Treatment of dyskeratosis congenita with Granulocyte Colony-Stimulating Factor and Erythropoietin

Aplastic anaemia is both frequent and difficult to manage in patients with dyskeratosis congenita (DC). We recently treated a 23-year-old male for a year with granulocyte colony-stimulating factor (G-CSF) and erythropoietin (Ep), with an excellent neutrophil response, and a transient effect on haemoglobin levels. G-CSF alone or combined with other cytokines may provide at least a partial effect in pancytopenic patients with DC.     

Guidelines for laboratory testing and result reporting of antibody to hepatitis C virus. Centers for Disease Control and Prevention.

Testing for the presence of antibody to hepatitis C virus (anti-HCV) is recommended for initially identifying persons with hepatitis C virus (HCV) infection (CDC. Recommendations for prevention and control of hepatitis C virus [HCV] infection and HCV-related chronic disease. MMWR 1998;47[No. RR-19] :1-33). Testing for anti-HCV should include use of an antibody screening assay, and for screening test-positive results, a more specific supplemental assay. Verifying the presence of anti-HCV minimizes unnecessary medical visits and psychological harm for persons who test falsely positive by screening assays and ensures that counseling, medical referral, and evaluation are targeted for patients serologically confirmed as having been infected with HCV. However, substantial variation in reflex supplemental testing practices exists among laboratories, and an anti-HCV-positive laboratory report does not uniformly represent a confirmed positive result. These guidelines expand recommendations for anti-HCV testing to include an option for reflex supplemental testing based on screening-test-positive signal-to-cut-off (s/co) ratios. Use of s/co ratios minimizes the amount of supplemental testing that needs to be performed while improving the reliability of reported test results. These guidelines were developed on the basis of available knowledge of CDC staff in consultation with representatives from the Food and Drug Administration and public health, hospital, and independent laboratories. Adoption of these guidelines by all public and private laboratories that perform in vitro diagnostic anti-HCV testing will improve the accuracy and utility of reported anti-HCV test results for counseling and medical evaluation of patients by health-care professionals and for surveillance by public health departments.     

The immune response of healthy adults to a reduced dose of hepatitis B vaccine

Three hundred thirty-six medical personnel from hemodialysis centers were treated with three doses, 20 μg each, of the Merck hepatitis B vaccine (at 0, 1, and 6 months). Within 1 month after the first injection, 41% converted to anti-HBs positivity; after the second injection the conversion rate rose to 80–90%; and after the booster, to 96–98%. The later rate remained unchanged during the 18-month follow-up period. Only 2.8% of those vaccinated did not respond to the vaccine. The patterns of immune responses to 20-μg doses were found to be exactly the same as to 40-μg doses. It is suggested that reduced doses of vaccine should be as efficacious as the larger ones.     

The effect of caffeine ingestion on physical performance after prolonged exercise

Summary The purpose of this study was to determine the effect of caffeine ingestion on physical performance after prolonged endurance exercise. Twenty three trained male volunteers participated in a 40-km march and were divided into two groups, matched for caffeine clearance rate and aerobic capacity. The experimental group ingested, prior to the march, a caffeinated drink at a dose of 5 mg·kg⁻¹ body mass and at the 3rd and 5th h of marching an additional drink at a dose of 2.5 mg·kg⁻¹ body mass. The control group ingested a drink of equal volume at the same times. Upon termination of the march each subject performed a cycle ergometer test at an intensity of 90% maximal oxygen consumption. Time to exhaustion and rate of perceived exertion (RPE) were recorded. Blood samples were drawn predrink, at the 3rd and 5th h of marching and immediately after the cycle ergometer test, and were analysed for caffeine, free fatty acids (FFA), lactate and glucose levels. Plasma FFA levels increased during the march (p<0.05), with no significant difference between groups. Lactate levels increased in the experimental group (p<0.05), with no significant change in the control group. Glucose levels did not change significantly in either group. After the cycle ergometer test, lactate levels were significantly higher in the experimental, as compared to the control group (3.77±0.33 vs 2.52±0.35 mmol·l⁻¹, respectively). There was no significant difference between treatments in the time to exhaustion on the cycle ergometer, but RPE was different (p<0.05). Under the conditions of this study, the results do not indicate caffeine ingestion as an ergogenic aid which will postpone exhaustion following prolonged endurance exercise. This work was presented, in part, at the Canadian Association of Sports Sciences Annual Meeting, October 1987, Lake Louise, Alberta, Canada     

Prevalence of human immunodeficiency virus type 1 p24 antigen in U.S. blood donors--an assessment of the efficacy of testing in donor screening. The HIV-Antigen Study Group

BACKGROUND. We performed a multicenter study in 1989 to determine whether screening whole-blood donors for human immunodeficiency virus type 1 (HIV-1) p24 antigen would improve transfusion safety by identifying carriers of the virus who are seronegative for HIV-1 antibody. METHODS. More than 500,000 donations were tested at 13 U.S. blood centers with test kits from two manufacturers. Units found repeatedly reactive were retested in a central laboratory; if the results were positive, they were confirmed by a neutralization assay. A subgroup of units was also tested for HIV-1 by the polymerase chain reaction. Selected donors confirmed or not confirmed as having p24 antigen were contacted for follow-up interviews to identify risk factors and undergo retesting for HIV-1 markers. RESULTS. Positive tests for p24 antigen were confirmed by neutralization in five donors (0.001 percent of all donations tested), all of whom were also positive for HIV-1 antibody and HIV-1 by polymerase chain reaction. Three of the antigen-positive donors had other markers of infectious disease that would have resulted in the exclusion of their blood; two had risk factors for HIV-1 that should have led to self-exclusion. Of 220 blood units with repeatedly reactive p24 antigen whose presence could not be confirmed by neutralization (0.04 percent of the donations studied), none were positive for HIV-1 antibody, HIV-1 by polymerase chain reaction (120 units tested), or virus culture (76 units tested)--attesting to the specificity of confirmatory neutralization. CONCLUSIONS. The finding that no donation studied was positive for p24 antigen and negative for HIV-1 antibody suggests that screening donors for p24 antigen with tests of the current level of sensitivity would not add substantially to the safety of the U.S. blood supply.     

Histocompatibility Determinants in Israeli Jewish Patients with Multiple Sclerosis

The distribution of 24 HLA antigens of the A and B loci was investigated in 197 Israeli Jewish patients with multiple sclerosis (MS) from various Jewish ethnic origins including central and eastern Europe, countries bordering the Mediterranean, the Middle East and from native-born Israelis. The results were compared with the HLA antigen frequencies in a control sample of 455 unrelated individuals representing the general Jewish population. The frequency of HLA-Bw40 among all MS patients (15%) was significantly greater (P less than 0.001) than among the controls (7%). In contrast to the findings in MS patients from other populations, there was no increased frequency of A3 and B7 and Dw2 was present in only one out of 28 patients. The study showed a similar distribution of HLA-A and -B locus antigens, especially of Bw40, in Jews of diverse ethnic origins represented in the control group.     

Inheritance of idiopathic torsion dystonia among Jews.

Idiopathic torsion dystonia (ITD) has long been considered to be genetically determined, but the pattern of inheritance has been unclear. It has been suggested that inheritance may differ in Jews and non-Jews. In the present study, data gathered in a nationwide survey of ITD in Israel were analysed. Between 1969 and 1980, 47 patients were collected, of whom 40 were of European origin. In these European Jews, the ITD frequency was about 1:23 000 live births, which was five-fold greater than in Jews of Afro-Asian origin. Assuming that all cases fit the same genetic model, an X linked or a simple autosomal recessive model of inheritance did not agree well with our data. An autosomal dominant model with low penetrance could have accounted for our observations and would yield an ITD gene frequency in European Jews of 3 to 4:100 000. In view of the increased ages of their fathers, the isolated cases may have included some new mutations. Multifactorial inheritance was also possible. However, it may be inappropriate to assume that all cases have the same genetic basis, or even that all are inherited.     

Multiple sclerosis and childhood infections

Migration from an area where MS is common to an area where it is rare (and vice versa) affects the risk of MS, provided migration occurs in childhood. A childhood infection might explain this effect. Therefore, the age pattern of infectious diseases in different regions was examined. A higher proportion of children showed positive titers to many viral diseases early in life in areas where MS is rare compared with those where MS is common. Also, mortality rates from a variety of infectious diseases correlated negatively with the MS mortality. Thus, infection early in life may "protect" against MS, and conversely, later infection, when the immune system has partially matured, may increase risk. MS may be an age-dependent, host-immune response to childhood infection.     

Creutzfeldt-Jakob disease

There has been significant advance in our understanding of CJD and similar spongiform encephalopathies in recent years. The range in clinical expression of the disease is better appreciated, and the existence of "atypical" cases of CJD is increasingly recognized. New ideas about the possible modes of natural transmission have been derived from case-control studies in different parts of the world.