31 Immunoproteins. Immunoelectrophoretic analysis of serum proteins in 1962 showed neithera paraproteinemia nor a typical picture of antibody deficiency syndrome,but a high frequency of some of the immunoglobulins was noted.1°** Complement fixation studies showed the Marshallese to have antibodies to most viruses except Asian influenza (an epidemicofthis disease later occurredin 1972). The antibody titers appeared somewhat lower in the exposed people. !° The older people had higherlevels of gamma globulins but slightly decreased albumin levels (1969).13.59.60 Tmmunodiffusion studies showed that the rise in gamma globulin levels was paralleled by an increase in immunoglobulin.t The increase in IgG moiety was the most pronounced, and it showedsignificantcorrelation with age (r=0.78). The increase in K light chains was also significantly correlated with age. The immunoglobulin levels were more depressed in the exposed group, particularly those of IgG, IgA, and L light chains (Table 18). However, by 1974 the gammaglobulin levels in the exposed people were nearly the sameas in the unexposed (Table 19). Lymphocytefunction. Tests on the phytohemagglutinin (PHA) stimulation of lymphocytes cul*Dr. R.D. Stoner at BNL did these analyses. **Drs. R. Biitler and A. Hassig at the Swiss Red Cross Labora- tory did these analyses. *These studies were done by Drs. J.L. Fahey and R. Woods of the National Cancer Immunoglobulin Center. 100 : 9OF- FT T Combined weighted data* T TI > Exposed @ Unexposed = Combined with standard “7 ° error means 80 i | _ r=0.99** | y=0.51 +0.38 x+0.01 x? 70 Percent aging duced immunological surveillance. Our interest in immunological capacity is related also to the consideration that impairmentof immunity is thought to be associated with the aging process. Antibody response. Three years after exposure a number of exposed and unexposed Rongelap people weretested for antibody responseto primary and secondarytetanus toxoid inoculations, with a mouse used for toxin-antitoxin assay of serum.§* The difference between the exposed and unexposed groups was notsignificant. Blood cell changes. The persistent lag in complete recovery of leukocytes was believed to reflect reduced bone marrowreserve and therefore reduced immunological reserve. The apparentrecent recovery of hemopoiesis in the exposed people to control levels may indicate an improvement in their immunological status. Table 18 shows that reductions in lymphocytes andplatelets and an increase in sedimentation rates were correlated with increasing age in the Marshallese. | “ 60f- 4 | 30/7 7 | 40 7 | 30 — “Coefficient for age | | 99K scores before summing 10- oOo. 20 _ correlation of each criterion used to weight I 30 i **Correlation with age significant at 1% level 40 | 50 | 60 | 70 4 “| L 80 ! 90 Age Figure 23. Biological age scores.1? tured from peripheral blood showed a definite decrease of responsiveness with increasing age of the individual (Table 18 and Figure 24) but no def- inite difference between exposed and unexposed groups.°?.60 In a more recent study, acetylation of nuclei of PHA-treated lymphocytes was measured at various times as a function of lymphocyte transformation and of aging.§! Decreased acetylation of nuclei is associated with increasing age and is roughly parallel to the decrease in lymphocyte transformation. Total acetate incorporation in the nuclei during thefirst hour of culture was correlated with acetylation of histones, but by 20 hr acetylation of other nuclear materials had also occurred. Chromosome counts. In 1969 chromosomecounts were made on PHA-stimulated lymphocytes cultured from peripheral blood from 78 unexposed and 27 exposed Rongelap people.® Both hypodiploid and polyploid levels were found to be related to the subject’s age. Females >50 and exposed males >50 had ~1.5 times as many hypodiploids as did the younger subjects; polyploid levels were sharply reduced in all subjects >50. Hy-