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J Säfwenberg

Publications and source records attributed to J Säfwenberg.

At least 19 recordsLinked to original sources
PubMed2004

Genetic heterogeneity at the glycosyltransferase loci underlying the GLOB blood group system and collection.

The aim of this study was to further explore the molecular genetic bases of the clinically important but rare blood group phenotypes p, P(1) (k) and P(2) (k) by analysis of the 4-alpha-galactosyltransferase (P(k)) and 3-beta-N-acetylgalactosaminyltransferase (P) genes responsible for synthesis of the related P(k) (Gb(3)) and P (Gb(4)) antigens respectively. Lack of these glycolipid moieties is associated with severe transfusion reactions and recurrent spontaneous abortions but also offers immunity against certain infectious agents. Blood samples from 20 p and 11 P(1) (k) or P(2) (k) individuals of different geographic and ethnic origin were investigated. DNA sequencing by capillary electrophoresis was performed following amplification of the coding regions in the P(k) or P genes. In the P(k) gene, nine novel and five previously described mutations were detected. One of the newly found mutations introduced an immediate stop, five shifted the reading frame introducing premature stop codons and three were missense mutations causing amino acid substitutions in conserved regions of the transferase. Four new and two previously described mutations in the P gene were found. Three of the novel alleles reported here carried nonsense mutations whilst the fourth allele had a missense mutation. The finding of 13 novel mutations in 14 alleles emphasizes further the genetic heterogeneity at the glycosyltransferase loci underlying the GLOB blood group system and collection.

Amino Acid Sequence↗
PubMed1997

Computerized delivery control--a useful and safe complement to the type and screen compatibility testing.

OBJECTIVES: Faster and less labor-intensive crossmatching procedures are needed, but they must be as safe as the traditional antiglobulin method. We present twelve years' experience with a procedure involving antibody screening, blood group checks, and computerized delivery control (ABCD test). METHODS: We use a computer for validation and printing documents and declaring compatibility between patient and blood component, based on screening results and earlier-recorded data about the patient. RESULTS: Of 257,400 units transfused during the period, 90% were declared compatible through the ABCD procedure, and 10% had to be crossmatched. We observed no hemolytic transfusion complications due to a failure of the procedure to detect red cell alloantibodies. Labor in the testing laboratory was reduced by 65% compared to a previous crossmatching period. Fewer blood units were returned unused. CONCLUSION: The procedure using a computerized system as a guard against human mistakes has been found to be safe and reliable and is now widely used in Sweden.

ABO Blood-Group System↗
PubMed1994

Obstetric implications of rhesus antigen distribution in Mozambican and Swedish women.

AB0 and Rhesus phenotypes were analyzed in 199 Mozambican women and the gene frequencies were calculated. The frequencies of the K and Fya antigens were also investigated. The findings were interpreted against the background of the corresponding phenotype distribution of a Swedish population. D- and Du-positive women amounted to 97.0%, which is significantly more than in Sweden (p < 0.001). Among AB0 groups it was found that blood group 0 is significantly more predominant in Mozambican than in Swedish women (p < 0.001). The reverse is true for blood group A (p < 0.001). Blood group B has a similar prevalence in Mozambican and Swedish women. The obstetric implication of the low prevalence of D-negative women is that the Rhesus alloimmunization problem may be of a much smaller magnitude than would be expected.

ABO Blood-Group System↗
PubMed1993

A simplified assay for the specific diagnosis of paroxysmal nocturnal hemoglobinuria: detection of DAF(CD55)- and HRF20(CD59)- erythrocytes in microtyping cards.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disease that is caused by a monoclonal stem cell defect. The affected cells lack the carbohydrate linkage between phosphatidylinositol and a group of membrane proteins of which three protect the cell against complement lysis. The absence of these three proteins, DAF(CD55), C8BP and HRF20(CD59), makes cells from the erythropoiesis, thrombopoiesis and myelopoiesis extensively sensitive to complement attack and affected patients suffer from intravascular hemolysis, thrombosis and increased susceptibility to infections. In this study we describe a swift and specific assay for the detection of CD55- and CD59- erythrocytes, which is suitable for screening of possible PNH patients.

Antigens, CD↗
PubMed1992

Parity-related prevalence of rhesus antigens among Mozambican parturients.

The potential risk of rhesus alloimmunization and the ensuing risk of fetal death with increasing parity were investigated in two groups of parturients; primiparous and grand multiparous (para > or = 5) women with liveborns. It was hypothesized that significantly fewer women of the latter than of the former group would be rhesus negative, since grand multiparity would be expected to be associated with an increased risk of late fetal death in rhesus-negative parturients. Primiparous (n = 390) and grand multiparous (n = 755) parturients with liveborns were studied in order to identify D- and Du-negative individuals. Sixteen out of 390 primiparas (4.10%) and 28/755 (3.71%) grand multiparas were D and Du negative. The difference did not reach statistical significance. It appears that being a D- and Du-negative grand multiparous parturient, in the absence of anti-D prophylaxis, is not a significant reproductive disadvantage to being primipara in terms of an increased risk of having stillborn babies.

ABO Blood-Group System↗
PubMed1992

Follow-up study of muscle function in children of mothers with myasthenia gravis during pregnancy.

Most infants whose mothers have myasthenia gravis are healthy at birth, but 10% to 15% have a transient neonatal form of myasthenia gravis. In this study, the muscular function and neuromuscular transmission were examined in 31 children, aged 3 months to 31 years (median, 10 years), of 15 myasthenic mothers. Eleven of these children had had the neonatal form of myasthenia gravis. The children were examined clinically and with neurophysiologic methods. Blood samples were taken for HLA typing, creatine kinase levels, and myoglobin and acetylcholine receptor antibody studies. Twenty-nine of the 31 children had no signs of neuromuscular disease. Two children (who had had neonatal myasthenia gravis) had a moderate stationary myopathy, probably unrelated to the myasthenia gravis of their mother. Creatine kinase levels were normal for all subjects. Acetylcholine receptor antibody levels were similar to those of a control population. The HLA type B8 antigen was not significantly more prevalent in the children who had had neonatal myasthenia gravis than in the healthy children. Neonatal myasthenia gravis in a previous sibling was the only factor in the material that predicted the occurrence of myasthenic symptoms in the neonatal period.

Adolescent↗
PubMed1988

Early relapse of acute inflammatory polyradiculoneuropathy after successful treatment with plasma exchange.

Symptoms reappeared within 2-4 weeks in 6 of 23 patients with acute Guillain-Barré syndrome who had demonstrated significant clinical improvement following plasma exchange therapy; all however improved to full recovery after a second series of plasma exchanges. The procedure appears to be associated with increased risk of early relapse. Our observations suggest that a relationship may exist between rapid removal of large amounts of plasma and the possibility of relapse.

Acute Disease↗
PubMed1988

The effect of iron fortification of the diet on clinical iron overload in the general population.

The gene coding for idiopathic hemochromatosis is prevalent in Sweden, the country with the highest iron fortification of food (42%) in the world. We wanted to study if this highly iron-fortified diet had negative effects on the iron situation in carriers of the iron-loading genes. Iron stores averaged 6.7 grams in male homozygotes who were mainly identified through laboratory screening. It was 3.4 grams in female homozygotes. By HLA typing of family members of these homozygous probands, 39 additional homozygotes and 172 heterozygotes were detected. Serum ferritin averaged 620 micrograms/l in 20 male and 168 micrograms/l in 19 female homozygotes in the family screening. Storage iron as measured by serum ferritin concentration was slightly but significantly higher in male heterozygotes than controls (117 micrograms/l versus 87 micrograms/l, p less than 0.02). There was no further increase in serum ferritin concentration with age after 40 years. Heterozygotes showed no clinical signs of iron damage. These findings do not indicate that carriers of the iron-loading genes in Sweden have been adversely affected by the highly iron-fortified diet of the country.

Administration, Oral↗
PubMed1987

The postpartum period constitutes an important risk for the development of clinical Graves' disease in young women.

In the present study, 93 consecutive women, 20-40 years of age, referred to our clinic from 1976-85 with Graves' disease, were examined with respect to a possible relation between onset of disease and previous pregnancy. An increased relative risk of 6.5 (3.8-11.0, 95% confidence interval) of developing Graves' disease within one year following delivery was found. After excluding the nulliparous women, almost 2 out of 3 women who developed Graves' disease in the principal child-bearing age of 20-35 years had a postpartum onset, suggesting an important role of immunomodulatory events following delivery for the development of this disease in young women. Future studies will ascertain to which extent the recognition of postpartum Graves' disease has implications on the choice of therapy in this group of women.

Adult↗
PubMed1985

Influence of the HLA-DR4 antigen and iodine status on the development of autoimmune postpartum thyroiditis.

HLA-A, -B, and -DR antigens were determined in all 50 women with a serum thyroid microsomal hemagglutination antibody (MsAb) titer equal to or greater than 1:100 in the first trimester of pregnancy in a population of 733 pregnant women. The DR4 antigen was found in 58.0% of the women compared to 33.7% in control subjects, which corresponds to a relative risk of 2.71 (P less than 0.01 by X2 test). The MsAb-positive women were examined regularly during the year after delivery for the development of thyroid dysfunction. The DR4 antigen frequency was found to be even higher, 69.0% (relative risk = 4.36; P less than 0.001), among the 29 women who developed hypothyroidism in the postpartum period. No other HLA antigen deviations were found among those 15 hypothyroid women in whom an initial thyrotoxic phase occurred before hypothyroidism. The B8, DR3 haplotype was found in 3 of 5 women who developed Graves' thyrotoxicosis alone. Urinary iodine excretion measured in some MsAb-positive women 3 (n = 19) or 6 months (n = 29) postpartum, respectively, was compatible with leakage of thyroid iodine during the initial destruction-induced thyrotoxic phase of postpartum thyroiditis, followed by low iodine excretion during the subsequent hypothyroid phase. We conclude that genes coding for the DR4 antigen may have a regulatory influence on MsAb production, which in turn affects the development of postpartum hypothyroidism. Thyroid iodine content and iodine intake also may have an impact on the severity of the thyrotoxic and the hypothyroid phases of autoimmune postpartum thyroiditis.

Adult↗
PubMed1984

Beneficial effects of plasma exchange in acute inflammatory polyradiculoneuropathy.

The results of a controlled trial in which 38 patients with severe acute inflammatory polyradiculoneuropathy took part indicate that plasma exchange favourably influenced the course of the disease. Significant benefits were seen in time until onset of improvement, course of muscular weakness, improvement in disability grades over the first 2 months, and working capacity after 1 month. Cost-benefit analysis showed that the exchange treatment resulted in net financial savings. The results suggest that plasma exchange may have a role in the treatment of severe acute inflammatory polyradiculoneuropathy.

Acute Disease↗
PubMed1984

HLA as a marker of the hemochromatosis gene in Sweden.

The frequency of HLA-A3 and HLA-B14 antigens was found to be significantly (P = less than 0.0001) higher in a series of 50 unrelated and unselected Swedish patients with idiopathic hemochromatosis (IH) than in controls, being 66% and 32% for A3 and 22% and 2% for B14. The haplotype A3B14 was associated with the highest risk in this material (relative risk 23.4). One family with this haplotype was traced back to the end of the seventeenth century. The pattern of HLA antigens associated with IH in Sweden shows remarkable similarity to those reported from England and Brittany.

Female↗
PubMed1984

HLA -A, -B, -C and -DR antigens in individuals with sensitivity to cobalt.

In a skin investigation of 853 individuals working with hard metal manufacturing 39 cases of cobalt allergy were found. Thirty-five of the individuals with cobalt sensitivity and 102 matched controls were HLA-A, -B, -C and -DR typed. No significantly deviating HLA antigen frequencies were observed when the two groups were compared. Thus, there are no signs that a certain HLA antigen would dispose to cobalt allergy. In the cobalt sensitive group the B7 positive individuals showed particularly often simultaneous reactions to other contact allergens (p = less than 0.025). The B12 positive individuals had low reactivity (p = less than 0.0001) while the A28 positive showed high reactivity (p = less than 0.015).

Cobalt↗
PubMed1982

Treatment of the Guillain-Barré syndrome by plasmapheresis.

Treatment by plasmapheresis was performed in eight adult patients with the Guillain-Barré syndrome. One patient with a chronic relapsing form underwent four separate courses of plasmapheresis and her condition improved rapidly each time. Of seven patients with acute Guillain-Barré syndrome, the condition of three improved markedly, in one partially, and in three it did not improve in association with treatment. There were no apparent differences concerning clinical and neurophysiologic parameters between those whose conditions improved and those whose conditions did not.

Adolescent↗