Table 5.

Anti-B19 and anti-Streptococcus pneumoniae antibody concentrations in plasma pools obtained from Group I, II and IV donors

	Donors
	Group IA		Group IIB		Group IVC
Antibody specificity	Conc.	%	Conc.	% vs. Aa	Conc.	% vs. Aa
Parvovirus B19	n = 51				n = 41
IU/ml	32·2 ± 3·7	100			23·9 ± 4·6	−26*
IU/g Ig	3·8 ± 0·4	100			3·7 ± 0·7	−3
S. pneumoniae
Total serotypes	n = 51		n = 5		n = 41
μg/ml	35·4 ± 2·8b	100	34·3 ± 2·7	+1	22·5 ± 0·6	−36*
μg/g Igc	4·2 ± 0·3	100	4·1 ± 0·4	+1	3·5 ± 0·1	−17*
Serotype 10A	n = 10		n = 5		n = 31
μg/ml	1·4 ± 0·2	100	1·8 ± 0·3	+28	1·0 ± 0·3	−29*
μg/g Ig	0·17 ± 0·02	100	0·2 ± 0·04	+17	0·16 ± 0·04	−6
Serotype 18C	n = 10		n = 5		n = 31
μg/ml	1·1 ± 0·1	100	1·3 ± 0·2	+18	0·53 ± 0·2	−52*
μg/g Ig	0·13 ± 0·02	100	0·15 ± 0·03	+15	0·08 ± 0·03	−38*
Serotype 19A	n = 10		n = 5		n = 31
μg/ml	3·3 ± 0·5	100	7·0 ± 2·8	+112*	2·8 ± 1·0	−15
μg/g Ig	0·39 ± 0·06	100	0·84 ± 0·35	+115*	0·44 ± 0·16	+13

Specific anti-B19 and anti-pneumococcus antibody contents were measured by means of a specific ELISA, as described under Materials and Methods, in pools produced with Group I (A), Group II (B) or Group IV plasma (C). The number of batches (n) analysed is indicated.

^aRepresents the per cent of variation with respect to the level determined for Group I plasma pools, taken as 100%.

^bResults are expressed as means ± SD for all plasma pools of each type.

^cSpecific antibody contents expressed per g total immunoglobulin (see Table 3).

^*P-value highly significant < 0·001.