The effect of aging and acute illness on delayed hypersensitivity

Epicutaneous Patch Testing in Type IV Allergy Diagnostics: State of the Art and Best Practice Recommendations

This chapter summarises all relevant aspects of patch testing, closely following recommendations outlined in a recent European, and a German S3 guideline on diagnostic patch testing with contact allergens and medicinal products (drugs). Patch testing is indicated in patients suspected of suffering, or having been suffering, from delayed-type hypersensitivity leading to allergic contact dermatitis or other skin and mucosal diseases. Sections of this chapter include detailed indications, reasons for possibly postponing the test, considerations on choosing haptens (contact allergens) to test, various aspects of the application of patch test allergen preparations (storage, dosing) and of testing with individual materials provided by the patients. Special aspects of patch testing in cutaneous adverse drug reactions, children, or occupational contact dermatitis are outlined. Supplemental test methods, notably the repeated open application test, are briefly described. Finally, the final evaluation in terms of assessment of clinical relevance of reactions and patient counselling are outlined.

The Effect of Atopy in the Prevalence of Contact Sensitization: The Experience of a Greek Referral Center

Contact dermatitis is a well-known skin condition, which is related to stimuli and environmental exposure to chemicals, affecting all ages as well as both genders. In the present work, we attempt to investigate the patterns of contact sensitization, with respect to the personal history of atopy (AT), in Greece in a large number of allergens, using patch testing. The retrospective analysis included clinical routine data of 1978 patients collected from 2014 to 2016 in the Laboratory of Patch Testing, National Referral Centre of Occupational Dermatoses. Sensitization, in all cases, was tested with 28 allergens of the European baseline series as adjusted to our local circumstances and clinical experience. A total population of 1978 patients was evaluated, with a male-to-female ratio of 0.45 (1359 females/619 males). From our patient cohort, 693 (35%) patients were evaluated with a history of atopy, while 1285 (65%) were nonatopic. The five most prevalent allergens in the total population without AT were nickel sulphate 5% (15.47%), fragrance mix (I) 8% (9.10%), balsam of Peru (6.47%), cobalt chloride 1% (4.70%), and thiomersal 0.1% (4.10%). Respectively, in the total population with AT, the five most prevalent allergens were nickel sulphate 5% (10.36%), fragrance mix (I) 8% (5.11%), balsam of Peru (3.29%), thiomersal 0.1% (3.03%), and cobalt chloride 1% (2.78%). Contact dermatitis surveillance is of great importance towards the clinical and systematic understanding of the disease. Further studies should be directed towards that end, in order to facilitate more effective health policies.

European Society of Contact Dermatitis guideline for diagnostic patch testing - recommendations on best practice

The present guideline summarizes all aspects of patch testing for the diagnosis of contact allergy in patients suspected of suffering, or having been suffering, from allergic contact dermatitis or other delayed-type hypersensitivity skin and mucosal conditions. Sections with brief descriptions and discussions of different pertinent topics are followed by a highlighted short practical recommendation. Topics comprise, after an introduction with important definitions, materials, technique, modifications of epicutaneous testing, individual factors influencing the patch test outcome or necessitating special considerations, children, patients with occupational contact dermatitis and drug eruptions as special groups, patch testing of materials brought in by the patient, adverse effects of patch testing, and the final evaluation and patient counselling based on this judgement. Finally, short reference is made to aspects of (continuing) medical education and to electronic collection of data for epidemiological surveillance.

Allergic contact sensitivity in elderly patients

BACKGROUND AND AIMS

Aging has been shown to be correlated with the rate and type of contact sensitization, but only a few studies have evaluated patch test reactivity in elderly subjects with an adequately large population.

METHODS

The response patterns to patch testing in 1444 elderly subjects (>65 years) with suspected allergic contact dermatitis were studied, and the results compared with a control group of individuals with suspected allergic contact dermatitis, aged between 20 and 40 years.

RESULTS

The prevalence of the positive patch test to at least one hapten was significantly lower in the group of elderly patients compared with adult patients (40.7 vs 47.8%, p<0.0001). However, some allergens, i.e., primin, diaminodiphenylmethane, neomycin, lanolin alcohols, paraben mix, Euxyl K400 and quinoline mix, showed an increased sensitization rate in elderly patients compared with adult patients. These allergens are now less frequently employed in the workplace, or are substances particularly used in the formulation of topical treatment of age-related diseases, i.e., leg ulcer and xerosis. It was also found that the intensity of positive patch test reactions was significantly lower in elderly patients compared with younger subjects, with higher proportions of weak (+) positive reactions. Moreover, elderly patients showed a dynamic pattern of increasing intensity of patch test reactions at the second reading after 3 days compared with the first reading after 2 days more frequently than younger patients (60 vs 53%, p<0.0001).

CONCLUSIONS

These findings suggest an age-dependent decline of overall positive patch test reactions, but a higher sensitization rate to some allergens frequently used in the composition of topical treatments. The development of an allergic response in elderly patients was found to be delayed, and this may require an additional reading after 7 days and the interpretation of even weak reactions as valid positive patch test reactions.

Criteria for assessing cutaneous anergy in women with or at risk for HIV infection. HIV Epidemiologic Research Study Group

BACKGROUND

Controversy exists about both the clinical utility of anergy testing and the optimal criteria for defining anergy.

OBJECTIVE

We sought to assess various definitions of cutaneous anergy for ability to distinguish HIV status, level of immunodeficiency, and ability to mount a tuberculin reaction among women with or at risk for HIV infection.

METHODS

HIV-seropositive (n = 721) and HIV-seronegative (n = 358) at-risk women at academic medical centers in Baltimore, Detroit, New York, and Providence had cutaneous testing with mumps, Candida, tetanus toxoid, and tuberculin antigens. Associations with HIV status and CD4+ lymphocyte levels were analyzed.

RESULTS

Candida, mumps, and tetanus antigens alone or in combination elicited reactions significantly less often in HIV-seropositive than in HIV-seronegative women and less often in seropositive women with lower CD4+ counts, regardless of induration cutpoint chosen to define a positive reaction. The best antigen combinations for distinguishing groups included tetanus and mumps. Some women nonreactive to the 3 antigens ("anergic") had positive tuberculin reactions among both seropositive subjects (range, 1.1% to 2.9% depending on induration cutpoint for defining anergy) and seronegative subjects (range, 8.9% to 14%).

CONCLUSION

Absence of reactions to Candida, mumps, and tetanus antigens alone or in combination and at any induration cutpoint is associated with HIV status and with CD4+ level. Combinations, including tetanus and mumps antigens with an induration cutpoint of less than 2 mm, may be the best for defining anergy.

Immunologic mechanisms in mosquito allergy: correlation of skin reactions with specific IgE and IgG antibodies and lymphocyte proliferation response to mosquito antigens

BACKGROUND

Allergic reactions to mosquito bites are a common problem. Although IgE-mediated hypersensitivity has been reported, other immunologic mechanisms may be involved.

OBJECTIVES

To study the relationship between skin bite reactions and immunologic parameters.

METHODS

Forty-one subjects were experimentally exposed to mosquito (Aedes vexans) bites. Immediate and delayed skin reactions were traced at 20 minutes and 24 hours, respectively, after the bites. Sera were analyzed for mosquito salivary gland-specific IgE (mosquito-IgE) and IgG (mosquito-IgG) by ELISA. Lymphocyte proliferation assays with mosquito extract were also performed.

RESULTS

One of 41 subjects had only a delayed skin reaction to the bite, 23 had both immediate and delayed reactions, 6 had only immediate reactions, and 11 had no reaction. The mean mosquito-IgE and -IgG concentrations were higher in the subjects with immediate reactions than in those without immediate reactions (P < .007). The mean lymphocyte proliferation stimulation index was higher in the subjects with delayed reactions than in those without delayed reactions (P < .015). Further, both mosquito-IgE and -IgG levels correlated with skin immediate and delayed reactions (P < .04), while lymphocyte proliferation indices only correlated with skin delayed reactions (P < .006). Inverse correlations were found between the size of skin reactions and the number of years lived in Canada (P < .04), but not with age.

CONCLUSION

These results indicate that IgE-, lymphocyte- and, probably, local IgG immune-complex-mediated hypersensitivities are involved in mosquito allergy. Naturally acquired desensitization to mosquito bites occurs during long-term exposure.

The influence of age on transfer factor treatment of cellular immunodeficiency, chronic fatigue syndrome and/or chronic viral infections

A group of 222 patients suffering from cellular immunodeficiency (CID), frequently combined with chronic fatigue syndrome (CFS) and/or chronic viral infections by Epstein-Barr virus (EBV) and/or cytomegalovirus (CMV), were immunologically investigated and treated with transfer factor (TF). The age range was 17-77 years. In order to elucidate the influence of aging on the course of the disease and on treatment, 3 subgroups were formed: 17-43 years, 44-53 years, and 54-77 years. Six injections of Immodin (commercial preparation of TF by SEVAC, Prague) were given in the course of 8 weeks. When active viral infection was present, IgG injections and vitamins were added. Immunological investigation was performed before the start of therapy, and subsequently according to need, but not later than after 3 months. The percentages of failures to improve clinical status of patients were in the individual subgroups, respectively: 10.6%, 11.5% and 28.9%. The influence of increasing age on the percentage of failures to normalize low numbers of T cells was very evident: 10.6%, 21.2% and 59.6%. In individuals uneffected by therapy, persistent absolute lymphocyte numbers below 1,200 cells were found in 23.1%, 54.5% and 89.3% in the oldest group. Statistical analysis by Pearson's Chi-square test, and the test for linear trend proved that the differences among the individual age groups were significant. Neither sex, nor other factors seemed to influence the results. The results of this pilot study show that age substantially influences the failure rate of CID treatment using TF. In older people, it is easier to improve the clinical condition than CID: this may be related to the diminished number of lymphocytes, however, a placebo effect cannot be totally excluded.

Tuberculin skin test reactivity, anergy, and HIV infection in hospitalized patients. Longcope Firm of the Osler Medical Housestaff

PURPOSE

Detection of latent tuberculosis infection is an important step in the control of tuberculosis because high-risk persons may be given preventive therapy. The value of tuberculin skin testing in individuals with human immunodeficiency virus (HIV) infection, however, is limited by anergy. We evaluated the prevalence of tuberculin skin test reactivity, anergy, and HIV infection in a group of hospitalized patients in an area where both tuberculosis and HIV infection are prevalent.

PATIENTS AND METHODS

Three hundred fifty-one patients consecutively admitted to a medical service of a large urban teaching hospital were enrolled in the study. All those with no documented history of a positive tuberculin skin test were evaluated on admission with purified protein derivative (PPD) by the Mantoux test, and with anergy testing using a multiple-puncture device. HIV testing was offered to all patients who did not have a known history of HIV infection, and was performed when informed consent was obtained.

RESULTS

Forty-one patients (12%) had a documented history of a positive PPD. Of the remaining 310 patients, 62 (20%) had a PPD response of > or = 10 mm induration. Fifty-two (15%) of the 351 patients were HIV positive. None of the HIV-infected patients was PPD positive. Anergy was found in 63% of the HIV-infected patients and 28% of the HIV-seronegative patients. Independent risk factors for a positive PPD included age > 55, male sex, and hypertension. HIV infection, current steroid use, and a history of cancer were associated with a negative PPD. Independent risk factors for anergy included HIV infection, current corticosteroid use, renal failure pneumonia, and a history of cancer. Of the 62 new PPD-positive patients, 30 (48%) were candidates for chemoprophylaxis. Additionally, 30 (63%) of 48 HIV-seropositive patients who were completed testing were anergic and might be candidates for chemoprophylaxis. Almost all of the patients eligible for chemoprophylactic therapy would have been detected if only patients at increased risk for developing tuberculosis were screened.

CONCLUSIONS

Tuberculosis infection, HIV infection, and anergy were common in patients admitted to this medical service. Interpretation of PPD reactivity was confounded by a high prevalence of anergy, particularly in HIV-infected patients. A large proportion of patients tested were candidates for chemoprophylaxis. Routine tuberculin skin testing with anergy testing for high-risk patients on admission to the hospital is useful for identifying patients who might benefit from prophylaxis to help control the spread of tuberculosis.

Leukocyte migration inhibition studies and neutrophil cell function during aging in Nigerians

In this study, in vitro cell-mediated immune response was analysed in 150 healthy Nigerians between 6 and 95 years old by the leukocyte migration inhibitory factor (L-MIF) test. Lymphocytes were activated with the mitogen concanavalin A and candida, measles virus and mycobacterial antigens. Nonspecific cellular immune capacity was studied by the Nitroblue tetrazolium (NBT) test. Numerical estimates of leukocytes and lymphocyte subpopulations were done. Mean L-MIF activity obtained with the four lymphocyte activators decreased with rising age indicating a progressive decline in cellular immune function with age. There was no significant age-related change in formazan positivity rate for both unstimulated and stimulated NBT tests. No age-related change in number was observed for any of the leucocyte and lymphocyte subpopulations. These results show that cell-mediaging response in Nigerians immunity declines, but phagocyte function is unchanged during aging. Lymphocyte depletion or numerical alteration in resting T cell subsets could not be demonstrated to be responsible for depressed cell-mediated immunity in aging Nigerians.

Cutaneous defenses against dermatophytes and yeasts

Predispositions to the superficial mycoses include warmth and moisture, natural or iatrogenic immunosuppression, and perhaps some degree of inherited susceptibility. Some of these infections elicit a greater inflammatory response than others, and the noninflammatory ones are generally more chronic. The immune system is involved in the defense against these infections, and cell-mediated immunity appears to be particularly important. The mechanisms involved in generating immunologic reactions in the skin are complex, with epidermal Langerhans cells, other dendritic cells, lymphocytes, microvascular endothelial cells, and the keratinocytes themselves all participating in one way or another. A variety of defects in the immunologic response to the superficial mycoses have been described. In some cases the defect may be preexistent, whereas in others the infection itself may interfere with protective cell-mediated immune responses against the organisms. A number of different mechanisms may underlie these immunologic defects and lead to the development of chronic superficial fungal infection in individual patients. Although the immunologic defects appear to be involved in the chronicity of certain types of cutaneous fungal infections, treatment of these defects remains experimental at the present time.

Langerhans cell density in normal human oral mucosa and skin: relationship to age, smoking and alcohol consumption

The immune function of skin has been studied extensively and it has been suggested that epidermal Langerhans cell (LC) density and function decreases with increasing age. Little is known, however, about the effect of age on oral mucosal LC. Cryostat sections from biopsies of buccal mucosa, lip, hard palate, lateral border of tongue, floor of mouth and abdominal skin, obtained from 91 subjects (aged 16-96 yr), were reacted immunocytochemically with a monoclonal antibody against CD1a and then LC density was expressed as LC/mm epithelial surface length. No significant effect of age on mucosal or skin LC density was found, whilst a history of smoking was associated with an increase in LC density in lateral border of tongue and in biopsies of labial mucosa taken from men (P < 0.05). There was no significant difference between LC density in men and women in oral mucosa. Oral mucosal LC may therefore form a relatively stable population in the adult and thus the increased incidence of mucosal disease in the elderly may be the result of subtle changes in cell mediated immune function rather than changes in LC density.

The role of T cell phenotypes in decreased lymphoproliferation of the elderly

A possible mechanism of the decreased mitogen-induced lymphoproliferation of the elderly is a shift in the relative numbers of T lymphocyte subpopulations. Results from studies examining such changes have been conflicting. In an effort to resolve this conflict, alterations in T cell subsets in the peripheral blood of a large number of relatively healthy, elderly subjects (149; mean age 84.6) were evaluated. Although there were several differences in percentages of subpopulations between elderly and young subjects, no significant differences in the absolute numbers of lymphocytes, monocytes, or T cell subsets between the groups were observed. In addition, there was no correlation between mitogen-induced lymphoproliferation and T cell subsets. Since the decreased mitogen response could reflect a difference in the ability of one T cell subset to proliferate, the phenotype of the T cells after stimulation with PHA was determined. Although the elderly demonstrated a decreased number of all T cell subsets after PHA stimulation compared to young subjects, the most pronounced decrease was in CD8+ cells. Further, young individuals demonstrated a significant increase in the percentage of CD8+ cells (p less than 0.001) after 72 hr of culture with PHA; elderly subjects showed no change in the percentage of T cell subsets. Although both groups had an increase in interleukin 2 receptor (IL2R), transferrin receptor (TfR), and MHC class II Ag (HLA-DR) positive cells after PHA stimulation, the mean percentage of TfR+ cells was significantly greater in the young than in the elderly (p less than 0.05). This decreased expression of TfR+ cells in the elderly was reflected by a decreased percentage of CD8+ cells expressing TfR. In addition, the percentages of CD8+ cells, CD8+ cells expressing TfR, and CD8+ cells expressing IL2R after activation correlated with PHA-induced proliferation. These results suggest that the impaired lymphoproliferative ability of elderly cells is not related to the proportions of T cell subsets present in peripheral blood. Rather, there appears to be some defect in the ability of all T cells, but especially of the T suppressor/cytotoxic cells, of the elderly to respond to PHA manifested by a decreased expression of transferrin receptors.

Nutritional support of the chronically ill elderly female at risk for elective or urgent surgery

Among the elderly, those at highest risk are the chronically ill, inactive patients. Assessing macronutrient requirements and outcome depends on longitudinal studies. Seven chronically ill, elderly female patients suffering from persistent infections, were studied monthly, over a 6-month period to determine their protein and energy requirements. Calorie and protein requirements were based on clinical status. The results of the nutrition support program were monitored using: weight change, nitrogen balance, serum albumin levels, alterations in anthropometric measurements (triceps skinfold thickness and arm muscle circumference), and immune function tests. Based on the 6-month study period data, the calculated mean energy requirement for weight maintenance was 98% of calculated basal energy expenditure (BEE) and the mean protein required for nitrogen balance, 0.8 g/kg desired body weight (DBW). Excess caloric administration resulted in weight gain, determined to be fat (and/or fluid) but not lean body mass. When surgery is contemplated, there should be a 30% (factorial) increase over these base-line values. It is inadvisable to allow elderly patients to sustain any starvation, period given their inability to produce increases in body cell mass even in this 6-month period.

Defective mononuclear cell support of erythropoiesis in the elderly

As many as one third of anemic elderly patients have anemia as an isolated finding without demonstrable morphologic abnormality of the marrow, deficiency of hematinic vitamins, or minerals or disease known to cause secondary anemia. These people may have a pathologic process: anemia of senescence. Erythroid cells mature from nonlymphoid mononuclear cells; the maturation process is modulated by lymphokines. When assessed as end products of the humoral or cellular immune system, mononuclear cell function declines with host age. This study tests the hypothesis that mononuclear cell support of erythroid burst formation is defective in elderly subjects. Leukocyte-conditioned medium was prepared from each of five young and five elderly adults. Erythroid bursts from young or elderly adults were grown in culture medium containing leukocyte-conditioned medium from at least three young adults and at least three elderly adults. Erythroid bursts from either young or elderly adults were 1.4-3.0 times more numerous if the leukocyte-conditioned medium derived from a young rather than elderly adult. In addition, when culture medium contained leukocyte-conditioned medium from young adults, only half the elderly adults studied had erythroid bursts equal to those of young adults. These data support the hypothesis that mononuclear cell support of erythropoiesis in the elderly is defective.

Noradrenergic sympathetic innervation of the spleen: IV. Morphometric analysis in adult and aged F344 rats

Noradrenergic postganglionic sympathetic innervation of the spleen in 8-month-old (adult) and 27-month-old (aged) Fischer 344 (F344) rats was examined using fluorescence histochemistry for catecholamines coupled with stereologic point-counting analysis for quantitation of noradrenergic varicosities. Noradrenergic varicosities in the spleen were evaluated in four compartments: (1) vascular-, (2) trabecular-, (3) capsular-, and (4) parenchymal-associated fibers. The 27-month-old rats were subdivided further into two groups based upon behavioral testing for gustatory neophobia, a condition reported to be associated with acute locus coeruleus lesions in young rats and with diminished norepinephrine (NE) levels in central noradrenergic neurons in aged rats. In the 8-month-old rats, spleens displayed abundant innervation. Noradrenergic plexuses entered the spleen with the splenic artery and its branches, distributed into capsular and trabecular compartments, and followed the vasculature and trabeculae into splenic white pulp. Noradrenergic fibers entered the white pulp mainly in association with the central artery and its branches; liner and punctate varicosities branched mainly from vascular plexuses into the large, well-defined parenchyma of the white pulp, ending primarily among fields of T lymphocytes. Some fibers extended along the inner edge of the marginal zone and the parafollicular zone. Few noradrenergic varicosities were found in the red pulp. In both groups of aged rats, sympathetic noradrenergic innervation was diminished markedly.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunologic response in an elderly population with a mean age of 85

Previous studies of changes in immune responses in the elderly have been limited in both number and age of elderly subjects and have produced conflicting results. Using 260 subjects, mean age 84.6, the present study conclusively demonstrates that T cell response is decreased in the elderly. Decreases in response to phytohemagglutinin and concanavalin A were demonstrated in groups aged 70 to 79, 80 to 84, and 85 to 89, although a group 90 to 106 years old showed a decreased response only to phytohemagglutinin. None of the groups had a decreased response to pokeweed mitogen. No response to all three mitogens was observed in 13 percent of the group aged 70 to 89, but in none of the group aged 90 to 106 or in the young groups. No differences in natural killer cell cytotoxicity were observed among the elderly groups. In contrast to previous studies, these results suggest that: the decreased immune response of the elderly is not directly related to age, over age 70; and there may be a selection process in which subjects who live to the age of 90 are those in whom the least decrease in immune response is demonstrated.

Structural and functional changes of normal aging skin

Solar-induced cutaneous changes are more prevalent and profound in older persons and, thus, are often inappropriately attributed to the aging process, per se. Structural and functional alterations caused by intrinsic aging and independent of environmental insults are now recognized in the skin of elderly individuals. Structurally the aged epidermis likely becomes thinner, the corneocytes become less adherent to one another, and there is flattening of the dermoepidermal interface. The number of melanocytes and Langerhans cells is decreased. The dermis becomes atrophic and it is relatively acellular and avascular. Dermal collagen, elastin, and glycosaminoglycans are altered. The subcutaneous tissue is diminished in some areas, especially the face, shins, hands, and feet, while in others, particularly the abdomen in men and the thighs in women, it is increased. The number of eccrine glands is reduced and both the eccrine and apocrine glands undergo attenuation. Sebaceous glands tend to increase in size but paradoxically their secretory output is lessened. The nail plate is generally thinned, the surface ridged and lusterless, and the lunula decreased in size. There is a progressive reduction in the density of hair follicles per unit area on the face and scalp, independent of male-pattern alopecia. The hair shaft diameter is generally reduced but in some areas, especially the ears, nose, and eyebrows of men and the upper lip and chin in women, it is increased as vellus hairs convert to cosmetically compromising terminal hairs. Functional alterations noted in the skin of elderly persons include a decreased growth rate of the epidermis, hair, and nails, delayed wound healing, reduced dermal clearance of fluids and foreign materials, and compromised vascular responsiveness. Eccrine and apocrine secretions are diminished. The cutaneous immune and inflammatory responses are impaired, particularly cell-mediated immunity. Clinical correlates of these intrinsic aging changes of the skin include alopecia, pallor, xerosis, an increased number of benign and malignant epidermal neoplasms, increased susceptibility to blister formation, predisposition to injury of the dermis and underlying tissues, delayed onset and resolution of blisters and wheals, persistent contact dermatitis, impaired tanning response to ultraviolet light, increased risk for wound infections, prolongation of therapy necessary for onychomycosis, and thermoregulatory disturbances.

Anergy and the severely ill surgical patient

Delayed hypersensitivity skin test reaction was evaluated using Multitest CMI, an implement which provides seven standardized antigens in a single application. Eighty-two patients requiring Total Parenteral Nutrition for a variety of conditions were studied. The incidence of anergy was 65%. Seven anergic patients died, but there were no deaths in the reactive group, this difference being significant (P = 0.04). There was a significant association of anergy with carcinoma (P = 0.007) and anergic patients with carcinoma had a significantly greater risk of dying than reactive patients without carcinoma (P = 0.038). Anergic patients also had significantly lower nutritional parameters of serum albumin (P = 0.04), transferrin (P less than 0.001), absolute lymphocyte count (P = 0.009) and mid-arm muscle circumference (P = 0.02) compared to the reactive group.

In vivo and in vitro observation of cellular immune parameters in squamous cell carcinoma of the oral cavity and its correlation with tumor load and prognosis

In vivo and in vitro observations of cellular immune response in 70 patients with squamous cell cancer of the oral cavity and in 40 age-matched normal controls, were made using delayed hypersensitivity responses to DNCB, PPD, and Candida albicans extract (Dermatophytin 'O'), absolute lymphocyte counts, absolute T-cell numbers, and PHA-induced lymphocyte blastogenesis reactions as parameters. The results were correlated with clinical stage, tumor size, lymph node involvement, tumor differentiation, lymphoreticular responses, and outcome during a one-year follow-up period. A significant degree of impairment of both in vivo and in vitro parameters was found in oral cancer patients compared to normal control. The impairment was more prominent in advanced stages. Lymph node involvement was associated with impaired dermal hypersensitivity to recall antigens as well as a reduced T-cell population and blastogenic response. Only delayed hypersensitivity response to DNCB, PPD, and Candida showed a correlation with histologic features such as tumor differentiation and lymphoreticular response. Although absolute lymphocyte counts and T-cell population were reduced in the primary stage of the disease, the functional capacity of isolated lymphocytes to undergo blast formation was retained. PHA-induced lymphocyte blastogenesis showed a significant impairment only when the tumor was well established and disseminated beyond its local confines. Delayed hypersensitivity responses to DNCB, higher T-cell counts, and blastogenic indices were associated with recurrence-free survival. Immunologic parameters provide prognostic information beyond the clinical stage of the disease. Therefore, it seems that a multiparametric in vivo and in vitro observation of cellular immune response may be useful as an indicator of clinical course and prognosis of patients with squamous cell cancer of the oral cavity.

In vitro restoration of immune responses in aging humans by isoprinosine

The in vitro effects of isoprinosine (ISO) on the immune responses of aging humans were investigated. 64 healthy elderly humans (65 yr of age or over) were included in this study. Four immune parameters were measured, namely, Concanavalin A (ConA)-induced lymphocyte proliferation, natural killer cell (NK) activity, neutrophil chemotaxis, and interleukin-2 (IL-2) production. The ConA-induced lymphocyte proliferation was depressed in 55 of the 64 individuals (85.9%%), while the NK activity was depressed in 41 of the 64 individuals (64%). Neutrophil chemotaxis was depressed in 52 of the 64 individuals (81.1%) and IL-2 production was depressed in 35 of the 64 individuals (54.6%). In the presence of ISO, ConA-induced lymphocyte proliferation, NK activity, neutrophil chemotaxis, and IL-2 production were restored to normal or near normal levels in 50 of the 55 (90.0%), 35 of the 41 (85.3%), 44 of the 52 (84.6%), and 25 of the 35 (71.4%) aging humans, respectively. Our results indicate that ISO acts as an immune potentiator in these in vitro immune assays.

Ageing and the immune response--a unifying hypothesis?

In this article we review the abnormalities in immune function which have been described in relation to ageing. It is suggested that thymic involution may not be the only underlying cause. Many similar changes can be induced by the endotoxins from the cell walls of Gram-negative bacteria. The colon is a large repository for these organism and bacterial breakdown products are found in portal venous blood. Spillover into the peripheral circulation is prevented by the hepatic Kupffer cells degrading these substances. A waning in Kupffer cell function is well documented in association with ageing and there may be spillover of endotoxins into the peripheral circulation in elderly individuals. It is suggested that such spillover of endotoxins may contribute to some of the immunological changes previously attributed to ageing.

Interaction between Clostridium difficile and polymorphonuclear leucocytes from the elderly and post-operative cancer patients: phagocytosis and bactericidal function

The ability of polymorphonuclear leucocytes (PMNs) from elderly healthy subjects and post-operative cancer patients to ingest and kill Clostridium difficile was studied. The percentage of phagocytosis in clinically healthy subjects aged 69-82 years ranged from 20.2 +/- 3.2 (mean +/- SD) to 34.1 +/- 4.2, depending on the strain of C. difficile, from 6.7 +/- 2.2 to 11.2 +/- 2.2 in post-operative cancer patients aged 65-69, and from 68.4 +/- 3.1 to 81.1 +/- 6.3 in young healthy control subjects. In both study groups, the defect was in part serum-associated. Although the total number of bacteria killed by the PMNs was reduced in the two study groups, the percentage of ingested bacteria killed by the PMNs was similar to that in the young healthy subjects. These differences were not noted when Escherichia coli and Staphylococcus aureus were used as the test organisms. The defective PMN function against C. difficile in the elderly and post-operative cancer patients described in this study may offer an explanation as to why these individuals are at high risk of developing antibiotic-associated colitis.

Community-acquired bacterial pneumonia in the elderly

Pneumonia remains the leading infectious disease-related cause of death among the elderly. Streptococcus pneumoniae is the most frequent pathogen isolated from aged individuals with community-acquired pneumonia. Other common bacteria that cause this disease include Haemophilus influenzae and Legionella pneumophila. Manifestations of pneumonia in the elderly can be subtle and result in delayed recognition and treatment. Gram stain evaluation and culture of non-contaminated expectorated sputum remain the conventional techniques to guide initial antibiotic selection. While the presence of a new infiltrate on chest X-ray confirms the clinical diagnosis of pneumonia, the radiographic appearance of the infiltrate cannot accurately define the etiologic agent. Specific therapeutic measures include administration of appropriate antibiotics, correction of fluid and electrolyte imbalances, nutritional support and treatment of concomitant disorders. Preventive measures include use of influenza vaccine, amantadine and pneumococcal vaccine.

The relationship between cutaneous cellular immune responsiveness and mortality in a nursing home population

The survival over 18 months of 29 nursing home residents was compared with results of cutaneous testing of cell-mediated immunity at the start of the period of observation. Eight antigens were used to evaluate immunity by intradermal injection of each antigen and measurement of the areas of induration at 48 and 72 hours. A difference in responses was seen between the survivors and those who died, although this difference was statistically significant at 72 hours only. As expected, survivors had more (3.1, compared with 1.47) and larger (8.6 mm, compared with 3.2 mm) reactions at 72 hours than those who died.

Delayed cutaneous hypersensitivity in normals: choice of antigens and comparison to in vitro assays of cell-mediated immunity

In 81 normal subjects, ages 19 to 100 yr (mean 52), we studied the prevalence of positive 48 hr skin reactions to six antigens: fluid tetanus toxoid, Candida albicans, SK/SD, Trichophyton, PPD, and coccidioidin. Of these, C. albicans was most frequently reactive (92%); SK/SD (51%) and tetanus (49%) were less so. Each of the remaining three antigens was reactive in less than 42% of the subjects. The minimum number of antigens required to detect delayed hypersensitivity in 100% of subjects was two: C. albicans and tetanus. We found no correlation between skin reactivity at 20 min, 6 hr, and 48 hr for most of the antigens studied, suggesting different mechanisms for reactions occurring at each time. In 60 of the subjects, lymphocyte stimulation index (LSI) with tetanus toxoid and monocyte chemotaxis (MC) assays were done. The natural log of the area of induration at 48 hr after tetanus skin testing (I48) increased as a function of LSI (p less than 0.005) and MC (p less than 0.025) by multiple regression analysis. Skin testing was less sensitive than LSI as a test for cell-mediated immunity in our population. However, because of availability and correlation with LSI, delayed cutaneous hypersensitivity should be tested initially. For this purpose, tetanus toxoid appears to be a useful antigen when used in combination with C. albicans.

Restoration of immune responses of aging hamsters by treatment with isoprinosine

Immune competence declines with advanced age in hamsters, as in other laboratory mammals and in humans. We found significant alterations in the functional parameters of different populations of immunocytes (natural killer cells, T cells, monocytes, and suppressor cells) in aging hamsters, beginning at approximately 14 mo of age. Natural killer cytotoxicity, phytohemagglutinin-induced lymphocyte stimulation, and monocyte chemotaxis were decreased in aging Lak:LvG(Syr) outbred hamsters. When old hamsters were given a single injection (5 mg/kg body wt) of isoprinosine, a chemical immune potentiator, these three immune parameters increased almost to the levels found in young adult hamsters but returned to pretreatment levels after 7 d. Suppressor cell activity for the lymphocyte response to phytohemagglutinin, which increased with age, was decreased after treatment. In old hamsters treated with weekly injections of isoprinosine, these four immunological parameters remained at or near the levels found in young adults.

Persistent cutaneous cellular immune responsiveness in a nursing home population

Mantoux-type skin tests were applied to 29 elderly residents of an intermediate care floor of a nursing home. Eight antigens were used with each resident, and the size of the reactions was measured at 6, 24, 48, and 72 hours. All but one resident had at least one response greater than or equal to 3 mm at 48 or 72 hours, and most had more than one response of that size. At 48 compared with 72 hours, there was one more responder and the mean size of the reactions to each antigen was greatest. However, there were two responders at 72 hours who did not react at 48 hours, and the total number of reactions in the group was greater at the later reading. Only one resident did not produce any response at either 48 or 74 hours. The minimum number of antigens needed to identify all responsive subjects was five (PPD-Avian, coccidioidin, histoplasmin, streptokinase-streptodornase, and trychophytin). The purified protein derivative of tuberculin skin test was repeated on subjects who had an initial response less than 10 mm, and one increase of more than 6 mm was observed in a resident who was initially unresponsive to that antigen.

Delayed hypersensitivity. A critical evaluation of five recall antigens in a large reference population

The reactivity to five recall antigens, candida, mumps, PPD, varidase and trichophyton and the corresponding diluents was tested in 840 healthy persons aged between 17 and 101 years. Candida antigen was tested in a lower (l) and a higher (h) dose. The size of reactions did not follow a Gaussian distribution and we therefore used the 10th and 5th percentiles instead of standard deviation to define the limits between positive, weak and negative reactions. The number of positive reactions to each of candida-h, mumps, PPD and varidase was between 80 and 95 per cent in patients less than 60 years of age and above this age it varied between 0 and 85 per cent. The number of positive reactions to candida-l and trichophytin was low in all ages. The reactivity was regarded as normal if there was a positive reaction i.e.sum of right angle diameters >10 mm to atl east one antigen, relatively anergic if there was only a weak reaction (7-9 mm) and anergic if there was a negative reaction (0-6 mm) to all antigens. A normal reaction was found in 100 per cent of subjects up to 60 years of age, and in 95 per cent up to 30 years. Among those with normal reactivity, positive results were found with candida-h alone in between 67-93 per cent, candida-h + mumps between 92-100 per cent and candida + mumps + PPD in 100 per cent irrespective of age.

Biological markers and breast cancer. A multiparametric study. II. Depressed immune competence

Immune functions were evaluated in 207 carefully staged breast cancer patients, 54 patients with benign breast diseases and 152 normal controls. All patients were followed for at least five years and the prognostic significance of immune competence determined at diagnosis was established. The parameters employed were dermal hypersensitivity to four skin test antigens and to 2,4-dinitrochlorobenzene (DNCB), blastogenic responses to PHA (phytohemagglutinin), ConA (Concanavalin A), and PW (Pokeweed mitogen) mitogens and percentage of T- and B-lymphocytes. A significant degree of impairment of immune functions was found in breast cancer patients when compared to controls; this was illustrated by depressed T-cell counts and low responses to PHA, ConA and PW mitogens and by depressed responses to recall antigens. However, only lymphocyte stimulation with PHA, percentage of T-cells and dermal hypersensitivity tests showed a continued decrease with advancing stages of the disease. Moreover, among cancer patients with low responses to recall antigens, 61% died before five years, 16% showed progressive disease and only 22% were disease-free after five years of follow-up; compared to 30, 18 and 52%, respectively, in patients with normal responses to recall Ags (overall P value less than or equal to 0.005). A similar relation could be illustrated in patents with low PHA responses as 42% of these patients died before five years, 19% showed progressive disease and 39% were disease-free compared to 26, 19, and 54%, respectively. In patients with normal PHA responses (overall P value less than or equal to .05). It is concluded that initial immunocompetence, determined by parameters of cell-mediated immunity, could be significantly depressed in patients with localized or even premalignant breast disease as well as in advanced cancer. Depressed responses to PHA and dermal hypersensitivity to recall antigens seem to indicate a poorer prognosis. There is no single ideal biological marker as yet. Combined with our previous results on serum proteins, this current study may help us, at the time of initial treatment, in the identification of a subset of Stage I breast cancer patients likely to do poorly.

Utility of skin testing in nutritional assessment: a critical review

To evaluate the claim that delayed cutaneous hypersensitivity skin testing is useful in nutritional assessment of hospitalized patients, we reviewed the English language literature of the last 12 years. Although several hundred publications discussed delayed cutaneous hypersensitivity testing and nutritional status, only 15 provided new, objective data correlating these variables in hospitalized adults. Of these, only three provided age-matched control groups to control for antigen variability, lack of prior exposure, and other technical problems. The majority of reports took no account of diseases (cancer, immune disease, infection) or therapies (radiation, drugs, surgery) known to affect skin test response. In the reports specifying different degrees of malnutrition, the most important group, those with less than obvious malnutrition, were not abnormal by skin testing. Ten reports described serial skin testing during nutritional intervention. Non reported serially tested controls without nutritional intervention, important since serial testing alone can augment skin test response. Nonnutritional intercurrent therapy which might affect skin tests was seldom mentioned. In the few reports specifying that nutritional repletion was even achieved, repleted patients were not separated from unrepleted in subsequent analyses. No report examined skin testing for its predictive accuracy, cost/benefit ratio, or influence on outcome. Because of these problems in experimental design, the frequent lack of appropriate controls, and the low specificity of abnormal delayed cutaneous hypersensitivity responses, we conclude that the utility of skin testing in nutritional assessment remains unproved.

The thymus: clock for immunologic aging?

A brief overview of the effects of age on T cell function is presented. Normal immune functions can begin to decline shortly after an individual reaches sexual maturity. Foremost among the cellular changes are those in the stem cells as reflected in their growth properties and the availability of precursor T cells, and in the T cells, in which a shift in subpopulations may be occurring. Present evidence indicates that thymic involution precedes, and therefore may be responsible for, the age-dependent decline in the ability of the immune system to generate functional T cells. It now appears that the primary effect of thymic involution is on a T cell differentiation pathway; the more mature T cells are affected first, the less mature T cells only later. Thus, the thymus may be the aging clock for the immune system. Current studies are centered on processes regulating growth and atrophy of the thymus, and methods for restoring the impaired immune function of elderly individuals.

An overview of immune aging

A brief overview of the effect of age on the function of cells of the immune system is presented. Normal immune functions can begin to decline shortly after an individual reaches sexual maturity. Foremost among the cellular changes are those in the stem cells as reflected in their growth properties and the availability of precursor T cells, and in the T cell where a shift in subpopulations may be occurring. Present evidence indicates that thymic involution precedes and therefore may be responsible for the age dependent decline in the ability of the immune system to generate functional T cells. It now appears that the primary effect of thymic involution is on a T cell differentiation pathway affecting the more mature T cells first and only later the less mature T cells. Thus, the thymus may be the aging clock for the immune system. Future studies should be centered around processes regulating growth and atrophy of the thymus.

Zinc and immunocompetence in protein-energy malnutrition

Malnourished children have thymic atrophy which is reversed by zinc supplementation. To see if their defect in cell-mediated immunity was also associated with zinc deficiency ten children were skin-tested with Candida antigen on both arms. One test site was covered with local zinc sulphate and the other with placebo ointment. There was a highly significant increase in the typical delayed-hypersensitivity reaction at the site covered with zinc. The magnitude of the difference between the supplemented and unsupplemented arms correlated negatively with the plasma-zinc concentration. These data show that zinc deficiency is a cause of the immunoincompetence seen in malnutrition. The normal reactions of the zinc-supplemented side indicate that, of the many nutritional deficits of malnourished children, zinc deficiency specifically impairs the cell-mediated immune system. Local skin-testing with and without zinc may provide a measure of zinc status. Local application of zinc may enhance the reliability of tests to diagnose diseases such as tuberculosis in malnourished patients.

Skin reactivity to Candida and streptokinase-streptodornase antigens in normal pediatric subjects: influence of age and acute illness

Tests for delayed cutaneous hypersensitivity were carried out with Candida and streptokinase-streptodornase antigens in 245 normal pediatric subjects, ranging in age from 17 days to 5 10/12 years. The group comprised patients with a variety of acute illnesses and a series of control subjects. There was a progressive increase in the frequency of cutaneous responses with age. About one-third of infants under one year and four-fifths of one to five-year-old children had positive induration reactions to at least one antigen. Candida was the more reactive antigen in the first year of life; thereafter there was comparable responsiveness to both antigens. Our results showed no difference in percent reactivity between acutely ill and control subjects.

Peripheral blood lymphocyte response to phytomitogens in systemic lupus erythematosus

The response of peripheral blood lymphocytes to the phytomitogens, PHA, Con A, and PWM, was evaluated in 30 SLE patients and in 30 age, sex, and race-matched controls using dose and time responses. The proliferative response to the three phytomitogens was not depressed in this group of subacute and chronic SLE patients. Active lupus nephritis and a slow acetylator phenotype were associated with a decreased lymphocyte response. The incidence of a slow acetylator phenotype in spontaneous SLE was 68%. In interpreting the lymphocyte response to phytomitogens, the importance of a clear definition of the SLE group under study, the activity of the disease, and treatment status are emphasized.