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127. The multitest system for assay of delayed cutaneous hypersensitivity (DCH) to ubiquitous antigens
VOLUME 61 NUMBER 3
ously describecl. The application of SPRAc has now been extended to the measurement of IgG antibody to ragweed (Rw). The test procedure for Rw-SPRAc is the same as that for BV-SPRAc except for the use of paper discs coupled with ragweed extract. A pool of sera containing specific IgG antibody to Rw obtained from healthy volunteers hyperimmumzed with Rw extract was used as the standard and the results expressed in arbitrary units. One hundred fourteen sera from nonimmunized and 116 sera from immunized Rw-sensitive patients were examined. The mean values and the standard deviations of these two groups were 8.0 & 13.4 U/ml and 32.7 & 28.9 U/ml, respectively. Sera from 30 healthy individuals were also examined; 22 had undetectable levels (<2.3 U/ml) and 8 had levels of IgG antibody to Rw ranging from 2.3 to 8.5 U/ml. When these 8 sera were preincubated with 6Opg of Rw extract prior to the test, all the values decreased to the background level. All sera were tested in duplicate. There was an average difference of 8.7% between duplicate assays. The mean coefficient of variation of the Rw-SPRAc obtained from the measurements of 9 sera at 4 different dilutions was 10.4%, which was similar to that of BV-SPRAc (9.6%, n = 5). The Rw-SPRAc seems to be a reliable test applicable for the clinical investigations of patients during immunotherapy.
e multitest system for assay of delayed cutaneous hypersensitivity (DCH) to ubiquitous antigens. C. T. Anderson, M.D., . Rcvmiantzeff, Ph.D., and W. T. Kniker, San Antonio, Texas.
M.D.,
The most convenient and useful method for evaluation of ceh-mediated immunity is testing DCH to antigens from a variety of commonly encountered microorganisms. Because the conventional Mantoux method and available antigens are net wholly satisfactory, we evaluated a new plastic, disposable device for simultaneous application of up to 8 antigens by multiple prick puncture (Lincoln Labs). Eight antigens in 70% glycerol were prepared by Institut Merieux; each was standardized chemically and biologically by DCH reactions in sensitized guinea pigs. Over 600 healthy adults ranging in age from 18 to 92 yr were tested with the antigens at full strength and half-log dilutions. Each antigen showed positive 24- and/or 48-hr reactions in the majority of tested individuals. Peak incidence of DCII to streptococcal, tetanus toxoid, and mumps antigens occurred in younger adults, while that to tuberculin was in oIder adults. Responses to diphtheria toxoid, Candida, tricophyton, and proteus antigens were comparable at ah ages. With identical antigen in all 8 test heads, there was remarkable reproducibility of DCH reactions. False positive responses to dry points or glycerol diluent occurred 1% of the time. The multitest system appears to be a safe, rapid, and painless means of evaluating DCH to multiple standardized antigens in a reproducible manner, with the potential for detecting changes in cell-mediated immunity in diseased individuals who are tested periodically.
128. Studies on proposed refe allergen extracts and an antic serum pool for RAST. Arthur and Harold
Baer, Ph.D., Bethesd
This study was conducted to determine if freeze-dried cat allergen extracts are useful as reference standards for the radioallergosorbent test (RAST), Lots 206 and 307 from pelts and cat serum, saliva, and urine were coupled to cyanogen bromide-activated paper discs and reacted with allergic sera. These included SP-1 (a serum pool from 5 untreated individuals with positive RAST and allergy to cats), SP-2 (a serum pool made from 3 individuals with allergy to cats), and 22 individual cat-allergic sera. SP-1 reacted strongly to 206, saliva, and urine and minimally to cat serum. SP-2 reacted strongly to 206, serum, and urine and minimally to saliva. The 22 individual sera fell into three groups positive for pelt-serum, pelt-saliva, or pelt-serum-saliva. Lot 206 was twice as reactive as 307 with SP-1; they were equal with SP-2 and variably reactive with individua1 sera Pelt Lots 206 and 307 are adequate for RAST standards, since both appear to contain allergens from cat serum, saliva, and urine and both reacted with all allergic sera and pools. The slight quantitative difference between 206 and 307 may be due to dissimilar content of allergens. Serum and saliva contain distinct allergens. It was not established that pelt or urine contained additional allergens. SP- 1 could be improved as a reference serum pool if additional sera reactive to cat serum allergens were added. SP-2 was deficient in reactivity to saliva allergens. This emphasizes the potential variability of serum pools.
129. Aging and immunoco testing. C. E. 6uckiey Ill, MD Durham,
N. C.
Mantoux skin tests with recall antigens are useful in immunocompetence testing. Age-dependent changes in cellmediated immunity compromise the reliability of immunocompetence testing in older patients. The influence of aging on recall antigen testing was evaluated in 1,350 patients aged 14 to 80 yr. Responses were measured to IO units of streptodornase (Lederle), mumps virus .&in test antigen (Lilly), and a l/ 1,000 dilution of Ca&& U&XZ~~ oidiomycin (Hollister-Stier) at 0.25,6,24,48, and 72 hr. A sixth-order polynomial least-squares regression was used to fit the age-dependent changes. Age-dependent trends detected at 0.25 and 6 hr were small; prominent differences were detected 24 to 72 hr after antigen cbahenge. In 22 healthy control subjects, 98% of the age-adjusted responses fell within the distribution of responder patients. The distribution of responses about the age-adjusted geometric means was used to estimate the percentile ranking of prospectively tested subjects to all 3 test antigens. Tbe averaged percentile rankings of the 24 to 72 hr responses of 54 patients with carcinoma were significantly less than patient and healthy
ously describecl. The application of SPRAc has now been extended to the measurement of IgG antibody to ragweed (Rw). The test procedure for Rw-SPRAc is the same as that for BV-SPRAc except for the use of paper discs coupled with ragweed extract. A pool of sera containing specific IgG antibody to Rw obtained from healthy volunteers hyperimmumzed with Rw extract was used as the standard and the results expressed in arbitrary units. One hundred fourteen sera from nonimmunized and 116 sera from immunized Rw-sensitive patients were examined. The mean values and the standard deviations of these two groups were 8.0 & 13.4 U/ml and 32.7 & 28.9 U/ml, respectively. Sera from 30 healthy individuals were also examined; 22 had undetectable levels (<2.3 U/ml) and 8 had levels of IgG antibody to Rw ranging from 2.3 to 8.5 U/ml. When these 8 sera were preincubated with 6Opg of Rw extract prior to the test, all the values decreased to the background level. All sera were tested in duplicate. There was an average difference of 8.7% between duplicate assays. The mean coefficient of variation of the Rw-SPRAc obtained from the measurements of 9 sera at 4 different dilutions was 10.4%, which was similar to that of BV-SPRAc (9.6%, n = 5). The Rw-SPRAc seems to be a reliable test applicable for the clinical investigations of patients during immunotherapy.
e multitest system for assay of delayed cutaneous hypersensitivity (DCH) to ubiquitous antigens. C. T. Anderson, M.D., . Rcvmiantzeff, Ph.D., and W. T. Kniker, San Antonio, Texas.
M.D.,
The most convenient and useful method for evaluation of ceh-mediated immunity is testing DCH to antigens from a variety of commonly encountered microorganisms. Because the conventional Mantoux method and available antigens are net wholly satisfactory, we evaluated a new plastic, disposable device for simultaneous application of up to 8 antigens by multiple prick puncture (Lincoln Labs). Eight antigens in 70% glycerol were prepared by Institut Merieux; each was standardized chemically and biologically by DCH reactions in sensitized guinea pigs. Over 600 healthy adults ranging in age from 18 to 92 yr were tested with the antigens at full strength and half-log dilutions. Each antigen showed positive 24- and/or 48-hr reactions in the majority of tested individuals. Peak incidence of DCII to streptococcal, tetanus toxoid, and mumps antigens occurred in younger adults, while that to tuberculin was in oIder adults. Responses to diphtheria toxoid, Candida, tricophyton, and proteus antigens were comparable at ah ages. With identical antigen in all 8 test heads, there was remarkable reproducibility of DCH reactions. False positive responses to dry points or glycerol diluent occurred 1% of the time. The multitest system appears to be a safe, rapid, and painless means of evaluating DCH to multiple standardized antigens in a reproducible manner, with the potential for detecting changes in cell-mediated immunity in diseased individuals who are tested periodically.
128. Studies on proposed refe allergen extracts and an antic serum pool for RAST. Arthur and Harold
Baer, Ph.D., Bethesd
This study was conducted to determine if freeze-dried cat allergen extracts are useful as reference standards for the radioallergosorbent test (RAST), Lots 206 and 307 from pelts and cat serum, saliva, and urine were coupled to cyanogen bromide-activated paper discs and reacted with allergic sera. These included SP-1 (a serum pool from 5 untreated individuals with positive RAST and allergy to cats), SP-2 (a serum pool made from 3 individuals with allergy to cats), and 22 individual cat-allergic sera. SP-1 reacted strongly to 206, saliva, and urine and minimally to cat serum. SP-2 reacted strongly to 206, serum, and urine and minimally to saliva. The 22 individual sera fell into three groups positive for pelt-serum, pelt-saliva, or pelt-serum-saliva. Lot 206 was twice as reactive as 307 with SP-1; they were equal with SP-2 and variably reactive with individua1 sera Pelt Lots 206 and 307 are adequate for RAST standards, since both appear to contain allergens from cat serum, saliva, and urine and both reacted with all allergic sera and pools. The slight quantitative difference between 206 and 307 may be due to dissimilar content of allergens. Serum and saliva contain distinct allergens. It was not established that pelt or urine contained additional allergens. SP- 1 could be improved as a reference serum pool if additional sera reactive to cat serum allergens were added. SP-2 was deficient in reactivity to saliva allergens. This emphasizes the potential variability of serum pools.
129. Aging and immunoco testing. C. E. 6uckiey Ill, MD Durham,
N. C.
Mantoux skin tests with recall antigens are useful in immunocompetence testing. Age-dependent changes in cellmediated immunity compromise the reliability of immunocompetence testing in older patients. The influence of aging on recall antigen testing was evaluated in 1,350 patients aged 14 to 80 yr. Responses were measured to IO units of streptodornase (Lederle), mumps virus .&in test antigen (Lilly), and a l/ 1,000 dilution of Ca&& U&XZ~~ oidiomycin (Hollister-Stier) at 0.25,6,24,48, and 72 hr. A sixth-order polynomial least-squares regression was used to fit the age-dependent changes. Age-dependent trends detected at 0.25 and 6 hr were small; prominent differences were detected 24 to 72 hr after antigen cbahenge. In 22 healthy control subjects, 98% of the age-adjusted responses fell within the distribution of responder patients. The distribution of responses about the age-adjusted geometric means was used to estimate the percentile ranking of prospectively tested subjects to all 3 test antigens. Tbe averaged percentile rankings of the 24 to 72 hr responses of 54 patients with carcinoma were significantly less than patient and healthy