viewer.

P53-dependent upregulation of neutral sphingomyelinase-2: role in doxorubicin-induced growth arrest

Neutral sphingomyelinase-2 (nSMase2) is a ceramide-generating enzyme that has been implicated in growth arrest, apoptosis and exosome secretion. Although previous studies have reported transcriptional upregulation of nSMase2 in response to daunorubicin, through Sp1 and Sp3 transcription factors, the role of the DNA damage pathway in regulating nSMase2 remains unclear. In this study, we show that doxorubicin induces a dose-dependent induction of nSMase2 mRNA and protein with concomitant increases in nSMase activity and ceramide levels. Upregulation of nSMase2 was dependent on ATR, Chk1 and p53, thus placing it downstream of the DNA damage pathway. Moreover, overexpression of p53 was sufficient to transcriptionally induce nSMase2, without the need for DNA damage. DNA-binding mutants as well as acetylation mutants of p53 were unable to induce nSMase2, suggesting a role of nSMase2 in growth arrest. Moreover, knockdown of nSMase2 prevented doxorubicin-induced growth arrest. Finally, p53-induced nSMase2 upregulation appears to occur via a novel transcription start site upstream of exon 3. These results identify nSMase2 as a novel p53 target gene, regulated by the DNA damage pathway to induce cell growth arrest.

Attitudes towards blood donation in Trinidad and Tobago

The aims of this study were to determine the factors that influence blood donation in different demographic groups in a multi-ethnic, multicultural community, and to devise a strategy for a national campaign to increase voluntary non-remunerated blood donations. The majority (87%) of blood donations in Trinidad and Tobago are replacement donations. Seventy per cent of the country's transfusion needs are not met. In 1998, the World Health Assembly recommended that reliance on replacement donations should be phased out due to their association with an increased risk of transfusion-transmitted infections. An observer-administered questionnaire was completed by 1423 respondents in a multi-ethnic borough in central Trinidad. Respondents were classified as donors or non-donors and grouped by age, race, religion, employment status and highest level of education. The prevalence of a history of blood donation and the factors that encouraged donation or conversely discouraged donation in each demographic group were recorded. A total of 1146 (81.2%) respondents had never donated blood. Of the 277 (18.8%) who had previously donated, replacement for a family member or friend was the most common reason (86.9%). The prevalence of donation was low in all racial, religious, gender, educational and age groups. However, there were significant demographic variations. The majority (71.3%) of non-donors cited a lack of information as a major reason for non-donation and expressed a willingness to donate if access to information and donation facilities were improved. Voluntary blood donation in Trinidad and Tobago could be greatly increased by a national education campaign and increased accessibility to donation centres. This would ensure a safer and more reliable blood supply.

Functional domains of the HIV-1 rev gene required for trans-regulation and subcellular localization

The rev gene of human immunodeficiency virus type 1 (HIV-1) encodes a 116 amino acid nuclear regulatory protein (Rev) that increases the cytoplasmic expression of viral mRNAs containing the Rev response element (RRE) and coding for the structural proteins, Gag and Env. To identify the functional domains of Rev, amino acid deletion and chain termination mutations were introduced in the Rev coding region. The ability of these mutants to increase the cytoplasmic expression of a Rev-test plasmid (pSV-AR), containing the RRE cloned into the 3' noncoding region of the CAT gene in plasmid pSV2CAT, was examined in transient expression assays in HeLa cells. Our results indicate that three distinct regions mapping within the N-terminal 98 amino acids of Rev are essential for its activity. The subcellular localization of the various Rev proteins was examined in COS cells by indirect immunofluorescence. Rev was found to localize predominantly in the nucleolus of transfected cells. All mutant Rev proteins, with the exception of a deletion mutant (rev delta 41-44) lacking four Arg residues of a highly basic domain, were found to localize in the nucleolus. Mutant rev delta 41-44 exhibited weak diffuse fluorescence in the nucleus with a tendency to accumulate in the cytoplasm. A 15 amino acid region encompassing this basic domain (38-52) when fused to the Escherichia coli beta-galactosidase gene efficiently directed the fusion gene product to the nucleus and nucleolus, suggesting a role for this domain in the nucleolar localization of Rev.

The effect of transforming growth factor beta one (TGF-beta 1) on wound healing, with or without barrier membranes, in a Class II furcation defect in sheep

The purpose of this study was to analyse the effect of TFG-beta 1 on wound healing in standardized Class II furcation defects of 48 mandibular second premolar teeth in 24 sheep. The experimental design included a control group (carrier only, 25% pluronic F-127), and 2 experimental groups: group A (80 micrograms/ml TGF-beta 1 + carrier) and group B (80 micrograms/ml TGF-beta 1 + carrier covered with a barrier membrane). Sheep were killed either 2 wk or 6 wk after surgery. Mesiodistal sections of the decalcified specimens were quantified histologically using stereology. Percentage volumes of regenerated bone, fibrous connective tissue and cementum were calculated for each furcation defect. Mean values were analysed using multiple ANOVA; p values were calculated using paired and unpaired Student's t-tests. After 2 wk there was more bone in group B than either of the other 2 groups, but this was not statistically significant. By 6 wk more bone was present in group A than in the control group (p < 0.02) and also in group B when compared with both group A and the control group (p < 0.02 and p < 0.44), respectively. In the 4 wk between sampling significantly more bone had formed (group A < 0.05 and group B p < 0.003, respectively). A negative correlation existed between volumes of bone and fibrous connective tissue and no significant differences between the volumes of cementum were evident between any of the groups. This study demonstrated that TGF-beta 1 encouraged bone regeneration in Class II furcation defects in sheep, an effect enhanced by the presence of a barrier membrane. This is the first report on the use of TGF-beta 1 in conjunction with GTR in periodontal defects.

p53 protein detected by immunohistochemical staining is not always mutant

The expression of the tumour suppressor gene p53 was analyzed in a variety of human solid tumours by immunohistochemistry and direct DNA sequencing. Positive nuclear staining using a panel of anti-p53 antibodies was used to select tumours for further genetic analysis. Using PCR amplification followed by immobilization onto magnetic beads and direct sequencing, we sequenced exons 5-9 of the p53 gene from 9 melanomas, 8 nasopharyngeal carcinomas, 16 sporadic breast carcinomas and 11 patients from familial breast cancer families. No sequence alterations of the p53 gene were detected in either the melanoma or nasopharyngeal tumours and only 19% of the primary breast carcinomas showed a variant band indicative of a mutation. Our results indicate firstly that p53 mutations are not generally involved in the tumour types studied and secondly the data emphasize the disparity encountered when attempting to correlate p53 immunohistochemical positivity with mutations within the p53 gene.

Phosphopeptide quantitation using amine-reactive isobaric tagging reagents and tandem mass spectrometry: application to proteins isolated by gel electrophoresis

Polyacrylamide gel electrophoresis is widely used for protein separation and it is frequently the final step in protein purification in biochemistry and proteomics. Using a commercially available amine-reactive isobaric tagging reagent (iTRAQ) and mass spectrometry we obtained reproducible, quantitative data from peptides derived by tryptic in-gel digestion of proteins and phosphoproteins. The protocol combines optimized reaction conditions, miniaturized peptide handling techniques and tandem mass spectrometry to quantify low- to sub-picomole amounts of (phospho)proteins that were isolated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Immobilized metal affinity chromatography (FeIII-IMAC) was efficient for removal of excess reagents and for enrichment of derivatized phosphopeptides prior to matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis. Phosphopeptide abundance was determined by liquid chromatography/tandem mass (LC/MS/MS) using either MALDI time-of-flight/time-of-flight (TOF/TOF) MS/MS or electrospray ionization quadrupole time-of-flight (ESI-QTOF) MS/MS instruments. Chemically labeled isobaric phosphopeptides, differing only by the position of the phosphate group, were distinguished and characterized by LC/MS/MS based on their LC elution profile and distinct MS/MS spectra. We expect this quantitative mass spectrometry method to be suitable for systematic, comparative analysis of molecular variants of proteins isolated by gel electrophoresis.

Use of polymerase chain reaction to demonstrate cytomegalovirus DNA in CSF of patients with human immunodeficiency virus infection

We used the polymerase chain reaction (PCR) to demonstrate cytomegalovirus (CMV) DNA in the CSF of a patient with the CMV radiculomyelopathy syndrome. To investigate the significance of this finding, we also performed PCR for CMV on CSF samples from 30 patients with human immunodeficiency virus (HIV) infection and neurologic disease, four patients with solid organ transplants including three with active CMV infection, and 10 patients with no clinical suspicion of HIV or CMV infection. There was CMV DNA only in patients with HIV, and it was present more often in patients with evidence of spinal cord dysfunction. Our results suggest that PCR may be useful in the rapid diagnosis of CMV infection of the CNS in patients with HIV and that the radiculomyelopathy syndrome may represent only part of a spectrum of CMV-induced spinal cord dysfunction in these patients.

In vivo measurements of macular and nerve fibre layer thickness in retinal arterial occlusion

AIM

To investigate the structure-function relationship in patients with retinal arterial occlusion by measuring the macular and the peripapillary retinal nerve fibre layer (RNFL) thickness and the visual sensitivity.

METHODS

This is an observational case series with three patients with central retinal arterial occlusion (CRAO) and two patients with branch retinal arterial occlusion (BRAO). The macular/peripapillary RNFL thickness and the visual field were measured with Stratus optical coherence tomography (OCT) and Humphrey visual field analyzer, respectively, at least 1 year after the diagnosis of CRAO or BRAO.

RESULTS

The macular thickness, in particular the inner retinal layer, and the peripapillary RNFL thickness were reduced in patients with retinal arterial occlusion. The decrease in the macular and the peripapillary RNFL thickness corresponded to the sites of retinal arterial occlusion with diffuse and segmental thinning found in CRAO and BRAO, respectively. Visual field defects were found in the corresponding locations of macular and RNFL thinning, and closely correlated with the degree of the structural damage.

CONCLUSIONS

Structural damages in terms of reduction in the macular and peripapillary RNFL thickness were evident in patients with retinal arterial occlusion. A close structure-function correlation was found and a worse functional outcome is associated with a more extensive thinning of the macula and RNFL. OCT measurements of the macular/peripapillary RNFL thickness provide useful indicators to reflect the severity of the disease in retinal arterial occlusion and serve as a new paradigm to study and monitor the disease longitudinally.