An observational study on the safety of COVID-19 vaccination in patients with myasthenia gravis

OBJECTIVE

There is concern that the coronavirus disease (COVID-19) vaccine may trigger or worsen autoimmune diseases. The objective of this study was to determine the impacts of COVID-19 vaccination on symptom severity in patients with myasthenia gravis (MG).

METHODS

A total of 106 enrolled patients with MG who were vaccinated against COVID-19 were followed up, and a questionnaire was used to document in detail the exacerbation of muscle weakness after vaccination and all other uncomfortable reactions after vaccination. Demographic, clinical characteristics, medication, and vaccination data were collected by follow-up interview. The main observation outcome was whether the MG symptoms of patients were exacerbated. The definition of exacerbation is according to the subjective feeling of the patient or a 2-point increase in daily life myasthenia gravis activity score relative to before vaccination, within 30 days after vaccination.

RESULTS

Of 106 enrolled patients [median age (SD) 41.0 years, 38 (35.8%) men, 53 (50.0%) with generalized MG, 74 (69.8%) positive for acetylcholine receptor antibody, and 21 (19.8%) with accompanying thymoma], muscle weakness symptoms were stable in 102 (96.2%) patients before vaccine inoculation. Muscle weakness worsened in 10 (9.4%) people after vaccination, of which 8 patients reported slight symptom worsening that resolved quickly (within a few days). Two (1.9%) of patients showed serious symptom aggravation that required hospitalization.

CONCLUSION

Our results suggest that inactivated virus vaccines against COVID-19 may be safe for patients with MG whose condition is stable. Patients with generalized MG may be more likely to develop increased muscle weakness after vaccination.

[Analysis of clinical characteristics and related genetic variation of juvenile myasthenia gravis]

Objective: To analyze the clinical characteristics and related genetic variation of juvenile myasthenia gravis (MG) patients. Methods: We collected the clinical data of adolescent MG patients who were treated in the Department of Neurology of the First Affiliated Hospital of Sun Yat-sen University from June 2019 to May 2020. After obtaining the patient's informed consent, the blood samples were collected. The Whole Exome Sequencing (WES) was performed on peripheral blood samples. And use biological information software and SPSS 22.0 for data processing and result analysis. Results: According to the inclusion and exclusion criteria, 54 patients with juvenile MG were included, 28 males and 26 females. And the average age of onset was (3.79±0.89) years. Among the enrolled patients, there were 52 (96.3%) patients with ocular MG, the MG-ADL scores of 54 patients were (3.44±0.44) points, and the titer of AChR antibody was (5.88±2.45) nmol/L. Two patients had thymic hyperplasia, and 5 patients had a family history of MG.A total of 169 variant genes were found in 54 patients, of which TTN gene variants had the largest number, with a total of 17 variants (31.5%). In the TTN gene variant group, 7(41.2%) patients had eye fixation symptoms, and 4 (10.8%) patients in the non-mutation group had eye fixation symptoms. And The difference between the two groups was statistically significant (P=0.016). In addition, the synaptic nucleus envelope protein-1 (SYNE1) and the ryanodine receptor-1 (RYR1) gene variations were also found in 7 cases (13.2%), and no clear relationship between these gene variations and clinical manifestations of MG was found. Conclusions: The incidence of juvenile MG was preschoolers with no gender difference, and ocular MG was more common. The proportion of TTN gene variation in adolescent MG was higher, suggesting that this gene may be a potential therapeutic target for juvenile MG patients.

[Clinical characteristics and outcomes of myasthenia gravis patients with double positive antibodies against acetylcholine receptor and muscle-specific tyrosine kinase]

Objective: To investigate the clinical manifestations, treatment characteristics and outcomes of myasthenia gravis (MG) dually positive for anti-acetylcholine receptor antibody (AChR-Ab) and anti-muscle-specific tyrosine kinase antibody (MuSK-Ab). Method: MG patients hospitalized in the First Affiliated Hospital of Sun Yat-sen University from August 2017 to November 2020 were retrospectively collected. Thirty-four MuSK-Ab positive MG (MuSK-MG) patients, 11 double-antibodies positive MG (DP-MG) patients, and 80 AChR-Ab positive MG (AChR-MG) patients were included and allocated to three different groups. The clinical data of patients in the three groups were collected, and the differences of demographic characteristics, clinical manifestations and treatment outcomes between DP-MG patients and AChR-MG and MuSK-MG patients were analyzed. Result: The proportion of female and male patients in DP-MG group was 7/11 and 4/11 respectively, and the onset age of DP-MG was (41±27) years.The difference in gender distribution between DP-MG and AChR-MG groups was statistically significant (P<0.05). The proportion of extraocular muscle involvement in the DP-MG and MuSK-MG groups (8/11 and 52.9%) was lower than that in the AChR-MG group (83.8%), and the difference was statistically significant (P<0.05). The incidence of myasthenia crisis in DP-MG and MuSK-MG groups (54.5% and 61.8%) were higher than that in AChR-MG group (20.0%), with astatistically significant difference(P<0.05). The positive rate of neostigmine test in DP-MG and MuSK-MG groups(8/11 and 74.2%) were lower than that of AChR-MG group (96.8%), and the positive rate of low frequency repetitive nerve stimulation (RNS) in DP-MG group (5/10) was lower than that in AChR-MG group (85.1%), with statistically significant differences (all P<0.05). MuSK-Ab titer was positively correlated with the course of disease (r=0.466, P<0.05), and antibody titer decreased after symptom improvement (P<0.05). The response of patients in DP-MG and MuSK-MG groups to cholinesterase inhibitors (2/11 and 9.1%) was worse than that in the AChR-MG group (66.3%), and the incidence of side effects in the two groups (5/11 and 39.4%) was higher than that in the AChR-MG group (15.0%), with statistically significant differences (all P<0.05). There were 4 DP-MG patients underwent thymectomy, and the pathological results detected two cases of thymoma and two cases of thymic hyperplasia. Subsequent follow-up showed that 5 (5/11) DP-MG patients achieved minimal manifestation status or better status. Conclusion: The gender distribution, age of onset, pharmacological characteristics and electrophysiological examination of DP-MG patients were similar to those of MuSK-MG patients, but the severity of DP-MG patients was between that of AChR-MG and MuSK-MG patients.

[Characteristics of electromyography in 111 patients with generalized myasthenia gravis: a retrospective study]

Objective: To retrospectively analyze the characteristics of the electromyography (EMG) study in generalized myasthenia gravis (gMG) patients. Methods: A total of 111 gMG patients were enrolled. Patients were divided into two groups: 36 severe patients discontinuing pyridostigmine bromide (PB) for 8 hours were included in 8 h group, and 75 g MG patients discontinuing PB for at least 18 hours were included in>18 h group. The clinical information and EMG study data were collected and analyzed. Results: There were statistically significant differences in the initial location of the myasthenia muscle (P=0.027), the affected muscle detected by the EMG (P=0.015) and quantitative myasthenia gravis (QMG) score (P<0.01) between the two groups. Comparisons in each group revealed that the highest positive rate of low-frequency repetitive nerve stimulation (RNS) of facial in 8 h group and>18 h group was 94.4% and 60.0%, respectively. Comparisons between the two groups showed that the positive rate of low-frequency RNS in 8 h group was significantly higher than that in>18 h group (94.4% vs 70.7%, χ(2)=8.115, P=0.004). In particular, the positive rate of RNS in facial nerves and the extent of the amplitude decrease under different electrical stimulations (1 Hz, 3 Hz, and 5 Hz) were dramatically higher in the 8 h group (P<0.01). Conclusions: For gMG patients, the facial and accessory nerve detection can improve the positive rate of RNS. Different muscles had various sensitivity to PB, and orbicularis oculi muscle seemed the least sensitive muscle to PB. For suspect MG patients in severe condition, only discontinuing PB medication for 8 h before low-frequency RNS testing can avoid the deterioration and also obtain similar positive rate.

[Correlation factors of 127 times pre-crisis state in patients with myasthenia gravis]

Objective: To investigate the clinical features of the Pre-Crisis State and analyze the correlated risk factors of Pre-Crisis State of myasthenia crisis. Methods: We included 93 patients with myasthenia gravis (MG) who experienced 127 times Pre-Crisis State between October 2007 and July 2016. Those patients were hospitalized in the MG specialize center, Department of Neurological Science, first Affiliated Hospital of Sun Yat-sen University. The information of the general situation, the clinical manifestations and the blood gas analysis in those patients were collected using our innovated clinical research form. Statistic methods were applied including descriptive analysis, univariate logistic analysis, multivariate correlation logistic analysis, etc. Results: (1)The typical features of MG Pre-Crisis State included: dyspnea (127 times, 100% not requiring intubation or non-invasive ventilation), bulbar-muscle weakness (121 times, 95.28%), the increased blood partial pressure of carbon dioxide (PCO(2)) (94 times, 85.45%), expectoration weakness (99 times, 77.95%), sleep disorders (107 times, 84.25%) and the infection (99 times, 77.95%). The occurrence of dyspnea in combination with bulbar-muscle weakness (P=0.002) or the increased blood PCO(2) (P=0.042) often indicated the tendency of crisis. (2) The MG symptoms which were proportion to the occurrence of crisis includes: bulbar-muscle weakness (P=0.028), fever (P=0.028), malnutrition (P=0.066), complications (P=0.071), excess oropharyngeal secretions (P=0.005) and the increased blood PCO(2) (P=0.007). The perioperative period of thymectomy would not increase the risk of crisis. Conclusions: Dyspnea indicates the occurrence of the Pre-Crisis State of MG. In order to significantly reduce the morbidity of myasthenia crisis, the bulbar-muscle weakness, the increased blood PCO(2), expectoration weakness, sleep disorders, infection & fever and excess oropharyngeal secretions should be treated timely.

Apolipoprotein D Expression in Primary Brain Tumors: Analysis by Quantitative RT-PCR in Formalin-fixed, Paraffin-embedded Tissue

Apolipoprotein D (apoD) expression has been shown to correlate both with cell cycle arrest and with prognosis in several types of malignancy, including central nervous system astrocytomas and medulloblastomas. ApoD expression was investigated by real-time quantitative RT-PCR using RNA extracted from 68 formalin-fixed, paraffin-embedded brain specimens. Glyceraldehyde phosphate dehydrogenase was used as an internal control. Quantitation was achieved on all specimens. Sixteen poorly infiltrating WHO grade I glial neoplasms (i.e., pilocytic astrocytomas and gangliogliomas) showed an average 20-fold higher apoD expression level compared with the 20 diffusely infiltrating glial neoplasms (i.e., glioblastoma, anaplastic astrocytoma, oligodendrogliomas; p=0.00004). A small number of exceptions (i.e., two high-expressing glioblastomas and three low-expressing gangliogliomas) were identified. Analyzed as individual tumor groups, poorly infiltrating grade I pilocytic astrocytomas and gangliogliomas differed significantly from each tumor type within the diffusely infiltrating higher-grade category ( p<0.05 for each comparison) but not from each other ( p>0.05). Conversely, each individual tumor type within the diffusely infiltrating category differed significantly from both pilocytic astrocytomas and gangliogliomas ( p<0.05) but did not vary from other infiltrating tumors ( p>0.05). Ependymomas, non-infiltrating grade II neoplasms, expressed levels of apoD similar to or lower than levels expressed by the diffusely infiltrating gliomas. Ten medulloblastomas with survival longer than 3 years averaged slightly higher apoD expression than four fatal medulloblastomas; however, this result was not statistically significant and individual exceptions were notable. In 17 of the medulloblastomas, MIB-1 proliferation rates quantitated by image cytometry did not correlate with apoD expression. In addition, apoD expression was 5-fold higher in the slowly proliferating grade I glial neoplasms compared with non-proliferating normal brain tissue ( p=0.01), suggesting that apoD expression is not simply an inverse measure of proliferation. ApoD expression measured by quantitative RT-PCR may be useful in the differential diagnosis of primary brain tumors, particularly pilocytic astrocytomas and gangliogliomas.

Evaluation of PIMA point-of-care CD4 analyzer in Yunnan, China

Background:

CD4 count is used to determine antiretroviral therapy (ART) eligibility. In China, flow cytometers are mostly located in urban areas with limited access by patients residing in remote areas. In an attempt to address this issue, we conducted a study to validate the performance of Alere PIMA point-of-care CD4 analyzer.

Methods:

Venous and finger-prick blood specimens were collected from HIV-positive participants from two voluntary counseling and testing sites in Yunnan Province. Both venous and finger-prick blood specimens were tested with the PIMA analyzer. Venous blood specimens tested with the Becton Dickinson FACSCalibur were used as a reference.

Results:

Venous specimens from 396 and finger-prick specimens from 387 persons were available for analysis. CD4 counts by PIMA correlated well with those from FACSCalibur with an R² of 0.91 for venous blood and 0.81 for finger-prick blood. Compared to FACSCalibur, the PIMA analyzer yielded lower counts with a mean bias of − 47.0 cells/μl (limit of agreement, [LOA]: −204–110 cells/μl) for venous blood and −71.0 cells/μl (LOA: −295–153 cells/μl) for finger-prick blood. For a CD4 threshold of 350 cells/μl, the positive predictive value (PPV) of PIMA was 84.2% and 75.7% and the negative predictive value (NPV) was 97.6% and 95.8% for venous and finger-prick blood, respectively. For an ART threshold of 500 cells/μl, the corresponding PPV was 90.3% and 84.0% and NPV was 94.3% and 93.4%, respectively.

Conclusions:

CD4 counting using venous blood with PIMA analyzers is a feasible alternative to a large flow cytometer to determine ART eligibility.

Development and implementation challenges of a quality assured HIV infant diagnosis program in Nigeria using dried blood spots and DNA polymerase chain reaction

Nigeria has one of the highest HIV burdens as well as mother-to-infant transmission rates in the world. A pilot program using polymerase chain reaction (PCR)-based testing of dried blood spot (DBS) specimens was implemented to enable early identification of HIV-infected infants and timely referral and linkage to care. From February 2007 to October 2008, whole blood was collected by finger prick to prepare DBS from infants <18 months presenting in six public mother-and-child health facilities in Lagos, Nigeria. The DBS were tested using the Roche Amplicor HIV-1 DNA Test, v1.5. To monitor laboratory testing quality, all of the PCR-positive and 10% of the PCR-negative DBS were retested by the same method at another reference laboratory. Three hundred and sixty-five randomly selected infants were screened using HIV rapid tests (RT) according to the national algorithm and RT-negative and PCR-positive specimens were also tested using Genscreen enzyme-linked immunosorbent assay (EIA) (Bio-Rad, France). The turnaround time (TAT) from sample collection, testing, and dispatching of results from each health facility was monitored. A total of 1,273 infants with a median age of 12.6 weeks (1 day to 71.6 weeks) participated in the program and 280 (22.0%) were PCR positive. HIV transmission levels varied greatly in the different health facilities ranging from 7.1% to 38.4%. Infants aged 48 to 72 weeks had the highest level of PCR positivity (41.1%). All PCR-positive specimens were confirmed by retesting. The mean turnaround time from DBS collection to returning of the laboratory result to the health facilities was 25 days. Three infants were found to be HIV antibody negative by rapid tests but were positive by both PCR and the fourth generation EIA. The DBS-based PCR program accurately identified all of the HIV-infected infants. However, many programmatic challenges related to the laboratory and TAT were identified.

Genetic diversity and drug resistance among newly diagnosed and antiretroviral treatment-naive HIV-infected individuals in western Yunnan: a hot area of viral recombination in China

Background

The emergence of an HIV-1 epidemic in China was first recognized in Dehong, western Yunnan. Due to its geographic location, Dehong contributed greatly in bridging HIV-1 epidemics in Southeast Asia and China through drug trafficking and injection drug use; and also extensively to the HIV genetic diversity in Yunnan and China. We attempt to monitor HIV-1 in this area by studying the HIV-1 genetic distribution and transmitted drug resistance (TDR) in various at-risk populations.

Methods

Blood samples from a total of 320 newly HIV-1 diagnosed individuals, who were antiretroviral therapy (ART)-naive, were collected from January 2009 to December 2010 in 2 counties in Dehong. HIV-1 subtypes and pol gene drug resistance (DR) mutations were genotyped.

Results

Among 299 pol sequences successfully genotyped (93.4%), subtype C accounted for 43.1% (n=129), unique recombinant forms (URFs) for 18.4% (n=55), CRF01_AE for 17.7% (n=54), B for 10.7% (n=32), CRF08_BC for 8.4% (n=25) and CRF07_BC for 1.7% (n=5). Subtype distribution in patients infected by different transmission routes varied. In contract to the previous finding of CRF01_AE predominance in 2002-2006, subtype C predominated in both injecting drug users (IDUs) and heterosexually transmitted populations in this study. Furthermore, we found a high level of BC, CRF01_AE/C and CRF01_AE/B/C recombinants suggesting the presence of active viral recombination in the area. TDR associated mutations were identified in 4.3% (n=13) individuals. A total of 1.3% of DR were related to protease inhibitors (PIs), including I85IV, M46I and L90M; 0.3% to nucleoside reverse transcriptase inhibitors (NRTIs), including M184I; and 2.7% to non-nucleoside reverse transcriptase inhibitors (NNRTIs), including K103N/S, Y181C, K101E and G190A.

Conclusion

Our work revealed diverse HIV-1 subtype distributions and intersubtype recombinations. We also identified a low but significant TDR mutation rate among ART-naive patients. These findings enhance our understanding of HIV-1 evolution and are valuable for the development and implementation of a comprehensive public health approach to HIV-1 DR prevention and treatment in the region.

Influence of different flow-triggering levels on the breathing effort of mechanically ventilated patients

BACKGROUND

Although a sensitive flow triggering (FT) level is supposed to be associated with reduced breathing effort, the incidence of autotriggering (AT) is likely to be increased. The actual effects of various FT levels on the work of breathing and occurrence of AT in mechanically ventilated patients are unknown. We investigated the effects of different FT levels (1-8 L/min) on breathing effort and incidence of AT in mechanically ventilated patients under pressure support ventilation using a Puritan-Bennett 840 ventilator.

METHODS

Eight FT levels were randomly studied in mechanically ventilated patients under pressure support ventilation. The triggering effort (pressure-time product of triggering, PTPtr) was assessed by quantitating a segment of the pressure-time product of the esophagus (PTPes). The total PTPes, inspiratory work of breathing (Wi) and P0.1 were determined.

RESULTS

Nine patients with appropriately recorded signals were included. The incidence of AT significantly decreased with increasing FT level (FT1, 1 L/min: 30.7%, FT8: 0.2%). PTPtr significantly increased with increasing FT level (0.020 ± 0.004 cmH2O • S in FT1 to 0.190 ± 0.017 cmH2O • S in FT8), but P0.1 remained similar. PTPtr accounted for only1-3% of total PTPes. Wi and PTPes were significantly lower only at FT1, but there was no significant difference in Wi and PTPes at different FT levels when AT breaths were excluded.

CONCLUSION

A higher FT level was associated with lower incidence of AT, but without a significant increase in breathing effort. A higher FT level may be more reasonable in mechanically ventilated patients with this particular ventilator.

Two types of nanoparticle-based bio-barcode amplification assays to detect HIV-1 p24 antigen

Background

HIV-1 p24 antigen is a major viral component of human immunodeficiency virus type 1 (HIV-1) which can be used to identify persons in the early stage of infection and transmission of HIV-1 from infected mothers to infants. The detection of p24 is usually accomplished by using an enzyme-linked immunosorbent assay (ELISA) with low detection sensitivity. Here we report the use of two bio-barcode amplification (BCA) assays combined with polymerase chain reaction (PCR) and gel electrophoresis to quantify HIV-1 p24 antigen.

Method

A pair of anti-p24 monoclonal antibodies (mAbs) were used in BCA assays to capture HIV-1 p24 antigen in a sandwich format and allowed for the quantitative measurement of captured p24 using PCR and gel electrophoresis. The first 1 G12 mAb was coated on microplate wells or magnetic microparticles (MMPs) to capture free p24 antigens. Captured p24 in turn captured 1D4 mAb coated gold nanoparticle probes (GNPs) containing double-stranded DNA oligonucleotides. One strand of the oligonucleotides was covalently immobilized whereas the unbound complimentary bio-barcode DNA strand could be released upon heating. The released bio-barcode DNA was amplified by PCR, electrophoresed in agarose gel and quantified.

Results

The in-house ELISA assay was found to quantify p24 antigen with a limit of detection (LOD) of 1,000 pg/ml and a linear range between 3,000 and 100,000 pg/ml. In contrast, the BCA-based microplate method yielded an LOD of 1 pg/ml and a linear detection range from 1 to 10,000 pg/ml. The BCA-based MMP method yielded an LOD of 0.1 pg/ml and a linear detection range from 0.1 to 1,000 pg/ml.

Conclusions

When combined with PCR and simple gel electrophoresis, BCA-based microplate and MMPs assays can be used to quantify HIV-1 p24 antigen. These methods are 3–4 orders of magnitude more sensitive than our in-house ELISA-based assay and may provide a useful approach to detect p24 in patients newly infected with HIV.

Past, present and future molecular diagnosis and characterization of human immunodeficiency virus infections

Substantive and significant advances have been made in the last two decades in the characterization of human immunodeficiency virus (HIV) infections using molecular techniques. These advances include the use of real-time measurements, isothermal amplification, the inclusion of internal quality assurance protocols, device miniaturization and the automation of specimen processing. The result has been a significant increase in the availability of results to a high level of accuracy and quality. Molecular assays are currently widely used for diagnostics, antiretroviral monitoring and drug resistance characterization in developed countries. Simple and cost-effective point-of-care versions are also being vigorously developed with the eventual goal of providing timely healthcare services to patients residing in remote areas and those in resource-constrained countries. In this review, we discuss the evolution of these molecular technologies, not only in the context of the virus, but also in the context of tests focused on human genomics and transcriptomics.

Comparison of HIV-1 detection in plasma specimens and dried blood spots using the Roche COBAS Ampliscreen HIV-1 test in Kisumu, Kenya

The World Health Organization recommends screening donor blood for HIV in centralized laboratories. This recommendation contributes to quality, but presents specimen transport challenges for resource-limited settings which may be relieved by using dried blood spots (DBS). In sub-Saharan Africa, most countries screen donor blood with serologic assays only. Interest in window period reduction has led blood services to consider adding HIV nucleic acid testing (NAT). The U.S. Food and Drug Administration (FDA) mandates that HIV-1 NAT blood screening assays have a 95% detection limit at or below 100 copies/ml and 5000 copies/ml for pooled and individual donations, respectively. The Roche COBAS Ampliscreen HIV-1 test, version 1.5, used for screening whole blood or components for transfusion, has not been tested with DBS. We compared COBAS Ampliscreen HIV-1 RNA detection limits in DBS and plasma. An AIDS Clinical Trials Group, Viral Quality Assurance laboratory HIV-1 standard with a known viral load was used to create paired plasma and DBS standard nine member dilution series. Each was tested in 24 replicates with the COBAS Ampliscreen. A probit analysis was conducted to calculate 95% detection limits for plasma and DBS, which were 23.8 copies/ml (95% CI 15.1-51.0) for plasma and 106.7 copies/ml (95% CI 73.8-207.9) for DBS. The COBAS Ampliscreen detection threshold with DBS suggests acceptability for individual donations, but optimization may be required for pooled specimens.

Quality assurance in the HIV/AIDS laboratory network of China

Background In 2009, there were 8273 local screening laboratories, 254 confirmatory laboratories, 35 provincial confirmatory central laboratories and 1 National AIDS Reference Laboratory (NARL) in China. These laboratories were located in Center for Disease Control and Prevention (CDC) facilities, hospitals, blood donation clinics, maternal and child health (MCH) hospitals and border health quarantine health-care facilities.

Methods The NARL and provincial laboratories provide quality assurance through technical, bio-safety and managerial training; periodic proficiency testing; on-site supervisory inspections; and commercial serologic kit evaluations.

Results From 2002 to 2009, more than 220 million HIV antibody tests were performed at screening laboratories, and all reactive and indeterminate samples were confirmed at confirmatory laboratories. The use of highly technically complex tests, including CD4 cell enumeration, viral load, dried blood spot (DBS)-based early infant diagnosis (EID), drug resistance (DR) genotyping, HIV-1 subtyping and incidence assays, have increased in recent years and their performance quality is closely monitored.

Conclusion China has made significant progress in establishing a well-coordinated HIV laboratory network and QA systems. However, the coverage and intensity of HIV testing and quality assurance programmes need to be strengthened so as to ensure that more infected persons are diagnosed and that they receive timely prevention and treatment services.

Scaling up HIV rapid testing in developing countries: comprehensive approach for implementing quality assurance

In the last few years, the use of HIV rapid testing has expanded worldwide in response to the call for universal access to prevention, care, and treatment by UNAIDS and the World Health Organization. HIV rapid testing is performed by people with varied skills in laboratory and nonlaboratory settings. Accurate HIV diagnostic testing is the first step to identifying infected persons for follow-up referral and care. However, there are several challenges related to test kit quality, test selection, testing algorithms, training, quality assurance (QA), quality of new lots, and postmarket performance. We highlight various issues that impact the quality of HIV rapid testing and provide solutions to monitor and improve test accuracy, especially in resource-limited settings. These include the use of validated kits, training with emphasis on QA, use of a standardized log book, dried-tube specimen-based proficiency testing, new kit lot verification, and postmarket surveillance. Systematic implementation of these tools should greatly enhance the quality of HIV rapid testing.

MagaZorb: a simple tool for rapid isolation of viral nucleic acids

Effective isolation of nucleic acids from samples containing viral materials is an essential step for accurate diagnosis of viral infections. The necessity of this critical step before analytical identification and diagnosis of viral infections is paramount to screening programs and to identifying and monitoring epidemics and pandemics. With molecular assays rapidly evolving into routine practice, clinical laboratories face several challenges, including presence of small amounts of viral nucleic acids in abundant levels of genomic DNA and total RNA, processing of various sample types, and carry-over of polymerase chain reaction inhibitors, which could significantly affect polymerase chain reaction and microarray results. MagaZorb nucleic acid isolation technology overcomes these challenges and offers a simple and reliable method for isolation of high-quality and high-yield nucleic acids. Although the MagaZorb technology is readily adaptable to automated platforms, it is also well suited to laboratories in remote areas of resource-poor countries, because a simple magnet is the only device required to perform the procedure manually. Performance characteristics and clinical application of the MagaZorb technology are briefly described here.

Dried tube specimens: a simple and cost-effective method for preparation of HIV proficiency testing panels and quality control materials for use in resource-limited settings

HIV testing has rapidly expanded worldwide, but proficiency testing (PT) programs to monitor and improve the quality of testing are often lacking in resource-limited settings (RLS). Traditional PT programs and quality control reagents use serum or plasma specimens requiring stringent conditions for storage and transportation. A novel, simple and easy to use approach, based on dried tube specimens (DTS), was developed that can help monitor the quality of HIV antibody testing in RLS. DTS were prepared by drying 20 microl of specimen overnight at room temperature. The addition of a green dye (0.1%) made the DTS pellets visible without affecting the test results. Before testing, the DTS were rehydrated with 200 microl of PBS-Tween buffer. A panel of 303 DTS samples (135 HIV positive and 168 HIV negative) was evaluated with two rapid tests. Sensitivity and specificity with the Determine HIV-1/2 test were 99.3% and 99.4%, respectively, and with OraQuick were 98.5% and 100%, respectively. Stability studies showed that HIV-specific antibodies in the DTS specimens were stable at 4 degrees C and 25 degrees C for 4 weeks, with only marginal decline at 37 degrees C and 45 degrees C over 4 weeks. The DTS-based PT program was piloted successfully in 24 testing sites in Kenya. Results demonstrate that the DTS is a simple to use, practical method to prepare and distribute PT panels and quality control specimens to monitor HIV testing practices in RLS.

Dried blood spots for the diagnosis and quantitation of HIV-1: stability studies and evaluation of sensitivity and specificity for the diagnosis of infant HIV-1 infection in Thailand

Molecular methods for HIV-1 infection using dried blood-spot (DBS) for HIV-1 CRF01_AE subtypes have not been fully optimized. In this study assays for HIV-1 diagnosis or quantitation were evaluated using infant DBS from Thailand. Paired DBS and whole blood samples from 56 HIV-1 CRF01_AE or B'-infected infants were tested for infant diagnosis using modified Amplicor DNA PCR and NucliSens RNA NASBA and an in-house real-time PCR assay. The Amplicor Monitor viral load (VL) assay, with modifications for DBS, was also evaluated. DBS VL were hematocrit corrected. Stability studies were done on DBS stored at -70 degrees C to 37 degrees C for up to 1 year. The DBS diagnostic assays were 96-100% sensitive and 100% specific for HIV-1 diagnosis. DBS HIV-1 VL were highly correlated with plasma VL when corrected using the actual or an assumed hematocrit factor (r(c)=0.88 or 0.93, respectively). HIV-1 DNA in DBS appeared to be more stable than RNA and could be detected after up to 9 months at most temperatures. DBS VL could be consistently determined when stored frozen. These results show that DBS can be used accurately instead of whole blood for the diagnosis of HIV-1 infection and VL quantitation, particularly if samples are appropriately stored.

Alternative algorithms for human immunodeficiency virus infection diagnosis using tests that are licensed in the United States

Serodiagnosis of human immunodeficiency virus (HIV) infection in the United States has traditionally relied on a sequential two-test algorithm: an initial screen with an enzyme immunoassay (EIA) and reflex testing of EIA-reactive specimens with a more specific supplemental test such as Western blotting or immunofluorescence. The supplemental tests are tedious, subjective, and expensive. In addition, there have been major improvements in the performance and accuracy of the EIA tests as well as the introduction of rapid serologic tests (RT) and HIV nucleic acid amplification tests (NAAT). Related to these improvements is the possibility that alternative algorithms using combinations of currently approved HIV tests may function as well as if not better than the current algorithm, with more flexibility, improved accuracy, and lower cost. To this end, we evaluated the performance of 12 currently licensed tests and 1 in-house HIV test (6 EIA, 4 RT, and 3 NAAT) on panels of plasma samples from HIV-infected (n = 621 HIV type 1 [HIV-1] and 34 HIV-2) and uninfected (n = 513) people and of sequential specimens from people early in seroconversion (183 specimens from 15 patients). Test combinations were analyzed in two dual-test (sensitivity-optimized and specificity-optimized) algorithms and in a three-test (tie-breaking) algorithm, and performance was compared to the conventional algorithm. The results indicate that alternative algorithm strategies with currently licensed tests compare favorably with the conventional algorithm in detecting and confirming established HIV infection. Furthermore, there was a lower frequency of discordant or indeterminate results that require follow-up testing, and there was improved detection of early infection.

Human herpesvirus 8 presence and viral load are associated with the progression of AIDS-associated Kaposi's sarcoma

OBJECTIVE

We present the largest longitudinal study to date that examines the association between Kaposi's Sarcoma (KS) disease progression and the presence and viral load of human herpesvirus 8 (HHV-8).

METHODS

Ninety-six men were enrolled at HIV clinics in Atlanta, Georgia, who had KS (n = 47) or were without KS but seropositive for HHV-8. Visits occurred at 6-month intervals for 2 years at which the patient's KS status was evaluated and oral fluid and blood were collected for quantification of HHV-8 DNA and antibodies.

RESULTS

The presence of HHV-8 DNA in blood was more common (P < 0.001) and the viral load higher (P < 0.001) in men with KS in comparison with men without KS. Mean HHV-8 viral loads in blood and oral fluids were associated with disease status, being highest among patients with progressing KS, intermediate among patients with stable KS, and lowest among patients with regressing KS. Consistent with our previous report high antibody titers to HHV-8 orf 65 were inversely associated with HHV-8 shedding in oral fluid.

CONCLUSIONS

We observed a significant association between changes in KS disease severity and the presence and viral load of HHV-8. HHV-8 viral load in blood may provide useful information to clinicians for assessment of the risk of further disease progression in patients with KS.

Identification of HIV-1 infected infants and young children using real-time RT PCR and dried blood spots from Uganda and Cameroon

Serodiagnosis of HIV infection in infants born to HIV-infected mothers is problematic due to the prolonged presence of maternal antibodies in infants. Nucleic acid-based amplification assays have been used to overcome this problem. Here a simplified, one-tube, real-time, duplex reverse transcription PCR (RT PCR) assay is shown to detect HIV-1 total nucleic acid (TNA) isolated from dried blood spots. The detection of TNA, as opposed to DNA alone, increases the HIV target molecules and thus makes the assay more robust. This method was used to detect HIV from the DBS collected from HIV-1 exposed infants and young children in Uganda (n=128) and Cameroon (n=315). The gold-standards used were a plasma viral assay in Uganda and Amplicor DNA assay in Cameroon. The concordance of this real-time assay and the gold standards was 99.2% (127/128) and 99.4% (313/315) with the Ugandan and Cameroonian samples, respectively. This simple and cost-effective assay is potentially useful for the diagnosis of pediatric HIV infection and for evaluating programs to reduce mother-to-child transmission of HIV-1.

Detection of human immunodeficiency virus type 1 DNA in dried blood spots by a duplex real-time PCR assay

A dried blood spot (DBS) is a well-accepted means for the collection, transport, and storage of blood samples for various epidemiologic, serologic, and molecular assays for human immunodeficiency virus (HIV) studies. It is particularly important for mother-to-infant-transmission studies of affected individuals living in remote areas. We have developed a real-time PCR method to detect HIV type 1 (HIV-1) DNA in dried blood spots. A cellular gene, RNase P, was coamplified with the HIV-1 DNA in the same tube to monitor the DNA extraction efficiency and the overall assay performance. Our assay is a one-tube, single-step closed-system assay and uses a dUTP/uracil DNA glycosidase anti-PCR contamination control. The HIV-1 primers and probe were derived from a conserved region of the long terminal repeat. The detection of RNase P is attenuated by lowering the forward and reverse primer concentrations so that its amplification will not overwhelm the HIV-1 amplification and yet will provide a semiquantitative measurement of the quality of the isolated DBS DNA. We examined 103 HIV-1-seropositive and 56 seronegative U.S. adults and found that our assay has a sensitivity of 98.1% (95% confidence interval [CI], 95.5% to 100%) and specificity of 100% (95% CI, 99% to 100%). The positive and negative predictive values are 100% and 96.6%, respectively. This duplex PCR assay may be useful in identifying HIV-1-infected persons, particularly infants born to seropositive mothers in remote areas of the world.

Evidence for both lytic replication and tightly regulated human herpesvirus 8 latency in circulating mononuclear cells, with virus loads frequently below common thresholds of detection

To address whether human herpesvirus 8 (HHV-8) DNA in peripheral blood mononuclear cells (PBMCs) might be the product of latent or lytic infection and to shed light on sporadic detection of HHV-8 DNA in individuals seropositive for the virus, we studied the frequency of infected cells, total virus load, and virus load per infected cell in PBMCs from men coinfected with HHV-8 and human immunodeficiency virus (HIV), some of whom had Kaposi's sarcoma. The low frequencies of infected cells detected (fewer than one per million cells in some individuals) suggest that the prevalence of the virus in circulating leukocytes was underestimated in previous studies that employed more conventional sampling methods (single, small-volume specimens). Mean virus loads ranged from 3 to 330 copies per infected PBMC; these numbers can represent much higher loads in individual lytically infected cells (>10(3) genomes/cell) in mixtures that consist predominantly of latently (relatively few genomes) infected cells. The presence in some subjects of high HHV-8 mean genome copy numbers per infected cell, together with viral DNA being found in plasma only from subjects with positive PBMCs, supports earlier suggestions that the virus can actively replicate in PBMCs. In some individuals, mean virus loads were less than 10 genomes per infected cell, suggesting a tightly controlled purely latent state. HHV-8 genome copy numbers are substantially higher in latently infected cells derived from primary effusion lymphomas; thus, it appears that HHV-8 is able to adopt more than one latency program, perhaps analogous to the several types of Epstein-Barr virus latency.

Waveforms of the ductus venosus blood flow in normal human fetuses aged 8-38 weeks

BACKGROUND

We attempted to establish normal Doppler flow velocity waveform patterns in the human fetal ductus venosus (DV), and also to establish a standardized measurement technique.

METHODS

Ductus venosus blood flow was measured in a prospective study involving 545 fetuses aged between 8 and 38 weeks in utero, the mothers of whom received prenatal care in Kaohsiung Chang Gung Memorial Hospital in a 12-month period in 1998-1999. Several DV hemodynamic parameters were assessed, including peak systolic velocity (DVP), peak systolic/diastolic (S/D) ratio, time-averaged velocity (TAMX), maximum velocity during atrial contraction (DVM), pulsatility index (PI), Pourcelot's resistance index (RI), and fetal heartbeat (FHB).

RESULTS

Technically acceptable ductus venosus blood flow velocity waveform patterns were collected from 490 of 545 pregnant women (89.9%). The mean +/- SD value for the peak systolic DV velocity during the time period of 8 to 38 weeks in utero was 0.33 +/- 0.11 meters/sec (m/s), the TAMX being 0.24 +/- 0.09 m/s. The maximum velocity during atrial contraction was 0.15 +/- 0.09 m/s, and the peak S/D velocity ratio was 2.5 +/- 1.01. The PI, Pourcelot's RI and fetal heart beat were, 0.67(+/- 0.21), 0.64 (+/- 0.11), and 163.3 (+/- 18.82 bpm), respectively. Significant increases in DVP, TAMX, and DVM with advancing gestational age were established, and decreases in PI, RI, S/D, and FHB with advancing gestational age were also observed.

CONCLUSIONS

Further investigation of DV hemodynamics throughout pregnancy may enable a greater understanding of normal placental perfusion, the fetal venous return to the heart and associated cardiac function.

Prenatal sonographic appearance of Beare-Stevenson cutis gyrata syndrome: two- and three-dimensional ultrasonographic findings

Beare-Stevenson cutis gyrata syndrome is characterized by craniofacial anomalies, particularly craniosynostosis, ear defects, cutis gyrata, acanthosis nigricans, anogenit anomalies, skin tags, and prominent umbilical stump. The prenatal two- and three-dimensional ultrasonographic findings of this rare condition is reported. The detection was made at 32 weeks of gestation in a woman with polyhydramnios and fetal head anomaly. The ultrasound appearance and postnatal follow-up are presented.

First trimester diagnosis of holoprosencephaly and cyclopia with triploidy by transvaginal three-dimensional ultrasonography

We present the prenatal three-dimensional (3D) ultrasound findings in a case of holoprosencephaly and cyclopia at 11 weeks gestation. Only holoprosencephaly with missing cyclopia were initially diagnosed because suboptimal views of the fetal face were obtained with transvaginal two-dimensional (2D) ultrasonography due to fetal position. Chromosomes identified by analysis of a fluid sample from early amniocentesis demonstrated a triploidy (69, XXX), spontaneous fetal demise occurred at 12 weeks and the pregnancy was terminated. This case demonstrated the usefulness of transvaginal 3D ultrasonography in establishing the final diagnosis.

Maternal serum screening for down syndrome in pregnancies conceived by intra-uterine insemination

The purpose of our study was to assess the influence of intra-uterine insemination (IUI) on the results of maternal serum Down syndrome screening. 43 women with IUI pregnancies and 4507 healthy women who conceived were studied. Ovulation in IUI pregnancies was induced by clomiphene and/or human menopausal gonadotrophin (hMG). Maternal serum levels of free beta-human chorionic gonadotrophin (hCG) and alpha-fetoprotein (AFP) were measured for Down syndrome screening. It was considered screen-positive when the risk of Down syndrome was 1 in 270 or greater in the second trimester. The value of maternal serum AFP was significantly lower in the IUI group (median=0.760 MoM) than in the control group (median=1.050 MoM). However, the value of free beta-hCG was not significantly different between the two groups. The positive rate of maternal serum Down syndrome in IUI pregnancies was similar to that of the control group. Our results indicate that IUI pregnancy may be associated with a lower level of AFP, although the mechanism for this difference remains unknown.

Prenatal diagnosis of trisomy 20 mosaicism by maternal serum screening for Down syndrome

We report two cases of prenatally diagnosed trisomy 20 mosaicism associated with positive Down syndrome screening at 16 weeks' gestation. Both infants exhibited normal growth and mental development. These cases suggest that the multiple-marker screening test may play an important role in prenatal detection and diagnosis of chromosomal anomalies in addition to Down syndrome.

Retinal detachment in postpartum preeclampsia and eclampsia: report of two cases

Retinal detachment is an unusual complication of hypertensive disorder in pregnancy. It has been reported in 1% to 2% of patients with severe preeclampsia and in 10% of patients with eclampsia. Choroidal ischemia may be the cause of retinal detachment. We know that mild arteriolar spasm involving the bulbar conjunctival vessels has been observed in the normal pregnancy, but in pregnancy-induced hypertension the vasospasm may be severe and result in choroidal ischemia. Most patients with retinal detachment in pregnancy-induced hypertension have had full spontaneous resolution within a few weeks, and they did not have any sequelae. Medical treatment with antihypertensive drugs and steroids may be helpful. We report two rare cases of retinal detachment and persistent hypertension in association with postpartum eclampsia and post-cesarean section preeclampsia. These patients had normotension throughout pregnancy. Preeclampsia or eclampsia developed after delivery, and blurred vision, headache, and reduced vision accompanied serous retinal detachment. The serous retinal detachment disappeared within 3 weeks. Good outcomes were found in the follow-up examinations in both of these cases. For women who had been normotensive at the time of delivery and then complained in the postpartum period of blurred vision, headaches, nausea and vomiting, we should consider the possibility of retinal detachment and perform fundoscopy.

Population-based screening for hemochromatosis using phenotypic and DNA testing among employees of health maintenance organizations in Springfield, Missouri

BACKGROUND

Hemochromatosis reportedly affects 3 to 8 persons per 1,000 and is associated with an elevated risk of morbidity and mortality. We sought to ascertain its prevalence in a community and to assess the association between phenotype and genotype.

METHODS

All health maintenance organization employees were invited to participate in hemochromatosis screening using a repeated elevation of the transferrin saturation test as the case definition (> or = 50% in women and > or = 60% in men with no other cause). Iron overload from hemochromatosis was defined as serum ferritin concentration > or = 95th percentile and mobilizable iron > or = 99th percentile for age and sex, or hepatic iron index > or = 1.9. The HFE gene was analyzed for mutations.

RESULTS

Participation among employees was 28% (1,653 of 6,000); 83% were women. The prevalence of hemochromatosis was 8 per 1,000 (13 of 1,653), and the prevalence of iron overload from hemochromatosis was 4 per 1,000 (5 of 1,653). Compared with those who had no HFE mutation, the relative risk (RR) for hemochromatosis was greatest for C282Y homozygotes (RR = 147), compound heterozygotes (RR = 19), and H63D homozygotes (RR = 9). Overall, 38% of participants had at least one HFE mutation. Screening based on an initial elevated transferrin saturation test had the best sensitivity, whereas DNA testing offered the best specificity and predictive value positive for iron overload disease.

CONCLUSIONS

In this population, we found a greater than expected prevalence of hemochromatosis and demonstrated a clear association with the HFE genotype. Promotion of screening is complicated by controversies in case definition and the large number of persons who will be detected before they have clinically significant iron loading, in whom the risk of clinical disease is unknown. Larger screening studies in more diverse populations are necessary to characterize the burden of disease and to follow those at risk (based on HFE or iron status measures) to establish the natural history of hemochromatosis.

Prenatal diagnosis of de novo interstitial deletion of proximal 4q by maternal serum screening for Down syndrome

Deletion of the proximal portion of chromosome 4q is apparently rare. To our knowledge, prenatal diagnosis of the interstitial deletion of 4q12-21.1 has never been reported. We present a prenatal case of 4q deletion in association with a positive Down syndrome screening test of an elevated maternal serum free beta human chorionic gonadotrophin (beta-hCG) level. The prenatal sonogram revealed intra-uterine growth retardation (IUGR) and shortening of the femur. Facial dysmorphism included micrognathia, depressed nasal bridge and low-set ears, these anomalies were evident at the postnatal examination. All of the anomalies were consistent with those described in proximal 4q deletion syndrome. Our case suggests that chromosome studies may be indicated for patients with high maternal serum free beta-hCG and IUGR in the early second trimester.

Thermolabile methylenetetrahydrofolate reductase polymorphism (C677T) and total homocysteine concentration among African-American and white women

A polymorphism associated with a thermolabile variant (C677T) of the enzyme methylenetetrahydrofolate reductase has been associated with both elevated total homocysteine (tHcy) levels and risk for cardiovascular disease. Data from the Stroke Prevention in Young Women Study were used to determine the prevalence of the C677T genotype and to assess whether environmental factors modified the association between genotype and tHcy concentration. The C677T genotype prevalence was 80% -/-, 20% +/-, and 0% +/+ among 46 African-American women; and 39% -/-, 53% +/-, and 8% +/+ among 77 white women (P < 0.01). There was a trend toward higher tHcy levels in African-American women with the +/- genotype when compared with the -/- genotype (6.9 mumol/L vs 5.3 mumol/L respectively, p = 0.10); no association was found among the white women (6.0 mumol/L, -/-; 4.5 mumol/L, +/-; and 6.2 mumol/L, +/+; p = 0.67). Among African American women, those who smoked and were +/- genotype had the highest tHcy levels (8.0 mumol/L); while among white women, those who smoked and were -/- had the highest tHcy levels (8.1 mumol/L). Despite being hampered by a limited sample size, the thermolabile allele is significantly less common among African-American than white women. The association between genotype and tHcy concentration is influenced by smoking and multivitamin use.

Platelet glycoprotein receptor IIIa polymorphism P1A2 and ischemic stroke risk: the Stroke Prevention in Young Women Study

BACKGROUND AND PURPOSE

Platelet glycoprotein IIb/IIa (GpIIb-IIIa), a membrane receptor for fibrinogen and von Willebrand factor, has been implicated in the pathogenesis of acute coronary syndromes but has not been previously investigated in relation to stroke in young adults.

METHODS

We used a population-based case-control design to examine the association of the GpIIIa polymorphism P1A2 with stroke in young women. Subjects were 65 cerebral infarction cases (18 patients with and 47 without an identified probable etiology) 15 to 44 years of age from the Baltimore-Washington region and 122 controls frequency matched by age from the same geographic area. A face-to-face interview for vascular disease risk factors and a blood sample for the P1A2 allele and serum cholesterol were obtained from each participant. Logistic regression was used to estimate the odds ratio for one or more P1A2 alleles after adjustment for other risk factors.

RESULTS

Among cases and controls, the prevalence rates of one or more P1A2 alleles were 21% and 22% among blacks and 36% and 28% among whites, respectively. This genotype was significantly associated with hypertension only in black control subjects but otherwise not with any of the established vascular risk factors. The adjusted odds ratio for cerebral infarction of one or more P1A2 alleles was 1.1 (confidence interval [CI], 0.6 to 2.3) overall, 0.5 (CI, 0.1 to 7.1) among blacks, and 1.4 (CI, 0.5 to 3.7) among whites. For the cases with an identified probable etiology, the corresponding odds ratios were 3.0 (CI, 0.9 to 10.4) overall, 0.7 (CI, 0.1 to 7.1) among blacks, and 12.8 (CI, 1.2 to 135.0) among whites.

CONCLUSIONS

No association was found between the P1A2 polymorphism of GpIIIa and young women with stroke. However, subgroup analyses showed that the P1A2 polymorphism of GpIIIa appeared to be associated with stroke risk among white women, particularly those with a clinically identified probable etiology for their stroke. Further work with an emphasis on stroke subtypes and with multiracial populations is warranted.

Partial trisomy 13 [46,XY,dup(13)(q14-31)]: a case report

We report a fetus with partial trisomy 13 [46,XY,dup(13)(q14-31)] which was found during an amniocentesis performed due to the age of the mother. This duplication segment (13q 14-31) has not been reported in literature. The clinical features of our patient included cleft lip/palate, low set ears, depressed nasal bridge, hypertelorism, and epicanthal fold. After termination of the pregnancy, the fetus was sent for an autopsy. The autopsy report was compatible with the gross findings and no other abnormalities, including central nervous, cardiac, and renal system, were found. The level of maternal alpha-fetoprotein, 2.67 MoM, was opposite with the common phenomenon in complete trisomy 13.

Correlation between genotype and phenotype in hereditary hemochromatosis: analysis of 61 cases

This report assesses the degree of iron overload in a cohort of patients in relationship to the presence or absence of the recently described 845 G-->A (C282Y) and 187 C-->G (H63D) mutations in the HFE (HLA-H) gene. Sixty-one patients with hereditary hemochromatosis diagnosed either with liver biopsy or on clinical grounds were included in this analysis. Forty-one patients were homozygous for C282Y, the genotype considered to be characteristic of hereditary hemochromatosis. At the time of this analysis, 37 of these 41 patients had achieved a state of iron depletion and mobilizable iron was calculated: 19 had less than 4 grams. Twenty-five of these 41 patients had liver biopsies; 4 of these patients had a hepatic iron index less than 1.9. Of the 4 patients with a normal hepatic iron index, 3 had a quantitative hepatic iron of greater than 50 micromol/g dry weight, and one had an inadequate biopsy sample. These findings support our suspicion that individuals may have hereditary hemochromatosis and homozygous C282Y despite relatively low body iron stores. Five patients were compound heterozygotes for C282Y and H63D. Four of these patients underwent liver biopsy; two had a hepatic iron index greater than 1.9. a third patient had a hepatic iron index of 1.3 but a quantitative hepatic iron of 90.6 micromol/g dry weight. All patients were phlebotomized to a state of iron depletion and only one of these patients had a mobilizable iron greater than 4 grams. Three patients were homozygous for H63D; these patients had either a hepatic iron index >1.9 or greater than 4 grams of mobilizable iron. Patients with homozygous H63D and significant iron overload are not well described. Seven patients were heterozygous for either C282Y or H63D; 4 had significant iron overload but three did not. Five patients had no HFE mutations; one of these patients unequivocally has iron overload with a hepatic iron index of 4.4 We conclude that: (1) Identification of HFE mutations will be clinically useful in identifying patients with hereditary hemochromatosis, (2) Patient genotyping will help confirm a diagnosis of hereditary hemochromatosis in some patients with relatively low body iron stores, (3) Significant iron loading can occur in the absence of homozygous C282Y, adding to the evidence that genes other than HFE may be involved in iron loading, and (4) Homozygous H63D can be associated with significant iron overload.

Diagnosis of perinatal human immunodeficiency virus infection by polymerase chain reaction and p24 antigen detection after immune complex dissociation in an urban community hospital

Results of polymerase chain reaction (PCR) and p24 antigen detection after immune complex dissociation (p24-ICD) were compared with antibody results after 18 months of age for human immunodeficiency virus (HIV) diagnosis in 345 prospectively followed, perinatally exposed infants. Of 59 infected and 286 uninfected infants tested at 1-6 months of age, sensitivity and specificity were, respectively, 100% and > 97% for PCR and 90% and > 97% for p24-ICD. Testing was done on > or = 2 occasions in the first 6 months of life in 43 infected infants; 77% had > or = 2 positive results with the same test. Of these infants, 68% had 2 positive p24-ICD tests. In uninfected infants, 96% had only negative tests; none had > 1 positive. By 6 months, all uninfected infants with > or = 2 PCR results could have been diagnosed. HIV status can be determined by PCR by age 6 months in most HIV-exposed infants. p24-ICD should not be used alone, because of its lower sensitivity, but may be useful in areas without advanced laboratory support.

Late postnatal mother-to-child transmission of HIV-1 in Abidjan, Côte d'Ivoire

BACKGROUND

HIV-1 can be transmitted from an infected mother to her infant through breastfeeding, although the precise risk of transmission by this route is unknown. A long-term follow-up of children born to HIV-infected women in Abidjan, Côte d'Ivoire, has enabled us to estimate this risk.

METHODS

Children born to 138 HIV-1-seropositive women, 132 HIV-2-seropositive women, 69 women seroreactive to both HIV-1 and HIV-2, and 274 HIV-seronegative women were enrolled at birth and followed up for as long as 48 months. All children were breastfed (median duration 20 months). Blood samples for either or both HIV PCR and HIV serology were obtained at 1, 2, and 3 months of age, and every 3 months thereafter. Early HIV infection was defined as a positive HIV-1 PCR result obtained in the first 6 months of life. Late postnatal transmission was diagnosed when a child had a negative PCR at 3 or 6 months of age, followed by either or both a positive HIV-1 PCR at 9 months or older, or persistently positive HIV-1 serology at 15 months or older.

FINDINGS

82 children born to HIV-1-seropositive mothers and 57 children born to mothers seropositive for both HIV-1 and HIV-2 had PCR results for samples taken within the first 6 months. By 6 months of age, 23 (28%; 95% CI 19-39) of the 82 children born to HIV-1-seropositive mothers and ten (18%; 95% CI 9-30) of the 57 children born to dually seropositive mothers were HIV-1 infected. Among children whose PCR results were negative at or before age 6 months, and who were followed up beyond 6 months, an additional four (9%) of the 45 children born to HIV-1-seropositive mothers and two (5%) of the 39 children born to dually seropositive mothers became HIV infected. The estimated rates of late postnatal transmission, with account taken of loss to follow-up and the observed pattern of weaning, were 12% (95% CI 3-23) and 6% (0-14), respectively. One of the five children whose mothers seroconverted from HIV-negative to HIV-1, and one of seven children whose mothers seroconverted from HIV-2 to dual reactivity, became HIV-1 positive. No case of late postnatal transmission occurred in children born to HIV-2-positive or persistently HIV-negative mothers.

INTERPRETATION

Breastfed children born to mothers seropositive for HIV-1 alone or seropositive for HIV-1 and HIV-2 in Abidjan are at substantial risk of late postnatal transmission. Early cessation of breastfeeding at 6 months of age should be assessed as a possible intervention to reduce postnatal transmission of HIV.

Detection of HIV type 1 env subtypes A, B, C, and E in Asia using dried blood spots: a new surveillance tool for molecular epidemiology

Global surveillance of HIV-1 subtypes for genetic characterization is hampered by the biohazard of processing and the difficulties of shipping whole blood or cells from many developing country regions. We developed a technique for the direct automated sequencing of viral DNA from dried blood spot (DBS) specimens collected on absorbent paper, which can be mailed unrefrigerated in sturdy paper envelopes with low biohazard risk. DBS were collected nonrandomly from HIV-1-infected, mostly asymptomatic, patients in five Asian countries in 1991, and shipped via airmail or hand carried without refrigeration to Bangkok, and then transshipped to North America for processing. After more than 2 years of storage, including 6 months at ambient temperatures, proviral DNA in the DBS was amplified by nested PCR, and a 389-nucleotide segment of the C2-V3 env gene region was sequenced, from which 287 base pairs were aligned and subtyped by phylogenetic analysis with neighbor-joining and other methods. From southern India, there were 25 infections with subtype C and 2 with subtype A. From Myanmar (Burma), we identified the first subtype E infection, as well as six subtype BB, a distinct cluster within subtype B that was first discovered in Thailand and that has now appeared in China, Malaysia, and Japan. From southwest China, one BB was identified, while a "classical" B typical of North American and European strains was found in Indonesia. From Thailand, five DBS of ambiguous serotype were identified as three B, one BB, and one E. A blinded control serotype E specimen was correctly identified, but a serotype BB control was not tested. Most HIV-1 in southern India appears to be env subtype C, with rare A, as others have reported in western and northern India. The subtypes BB and E in Myanmar, and the BB in China, suggest epidemiological linkage with these subtypes in neighboring Thailand. DBS are a practical, economical technique for conducting large-scale molecular epidemiological surveillance to track the global distribution and spread of HIV-1 variants.

Estimating the timing of mother-to-child transmission of human immunodeficiency virus in a breast-feeding population in Kinshasa, Zaire

Breast-fed infants born to human immunodeficiency virus (HIV)-infected mothers in Kinshasa, Zaire, were monitored a mean of 18 months. HIV infection in infants was determined by polymerase chain reaction (PCR), HIV culture, or ELISA. PCR test results for HIV DNA on venous blood drawn from children ages 0-2 days and 3-5 months were used to estimate proportions of mother-to-child transmission and transmission risks during the intrauterine, intrapartum/early postpartum, and late postpartum periods. Among 69 HIV-infected children (26% of the cohort), 23% (95% confidence interval [CI], 14%-35%) were estimated to have had intrauterine, 65% (CI, 53%-76%) intrapartum/early postpartum, and 12% (CI, 5%-22%) late postpartum transmission. The estimated risks for intrauterine, intrapartum/early postpartum, and late postpartum infection, respectively, were 6% (16/261; CI, 4%-10%), 18% (45/245; CI, 14%-24%), and 4% (8/189; CI, 2%-8%). These results support earlier studies indicating that most transmission occurs during labor and delivery or in the early postpartum period and that the risk of HIV transmission through breast-feeding during the postpartum period is substantial.

5,10 Methylenetetrahydrofolate reductase genetic polymorphism as a risk factor for neural tube defects

Persons with a thermolabile form of the enzyme 5,10 methylenetetrahydrofolate reductase (MTHFR) have reduced enzyme activity and increased plasma homocysteine which can be lowered by supplemental folic acid. Thermolability of the enzyme has recently been shown to be caused by a common mutation (677C-->T) in the MTHFR gene. We studied 41 fibroblast cultures from NTD-affected fetuses and compared their genotypes with those of 109 blood specimens from individuals in the general population. 677C-->T homozygosity was associated with a 7.2 fold increased risk for NTDs (95% confidence interval: 1.8-30.3; p value: 0.001). These preliminary data suggest that the 677C-->T polymorphism of the MTHFR gene is a risk factor for spina bifida and anencephaly that may provide a partial biologic explanation for why folic acid prevents these types of NTD.

Dried blood spots collected on filter paper: an international resource for the diagnosis and genetic characterization of human immunodeficiency virus type-1

The collection of dried blood spots (DBS) on filter paper provides a powerful approach for the development of large-scale, population-based screening programs. DBS methods are particularly valuable in developing countries and isolated rural regions where resources are limited. Large numbers of field specimens can be economically collected and shipped to centralized reference laboratories for genetic and (or) serological analysis. Alternatively, the dried blood can be stored and used as an archival resource to rapidly establish the frequency and distribution of newly recognized mutations, confirm patient identity or track the origins and emergence of newly identified pathogens. In this report, we describe how PCR-based technologies are beginning to interface with international screening programmes for the diagnosis and genetic characterization of human immunodeficiency virus type 1 (HIV-1). In particular, we review recent progress using DBS specimens to resolve the HIV-1 infection status of neonates, monitor the genetic evolution of HIV-1 during early infancy and establish a sentinel surveillance system for the systematic monitoring of HIV-1 genetic variation in Asia.

A prospective population-based study of HIV perinatal transmission

OBJECTIVE

To estimate the perinatal HIV transmission rate and describe the natural history of infant HIV infection in a situation in which HIV status is known in more than 95% of delivering women.

DESIGN

A cohort of HIV-exposed infants born between 7 July 1987 and 30 June 1990, whose mothers were identified by routine voluntary universal HIV testing, were followed using clinical and laboratory measures.

SETTING

Grady Memorial Hospital, a major health-care site for individuals of lower socioeconomic status in Atlanta, Georgia, USA, with approximately 7000 deliveries per year.

PATIENTS

HIV-exposed infants (n = 165), 98% of whom were African American.

RESULTS

Annual maternal HIV seroprevalence increased from 0.58 to 0.86%. The annual proportion of HIV-positive women having a second delivery increased from 4.3 to 25%. Clinical outcome was known for 132 out of 165 infants (22 infected and 110 uninfected), the transmission rate was 17% (confidence interval, 11-24%). The rate declined to 11% by the third year of the study. Gestational growth, prematurity and mode of delivery were unrelated to infant outcome. There was a trend for intravenous drug use to be more common in mothers of infected infants (P = 0.08). After 35 months median follow-up of infected infants, eight out of 22 (36%) had an opportunistic infection (seven Pneumocystis carinii pneumonia); three out of 22 (14%) had lymphocytic interstitial pneumonia, and 10 out of 22 (45%) were asymptomatic or had only nonspecific symptoms. Cumulative mortality in infected infants was 9, 32 and 32% by 1, 2 and 3 years of age, respectively.

CONCLUSION

In this cohort of HIV-exposed infants, perinatal HIV transmission was 17% overall. Factors affecting the transmission rate and possible future changes in the rate require further study.

Biological, serological, and genetic characterization of HIV-1 subtype E isolates from northern Thailand

Twenty-three HIV-1 isolates were recovered from PBMCs from 26 HIV-1-seropositive individuals in northern Thailand. The viruses grew readily in human PBMCs but only 7 of 17 (41.2%) and 5 of 17 (29.4%) replicated and only at a low level in primary macrophages and in established T cell lines, respectively. By immunoblot assays, sera from Thai subjects were strongly reactive with gp120 from a Thailand isolate, moderately reactive with a Rwandan isolate, and weakly reactive with a North American strain. These three viruses represent, respectively, examples of subtypes E, A, and B as classified by the sequences of the envelope region. Serological assays indicated that broadly reactive rather than type-specific neutralizing activity was detected among these northern Thai sera. The majority of the sera (approximately 75%) neutralized a representative Thailand isolate and the Rwanda isolate but only 55% neutralized the North American strain. However, the difference was not statistically significant. The genetic analyses indicated that nearly all the Thai isolates were highly homogeneous and distinct from the North American/European consensus sequence (subtype B); they belong to subtype E. This is the first report providing biological, serological, and genetic characterization of HIV-1 strains from Thailand. The findings suggest these viruses were recently introduced into the country and that serological evaluation of viral strains needs to be considered along with genetic subtyping when developing an HIV-1 vaccine.

Lack of association between anti-V3 loop antibody and perinatal HIV-1 transmission in Kinshasa, Zaire, despite use of assays based on local HIV-1 strains

Maternal antibodies against the V3 loop principal neutralizing domain (PND) have been reported to protect against perinatal HIV-1 transmission. To study this association in an African city with a long-standing HIV epidemic and no established "consensus sequence" for the V3 loop region of gp120, we determined the DNA sequence for the V3 region of HIV-1 from 13 HIV-1-infected residents of Kinshasa, Zaire, and developed peptide enzyme immunoassays (EIAs) reflecting the V3 loop PND for those HIV-1 strains. Using the most broadly reactive locally derived V3 loop peptide in a limited-antigen EIA, there was no significant difference in the perinatal HIV-1 transmission risk between 64 women with anti-V3 loop antibody (transmission risk, 30%) and 104 women without anti-V3 loop antibody (transmission risk, 25%; p = 0.5); this finding was unchanged after we controlled for maternal AIDS and low birth weight. Although we used assays for V3 loop antibody based on local HIV-1 strains and evaluated a large number of mother-child pairs, we found no evidence that maternal anti-V3 loop PND antibody protects against perinatal HIV-1 transmission.

Genetic diversity of human immunodeficiency virus type 1 strains in Kinshasa, Zaire

The envelope (env) gene of human immunodeficiency virus type 1 (HIV-1) was amplified by polymerase chain reaction (PCR) from the peripheral blood mononuclear cells (PBMCs) of 14 HIV-1-infected women from Kinshasa, Zaire. Amplified DNA was directly sequenced with a primer specific for the HIV-1 env C2 region. The predicted amino acid sequences for the C2-V3 region for the 14 specimens are presented. The tetrapeptide sequence, GPGQ, located at the crown of the V3 loop, is conserved in all specimens. The same tetrapeptide sequence is present in the Zairian isolate MAL, but not in other published Zairian isolates (Z6, ELI, Z321, JY1, and NDK). Sequence comparison of the env C2-V3 region among the 14 specimens from Kinshasa revealed a 9-25% range of nucleotide divergence, with an average of 16%. Divergence between the 14 specimens and the Zairian isolates MAL, Z6, ELI, Z321, JY1, and NDK ranged from 13 to 31%. A range of 18-28% nucleotide sequence divergence was demonstrated between the 14 Kinshasa specimens and the North American isolate MN. These results demonstrate the importance of examining HIV-1 samples from diverse geographic origins in the development of effective HIV-1 vaccines.