Detection of cytokines in nasal lavage samples of patients with cystic fibrosis: comparison of two different cytokine detection assays.

BACKGROUND: Cystic fibrosis (CF) is a genetic multisystem disorder. Inflammatory processes, which presumably begin early in infancy, play a crucial role in the progression of the disease. The detection of inflammatory biomarkers, especially in the airways, has therefore gained increasing attention. Due to improved treatment options, patients with CF produce less sputum. Nasal lavage samples therefore represent a promising alternative to induced sputum or bronchoalveolar lavage specimens. However, methodology of cytokine measurements is not standardised and comparisons of results are therefore often difficult. The aim of this study was to identify suitable detection methods of cytokines in nasal lavage samples by comparison of two different assays. METHODS: Nasal lavage samples were obtained from the same patient at the same time by trained respiratory physiotherapists using a disposable syringe and 10 ml of 0.9% sodium chloride per nostril during outpatient visits. The cytokines IL-17 A, IL-2, IL-6 and IL-10 were measured using two different assays (BD™ and Milliplex®), which have already been applied in sputum and nasal lavage samples, despite different lower detection limits. RESULTS: 22 participants were included in the study. In 95.5% of measurements, values were below the limit of detection with respect to the BD™ assay. Only IL-6 could be detected in approximately half of the patients. Individual cytokine levels were considerably higher when measured with Milliplex®, which is also reflected in a statistically significant manner (p = < 0.01). CONCLUSION: The right choice of analysis method is crucial for measuring inflammatory markers in nasal lavage samples. Compared to the literature, Milliplex® showed higher detection rates and similar concentrations to other studies. TRIAL REGISTRATION: Ethics approval was obtained from the ethics committee at Medical University of Innsbruck (EK Nr: 1055/2022).

Method comparison of HPLC-ninhydrin-photometry and UHPLC-PITC-tandem mass spectrometry for serum amino acid analyses in patients with complex congenital heart disease and controls.

INTRODUCTION: Metabolomics studies are not routine when quantifying amino acids (AA) in congenital heart disease (CHD). OBJECTIVES: Comparative analysis of 24 AA in serum by traditional high-performance liquid chromatography (HPLC) based on ion exchange and ninhydrin derivatisation followed by photometry (PM) with ultra-high-performance liquid chromatography and phenylisothiocyanate derivatisation followed by tandem mass spectrometry (TMS); interpretation of findings in CHD patients and controls. METHODS: PM: Sample analysis as above (total run time, ~ 119 min). TMS: Sample analysis by AbsoluteIDQ® p180 kit assay (BIOCRATES Life Sciences AG, Innsbruck, Austria), which employs PITC derivatisation; separation of analytes on a Waters Acquity UHPLC BEH18 C18 reversed-phase column, using water and acetonitrile with 0.1% formic acid as the mobile phases; and quantification on a Triple-Stage Quadrupole tandem mass spectrometer (Thermo Fisher Scientific, Waltham, MA) with electrospray ionisation in the presence of internal standards (total run time, ~ 8 min). Calculation of coefficients of variation (CV) (for precision), intra- and interday accuracies, limits of detection (LOD), limits of quantification (LOQ), and mean concentrations. RESULTS: Both methods yielded acceptable results with regard to precision (CV < 10% PM, < 20% TMS), accuracies (< 10% PM, < 34% TMS), LOD, and LOQ. For both Fontan patients and controls AA concentrations differed significantly between methods, but patterns yielded overall were parallel. CONCLUSION: Serum AA concentrations differ with analytical methods but both methods are suitable for AA pattern recognition. TMS is a time-saving alternative to traditional PM under physiological conditions as well as in patients with CHD. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier NCT03886935, date of registration March 27th, 2019 (retrospectively registered).

The value of axillary skin electron microscopic analysis in the diagnosis of lysosomal storage disorders.

Both lysosomal storage diseases and mitochondrial diseases are a group of genetic-inherited metabolic disorders. In an era, where "old fashioned methods" are apparently being replaced by evolving molecular techniques (i.e. exome and whole genome sequencing), the "old fashioned methods" might help to characterise and thus narrow down the potential differential diagnosis. Therefore, we retrospectively evaluated the relevance of electron microscopy of axillary skin for the diagnosis of lysosomal storage or mitochondrial diseases (=inherited metabolic disorders of energy metabolism). Methods and patients: We included 74 patients with developmental delay with regression or neurodegeneration who underwent an axillary skin biopsy for both fibroblast culture and electron microscopy. Because of insufficient skin biopsy quality, for 8 patients no electron microscopy result was obtained. The electron microscopy biopsies revealed abnormalities in 37/66 (56.1%) patients. 29/66 electron microscopy biopsies showed normal results. A definite diagnosis was established in 21/66 (31.8%) patients with a pathological results of axillary skin electron microscopy analysis. In total, in 25/66 (37.8%) of the patients who underwent an axillary skin electron microscopy analysis, a definite diagnosis was finally established. Taking an axillary skin biopsy during anaesthesia or with use of local intradermal lidocaine application is an inexpensive alternative and useful to establish a diagnosis in patients suspected to have a lysosomal storage disease (or inherited metabolic disorder of energy metabolism).

Breast milk feeding in infants with inherited metabolic disorders other than phenylketonuria - a 10-year single-center experience.

BACKGROUND: Published data on breast milk feeding in infants suffering from inherited metabolic disorders (IMDs) other than phenylketonuria (PKU) are limited and described outcome is variable. OBJECTIVE: We aimed to evaluate retrospectively whether breastfeeding and/or breast milk feeding are feasible in infants with IMDs including organic acidemias, fatty acid oxidation disorders, urea cycle disorders, aminoacidopathies or disorders of galactose metabolism. METHODS: Data on breastfeeding and breast milk feeding as well as monitoring and neurological outcome were collected retrospectively from our database of patients with the mentioned IMD, who were followed in our metabolic center within the last 10 years. RESULTS: Twenty patients were included in the study, who were either breast fed on demand or received expressed breast milk. All the infants were evaluated clinically and biochemically at 2-4-week intervals, with weight gain as the leading parameter to determine metabolic control. Good metabolic control and adequate neurological development were achieved in all patients but one, who experienced the only metabolic crisis observed within the study period. CONCLUSION: Breast milk feeding with close clinical and biochemical monitoring is feasible in most IMD and should be considered as it offers nutritional and immunological benefits.

Universal Mass Vaccination Against Rotavirus: Indirect Effects on Rotavirus Infections in Neonates and Unvaccinated Young Infants Not Eligible for Vaccination.

BACKGROUND: Rotavirus (RV)-associated infections account for high numbers of hospitalizations in neonates and young infants. Universal mass vaccination (UMV) has been shown to prevent the burden of disease in vaccinated children. METHODS: The present study investigated the long-term effects of UMV on RV-associated hospitalizations in children with particular focus on neonates and young infants (≤42 days old) not eligible for vaccination. Ten years of Austrian surveillance data were compared, including 10 960 laboratory-confirmed RV cases before (prevaccination period [PreVP]) and after (postvaccination period [PostVP]) introduction of UMV. RESULTS: A postvaccination decrease in hospitalized community-acquired RV infections by 89.3% was seen in all age groups, including unvaccinated neonates and young infants. Of the latter, 27.6% had a nosocomial RV infection in PreVP, and 19.3% in PostVP. Overall, the proportion of nosocomial RV infections increased from 5.5% in PreVP to 13.0% in PostVP. Breakthrough infections, usually after incomplete RV vaccination, could be identified in 6.2% of patients. CONCLUSIONS: Unvaccinated neonates and infants ≤42 days old may indirectly benefit from UMV by reduction of RV infections. Breakthrough infections underline the importance of early and complete protection by the vaccine. In older patients, heightened awareness of nosocomial RV infections is warranted. Identification of RV reservoirs is also needed.

Efforts of the human immune system to maintain the peripheral CD8+ T cell compartment after childhood thymectomy.

BACKGROUND: Homeostatic mechanisms to maintain the T cell compartment diversity indicate an ongoing process of thymic activity and peripheral T cell renewal during human life. These processes are expected to be accelerated after childhood thymectomy and by the influence of cytomegalovirus (CMV) inducing a prematurely aged immune system. The study aimed to investigate proportional changes and replicative history of CD8+ T cells, of recent thymic emigrants (RTEs) and CD103+ T cells (mostly gut-experienced) and the role of Interleukin-(IL)-7 and IL-7 receptor (CD127)-expressing T cells in thymectomized patients compared to young and old healthy controls. RESULTS: Decreased proportions of naive and CD31 + CD8+ T cells were demonstrated after thymectomy, with higher proliferative activity of CD127-expressing T cells and significantly shorter relative telomere lengths (RTLs) and lower T cell receptor excision circles (TRECs). Increased circulating CD103+ T cells and a skewed T cell receptor (TCR) repertoire were found after thymectomy similar to elderly persons. Naive T cells were influenced by age at thymectomy and further decreased by CMV. CONCLUSIONS: After childhood thymectomy, the immune system demonstrated constant efforts of the peripheral CD8+ T cell compartment to maintain homeostasis. Supposedly it tries to fill the void of RTEs by peripheral T cell proliferation, by at least partly IL-7-mediated mechanisms and by proportional increase of circulating CD103+ T cells, reminiscent of immune aging in elderly. Although other findings were less significant compared to healthy elderly, early thymectomy demonstrated immunological alterations of CD8+ T cells which mimic features of premature immunosenescence in humans.

Tick-borne encephalitis in a child with previous history of completed primary vaccination.

We report the case of a 13-year-old girl who presented with fever, headache, nausea and pain behind the right ear. Cerebrospinal fluid (CSF; leukocytes 227/µL), electroencephalogram and cerebral magnetic resonance imaging were indicative of meningoencephalitis. Despite intensive therapy the general condition worsened and the patient was admitted to the intensive care unit. Serological analysis of CSF and serum indicated acute tick-borne encephalitis virus (TBEV) infection (IgG and IgM positive). TBEV infection has been reported after incomplete and complete vaccination. TBEV vaccination breakthrough in childhood has been shown to cause severe disease. It has been suggested that immunized patients develop more severe disease due to altered immune response, but the exact mechanism is unknown. In the presence of typical symptoms and a history of vaccination, possible vaccination breakthrough or missing booster vaccination should be considered.

The impact of Rotavirus mass vaccination on hospitalization rates, nosocomial Rotavirus gastroenteritis and secondary blood stream infections.

BACKGROUND: The aim of the study was to evaluate the effects of universal mass vaccination (UMV) against rotavirus (RV) on the hospitalization rates, nosocomial RV infections and RV-gastroenteritis (GE)-associated secondary blood stream infections (BSI). METHODS: The retrospective evaluation (2002-2009) by chart analysis included all clinically diagnosed and microbiologically confirmed RV-GE cases in a large tertiary care hospital in Austria. The pre-vaccination period (2002-2005) was compared with the recommended and early funded (2006-2007) and the funded (2008-2009) vaccination periods. Primary outcomes were RV-GE-associated hospitalizations, secondary outcomes nosocomial RV disease, secondary BSI and direct hospitalization costs for children and their accompanying persons. RESULTS: In 1,532 children with RV-GE, a significant reduction by 73.9% of hospitalized RV-GE cases per year could be observed between the pre-vaccination and the funded vaccination period, which was most pronounced in the age groups 0-11 months (by 87.8%), 6-10 years (by 84.2%) and 11-18 years (88.9%). In the funded vaccination period, a reduction by 71.9% of nosocomial RV-GE cases per year was found compared to the pre-vaccination period. Fatalities due to nosocomial RV-GE were only observed in the pre-vaccination period (3 cases). Direct costs of hospitalized, community-acquired RV-GE cases per year were reduced by 72.7% in the funded vaccination period. The reduction of direct costs for patients (by 86.9%) and accompanying persons (86.2%) was most pronounced in the age group 0-11 months. CONCLUSIONS: UMV may have contributed to the significant decrease of RV-GE-associated hospitalizations, to a reduction in nosocomial RV infections and RV-associated morbidity due to secondary BSI and reduced direct hospitalization costs. The reduction in nosocomial cases is an important aspect considering severe disease courses in hospitalized patients with co-morbidities and death due to nosocomial RV-GE.

Common variable immunodeficiency with granulomatous-lymphocytic interstitial lung disease treated with monoclonal antibodies against COVID-19: A case report.

Common variable immunodeficiency (CVID) is the most prevalent primary immunodeficiency. We present a 22-year-old Caucasian woman with CVID and granulomatous lymphocytic interstitial lung disease who contracted COVID-19 and was successfully treated with sotrovimab and molnupiravir. This treatment may have contributed to the relatively mild disease course of COVID-19 in our patient.

Immunogenicity of meningococcus C vaccination in a patient with atypical hemolytic uremic syndrome (aHUS) on eculizumab therapy.

We report successful kidney transplantation in a 10-yr-old boy with aHUS and heterozygous factor H mutation using the terminal complement inhibitor eculizumab to avoid recurrence of aHUS in the renal graft. Vaccination against meningococcus C (Men C) is essential in patients with dysfunction of the complement system, as induced by eculizumab. In our patient, we report waning SBA titers but maintenance of protective SBA titers (≥1:8) after kidney transplantation under immunosuppressive therapy with mycophenolate mofetil, tacrolimus, steroids, and eculizumab over a 27-month observational period. Our case illustrates that a humoral immune response to conjugate Men C vaccination may be mounted and maintained despite chronic renal disease, kidney transplantation, immunosuppressive drugs, and immunomodulatory therapy with eculizumab. However, it remains unclear whether serologically defined protective SBA titers mediate true protection from invasive meningococcal disease in an immunocompromised patient, particularly under treatment with a complement inhibitor. Thus, close monitoring of SBA titers seems mandatory in this patient.

Immunological Memory and Affinity Maturation After Vaccination in Patients With Propionic Acidemia.

Earlier studies have recommended routine childhood immunization in patients with propionic acidemia (PA); however, the literature presents insufficient data on the response to vaccines, notably specific IgG concentrations and avidity maturation, after measles, mumps, rubella (MMR), and diphtheria/tetanus (DiphtTe) vaccinations in this population. In patients with PA, cellular and humoral changes of the immune system (e.g. a decreased CD4+ T cell count, with a reversal of CD4/CD8 T cell ratio, a deficient gamma-globulin fraction, and in one case a decreased lymphocyte blastogenesis) have been reported. Former reports also detected pancytopenias accompanying febrile infections in PA patients. In the current study, we analyzed vaccine-specific IgG concentrations and avidity maturation after MMR and DiphtTe vaccinations in 10 patients with PA. Compared to gender and age matched controls, all 10 had protective IgG concentrations for at least one tested antigen, and in 6 out of 10 patients high relative avidity indices for measles and rubella were detected. In summary, the present study revealed a sufficient immune response and outcome, indicating an acceptable humoral memory in patients with PA after booster vaccinations.

Targeted metabolomic analysis of serum amino acids in the adult Fontan patient with a dominant left ventricle.

Growing interest lies in the assessment of the metabolic status of patients with a univentricular circulation after Fontan operation, especially in changes of amino acid metabolism. Using targeted metabolomic examinations, we investigated amino acid metabolism in a homogeneous adult Fontan-patient group with a dominant left ventricle, seeking biomarker patterns that might permit better understanding of Fontan pathophysiology and early detection of subtle ventricular or circulatory dysfunction. We compared serum amino acid levels (42 analytes; AbsoluteIDQ p180 kit, Biocrates Life Sciences, Innsbruck, Austria) in 20 adult Fontan patients with a dominant left ventricle and those in age- and sex-matched biventricular controls. Serum concentrations of asymmetric dimethylarginine, methionine sulfoxide, glutamic acid, and trans-4-hydroxyproline and the methionine sulfoxide/methionine ratio (Met-SO/Met) were significantly higher and serum concentrations of asparagine, histidine, taurine, and threonine were significantly lower in patients than in controls. Met-SO/Met values exhibited a significant negative correlation with oxygen uptake during exercise. The alterations in amino acid metabolome that we found in Fontan patients suggest links between Fontan pathophysiology, altered cell energy metabolism, oxidative stress, and endothelial dysfunction like those found in biventricular patients with congestive heart failure. Studies of extended amino acid metabolism may allow better understanding of Fontan pathophysiology that will permit early detection of subtle ventricular or circulatory dysfunction in Fontan patients.

Targeted metabolomic analysis of serum phospholipid and acylcarnitine in the adult Fontan patient with a dominant left ventricle.

BACKGROUND: Patients with a Fontan circulation have altered cholesterol and lipoprotein values. We analysed small organic molecules in extended phopsholipid and acylcarnitine metabolic pathways ('metabolomes') in adult Fontan patients with a dominant left ventricle, seeking differences between profiles in baseline and Fontan circulations. METHODS: In an observational matched cross-sectional study, we compared phosphatidylcholine (PC), sphingomyelin (SM), and acylcarnitine metabolomes (105 analytes; AbsoluteIDQ® p180 kit (Biocrates Life Sciences AG, Innsbruck, Austria) in 20 adult Fontan patients having a dominant left ventricle with those in 20 age- and sex-matched healthy controls. RESULTS: Serum levels of total PC (q-value 0.01), total SM (q-value 0.0002) were significantly lower, and total acylcarnitines (q-value 0.02) were significantly higher in patients than in controls. After normalisation of data, serum levels of 12 PC and 1 SM Fontan patients were significantly lower (q-values <0.05), and concentrations of 3 acylcarnitines were significantly higher than those in controls (q-values <0.05). CONCLUSION: Metabolomic profiling can use small specimens to identify biomarker patterns that track derangement in multiple metabolic pathways. The striking alterations in the phospholipid and acylcarnitine metabolome that we found in Fontan patients may reflect altered cell signalling and metabolism as found in heart failure in biventricular patients, chronic low-level inflammation, and alteration of functional or structural properties of lymphatic or blood vessels. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier NCT03886935.

Thymectomy in early childhood: significant alterations of the CD4(+)CD45RA(+)CD62L(+) T cell compartment in later life.

The study was aimed to assess indicators of immunosenescence, such as the total counts of peripheral blood CD4(+)CD45RA(+)CD62L(+) (naive) T cells, the numbers of T cell receptor excision circles (TRECs), and Ki67-expression as marker of peripheral replication in thymectomized patients (TP) (n=101) compared to age-matched healthy donors (HD) (n=81). In TP, there was an inverse correlation between naive T cells and chronological age (p<0.001) or time post thymectomy (p<0.001). TP demonstrated lower TREC numbers in naive T cells compared to HD (p<0.001). TREC numbers negatively correlated with time post thymectomy (p<0.001). Percentages of Ki67-expresssing naive T cells were higher in TP compared to HD (p<0.05). The findings of the presented long-term follow up cohort of thymectomized patients indicate that changes of the peripheral naive T cell subset in TP may resemble the findings of an aging immune system in elderly persons after thymic involution. Our data provide evidence that peripheral T cell homeostasis in TP is maintained at minimal levels mainly by extrathymic expansion of existing naive T cells in the periphery to compensate the diminished thymic output.

Vaccination Status in Pediatric Solid-Organ Transplant Recipients and Their Household Members.

OBJECTIVES: Vaccine-preventable diseases remain a major cause of morbidity and mortality in solid-organ transplant candidates and recipients. Newer recommendations include vaccination of all household members to create a herd immunity around the transplant recipient. This study evaluated the vaccination status of pediatric solid-organ transplant recipients and their household members. MATERIALS AND METHODS: We evaluated 30 pediatric solid-organ transplant recipients (14 kidney, 13 liver, 3 heart) and their household members (26 siblings, 30 parents) at time of transplant. RESULTS: Fourteen recipients (47%) received scheduled vaccinations before solid-organ transplant and were up to date for their age with their diphtheria, tetanus, pertussis; hepatitis B virus; poliomyelitis; Haemophilus influenzae type B; Streptococcus pneumoniae conjugate vaccine; and measles, mumps, and rubella vaccinations. Another 7 recipients (23%) had partially completed their schedules, only missing the second dose of the measles, mumps, and rubella vaccine. Fifteen siblings (58%) had either completed (n = 13, 50%) or partially completed (n = 2, 8%) their vaccinations. All 30 parents were either unaware of their vaccination status (n = 10, 33%) or had only incomplete vaccination records (n = 20, 67%). CONCLUSIONS: We found that most pediatric solid-organ transplant recipients to be appropriately vaccinated. However, vaccination status in household members, especially in parents, was disappointing.

Impact of the Fontan Operation on Organ Systems.

In patients having undergone the Fontan operation, besides the well discussed changes in the cardiac, pulmonary and gastrointestinal system, alterations of further organ systems including the hematologic, immunologic, endocrinological and metabolic are reported. As a medical adjunct to Fontan surgery, the systematic study of the central role of the liver as a metabolizing and synthesizing organ should allow for a better understanding of the pathomechanism underlying the typical problems in Fontan patients, and in this context, the profiling of endocrinological and metabolic patterns might offer a tool for the optimization of Fontan follow-up, targeted monitoring and specific adjunct treatment.

Mitochondrial DNA mutation "m.3243A>G"-Heterogeneous clinical picture for cardiologists ("m.3243A>G": A phenotypic chameleon).

OBJECTIVE: In general, a mitochondrial disorder is diagnosed on the basis of symptom combinations and confirmed by genetic findings. However, patients carrying the m.3243A>G mutation in the mitochondrial tRNA leucine 1 (MT-TL1) do not always meet all the proposed criteria for the most frequently encountered mitochondrial syndrome "MELAS," an acronym for Mitochondrial Encephalomyopathy, Lactic Acidosis, and at least one Stroke-like episode. We here present various phenotypic characteristics of the mitochondrial mutation m.3243A>G with particular focus on cardiac manifestations. METHODS AND RESULTS: We followed nine patients (1 month to 68 years old; median 42 years; four female and five male) from nine different families with this m.3243A>G mutation in the MT-TL1. The classical "MELAS" criteria are met by only three of these patients. Electrocardiography (ECG) shows preexcitation pattern with short PR intervals and delta waves (Wolff-Parkinson-White) in three patients and sick sinus syndrome plus atrioventricular block I in one patient. Hypertrophic cardiomyopathy was found in eight patients with moderate to severe regurgitation of various valves. CONCLUSION: Cardiac manifestation can encompass hypertrophic or dilated cardiomyopathy, as well as preexcitation syndromes or conduction delay. In general, the clinical presentation to meet the "MELAS" criteria varies due to heteroplasmy. Thus, cardiologists should screen patients with unexplained cardiac features in the context of deafness, short stature and learning disabilities for mtDNA mutations, especially the m.3243A>G mutation. A clear diagnosis is essential as a basis for prognostic advice concerning the disease course and clinical impact on family testing.

Differential clinical presentation of Adamantiades-Behçet's disease in non-endemic and endemic areas: retrospective data from a Middle-European cohort study.

OBJECTIVES: To assess demographical and clinical data in a Middle-European cohort of patients with Adamantiades-Behçet's disease (ABD), together with the use of medication in adherence to international guidelines. METHODS: In a retrospective cohort study, in- and outpatients of an Austrian secondary and tertiary university hospital center were analyzed independent from the medical discipline involved. After ethics approval, screening for ABD-patients in the clinical information system resulted in 1821 documents from 1997 to 2016. Patients fulfilling the International Criteria for Behçet's Disease were included, and ABD symptoms and signs together with medical interventions for immunosuppression, anticoagulation and pain management were identified by individual chart reviews and evaluated for conformity with international recommendations. RESULTS: A total of 76 ABD patients were identified with 39.1% Austrian and 37.0% Turkish origin. Genital aphthae and skin manifestations were more frequent, neurological, gastrointestinal and vascular manifestations less frequent in ABD patients of Turkish origin living in Austria compared to those living in Turkey (each P < 0.05). The male-to-female ratio averaged 0.86 (0.39 in patients with Austrian and 1.43 with Turkish backgrounds), and was 3.3 in patients with venous manifestations. Out of 174 medical interventions, 55.2% fully matched the European League Against Rheumatism recommendations of 2008, and 93.7% were considered at least as equal to the recommendations. Indications for tumor necrosis factor inhibition were in line with the 2007 Sfikakis recommendations. CONCLUSIONS: In this Middle-European ABD cohort clinical presentations between patients of Austrian and Turkish origin do not strongly vary, whereas Turkish patients from the non-endemic Innsbruck cohort present differently compared to patients living in Turkey. The role of such cohort analyses will increase, from the epidemiological as well as the management perspective.

Rediscovering Pertussis.

Pertussis, caused by Bordetella (B.) pertussis, a Gram-negative bacterium, is a highly contagious airway infection. Especially in infants, pertussis remains a major health concern. Acute infection with B. pertussis can cause severe illness characterized by severe respiratory failure, pulmonary hypertension, leucocytosis, and death. Over the past years, rising incidence rates of intensive care treatment in young infants were described. Due to several virulence factors (pertussis toxin, tracheal cytotoxin, adenylate cyclase toxin, filamentous hemagglutinin, and lipooligosaccharide) that promote bacterial adhesion and invasion, B. pertussis creates a unique niche for colonization within the human respiratory tract. The resulting long-term infection is mainly caused by the ability of B. pertussis to interfere with the host's innate and adaptive immune system. Although pertussis is a vaccine-preventable disease, it has persisted in vaccinated populations. Epidemiological data reported a worldwide increase in pertussis incidence among children during the past years. Either acellular pertussis (aP) vaccines or whole-cell vaccines are worldwide used. Recent studies did not detect any differences according to pertussis incidence when comparing the different vaccines used. Most of the currently used aP vaccines protect against acute infections for a period of 6-8 years. The resurgence of pertussis may be due to the lack of herd immunity caused by missing booster immunizations among adolescents and adults, low vaccine coverages in some geographic areas, and genetic changes of different B. pertussis strains. Due to the rising incidence of pertussis, probable solution strategies are discussed. Cocooning strategies (vaccination of close contact persons) and immunizations during pregnancy appear to be an approach to reduce neonatal contagiousness. During the past years, studies focused on the pathway of the immune modulation done by B. pertussis to provide a basis for the identification of new therapeutic targets to enhance the host's immune response and to probably modulate certain virulence factors.