Risk of new alloimmunization in patients on anti-CD38 treatment using tube LISS-IAT method.

BACKGROUND: Daratumumab is a monoclonal antibody that targets CD38, a transmembrane protein expressed on many cells including RBCs and to a greater extent on myeloma cells. It has been used for treatment of multiple myeloma and autoimmune diseases. Transfusion management of patients on such therapy can be challenging as these drugs cross-react with RBC surface antigens and cause panreactivity. MATERIAL AND METHODS: A retrospective study of the 68 patients treated with anti-CD38 from 2018-2023 was carried out. Data regarding transfusion history and antibody screens were analyzed. Depending whether they had immunohematological work-up before or during the treatment- DAT, antibody screen (CAT and tube), RBC pheno/genotyping and serologic cross-matches (CAT and tube) were performed for each patient. All cases with positive CAT IAT were retested in LISS-tube and cross-matches were performed with phenotypically matched units in LISS-tube. RESULTS: Antibody screen has shown panagglutination with all panel cells with low and variable agglutination intensity (weak to 2 +). Panagglutination remained positive for 1 - 6 months after drug cessation. Positive DAT was seen in 60,6% patients, while autocontrol was negative. Ficin treated panel-cells eliminated nonspecific reactivity. LISS-tube antibody screen and cross-matches were negative for all patients, apart from 3 patients who had preexisting antibodies. No new antibodies were detected during the course of the study. CONCLUSION: Among study group there were no newly identified alloantibodies, meaning that the policy of transfusing them with matched RBCs and performing IAT/cross-matches in tube is a safe and effective policy according to the findings of this study.

Platelet Serotonin (5-HT) Concentration, Platelet Monoamine Oxidase B (MAO-B) Activity and HTR2A, HTR2C, and MAOB Gene Polymorphisms in Asthma.

The complex role of the serotonin system in respiratory function and inflammatory diseases such as asthma is unclear. Our study investigated platelet serotonin (5-HT) levels and platelet monoamine oxidase B (MAO-B) activity, as well as associations with HTR2A (rs6314; rs6313), HTR2C (rs3813929; rs518147), and MAOB (rs1799836; rs6651806) gene polymorphisms in 120 healthy individuals and 120 asthma patients of different severity and phenotypes. Platelet 5-HT concentration was significantly lower, while platelet MAO-B activity was considerably higher in asthma patients; however, they did not differ between patients with different asthma severity or phenotypes. Only the healthy subjects, but not the asthma patients, carrying the MAOB rs1799836 TT genotype had significantly lower platelet MAO-B activity than the C allele carriers. No significant differences in the frequency of the genotypes, alleles, or haplotypes for any of the investigated HTR2A, HTR2C and MAOB gene polymorphisms have been observed between asthma patients and healthy subjects or between patients with various asthma phenotypes. However, the carriers of the HTR2C rs518147 CC genotype or C allele were significantly less frequent in severe asthma patients than in the G allele carriers. Further studies are necessary to elucidate the involvement of the serotonergic system in asthma pathophysiology.

Serological and molecular characterisation of the most prevalent weak D variants in Croatian population.

INTRODUCTION: Existence of hundreds of RHD gene variants contributes to variable D antigen expression and inconsistencies in reporting the RHD results. The aim of the study was to determine the serological and molecular characteristics of the most prevalent RHD alleles encoding serologically weak D variants. MATERIAL AND METHODS: Blood donors (n = 145 924) were typed for D antigen using the direct serologic micromethod. Nonreactive samples were analysed in IAT method with the IgM/IgG anti-D monoclonal blend, and 0,2% (n = 263) confirmed weak D antigen expression. After genomic DNA extraction (Qiaqen, Germany), RHD genotyping was performed using in house reagents and PCR-SSP kits (Inno-Train, Germany). RESULTS: The prevalence of serologically weak D in blood donor population was 0.2% (n = 263). RHD genotyping confirmed weak D allele in 92.4% and partial D allele in 7.6%. The most common was weak D type 1 (49.7%) followed by weak D type 3 (24.7%) and type 2 (9.5%). Relatively high frequency was detected for weak D type 14 (4.6%) and type 64 (2.3%). In the category of partial D phenotypes, only DVI variant was found. Direct typing has shown great variability in the strength of reactions with different clones of anti-D reagents. CONCLUSION: Weak D type 1 is the most common weak D variant in Croatian blood donor population. The frequency of D variants and distribution of Rh phenotypes in our study was in concordance with other studies. It has been shown that serological methods and the combination of clones used, cannot distinguish variant D types, which justifies the use of molecular methods.

IMPACT OF AIR TRANSPORT ON BLOOD SAMPLE QUALITY.

The aim of this study was to establish the impact of air transport on blood samples packaged with and without cooling elements and effect of outdoor temperature on sample quality. Venous samples from 38 blood donors in winter and 36 in summer were tested for hemolysis and complete blood count. One tube per subject was kept in controlled conditions at +4 °C. Two sets of tubes were sent by plane from Zagreb to Brussels, one with and one without cooling elements, and another two sets were sent to London following the same principle. Packages with cooling elements were stored in controlled warehousing conditions at airports (+2 °C to +8 °C), whereas packages without cooling elements were stored in ambient warehouse conditions. Data loggers were used for temperature monitoring. Our research revealed statistically significant differences in several hematologic parameters when comparing the samples stored in controlled laboratory conditions and those transported by plane. These differences were more pronounced in the samples transported during the summer. Transport conditions without cooling elements had additional negative impact on the sample quality. Transport of samples using cooling elements and controlled warehousing conditions at airports are sometimes not sufficient to maintain laboratory storage conditions.

RhD alloimmunization by DEL variant missed in donor testing.

INTRODUCTION: Exposure to normal or variably expressed RhD antigens in an antigen-negative individual can elicit an immune response and lead to the formation of clinically significant anti-D alloantibodies. We present the case of anti-D alloimmunization by DEL variant missed in routine blood donor screening. MATERIAL AND METHODS: Blood donors were typed for D antigen using the direct serologic micromethod. Nonreactive samples were confirmed in the indirect antiglobulin method with an IgM/IgG anti-D monoclonal reagent. Genomic DNA was extracted using a commercial QIAamp DNA Blood Mini kit on the QIAcube device (Qiaqen, Germany). RHD genotyping was performed using the PCR-SSP genotyping kits- Ready Gene D weak, Ready Gene D weak screen, Ready Gene CDE, and Ready Gene D AddOn (Inno-Train, Germany). Unidentified alleles were sent for DNA genome sequencing. RESULTS: After identifying DEL positive blood units in RhD negative blood donor pool, a look-back study was performed to determine if their previous donations caused alloimmunization in recipients. Out of 40 D negative recipients, one developed anti-D alloantibody after 45 days. The patient did not receive other RhD positive blood products. Blood donor typed D negative in direct and indirect agglutination method. RHD screening was positive, but RHD genotyping and DNA sequencing showed no mutation indicating the normal genotype. CONCLUSION: Currently used methods in RHD genotyping are insufficient to identify many variant alleles, especially intronic variations. We suggest additional gene investigation including yet unexplored regions of regulation and intron regions to justify our serological finding.

ABO BLOOD GROUP GENOTYPES IN WOMEN WITH BREAST CANCER.

ABO blood group is a risk factor for several cancers, but it is not clear yet whether the risk of breast cancer is greater in particular ABO blood type carriers. The aim of this case-control study was to examine the correlation between ABO blood group genotypes, estrogen receptor (ER), progesterone receptor (PR) and HER2 status as tumor grade markers (I-III), and the occurrence of breast cancer. The research included 59 patients with invasive breast cancer and 80 asymptomatic, healthy women, blood donors. Genomic DNA was isolated using QIAampDNA Blood Mini Kit (QIAGEN, Germany). Genotyping was performed using in-house polymerase chain reaction with sequence-specific primers (PCR-SSP) method. Comparison of genotypes and phenotypes of ABO blood groups between patients and control group yielded p>0.05. There was no statistical significance of correlation between ABO genotypes/phenotypes in either patient group or control group. Testing the significance of different tumor grade occurrence, and ER, PR and HER2/neu status showed no statistical significance ​​in the occurrence of a particular tumor grade, or in ER, PR and HER2/neu status as tumor markers in O1A1 genotype compared to non-O1A1 genotypes. Our study results confirmed that there was no correlation between ABO blood type genotypes/phenotypes and breast cancer in study groups.

A1B and BB blood group genotypes are risk factors for pulmonary embolism.

BACKGROUND: Pulmonary embolism (PE) is a potentially life-threatening condition that mainly affects the people of advanced age. While certain blood group phenotypes (non­O blood group) are known risk factors for the development of venous thromboembolism (VTE), there is no research which investigated the association of blood group genotypes with severity of PE. The aim of this study was to investigate the frequency of ABO blood group genotypes among the population of patients with PE and to investigate the correlation of the pulmonary embolism severity index (PESI) score to specific ABO blood group genotypes. MATERIAL AND METHODS: In this cross-sectional study 74 patients with PE diagnosed using CT pulmonary angiography were included and 303 blood donors without VTE or congenital thrombophilia participated as a control group. After isolation of genomic DNA ABO blood group genotype was determined using the polymerase chain reaction sequence-specific amplification (PCR-SSP) method. RESULTS: We observed a significantly higher frequency of A1B and BB genotypes in patients with PE compared to healthy individuals (A1B 14.9% vs. 4.3%, P < 0.001; BB 5.4% vs. 0.7%, P = 0.004), while the O1O1 genotype was significantly less frequent in patients (24.3% vs. 37.3%, P = 0.036). Analyzing the severity of the clinical presentation according to the PESI score, we did not find a correlation between the severity of the clinical presentation and a certain blood type genotype. CONCLUSION: Patients with A1B and BB blood type genotype were at increased risk for developing pulmonary embolism, while patients with O1O1 genotype had a significantly lower risk of developing PE.

D variants in the population of D-negative blood donors in the north-eastern region of Croatia.

OBJECTIVES: The aim of this study was to determine RHESUS D GENE (RHD) allelic variants among Croatian D-negative blood donors and compare our results with respective data from other European countries. BACKGROUND: Altered or reduced D antigen expression can result in D variants, which can be mistyped and can lead to the alloimmunisation of the blood recipient. RHD genotyping can distinguish D variants: weak D, partial D and DEL, thus preventing alloimmunisation. MATERIAL/METHODS: A total of 6523 samples obtained from D-negative Croatian donors were screened for the presence of RHD using the real-time polymerase chain reaction (PCR) method. PCR-SSP was performed for D variant genotyping by using commercial genotyping kits (Inno-Train, Kronberg, Germany). Genomic DNA sequencing for all 10 exons of the RHD was performed when the genotyping kits failed to assign a D variant. RESULTS: RHD molecular screening revealed 23 (0.35%) RHD-PCR positive samples, all C/E positive, in decreasing frequency: 11 hybrid RHD-CE (2-9) D-CE variants, 4 weak partial D type 11 and 2 weak D type 2. Six samples remained unresolved and were sequenced. For 12 of 23 samples (excluding large hybrids), an adsorption/elution of anti-D serum was performed, confirming that all 12 were RhD+. The calculated frequency of clinically significant D alleles in RhD-negative blood donors was 1:543 (0.18%) or 1:53 (1.89%) in C/E blood donors. CONCLUSION: Data on the significant frequency of D variants among serologically D-negative blood donors in the north-eastern region of Croatia could help in introducing RHD molecular screening of blood donors in a routine workflow.

Plasma Brain-Derived Neurotrophic Factor (BDNF) Concentration and BDNF/TrkB Gene Polymorphisms in Croatian Adults with Asthma.

Brain-derived neurotrophic factor (BDNF) and its tropomyosin-related kinase B (TrkB) receptor might contribute to normal lung functioning and immune responses; however, their role in asthma remains unclear. Plasma BDNF concentrations, as well as BDNF and NTRK2 (TrkB gene) polymorphisms, were investigated in 120 asthma patients and 120 healthy individuals using enzyme-linked immunosorbent assay and polymerase chain reaction, respectively. The genotype and allele frequencies of BDNF Val66Met (rs6265) and NTRK2 rs1439050 polymorphisms did not differ between healthy individuals and asthma patients, nor between patients grouped according to severity or different asthma phenotypes. Although plasma BDNF concentrations were higher among healthy subjects carrying the BDNF Val66Met GG genotype compared to the A allele carriers, such differences were not detected in asthma patients, suggesting the influences of other factors. Plasma BDNF concentration was not affected by NTRK2 rs1439050 polymorphism. Asthma patients had higher plasma BDNF concentrations than control subjects; however, no differences were found between patients subdivided according to asthma severity, or Type-2, allergic, and eosinophilic asthma. Higher plasma BDNF levels were observed in asthma patients with aspirin sensitivity and aspirin-exacerbated respiratory disease. These results suggest that plasma BDNF may serve as a potential peripheral biomarker for asthma, particularly asthma with aspirin sensitivity.

ABO blood group genotypes and ventilatory dysfunction in patients with allergic and nonallergic asthma.

Aim ABO blood group genotypes are established as a genetic factor in pathophysiology of various diseases, such as cardiovascular disorders, cancers, infectious diseases and there is rising evidence of their involvement in other conditions. The aim of this study was to determine if ventilatory changes of lung function in asthma, measured by biomarkers/parameters, are connected to certain ABO blood group genotypes in Croatia. Methods A case-control study included 149 patients with asthma and 153 healthy individuals (blood donors). ABO genotyping on five main alleles was performed using PCR-SSP method. All patients had spirometry performed and severity of asthma was estimated. Clinical parameters of spirometry (FEV1, FEV/FVC, PEF), biomarkers FeNO, IgE and pO2 were measured. The χ2 test, Fisher's test, Kruskal-Wallis test and Spearman's correlation coefficients with p<0.05 were used as statistically significant. Results There was no determined statistically significant difference in both ABO genotypes and phenotypes between patient and control groups. Comparison of the lung function in different ABO phenotypes in asthmatic patients also did not show any statistically significant differences in FEV1 values, FEV/FVC ratio or PEF. Statistically significant differences in oxygenation between different ABO blood types have not been noticed (p=0.326). Differences in quantitative values of biomarkers (FeNO and IgE) between different ABO blood phenotypes in patients with asthma were not significant, except for IgE that had marginal values (p=0.074). Conclusion No correlation was found between certain ABO blood group genotypes and parameters/biomarkers of ventilatory dysfunction in patients with allergic and nonallergic asthma.

Anti-HBc prevalence among Croatian blood donors in a 14-year period (2004-2017): Assessment of trends, risks and need for implementing routine testing.

OBJECTIVES: The anti-HBc prevalence over a 14-years period (2004-2017), trends, infectivity, residual risk, and need for testing in blood donors (BD) of the Croatian Institute of Transfusion Medicine were assessed. MATERIAL AND METHODS: Anti-HBc was tested in 19,969 BD serum samples collected in 2004 (N=7561), 2013 (N=7318) and 2017 (N=5090). All serums were initially screened for HBsAg, anti-HCV, HIV Ag/Ab, and anti-TP. 2013 and 2017 samples were also tested by ID-NAT. RESULTS: Over a 14-years period, the anti-HBc prevalence significantly decreased among Croatian BD (5.24% in 2004, 2.56% in 2013, and 1.32% in 2017). Similarly, the prevalence of anti-HBc-only profiles decreased from 0.62% in 2004, 0.25% in 2013, and 0.21% in 2017. The 4-time decreasing trend was observed in all age groups of BD from 2017 but mostly among repeat donors (5.90% to 1.38%). First-time donors showed no significant difference in anti-HBc prevalence probably due to their younger age (<29 years) and HBV vaccine status. However, similar anti-HBs carriage rates (80.56%, 87.57%, and 82.09%) were reported in anti-HBc positive donors over the study period. HBsAg and HBV DNA were not detected. No OBI infection was found in the study despite an OBI frequency of 1:10,900 donations previously reported in Croatia. A HBV decreasing residual risks of 68, 88, and 12 per million donations were estimated for years 2004, 2013, and 2017, respectively. CONCLUSION: Anti-HBc testing is an additional measure of preventing HBV infection by transfusion. Implementation of anti-HBc testing will result in the deferral of 1.3% BD and should be supported by cost-benefit analyses.

THE ROLE OF CIGARETTE SMOKING AND ALCOHOL CONSUMPTION IN PULMONARY TUBERCULOSIS DEVELOPMENT AND RECURRENCE.

During a two-year period (2001-2003), 464 patients were treated for tuberculosis at Jordanovac Department for Lung Diseases in Croatia. Besides pulmonary tuberculosis in 97.7% of patients, patients were also treated for tuberculous pleurisy (0.9%), tuberculous laryngitis (0.6%), tuberculous meningitis (0.2%), tuberculous pericarditis (0.2%) and urogenital tuberculosis (0.4%). Out of the total number of patients, 57.3% declared themselves to be active smokers (men were predominant and made up to 80.8%) and 20.9% to be active alcohol consumers. Both risk factors, i.e. smoking and alcohol consumption, were present in 15.1% of all patients. The most common comorbidities were diabetes mellitus (30.4%), cardiac diseases (11.2%) and chronic obstructive pulmonary disease (8.0%). Lung carcinoma was the most common malignant disease (n=51), with Mycobacterium tuberculosis isolated in 33% of them. Seventy-two of 464 (15.5%) patients had recurrences of tuberculosis. Of these, 30.5% had one of the risk factors (20.8% were smokers and 9.7% consumed alcohol), while 32.5% of patients had both risk factors. In conclusion, cigarette smoking was proved to be the most significant risk factor for development of pulmonary tuberculosis and its recurrence.

ABO blood groups and psychiatric disorders: a Croatian study.

BACKGROUND: The prevalence of ABO alleles is different in different populations, and many studies have shown a correlation between the occurrences of some diseases and different genotypes of ABO blood groups. The aim of this study was to determine whether there is a significant association between psychiatric syndromes and ABO blood groups. MATERIALS AND METHODS: This case-control study involved 156 psychiatric patients and 303 healthy, unrelated, voluntary blood donors. Genomic DNA was isolated from blood on a QIAcube device using a QIAamp DNA Blood mini QIAcube kit. ABO genotyping on five basic ABO alleles was performed using allele-specific polymerase chain reaction analysis. RESULTS: Compared with healthy subjects, a significantly higher proportion of psychiatric patients had AB blood group (χ2=9.359, df=3, p=0.025) and, accordingly, a significantly higher incidence of A1B genotype (χ2=8.226, df=3, p=0.042). The odds ratio showed that psychiatric disorders occur almost three times more frequently in carriers of AB group compared to other blood groups. However, no statistically significant difference was found in the distribution of ABO blood groups among patients with different psychiatric diagnoses. Likewise, no correlations were found between ABO blood groups and other characteristics of the psychiatric patients (sex, psychiatric heredity, somatic comorbidity, suicidality). CONCLUSIONS: The results of this study support the hypothesis of an association between psychiatric disorders and ABO blood groups. The probability is that psychiatric disorders will occur almost three times more frequently in carriers of AB group compared to other ABO blood groups in the Croatian population.

Distribution of hepatitis C virus genotypes and subtypes in Croatia: 2008-2015.

OBJECTIVE: Hepatitis C virus (HCV) genotyping is an important part of pre-treatment diagnostic algorithms as it guides the choice of therapeutic regimens. The aim of this study was to analyse the distribution of HCV genotypes in patients with chronic hepatitis C from Croatia in the period 2008-2015. METHODS: The study enrolled 3,655 anti-HCV positive patients with available results of HCV genotyping from the three largest national HCV genotyping laboratories. RESULTS: The majority of HCV-infected individuals enrolled in the study were male (70.7%). Analysis of age distribution in a subset of 2,164 individuals showed a mean age of 40.9 years (SD 11.77 years). Croatian patients were mostly infected with HCV genotype 1 (56.6%), followed by genotype 3 (37.3%), genotype 4 (4.2%) and genotype 2 (1.8%). Genotype 1 subtyping in a subset of 1,488 patients showed 54% (803/1,488) of 1b infections and 46% (685/1,488) of 1a infections. Percentages of genotype 1 were the highest in Central/Northwestern and Eastern Croatia and the lowest in the Central/Southern Adriatic Region. Genotype 3 was most frequently found in the Central/Southern Adriatic Region (49.1%) but represented only 17.5% of infections in Eastern Croatia (p < 0.001). CONCLUSIONS: The results of this nine-year retrospective analysis on the distribution of HCV genotypes and subtypes in 3,655 HCV-infected individuals from Croatia showed that the majority of infections can be attributed to genotypes 1 and 3 with absence of major changes in the molecular epidemiology of the two most frequent HCV genotypes infection in Croatia in the past 20 years.

The Role of Pai-1 Gene 4g/5g Polymorphism and Diagnostic Value of Biomarkers in Allergic and Non-Allergic Asthma Phenotype.

Asthma is a chronic inflammatory disease that is characterized by reversible obstruction of airways, bronchial hyper-reactivity and airway remodeling. The etiology of asthma is multifactorial, with inheritance playing an important role. The aim of our study was to investigate the importance of biomarkers of asthma and the role of plasminogen activator inhibitor-1 (PAI-1) gene as a genetic factor that could be involved in the pathogenesis of asthma. The research was conducted at Jordanovac University Department for Lung Diseases and Croatian Institute of Transfusion Medicine. The research included 149 patients with asthma and 89 healthy individuals. We collected demographic data of both study groups, determined asthma severity using GINA guidelines, and the values of biomarkers and PAI-1 by using laboratory techniques. Based on the results, we concluded that patients with allergic phenotype of asthma were younger, had better lung function and higher levels of IgE. By observing FeNO values, we were not able to distinguish asthmatic patients that had been diagnosed with obstruction of airways from asthmatic patients with normal lung function because FeNO indicates the inflammatory component of disease. The 4G/5G polymorphism of PAI-1 gene did not show any statistically significant difference in the distribution of 4G/4G, 4G/5G and 5G/5G between the group of asthmatic patients and control group.

Anti-D reagents should be chosen accordingly to the prevalence of D variants in the obstetric population.

BACKGROUND: Resolving ambiguous results of D antigen typing is crucial for appropriate and rational administration of anti-D immunoprophylaxis and transfusion practice in obstetric population. The aim of the study was to establish selection criteria of anti-D reagents for our population. METHODS: A total of 12 689 samples from primiparous women in Split-Dalmatia County, Croatia, were typed for RhD antigen during the period of 5 years. Ambiguous results were submitted to additional serologic investigation and genotyping. RHD genotyping was performed by commercial genotyping kits (Ready Gene weak D ® and Ready gene CDE, Inno-Train, Kronberg, Germany). Relative frequencies and accompanying 95% confidence intervals were used to estimate the prevalence of variants. RESULTS: The prevalence of D variants was 0.42% (95% CI 0.31; 0.53). The most common partial D variant was D Va (RHD*05.05), with the prevalence of 0.08% (95% CI 0.03; 0.13). All weak D variants were weak D types 1, 2 and 3 (RHD*weak D type 1, RHD*weak D type 2, RHD*weak D type 3). Weak D samples were distinguishable from partial D in routine typing due to the difference in reactivity of partial D samples with clones D7B8 and RUM-1. Cell line RUM-1 gives weak or negative reactions with partial DVa category. CONCLUSION: The most common partial D variant in our population is DVa. It is recommended to use cell lines which do not strongly agglutinate DVa variant in routine RhD typing. The appropriate choice of reagents will enable the serology methods to recognize the cases in which RHD genotyping is required.

Polymorphism 4G/5G of the plasminogen activator inhibitor 1 gene as a risk factor for the development of allergic rhinitis symptoms in patients with asthma.

Plasminogen activator inhibitor-1 (PAI-1) is a glycoprotein which has a role in tissue remodelling after inflammatory processes. The objective is to investigate the frequency of PAI-1 gene polymorphism (4G/5G) in patients with a lung ventilation dysfunction in asthma and allergic rhinitis. Genomic DNA was isolated and genotypes of polymorphism of PAI-1 4G/5G and ABO were determined using the methods of RT-PCR and PCR-SSP. Study group includes 145 adult patients diagnosed with chronic asthma, with all clinically relevant parameters and the laboratory markers of pO2, IgE and eosinophils in sputum and nasal swab. In the processing of data, appropriate statistical tests (Kolmogorov-Smirnov test, median, interquartile ranges, χ 2 and Mann-Whitney U tests) were used. Patients with symptoms of allergic rhinitis were significantly younger and had an almost four time higher levels of IgE (P = 0.001), higher pO2 (P = 0.002) and PEF (P = 0.036), compared to those who do not have these symptoms. Genotype PAI 4G/4G is significantly more common in patients with allergic rhinitis (28.1% vs. 16.1%; P = 0.017) compared to the genotype 5G/5G. Carriers of the genotype 4G/5G also have a borderline statistical significance. There were no statistically significant difference in the incidence of allergic rhinitis in the carriers of any ABO genotypes. The frequency of PAI genotype 4G/4G is significantly more common in patients with allergic rhinitis. The results suggest that the carriers of at least one 4G allele are at a higher risk for developing symptoms of allergic rhinitis in asthma.

Three-Year Experience in NAT Screening of Blood Donors for Transfusion Transmitted Viruses in Croatia.

BACKGROUND: Croatia implemented individual donation (ID)-NAT testing of blood donors in 2013 for three viruses HBV, HCV, and HIV-1 as a mandatory test for all blood donors. This study assessed the impact of NAT screening 3 years after its implementation. METHODS: A total of 545,463 donations were collected and screened for HBV, HCV, and HIV-1 using the Procleix Ultrio Plus Assay. All initially reactive (IR) NAT samples were retested in triplicate and, if repeatedly reactive (RR), NAT discriminatory assay (dNAT) was performed. ID-NAT positive donations were confirmed by RT-PCR on the COBAS AmpliPrep/TaqMan platform. RESULTS: Out of 545,463 samples tested, 108 (0.02%) were RR in NAT. There were 82 (75,9%) HBV reactive, 16 (14.8%) HCV reactive, and 10 (9.3%) HIV-1 reactive samples. 51 (47.2%) samples were ID-NAT positive only. Out of these 51 NAT yield cases, 1 window period HIV-1 and 50 occult HBV infections (OBI) were determined. There were only two potential HBV DNA transmissions from OBI donors. CONCLUSION: The implementation of NAT screening for three viruses has improved blood safety in Croatia. During the 3-year period, 1 window period HIV-1 and a number of occult HBV donations were identified.

Anti-D Antibodies in Pregnant D Variant Antigen Carriers Initially Typed as RhD.

BACKGROUND: To evaluate the incidence, the consequences, and the prevention strategy of anti-D alloimmunizations of D variant carriers in the obstetric population of Split-Dalmatia County, Croatia. METHODS: RhD immunization events were evaluated retrospectively for the period between 1993 and 2012. Women were tested for RhD antigen and irregular antibodies. Those with anti-D antibody who were not serologically D- were genotyped for RHD. They were evaluated for their obstetric and transfusion history and their titer of anti-D. The neonates were evaluated for RhD status, direct antiglobulin test (DAT), hemoglobin and bilirubin levels, transfusion therapy as well as phototherapy and outcome. RESULTS: Out of 104,884 live births 102,982 women were tested for RhD antigen. Anti-D immunization occurred in 184 women which accounts for 0.9% of individuals at risk of anti-D formation. 181 cases occurred in women serologically typed as D-. Three women were partial D carriers (DVa n = 2, DNB n = 1), initially typed RhD+, and recognized as D variant carriers after the immunization occurred. Anti-D titer varied from 1:1 to 1:16. Six children were RhD+, four had positive DAT, and two underwent phototherapy. CONCLUSION: Anti-D immunization occurred in pregnant partial D carriers (DVa, DNB). RhD+ children had serologic markers of hemolytic disease of the fetus and newborn (HDFN), with no cases of severe HDFN.