Jukka Koistinen

Selective IgA Deficiency in Blood Donors

Abstract. The frequency of selective deficiency of serum IgA was determined in a population of 64,588 new Finnish blood donors by Ouchterlonys double diffusion with 10 μg/ml as the limit of detection. The incidence was 1:396. Those found IgA‐deficient were retested by hemagglutination inhibition and by radioimmunoassay. The calculated incidences of IgA levels below 0.5 and 0.015 μg/ml were 1:500 and 1:800, respectively.

Familial Clustering of Selective IgA Deficiency

Abstract. Serum IgA levels of 35 healthy IgA‐deficient index cases, of their 180 first‐degree relatives, and of 31 other family members were studied. IgA deficiency was detected in 7.2% of the first‐degree relatives, which is significantly more than the 0.25% frequency of IgA deficiency in healthy Finnish blood donors. Subnormal serum IgA levels were found in additional 13 (7.2%) first‐degree relatives. The familial clustering of IgA deficiency seemed to be controlled by multigenic factors.

Long-term persistence of selective IgA deficiency in healthy adults

A follow-up study of 204 healthy blood donors with IgA deficiency, identified between 1971 and 1980, was carried out. Sera were initially screened by a double diffusion method and 182 were retested by a more sensitive haemagglutination inhibition method. A reexamination was performed in 1990 and, again, in 1991–1992 using an enzyme immunoassay (EIA) developed for the measurement of very low concentrations of IgA. The median follow-up period was 19 years, and in 159 (78%) subjects no serum IgA could be detected in any of the measurements. In 42 (21%) subjects, serum IgA was detectable (>0.18 mg/L), but the level was below the lower limit of the reference range for adults (800 mg/L) and remained relatively constant. Three subjects showed minute amounts of IgA by EIA (0.2–3 mg/L) in one of the follow-up samples in 1990–1992, but the level was below the detection limit of the EIA (0.05 mg/L) in the other sample. Thus, not only does primary IgA deficiency appear to be permanent, but also lower than normal serum IgA levels remain the same in healthy adults.

Long-term follow-up of anti-IgA antibodies in healthy IgA-deficient adults

A follow-up study of anti-IgA antibodies in 159 healthy blood donors with severe deficiency of serum IgA (<0.05 mg/L) and in 45 donors with decreased serum IgA levels (0.05–799 mg/L), identified in 1971–1980, was carried out. Initially anti-IgA antibodies were determined by a hemagglutination (HA) method and two reexaminations were done in 1990–1992 by an enzyme immunoassay. The median follow-up period was 19 years, during which anti-IgA level was changed considerably in only four persons, increased in two, and high level antibodies (>1/1000 by HA) appeared in two. In reexaminations anti-IgA antibodies were found in 30 (19%) subjects with severe IgA deficiency and the antibody levels remained relatively constant in those who had high and medium antibody levels. Anti-IgA antibodies were not found in subjects with decreased, but detectable serum IgA. Thus it seems that only those healthy adults who have severe IgA deficiency develop anti-IgA antibodies and their anti-IgA levels remain fairly constant Of the 159 subjects with severe IgA deficiency, 66 had a history of IgA exposure, but no correlation to anti-IgA development was noted.

The establishment of a network of European human research tissue banks.

This is a report of a workshop held on the establishment of human research tissue banking which was held in Levi, Finland 21–24 March 2002.There were 21 participants from 7 European countries. This meeting was attended by representatives from academia, research tissue banks and from the Biotech and Pharmaceutical Industries. The principal aim of the workshop was to find a way to progress the recommendations from ECVAM workshop 44 (ATLA 29, 125–134,2001) and ECVAM workshop 32 (ATLA 26, 763–777, 1998). The workshop represented the first unofficial meeting of the European Network of Research Tissue Banks (ENRTB) steering group. It is expected that in the period preceding the next workshop the ENRTB steering group will co-ordinate the ethical,legislative and organisational aspects of research tissue banking. Key issues dealt with by the Levi workshop included the practical aspects of sharing expertise and experiences across the different European members. Such collaboration between research tissue banks and end users of such material seeks to ultimately enable shared access to human tissue for medical and pharmaco-toxicological research while maintaining strict adherence to differences in legal and ethical aspects related to the use of human tissue in individual countries.

Weak Anti‐IgA Antibodies with Limited Specificity and Nonhemolytic Transfusion Reactions

Abstract. Anti‐IgA antibodies were studied in sera from patients with nonhemolytic transfusion reactions for which no serological reason had been found. Of the 158 sera that were studied by passive hemagglutination assay using twelve IgA myeloma proteins, 4 samples had class‐specific antibodies and 10 samples antibodies with limited specificity. Titers were 1:8 or less. 100 multitransfused hemophilia patients were studied with two IgA myeloma proteins. Four of the sera had anti‐IgA antibodies. Normal blood donor sera reacted with TgA only when antigens were first either digested with pepsin or stored for several months as dilute solutions in refrigerator. The results emphasize the need for fresh IgA proteins of good quality when human anti‐IgA antibodies are investigated.

Lack of Evidence of HTLV-I Antibodies in the Finnish Population

5,287 serum samples from 2 different sources in Finland, people possibly at risk and healthy blood donors, were tested for the presence of HTLV-I antibodies. No positive cases were found. The result suggests that this virus is not endemic in Finland. 10 cases gave repeatedly a low positive value in the enzyme immune assay (EIA) test but were confirmed negative with other tests that included western blot, passive agglutination and immunofluorescence. Four of these samples originated from healthy blood donors, 6 from other categories. Several of them showed restricted reactivity in western blots. Five HIV-positive sera, discovered during the study from people with possible risk factors, were also tested for HTLV-I but showed no reactivity.