Efficacy and safety of allergen immunotherapy in patients with allergy to molds: A systematic review.

BACKGROUND: Allergen immunotherapy (AIT) with mould extracts has been performed for many years but the final demonstration of its clinical efficacy is still missing, due to the small number of studies and their inconsistent results. OBJECTIVE: To systematically review efficacy and safety of AIT for the treatment of respiratory allergies to moulds. DESIGN: The primary outcomes were safety and reduction of symptoms (Symptom Score, SS) and medication use (Medication Score, MS) in patients treated with AIT compared to controls. The strength of the evidence was graded based on the risk of bias, consistency and magnitude of effect, according to the GRADE Working Group's guide. DATA SOURCES: Medline, Web of Science and the Cochrane Library (through September 2017) supplemented with manual searches of reference lists. ELIGIBILITY CRITERIA: Randomized studies of intervention comparing AIT to placebo/pharmacotherapy. Studies not reporting on our outcome of interest or without a control population were excluded. RESULTS: Nine studies (168 children, 99 adults; median sample size, 27) met the inclusion criteria. The risk of bias was moderate-to-high in all but one study. Low strength evidence supports the assumption that AIT is effective in reducing symptoms and medication use, with only four of nine studies reporting higher benefit of AIT vs. comparators. The highest benefit of AIT compared to pharmacotherapy/placebo was reported in studies with a longer follow-up (SMD for MS from -3.96 to -3.97 in favour of AIT) and low risk of bias (VAS for SS: 66.3 ± 13 in AIT group; 186.6 ± 39 in comparators; P < 0.05). No difference was reported with respect to study sample size, route of administration, age of participants. Generalised adverse reactions were reported in 12.5% of participants treated with sublingual immunotherapy, and 37.2% of participants treated with subcutaneous immunotherapy. CONCLUSIONS: Low strength evidence suggests that mould AIT is efficacious for the treatment of respiratory allergies. High-quality studies with an adequate sample size are needed.

Immunological and non-immunological mechanisms of allergic diseases in the elderly: biological and clinical characteristics.

A better hygiene, a Westernized diet, air pollution, climate changes, and other factors that influence host microbiota, a key player in the induction and maintenance of immunoregulatory circuits and tolerance, are thought to be responsible for the increase of allergic diseases observed in the last years. The increase of allergic diseases in elderly is related to the presence of other factors as several comorbidities that should interfere with the development and the type of allergic reactions. A central role is played by immunosenescence responsible for modifying response to microbiota and triggering inflamm-ageing. In addition, in elderly there is a shift from Th1 responses vs. Th2, hence favouring allergic responses. Better understanding of the mechanisms of immunosenescence and its effects on allergic inflammation will most certainly lead to improved therapy.

How to fit allergen immunotherapy in the elderly.

Asthma, allergic rhinitis (AR) and atopic dermatitis are very common in young people, but in the latest decades it was increasingly recognized that also individuals of higher ages, including the population over 65 years, are concerned. Actually, it is now acknowledged the aging does not considerably alter the immune response to allergens. Allergen immunotherapy (AIT) is the only treatment that works on the causes of allergy, but elderly people are commonly excluded from AIT, except the cases of insect sting allergy. A number of recent studies showed that aged individuals also successfully respond to AIT for respiratory allergy. Therefore, there is no reason to exclude elder patients from AIT. Anyhow, clinical conditions that are considered absolute or relative contraindications are quite frequent in this aged population, thus the risk/benefit ratio must be carefully evaluated for each patient, taking into account that the more frequent occurrence of co-morbidities and the consequent need of daily-based multidrug regimen can favor adverse effects. An important issue concern the ability of AIT, and particularly of sublingual immunotherapy, to significantly improve the quality of life, that often is particularly impaired in the elderly, reducing symptoms and drugs consumption.

Assessment of a qualitative serological assay to screen for allergic sensitization in elderly subjects.

We used a commercially available specific IgE qualitative serological assay to screen for allergic sensitization. Two hundred twenty-eight elderly subjects took part in the study. Skin-prick tests (SPTs) to a panel of relevant aeroallergens present in the study area were used as the diagnostic reference procedure (gold standard). Subjects with at least one positive SPT (≥3 mml n = 76) were considered to have developed an allergic sensitization. The qualitative assay correctly classified subjects as sensitized to an allergen or not sensitized in 257 of 288 cases (accuracy, 88.9%; 95% CI, 85.0-92.0%). The qualitative assay sensitivity was 70.0 (95% CI, 58.1-79.7) and specificity was 95.7 (95% CI, 92.1-98.0), positive predictive value (PPV) was 85.4 (95% CI, 85.1-93.4), negative predictive value (NPV) was 89.8 (95% CI, 85.1-93.4), positive likelihood ratio (LR(+)) was 16.5 (95% CI, 8.7-31.6), negative LR (LR(-)) was 0.31 (95% CI, 0.21-0.43), and the diagnostic odds ratio (DOR) was 52.2 (95% CI, 21.5-133.6). In the elderly subjects with respiratory symptoms, the qualitative assay correctly classified subjects as allergen sensitized or nonsensitized in 81 of 89 cases (accuracy, 91.0; 95% CI, 85.0-96.9). In this subgroup, the qualitative assay sensitivity was 94.6 (95% CI, 85.1-98.8), specificity was 84.8 (95% CI, 68.1-94.9), PPV was 91.3 (95% CI, 81.0-97.1), and NPV was 90.3 (95% CI, 74.2-97.9). LR(+) was 6.2 (95% CI, 3.0-14.2), LR(-) was 0.06 (95% CI, 0.02-0.17), and the DOR was 98.9 (95% CI, 18.0-621.4). The qualitative serological assay is a valuable tool for the diagnosis of allergic sensitization in a population of elderly subjects.

Efficacy of subcutaneous and sublingual immunotherapy with grass allergens for seasonal allergic rhinitis: a meta-analysis-based comparison.

BACKGROUND: Subcutaneous (SCIT) and sublingual (SLIT) immunotherapy are the 2 most prescribed routes for administering allergen-specific immunotherapy. They were shown to be effective in control of symptoms and in reducing rescue medication use in patients with allergic diseases, but their effectiveness has to be balanced against side effects. In recent years, SLIT has been increasingly prescribed, instead of SCIT, because of improved safety and easy administration. OBJECTIVE: We assessed which route is the most effective in the treatment of patients with seasonal allergic rhinitis to grass pollen. METHODS: An indirect meta-analysis-based comparison between SCIT and SLIT was performed. Treatment efficacy was determined as the standardized mean difference (SMD) in symptom and medication scores obtained with active treatment, SCIT or SLIT, compared with placebo. Studies were included if they were double-blind randomized controlled trials comparing SCIT or SLIT with placebo. Thirty-six randomized controlled trials (3014 patients; 2768 controls) were analyzed. RESULTS: The overall effect size of SCIT for symptom score (SMD, -0.92; 95%CI, -1.26 to -0.58) was significantly higher than SLIT, both administered via drops (SMD, -0.25; 95% CI, -0.45 to -0.05) and tablets (SMD, -0.40; 95%CI, -0.54 to -0.27). Similar results were reported for medication score (SCIT: SMD, -0.58; 95% CI, -0.86 to -0.30. SLIT drops: SMD, -0.37; 95% CI, -0.74 to -0.00. SLIT tablets SMD, -0.30; 95% CI, -0.44 to -0.16). CONCLUSIONS: Our results provide indirect but solid evidence that SCIT is more effective than SLIT in controlling symptoms and in reducing the use of antiallergic medications in seasonal allergic rhinoconjuntivitis to grass pollen.

What Evidence-based Medicine (EBM) Doesn't Say About Allergen-specific Immunotherapy (AIT).

Evidence-based allergology for the treatment of allergic rhinitis with allergen-specific immunotherapy (AIT) has been used in publications by the companies manufacturing AIT. The purpose of randomized controlled trials (RCTs) is to provide physicians, health authorities, patients, and their families with the best evidence upon which to base treatment decisions. However, some RCT results may do more harm than good because they serve the commercial interests of the companies producing and marketing AIT more than the interests of patients. Allergic rhinitis is a trivial disease that is not life-threatening and is easily controlled by drugs. In this paper, we analyze some of the more controversial points underlying the EBM supporting the use of AIT. The paradox behind RCT-based practice is that AIT is based on the results of incorrectly interpreted RCTs. International scientific societies and drug regulatory bodies should analyze trials more carefully, considering potential conflicts of interest.

Allergic Diseases in the Elderly.

Recent increases in allergic diseases are thought to be caused by better hygiene, Westernized diets, air pollution, climate change, and other factors that influence host microbiota, a key player in the induction and maintenance of immunoregulatory circuits and tolerance. The increase of allergic diseases in the elderly is also related to additional factors, such as various comorbidities that may interfere with the development and the type of allergic reactions. Immunosenescence plays a central role in these reactions, altering microbiota responses and triggering inflammageing. In addition, in the elderly, there is a shift from Th1 to Th2 immunity, thus favoring allergic responses. A better understanding of the mechanisms responsible for immunosenescence and its effects on allergic inflammation will most certainly lead to improved therapies.

Differences and similarities between allergic and nonallergic rhinitis in a large sample of adult patients with rhinitis symptoms.

BACKGROUND: Allergic rhinitis (AR) and nonallergic rhinitis (NAR) may present with different clinical and laboratory characteristics. METHODS: A total of 1,511 consecutive patients, aged 18-81 years, diagnosed with rhinitis, 56% females and 44% males, underwent complete allergic evaluation including skin prick test, blood eosinophil counts, nasal eosinophil counts, peak nasal inspiratory flow (PNIF) measurement and evaluation of nasal symptoms using a visual analog scale (VAS). RESULTS: A total of 1,107 patients (73%)had AR, whereas 404 (27%) had NAR. Patients with NAR were older and predominantly female. A higher nasal eosinophils count was associated with AR and a lack of clinical response to antihistamines. AR patients had more sneezing and nasal pruritus, whereas NAR was characterized mainly by nasal obstruction and rhinorrhea. AR patients had more severe symptoms and recurrent conjunctivitis, whereas NAR patients had slightly more frequent episodes of recurring headaches as well as olfactory dysfunction. PNIF, blood eosinophil counts and VAS of nasal symptoms were higher in patients with AR. In a final logistic regression model, 10 variables were statistically different between AR and NAR: age [OR 0.97 (95% CI 0.96-0.98)], sneezing [OR 4.09 (95% CI 2.78-6.00)], nasal pruritus [OR 3.84 (95% CI 2.60-5.67)], mild symptoms [OR 0.21 (95% CI 0.09-0.49)], intermittent/severe nasal symptoms [OR 3.66 (95% CI 2.06-6.50)], VAS [OR 1.06 (95% CI 1.04-1.08)], clinical response to antihistamines [OR 22.59 (95% CI 13.79-37.00)], conjunctivitis [OR 4.49 (95% CI 2.86-7.05)], PNIF [OR 1.01 (95% CI 1.00-1.01)] and nasal eosinophil counts [OR 1.14 (95% CI 1.10-1.18)]. Receiver operating characteristic analysis showed high predictive accuracy for a model including these variables independently of the diagnosis of AR/NAR (cutoff <0.74). CONCLUSIONS: We showed that the several clinical and laboratory parameters reported above may help to reinforce or exclude the diagnosis of AR obtained with skin prick test.

Polymorphisms of cyclo-oxygenases and 5-lipo-oxygenase-activating protein are associated with chronic spontaneous urticaria and urinary leukotriene E4.

The mechanisms of chronic spontaneous urticaria (CSU) continue to be unknown. Our working hypothesis is that polymorphisms of cyclo-oxygenases and 5-lipo-oxygenase-activating protein may be involved in the pathways leading to CSU. We examined five candidate polymorphisms of cyclo-oxygenases 1 and 2 and of 5-lipo-oxygenase-activating protein in 109 controls and in 94 CSU patients from Northern Italy. We also examined the levels of urinary leukotriene E4 (LTE4) before and after challenge with ASA. A multiple regression model was found to show that COX-2 5'UTR T/G, COX-2 Exon 10 T/C, and FLAP -336 G/A polymorphisms were significantly associated with CSU, with the minor allele more represented in CSU group. Similar results were obtained as regards the specific association with ASA-tolerated CSU and ASA-exacerbated CSU. Evaluating a polygenic model, reflecting the sum of the concomitant alleles associated with CSU (i.e. COX-2 5'UTR G allele, COX-2 Exon 10 C allele, and FLAP -336 G/A allele), the proportion of CSU patients increased progressively with the increasing number of unfavourable alleles. Finally, in a linear regression model after adjustment for disease status COX-1 22 T carriership remained a significant predictor of post-challenge high urinary LTE4 levels. Our results support the hypothesis that polymorphisms of cyclo-oxygenases and 5-lipo-oxygenase-activating protein may be associated with CSU.

Efficacy of sublingual immunotherapy with grass allergens for seasonal allergic rhinitis: a systematic review and meta-analysis.

BACKGROUND: The benefit of sublingual immunotherapy (SLIT) with grass allergens for seasonal allergic rhinitis has been extensively studied, but data on efficacy are still equivocal. OBJECTIVE: To assess the effectiveness of SLIT with grass allergens in the reduction of symptoms and medication in patients with seasonal allergic rhinitis to grass pollen. METHODS: Computerized bibliographic searches of MEDLINE (1995-2010) were supplemented by hand searches of reference lists. Studies were included if they were double-blind randomized controlled trials (RCTs) comparing SLIT to placebo and if they included patients with history of allergy to grass pollen treated with natural grass pollen extracts. Nineteen RCTs with 2971 patients were analyzed. The outcomes assessed were symptom and medication scores. RESULTS: Using a random-effects model, SLIT with grass allergens significantly reduces both symptoms (standardized mean difference, -0.32; 95% CI, -0.44 to -0.21) and medication use (standardized mean difference, -0.33; 95% CI, -0.50 to -0.16) compared with placebo. The treatment is more efficacious in adults than in children. Prolonging duration of preseasonal treatment for more than 12 weeks improves the treatment efficacy. CONCLUSION: This meta-analysis found that SLIT with grass allergens is effective in patients with seasonal allergic rhinitis compared with placebo. The benefit is clinically modest, and criteria are needed to identify patients most likely to benefit from SLIT.

Evaluation of serum s-IgE/total IgE ratio in predicting clinical response to allergen-specific immunotherapy.

BACKGROUND: To date, no predictive tests for the clinical response to allergen-specific immunotherapy (ASI) are available. Therefore an in vivo or in vitro test would be of great value. OBJECTIVE: We sought to evaluate pretreatment parameters used in diagnosing allergic rhinitis and determining serum specific IgE (s-IgE) levels, serum total IgE (t-IgE) levels, and blood eosinophil counts and to identify whether can be used to predict clinical improvement in monosensitized patients with allergic rhinitis with or without asthma treated with immunotherapy. METHODS: We analyzed 279 patients who had undergone 4 years of ASI administered either by means of the subcutaneous immunotherapy (76 patients) or sublingual immunotherapy (203 patients) routes. Serum t-IgE and s-IgE levels, blood eosinophil counts, and serum s-IgE/t-IgE ratios were calculated and tested for correlation with clinical response to ASI. Receiver operating characteristic curves were determined. Predicted probabilities and predictive areas under the curve were calculated. RESULTS: The clinical response to ASI was effective in 145 (52.0%) of 279 total patients, 42 (55.2%) of 76 patients treated with subcutaneous immunotherapy, and 103 (50.7%) of 203 patients treated with sublingual immunotherapy. A significant correlation was found between the serum s-IgE/t-IgE ratio and the clinical response to ASI, with high ratios (>16.2) associated with an effective response. The sensitivity and specificity of the area under the curve of the ratio were higher than those of serum s-IgE and t-IgE alone. CONCLUSION: The calculation of the serum s-IgE/t-IgE ratio for predicting the clinical response to ASI offers an advantage over measuring t-IgE and s-IgE levels in monosensitized patients for the following allergens: grass, Parietaria judaica, Olea europea, and house dust mite.

Small, dense low-density lipoproteins (LDL) are predictors of cardio- and cerebro-vascular events in subjects with the metabolic syndrome.

OBJECTIVE: Small, dense low-density lipoproteins (LDL) are a feature of the metabolic syndrome (MS) but their predictive role still remains to be established. We performed a 2-year follow-up study in 124 subjects with MS (63 +/- 6 years), as defined by the American Heart Association/National Heart, Lung and Blood Institute guidelines, to assess clinical and biochemical predictors of cerebro- and cardio-vascular events. METHODS AND RESULTS: Beyond traditional cardiovascular risk factors, we measured LDL size and subclasses by gradient gel electrophoresis. Clinical events were registered in the 25% of subjects. At univariate analysis subjects with events had increased prevalence of elevated fasting glucose (P = 0.0117), smoking (P = 0.0015), family history of coronary artery disease (P = 0.0033) and higher levels of total- and LDL-cholesterol (P = 0.0027 and P = 0.0023, respectively); LDL size was lower (P < 0.0001), due to reduced larger subclasses and increased small, dense LDL (all P < 0.0001). At multivariate analysis the following were independent predictors of events (univariate odd ratios were calculated): low HDL-cholesterol (OR 15.4, P = 0.0238), elevated fasting glucose (OR 12.1, P = 0.0102), elevated small, dense LDL (OR 11.7, P = 0.0004), elevated blood pressure (OR 9.2, P = 0.0392), smoking (OR 4.8, P = 0.0054). CONCLUSIONS: This is the first study that assessed the predictive role of small, dense LDL beyond traditional cardiovascular risk factors in subjects with MS.

Similarity and differences in elderly patients with fixed airflow obstruction by asthma and by chronic obstructive pulmonary disease.

BACKGROUND: Epidemiologic studies have demonstrated that elderly patients with fixed airflow obstruction can be affected by asthma or chronic obstructive pulmonary disease (COPD). METHODS: We studied 49 consecutive elderly outpatients, presenting fixed airflow obstruction, by clinical history (smoking), pulmonary function tests, blood gas analysis, and induced sputum. RESULTS: The age was not different in patients with COPD (n=28) and asthma (n=21) (70.2+/-3.9 years vs. 69.6+/-3.7 years), also the degree of fixed airflow obstruction was similar (FEV1: 58.3+/-1.5% vs. 59.0+/-1.4% of predicted). Patients with asthma had significantly more eosinophils in peripheral blood (0.43+/-0.05x10(-3)microL vs. 0.27+/-0.1x10(-3)microL, P<0.0001), and in induced sputum (5.0% [(p25th and p75th) 5.0-6.0%] vs. 1.0% [(p25th and p75th) 0.01-1.0%]; P<0.0001), as well as serum ECP (18.6+/-4.9ng/mL vs. 7.7+/-4.7ng/mL, P<0.0001) and ECP in the induced sputum (31.6+/-2.9ng/mL vs. 5.6+/-4.9ng/mL, P<0.0001). Finally, in induced sputum the eosinophils EG2+ were higher in patients with asthma than in patients with COPD (40.5 [(p25th and p75th) 39.3-44.3] MFI vs. 3.9 [(p25th and p75th) 0-11.4] MFI, P<0.0001). They also had significantly higher diffusing capacity, and a greater reversibility to steroids, after 14-day course of therapy, whereas the reversibility to 400microg of salbutamol was similar. CONCLUSION: Despite similar fixed airflow obstruction, elderly patients with asthma have distinct characteristics compared with patients with COPD.

Comparative effect of tacrolimus 0.1% ointment and clobetasol 0.05% ointment in patients with oral lichen planus.

BACKGROUND: Oral lichen planus (OLP) is considered to be an autoimmune disease of unknown aetiology that affects the mucosae, especially the oral cavity. OBJECTIVE: We compared tacrolimus 0.1% ointment and clobetasol 0.05% ointment for the treatment of OLP. PATIENTS AND METHODS: A total of 32 patients (20 females and 12 males; all white, Italian origin, mean age of 43.6+/-18.4 years; 16 patients per treatment group) were treated with tacrolimus or clobetasol ointment for 4 weeks in a randomized, double-blind, clinical trial. Pain severity, burning sensation, and mucosal lesion extension were assessed using a four-point scale. RESULTS: At the end of the treatment period, symptom scores were significantly lower in the tacrolimus group than in the clobetasol group. CONCLUSION: The results of this study suggest that tacrolimus 0.1% ointment is more effective than clobetasol propionate 0.05% ointment in the treatment of OLP. However, other studies are needed to confirm the effectiveness of this treatment before it can be recommended for use in clinical practice.

The characteristics of different diagnostic tests in adult mild asthmatic patients: comparison with patients with asthma-like symptoms by gastro-oesophageal reflux.

BACKGROUND: Diagnosing asthma cannot be always easy. It is important to consider the validity of the diagnostic tests, and/or how much more commonly they are positive in patients with asthma compared to healthy subjects and, particularly, to patients with asthma-like symptoms. OBJECTIVE: To evaluate the validity of diagnostic tests for asthma, in terms of sensitivity, specificity, positive and negative predictive values, in patients with bronchial asthma compared to patients affected by gastro-oesophageal reflux disease (GERD) with asthma-like symptoms, and healthy control subjects without asthma and gastro-oesophageal reflux (GER). DESIGN: Single-center, cross-sectional, observational study. PATIENTS: We studied 60 patients with mild asthma, 30 patients with GERD and asthma-like symptoms and 25 healthy control subjects. MEASUREMENTS: We measured provocative concentration of methacholine causing a 20% fall in the forced expiratory volume in 1s (MCh PC(20)/FEV(1)), the amplitude percent mean of peak expiratory flow (A%M of PEF), derived from twice-daily readings for >2 weeks, the FEV(1)/forced vital capacity (FEV(1)/FVC) ratio, the eosinophil count in blood and in induced sputum and the serum eosinophil cationic protein (ECP) levels. RESULTS: FEV(1)/FVC ratio, A%M of PEF, blood eosinophils counts and serum ECP levels were less sensitive and specific when the reference population was composed of patients with asthma-like symptoms by GER. While, MCh PC(20)/FEV(1) and induced sputum eosinophils count were the most sensitive (both 90%) and specific (89% and 92%, respectively) tests. CONCLUSION: Our findings demonstrate that MCh PC(20)/FEV(1) and the induced sputum eosinophil count are the most useful objective tests in patients with mild asthma. All patients with asthma presented both an MCh PC(20)/FEV(1) <1500 microg and eosinophils count in the induced sputum >1%.

The effect of allergen immunotherapy in the onset of new sensitizations: a meta-analysis.

BACKGROUND: Although the preventive efficacy of allergen immunotherapy (AIT) in the onset of new allergen sensitizations has been asserted by many reviews, position papers, and consensus conferences, the evidence available is from only 3 studies. The objective of this work was a systematic review to evaluate the preventive efficacy of AIT in the onset of new allergen sensitizations. The end-point was the risk difference (RD) in the onset of new allergen sensitizations between patients treated with AIT and pharmacotherapy. METHODS: Computerized bibliographic searches of MEDLINE, EMBASE, and the Cochrane Library (until November 30th, 2016) were done. Random-effects and fixed-effects model meta-analyses were performed. Randomized controlled trials or observational studies comparing children treated with AIT with house dust mite (HDM) to subjects who did not receive AIT, with a long-term observation period (at least 3 years including treatment and follow-up) have been included. RESULTS: Eight studies totaling 721 children (390 treated with AIT and 331 with pharmacotherapy) met the inclusion criteria. The risk of bias was high. Low evidence supports the conclusion that AIT prevents the onset of new allergen sensitizations, with 3 of 8 studies reporting a reduction in the onset of new sensitizations in patients treated with AIT vs pharmacotherapy. Our meta-analysis found no difference between AIT and pharmacotherapy, with high heterogeneity (RD, -0.10; 95% confidence interval [CI], -0.31 to 0.11; p = 0.32; I2 = 91.4%). CONCLUSION: The data of this systematic review do not support a preventive effect in the onset of new allergen sensitizations, in children treated with AIT in comparison with those treated with pharmacotherapy.

A study of serum immunoglobulin levels in elderly persons that provides new insights into B cell immunosenescence.

The literature on immunosenescence has focused mainly on T cell impairment. With the aim of gaining insight into B cell immunosenescence, we investigated the serum immunoglobulin levels in a cohort of 166 subjects (20-106 years). Serum IgG (and IgG subclasses) were quantified by the nephelometric technique, IgE by CAP system fluorescence enzyme immunoassay, and IgD by radial immunodiffusion (RID). There was an age-related increase of IgG and IgA; the IgG age-related increase was significant only in men, but IgG1 levels showed an age-related increase both in men and women, whereas IgG3 showed an age-related increase only in men. IgE levels remain unchanged, whereas IgD and IgM serum levels decreased with age; the IgM age-related decrease was significant only in women, likely due to the relatively small sample of aged men. Thus, in the elderly the B cell repertoire available to respond to new antigenic challenge is decreased. A lot of memory IgD- B cells are filling immunological space and the amount of naïve IgD+ B cells is dramatically decreased. This shift away from a population of predominantly naïve B cells obviously reflects the influences of cumulative exposure to foreign pathogens over time. These age-dependent B cell changes indicate that advanced age is a condition characterized by lack of clonotypic immune response to new extracellular pathogens. In any event, the increase of memory B cells and the loss of naïve B cells, as measured by serum IgD levels, could represent hallmarks of immunosenescence and could provide useful biomarkers possibly related to the life span of humans.