Serological Groups Research Articles

Association of human leukocyte antigen alleles with chronic lung diseases in rheumatoid arthritis.

Chronic lung diseases including interstitial lung disease and airway disease (AD) occur in RA patients. Interstitial lung disease and AD in RA are extra-articular manifestations that influence the prognosis quoad vitam of RA. Studies on associations of HLA alleles with RA have been carried out, and shared epitopes of several alleles are reported to be associated with RA susceptibility. Few association studies in RA subpopulations with chronic lung diseases have been conducted. The aim of the study was to identify HLA alleles predisposing to RA phenotypes including the presence of AD. Associations of HLA-DRB1 and DQB1 alleles with chronic lung diseases in RA were analysed. A positive association was found between the DR4 serological group and resistance to usual interstitial pneumonia [P = 0.0250, odds ratio (OR) 0.62, 95% CI: 0.41, 0.93]. The DR2 serological group was associated with susceptibility to usual interstitial pneumonia (P = 0.0036, OR = 1.86, 95% CI: 1.23, 2.81). An association was found for shared epitopes alleles with bronchiolitic AD (P = 0.0040, OR = 2.06, 95% CI: 1.24, 3.41). DQB1*03:01 was associated with bronchiectatic AD (P = 0.0021, corrected P-value (Pc) = 0.0315, OR = 1.99, 95% CI: 1.30, 3.06), as well as with emphysema (P = 0.0007, Pc = 0.0104, OR = 2.43, 95% CI: 1.49, 3.95). In combined analysis, a predisposing association of DQB1*03:01 (P = 1.94 ×10(-5), Pc = 0.0003, OR = 2.16, 95% CI: 1.53, 3.06) and a negative association of DQB1*03:02 (P = 0.0008, Pc = 0.0117, OR = 0.33, 95% CI: 0.17, 0.67) with bronchiectatic AD or emphysema were observed in RA. The present study identified an association of HLA-DQB1*03:01 with predisposition to, and DQB1*03:02 with resistance to, bronchiectatic AD or emphysema in RA.

Cytomegalovirus Infection and Rates of Antiviral Resistance Following Intestinal and Multivisceral Transplantation

BackgroundCytomegalovirus (CMV) disease is a common and clinically significant complication following intestinal or multivisceral transplantation. CMV disease is more common in cases of serologic mismatch between donor and recipient. Though in some cases it may be asymptomatic, in the immunosuppressed population it often manifests with evidence of systemic infection or end-organ disease. MethodsWe conducted a retrospective review of all patients undergoing intestinal or multivisceral transplantation over 8 years at our institution. ResultsForty-eight transplantations were performed, with 40% of the patients (19/48) having ≥1 episode of CMV viremia, which rose to 90% in the “donor-positive, recipient-negative” (DPRN) serologic mismatch group. The median time to 1st episode following transplantation was 22.3 weeks (range, 1–78) and median duration of each episode was 4.9 weeks (range, 1.6–37.4). Six of the 19 viremic patients (31.6%) developed virologic resistance with 4 of these occurring in the DPRN group. Four of the 6 patients with drug-resistant CMV died with CMV viremia. All patients with drug resistance acquired ganciclovir resistance; these patients were more challenging to manage with second-line toxicity-limited treatments, including foscarnet, cidofovir, and leflunomide. CMV immunoglobulin has been used and we briefly discuss the use of CMV-specific adoptive T-lymphocyte transfer in the management of 1 case. ConclusionsPost-transplantation CMV disease continues to be challenging to manage, and there is little consensus on optimal management strategies in this patient group, with a significant requirement for novel therapies; these may be pharmacologic or cell based. Extensive multidisciplinary discussion is important for most cases, but particularly for those patients who acquire virologic resistance.

Identification of epitopes on HLA-DRB alleles reacting with antibodies in sera from women sensitized during pregnancy

This report describes a HLAMatchmaker-based antibody analysis of post-pregnancy sera with antibodies against child-specific HLA-DR epitopes. These sera were reactive in IgG-binding assays with single allele bead (SAB) panels on a Luminex platform. The antibody specificity analysis focused on DRB epitopes that have been recorded in the International HLA Epitope Registry (http://www.epregistry.com.br) as experimentally verified with informative antibodies but we also considered other eplets that predict potential epitopes.The SAB panel has in several instances two or more alleles corresponding to the same serologically defined DR antigen and we selected six sera were with different reactivity patterns with DR1, DR4, DR13 and/or DR52 alleles. We demonstrate here how amino acid differences between these alleles can provide useful information in the determination of new epitope specificities of antibodies in these sera. Eight newly antibody-verified epitopes were identified including three that correspond to eplets paired with self-residue configurations. Epitope specificity information appears to be useful in the prediction of mismatch acceptability of non-SAB alleles within serological DR antigen groups.

DPB1 T-cell epitopes: Molecular definition

Aim Molecular characterisation of known differences of T-cell recognition of DPB1 alleles. Methods Propositional logic algorithm to search for best sequence properties to account for reported T-cell recognition differences. Results DPB1*09:01:01, DPB1*10:01 and DPB1*17:01 have been reported by Fleischhauer et al. to be mismatch high-risk (group 1) and DPB1*03:01:01, DPB1*14:01:01 and DPB1*45:01 to be mismatch intermediate-risk (group 2). DPB1 alleles have been previously classified in 4 serologic groups based on 2 dimorphic epitopes, the first epitope defined by amino acid position 56 and the second epitope by positions 85, 86 and 87. Fleischhauer’s group 1 and group 2 DPB1 alleles are both included in serologic group DP3 characterised by 56(E) on one hand and 85(E)-86(A)-87(V) on the other. [Human Immunology 2009 70:836] DP3 alleles can be further classified by amino acid positions 11, 65 and 76 into 3 subgroups that match Fleischhauer’s mismatch high-risk groups. This molecular characterisation into subgroup must be interpreted in the light of higher level groups defined by the 56 and 85–86–87 two dimorphic serologic epitopes. In this context, within the DP3 serologic group, T-cell group 1 is characterised by 11(L)-65(I) with tolerance for variation at position 76. T-cell group 2 is characterised by 65(L)-76(V) with tolerance for variation at position 11. Conclusions If the molecular characterisation of DPB1 T-cell epitopes presented here is correct, then DPB1*35:01:01 and the DPB1*17:01 exon 3 variant DPB1*131:01 should also be included in the high-risk group 1 together with DPB1*09:01:01, DPB1*10:01 and DPB1*17:01. DPB1*104:01 and the DPB1*03:01:01 exon 3 variant DRB1*124:01 should be included in group 2 together with DPB1*03:01:01, DPB1*14:01:01 and DPB1*45:01. DPB1*57:01 might also belong in group 2 depending on the tolerance for variation at position 11 in this group. (All these alleles are known common alleles. Undocumented alleles are excluded.)

LBP30: THE SPECIFICITY OF HLA-DP ANTIBODIES ARE DEFINED BY TWO DIMORPHIC EPITOPES

Aim The presence of HLA-DP antibodies may cause AMR. It has been reported that serologic epitopes of HLA-DP are defined by two sequence dimorphisms based on a small cohort of patients. Our aim was to determine whether the specificity of DP antibodies we identified in a much larger study were explained by these two serologic epitopes, and to characterize their reactivity patterns. Methods Among 2821 renal patients who were analyzed by SAB class II testing, 486 patients displayed HLA-DP antibodies. The association between DP antibody specificities was analyzed by hierarchical clustering to identify potential epitope patterns. 4 Sera displaying strong DP antibodies were then adsorbed by cells carrying the related epitope, the bound antibodies were eluted with acid, placed in a buffered solution and reanalyzed by SAB testing to identify which antigens remained reactive. Results Based on hierarchical clustering analysis, HLA-DP antibodies were categorized into 4 clusters (Fig. 1). These 4 clusters are largely consistent with the serologic groups as described by Cano et al. dependent on the presence of epitopes GPM or EAV at positions 85–87 or the presence of A or E at position 56. Antibodies against cluster 3 (DP6, 3, 14, 9, 17) are most common and were found in 160 patients. In contrast, antibodies against cluster 2 (DP401, 402, 2, 18, 28) are least common. Only 44 patients developed antibodies against cluster 2. This is likely due to the high frequency of this cluster (>60%) in the population. To confirm whether antibodies within each group recognize the same epitope, we performed the cell adsorption-elution assay. For example, we found cells carrying homologous HLA-DP2 can bind antibodies that are against cluster 2 and 4 antigens which share the epitope GPM 85–87 with HLA-DP2. Conclusion DP antibodies recognize two major dimorphic epitopes. HLA-DP epitope matching between the donor and recipient at these two critical epitopes should reduce post-transplant sensitization and improve transplant outcome.

IFAT and ELISA phase I/phase II as tools for the identification of Q fever chronic milk shedders in cattle

Q fever is a widespread zoonotic disease caused by Coxiella burnetii. In cattle the bacterial shedding can persist without symptoms for several months and the shedders identification is a critical issue in the control of the infection at herd level. Following the example of the human protocols for the assessment of Q fever infection status, the aim of this study was the evaluation of the antibody response dynamics to phase I and phase II antigens in C. burnetii shedder dairy cows by means of a phase-specific serology, to verify the suitability of the investigated tools in recognising milk shedders. A total of 99 cows were monitored during time and classified on the basis of serological and PCR results in five groups identifying different shedding patterns. The 297 sera collected in three sampling times were tested by means of ELISA IgG for differential phase I and phase II antibodies detection, while a selection of 107 sera were tested by means of phase specific IgM and IgG IFAT. Both ELISA IgG and IFAT IgG highlighted a low reactivity in non-shedder seropositive animals compared to chronic milk shedder animals. ELISA IgG seemed to perform better than IFAT IgG–IgM, showing significant serological differences among groups that allowed recognising specific serological group patterns, in particular for chronic and occasional milk shedders. These results supported the hypothesis that an animal classification based on phase patterns is reasonable, although it needs to be further investigated.

High-throughput multiplexed xMAP Luminex array panel for detection of twenty two medically important mosquito-borne arboviruses based on innovations in synthetic biology

Mosquito-borne arboviruses are emerging world-wide as important human and animal pathogens. This makes assays for their accurate and rapid identification essential for public health, epidemiological, ecological studies. Over the past decade, many mono- and multiplexed assays targeting arboviruses nucleic acids have been reported. None has become established for the routine identification of multiple viruses in a “single tube” setting. With increasing multiplexing, the detection of viral RNAs is complicated by noise, false positives and negatives. In this study, an assay was developed that avoids these problems by combining two new kinds of nucleic acids emerging from the field of synthetic biology. The first is a “self-avoiding molecular recognition system” (SAMRS), which enables high levels of multiplexing. The second is an “artificially expanded genetic information system” (AEGIS), which enables clean PCR amplification in nested PCR formats. A conversion technology was used to place AEGIS component into amplicon, improving their efficiency of hybridization on Luminex beads. When Luminex “liquid microarrays” are exploited for downstream detection, this combination supports single-tube PCR amplification assays that can identify 22 mosquito-borne RNA viruses from the genera Flavivirus, Alphavirus, Orthobunyavirus. The assay differentiates between closely-related viruses, as dengue, West Nile, Japanese encephalitis, and the California serological group. The performance and the sensitivity of the assay were evaluated with dengue viruses and infected mosquitoes; as few as 6–10 dengue virions can be detected in a single mosquito.

Differences in Clinical and Laboratory Findings between Group D and Non-Group D Non-Typhoidal Salmonella Gastroenteritis in Children.

PurposeTo investigate the differences in clinical features and laboratory findings between group D and non-group D non-typhoidal Salmonella (NTS) gastroenteritis in children.MethodsA retrospective chart review of children diagnosed with NTS confirmed by culture study was performed. The clinical features and laboratory findings of group D and non-group D NTS were compared.ResultsFrom 2003 to 2012, 75 cases were diagnosed as NTS at our center. The number of group D and non-group D patients was 45 and 30, respectively. The mean age was higher in group D than in non-group D patients (5.1 years vs. 3.4 years, p=0.038). Headaches were more frequently observed (p=0.046) and hematochezia was less frequently observed (p=0.017) in group D than in non-group D NTS gastroenteritis patients. A positive Widal test result was observed in 53.3% of group D and 6.7% of non-group D NTS cases (O-titer, p=0.030; H-titer, p=0.039). There were no differences in white blood cell counts, level of C-reactive protein and rate of antimicrobial resistance between group D and non-group D cases.ConclusionThe more severe clinical features such as headache, fever, and higher Widal titers were found to be indicative of group D NTS gastroenteritis. Additionally, group D NTS gastroenteritis was more commonly found in older patients. Therefore, old age, fever, headache, and a positive Widal test are more indicative of group D NTS than non-group D NTS gastroenteritis. Pathophysiological mechanisms may differ across serologic groups.

Genetics of Interstitial Lung Disease: Vol de Nuit (Night Flight).

Interstitial lung disease (ILD) is a chronic, progressive fibrotic lung disease with a dismal prognosis. ILD of unknown etiology is referred to as idiopathic interstitial pneumonia (IIP), which is sporadic in the majority of cases. ILD is frequently accompanied by rheumatoid arthritis (RA), systemic sclerosis (SSc), polymyositis/dermatomyositis (PM/DM), and other autoimmune diseases, and is referred to as collagen vascular disease-associated ILD (CVD-ILD). Susceptibility to ILD is influenced by genetic and environmental factors. Recent advances in radiographic imaging techniques such as high-resolution computed tomography (CT) scanning as well as high-throughput genomic analyses have provided insights into the genetics of ILD. These studies have repeatedly revealed an association between IIP (sporadic and familial) and a single nucleotide polymorphism (SNP) in the promoter region of the mucin 5B (MUC5B). HLA-DRB1*11 alleles have been reported to correlate with ILD in European patients with SSc, whereas in Japanese patients with RA, the HLA-DR2 serological group was identified. The aim of this review is to describe the genetic background of sporadic IIP, CVD-ILD, drug-induced-ILD (DI-ILD), pneumoconiosis, and hypersensitivity pneumonitis. The genetics of ILD is still in progress. However, this information will enhance the understanding of the pathogenesis of ILD and aid the identification of novel therapeutic targets for personalized medicine in future.

African swine fever virus CD2v and C-type lectin gene loci mediate serological specificity.

African swine fever (ASF) is an emerging disease threat for the swine industry worldwide. No ASF vaccine is available and progress is hindered by lack of knowledge concerning the extent of ASF virus (ASFV) strain diversity and the viral antigens responsible for protection in the pig. Available data from vaccination/challenge experiments in pigs indicate ASF protective immunity is haemadsorption inhibition (HAI) serotype-specific. A better understanding of ASFV HAI serological groups and their diversity in nature, as well as improved methods to serotype ASFV isolates, is needed. Here, we demonstrated that the genetic locus encoding ASFV CD2v and C-type lectin proteins mediates HAI serological specificity and that CD2v/C-type lectin genotyping provides a simple method to group ASFVs by serotype, thus facilitating study of ASFV strain diversity in nature, and providing information necessary for eventual vaccine design, development and efficacious use.

Microscopic changes in the kidneys of cows infected with Leptospira sp.

Abstract The article presents data on histopathological studies of the kidneys of cows, which either recovered or died from leptospirosis. Fragments of seven kidneys from slaughtered cows, positive for Leptospira antibodies in the microscopic agglutination test (MAT) (titres of 50 and higher) were used in the study. The MAT was conducted with eight serological groups of Leptospira: Canicola, Grippotyphosa, Hebdomadis, Icterohaemorrhagiae, Pomona, Sejroe, Tarassovi, and Australis. Microscopic changes in all morphological structures of the kidneys were presented. Micromorphological criteria, which can be used for post-mortem diagnosis of leptospirosis were established. They included: serous glomerulonephritis with granular dystrophy of podocytes, necrosis and collapse of the inner layer of Bowman's capsule, partial destruction of capsule and vascular glomeruli, granular and vacuolar degeneration and destruction of tubular epithelial cells, foci of interstitial oedema, and infiltrations predominantly with monocytes and isolated neutrophils. Microscopic changes in the kidneys suggest that the cows died from leptospirosis as a result of toxic shock syndrome.

Temporal trends in mortality among people who use drugs compared with the general Dutch population differ by hepatitis C virus and HIV infection status.

We aimed to identify temporal trends in all-cause and cause-specific mortality rates among people who use drugs (PWUD) compared with the general Dutch population and to determine whether mortality trends differed by hepatitis C virus (HCV)/HIV (co) infection status. Longitudinal cohort study. Using data from the Amsterdam Cohort Studies among 1254 PWUD (1985-2012), all-cause and cause-specific standardized mortality ratios (SMRs) were calculated; SMRs were stratified by serological group (HCV/HIV-uninfected, HCV-monoinfected, and HCV/HIV-coinfected) and calendar period. Temporal trends were estimated using Poisson regression. The overall all-cause SMR was 13.9 (95% confidence interval 12.6-15.3). The SMR significantly declined after 1996, especially due to a decline among women (P < 0.001). The highest SMR was observed among HCV/HIV-coinfected individuals during 1990-1996 (SMR 61.9, 95% confidence interval 50.4-76.0), which significantly declined after this period among women (P = 0.001). In contrast, SMR for HCV-monoinfected, and HCV/HIV-uninfected PWUD did not significantly change over time. The SMR for non-natural deaths significantly declined (P = 0.007), whereas the SMR for HIV-related deaths was the highest during all calendar periods. We found evidence for declining all-cause mortality among PWUD compared with the general population rates. Those with HCV/HIV-coinfection showed the highest SMR. The decline in the SMR seems to be attributable to the decline in mortality among women. Mortality rates due to non-natural deaths came closer to those of the general population over time. However, HIV-related deaths remain an important cause of mortality among PWUD when compared with the general Dutch population. This study reinforces the importance of harm-reduction interventions and HCV/HIV treatment to reduce mortality among PWUD.

Occurrence and Characterization of Bean common mosaic virus Strain NL1 in Iowa.

A legume survey in Story County was conducted to characterize legume viruses present in Iowa and potentially problematic to soybeans. Symptomatic (chlorosis, leaf curl, or vein banding) and non-symptomic leaves were selected from Apios americana, Cyamopsis tetragonolobus, Desmodium spp., Glycine max, Lablab purpureus, Lotus japonicus, Phaseolus coccineus, Phaseolus vulgaris, Vicia faba, Vigna ungulculata, and Chenopodium quinoa (an indicator species), and sent to Agdia Inc. for their Crop Screen: "Bean (Soybean)" tests. Cowpea mosaic virus (in L. purpureus), Southern bean mosaic virus (in A. americana), Soybean dwarf virus (in L. purpureus), and Tobacco streak virus (in Desmodium spp.) were identified. In addition, P. vulgaris was found positive in the serological Potyvirus group test, and was further characterized using reverse transcription (RT)-PCR using total RNA (Qiagen RNeasy extraction kit) from symptomatic leaves. A ~1-kb fragment of virus genome was amplified using degenerate primers, forward: 5' TGYGTNGAYGAYYTYAAYAA 3' (3) and reverse: 5' TCRTARAARTCRAAIGCRTAICKIG 3' (2). The closest GenBank BLAST hits for the sequence were BCMV strain NL1 (GenBank Accession No. AY112735) and BCMV MS1 (EU761198), both at 97% identity. RNA sequencing using an Illumina HiSeq 2500 (100 base paired ends) allowed construction of a nearly complete viral sequence from positions 38 to 10,037 nt (KM023744). This showed 99% similarity to BCMV-NL1 (AY112735) and 98% similarity to BCMV MS1 (EU761198). The BCMV isolate was recovered on the P. vulgaris cv. Taos Red and tested against a panel of Phaseolus, Glycine, and other hosts. Symptomatic hosts (vein-banding, mosaic, stunting, and leaf curl) were P. vulgaris cvs. Starlight, Tohono O'odham vaya Amarillo, Black Valentine Stringless, Sutter Pink, Hidatsa red, Stringless Green Refugee, Burpees Stringless Improved Bush, Princess d'Artois, Princess Double de Holland, and Dubelle Witte. Asymptomatic hosts included P. vulgaris cvs. Sierra, Great Northern Tara, Tara, and Vigna radiata. Non-host plants were P. vulgaris cvs. Michelite 62, Great Northern UI 31, Great Northern UI 123, Pure Gold Wax, Top Crop, Redlands Greanleaf B, Red Mexican UI 34, Imuna, Monroe, Pinto UI 114, Widusa, Othello, Sacramento, Red Kidney, Provider, Black Turtle Soup, Victor, and Witte boon, G. max cv. Williams, Cucumis sativus cv. Straight 8, Solanum lycopericum cv. Reine des Hatives, Vicia faba, Pisum sativum var. macrocarpon, V. unguiculata, and A. americana. The host range of the BCMV isolate on common bean differential species concurred with pathogenicity group I (1) and agreed with assignment as strain NL1. To our knowledge, this is the first complete characterization of a pathotype I strain NL1 of BCMV in the United States, combining biological typing and whole genome sequencing.

Plasmodium vivax infection: atypical memory B cells are expanded and associated with the persistence of Duffy binding protein II (DBPII) antibody response

Antibody responses generated during malaria infection represent an important component of acquired clinical immunity. Despite that, B cell subpopulations induced by the Plasmodium vivax (Pv) infection remains largely unknown. Here, we demonstrated that activated as well as “atypical” memory B cells (MBCs) are expanded in peripheral blood of Pv-exposed individuals, but their frequencies were not associated with acute infection. Aiming to investigate the association between peripheral B cells subsets and Pv-specific antibodies, we further followed-up 34 individuals exposed to P. vivax in the Brazilian Amazon area, an area of markedly unstable malaria transmission; after three cross-sectional survey (at 6-months intervals), ELISA-detected specific IgG (AMA-1, MSP1-19, DBPII) allowed the classification of those individuals as non-responder (NR), temporary (TR) or persistent responder (PR). For AMA-1 and MSP1-19 serological groups, the frequencies of MBCs (classical and atypical) and plasma cells (PCs) were similar among the groups. For DBPII group, we found a trend toward decreases classical MBCs according to the antibody response (NR>TR>PR). On the other hand, the frequencies of atypical MBCs increased according to the presence and persistence of DBPII antibody response (PR>TR>NR). Altogether, these results showed that atypical MBCs are expanded in Pv-exposed individuals (infected and non-infected), and it seems to be associated with the persistence of DBPII antibody response. Although preliminary, these results suggest that atypical MBCs contribute in generation of malarial antibody responses and provide insight into the role of atypical MBCs in P. vivax malaria immunity.

The Staphylococcal Cassette Chromosome mec type V from Staphylococcus aureus ST398 is packaged into bacteriophage capsids

The Staphylococcal Cassette Chromosome mec (SCCmec) confers methicillin resistance to Staphylococcus aureus. While SCCmec is generally regarded as a mobile genetic element, the precise mechanisms by which large SCCmec elements are exchanged between staphylococci have remained enigmatic. In the present studies, we observed that the clinical methicillin-resistant S. aureus (MRSA) isolate UMCG-M4 with the sequence type 398 contains four prophages belonging to the serological groups A, B and Fa. Previous studies have shown that certain serological group B bacteriophages of S. aureus are capable of generalized transduction. We therefore assessed the transducing capabilities of the phages from strain UMCG-M4. The results show that some of these phages can indeed transduce plasmid pT181 to the recipient S. aureus strain RN4220. Therefore, we also investigated the possible involvement of these transducing phages in the transmission of the large SCCmec type V (5C2&5) element of S. aureus UMCG-M4. While no transduction of the complete SCCmec element was observed, we were able to demonstrate that purified phage particles did contain large parts of the SCCmec element of the donor strain, including the methicillin resistance gene mecA. This shows that staphylococcal phages can encapsulate the resistance determinant mecA of a large SCCmec type V (5C2&5) element, which may lead to its transfer to other staphylococci.

ХАРАКТЕРИСТИКА ТОКСИГЕННОСТИ ЭНТЕРОБАКТЕРИЙ, ВЫДЕЛЕННЫХ ПРИ ЖЕЛУДОЧНО-КИШЕЧНЫХ БОЛЕЗНЯХ СЕЛЬСКОХОЗЯЙСТВЕННЫХ ЖИВОТНЫХ

In most Enterobacteriaceae family bacteria, being the main etiological agents of the diseases in young farm animals, there is no strict correlation between a serological group and toxic activity. Thus, when diagnosing the diseases, a direct identification of the bacterial adhesins or the toxin detection with the laboratory animals are conducted, and of these two procedures the animal test is usually long and difficult. We evaluated toxins and virulence in the pathogenic and opportunistic bacteria isolated from 1-5 days Holstein and Black Mottled calves with the diarrhea syndrome, and in the reference strains using different tests with the laboratory animals (white mice, the Self line guinea pigs, Chinchilla rabbits, and quail Coturnix comuni ). Most of the samples (64 of 86 isolates) were identified as Escherichia coli. In 34 E. coli isolates the O-antigen was not detected. In the test on white mice, infected intraperitoneally with a bacterial suspension, 35.0 % and 65.0 % of the bacteria were identified as pathogenic and nonpathogenic, respectively. Nevertheless, the toxins were detected in 53.9 % of the studied isolates and reference strains of Salmonella (2 strains), Klebsiella (2 strains), Kluyvera (a strain), Yersinia (3 straines), Escherichia (13 strains) genera. Moderate and low toxic properties were identified in 15.4 % and 38.5 % of these isolates, respectively, and in 46.1 % no toxigenic activity was found. By the histochemical methods, the histomorphological changes in tissues and organs of the laboratory animals were revealed under the experimental toxicoinfection caused by Enterobacteriaceae. At experimental toxemia, induced by E. coli and Y. pseudotuberculosis strains, a hydropic dystrophy of the villus epithelium cells developed in the small intestine, and a generalized microvascular reaction occurred in the gastric mucosa and in the mucosa of small and large intestines.

First Isolation and Characterization of Tenacibaculum soleae from Sea Bass Dicentrarchus labrax

Tenacibaculum soleae is a recently described pathogen that has been reported as the causative agent of considerable losses in sole cultures in Spain. This report documents the first case of T. soleae as an etiological agent of tenacibaculosis in farmed sea bass Dicentrarchus labrax. Its identification was performed employing phenotypical, serological and molecular methods. Although the sea bass isolates were homogeneous from a biochemical, chemotaxonomic and molecular point of view, they belonged to a serological group different from the type strain CECT7292, which can be of great importance in the development of future vaccines and other methods of disease prevention in sea bass industry. Virulence assays with a representative isolate confirmed the pathogenic potential for sea bass. The disease was experimentally reproduced by prolonged bath, while no mortalities could be recorded by intraperitoneal injection. The results presented here show that T. soleae must be taken into account as an important pathogen in the marine aquaculture industry.

HLA-DQ Barrier

Panel-reactive antibody (PRA) testing provides assessment of the breadth of sensitization a patient might have against human leukocyte antigen (HLA) antigens. The evolution of calculated PRA (cPRA) reflects the commitment of the transplant community to increase accessibility and promote equity to all patients awaiting kidney transplantation. Recent data from our center and others, however, suggested that a significant diversity of HLA-DQ antigens is not captured, which may lead to inequity in allocating cPRA points. HLA-DRB1-DQA1-DQB1 typing of 2182 individuals was evaluated for this study using Luminex-based sequence-specific oligonucleotide typing. A total of 3182 haplotypes were confirmed to have the level of resolution required for this study. The diversity of HLA-DQαβ alleles is greater than what is apparent using the serologic equivalents. The distribution of these alleles within a serologic group varies, with some alleles being more frequent than others; therefore, their representation within the current cPRA system is inaccurate. Three informative examples are given. Haplotypes of DR antigens with DQαβ alleles did not always follow the common published linkage disequilibrium, especially in populations where there is greater genetic diversity. The current cPRA system does not take into account the distribution of molecular equivalents within DQ serologic specificities. This can result is inequitable allocation of sensitization points and disadvantaging the more sensitized patients. To ameliorate this situation, the United Network for Organ Sharing system should allow inputting HLA-DQαβ alleles both for donor typing and as antibody specificities, which will lead to better representation of unacceptable DQ alleles and improve organ allocation equity.

Why do we use serological blood group phenotype determination in chronically transfused patients?

Why do we use serological blood group phenotype determination in chronically transfused patients?

Hematopoietic Progenitor Cell Mobilization In Response To G-CSF Is More Robust In Healthy African American Compared To Caucasian Donors

▪Hematopoietic progenitor cells (HPCs) collected by apheresis of G-CSF-stimulated donors have surpassed bone marrow as the predominant graft source for hematopoietic stem cell transplantation in adults. Among healthy allogeneic donors, demographic characteristics (age, sex, and BMI) and baseline hematologic parameters have been shown to affect HPC mobilization, leading to significant variability in peak levels of CD34 cell egress into the blood and in quantity of CD34 cells harvested by apheresis. Racial differences in G-CSF-mediated HPC mobilization are less well characterized. Benign physiologic neutropenia is common among healthy African Americans (AAs), and may be due to decreased stem cell reserve, fewer G-CSF receptors, or Duffy (null) blood group antigen-mediated decrease in leukocyte trafficking into the circulation. However, preliminary studies have shown relatively robust CD34+ cell mobilization among non-Caucasians given G-CSF (Vasu et al., Blood 2006).We retrospectively analyzed 1,096 consecutive healthy allogeneic related and unrelated first-time donors who self-characterized their race as AA or Caucasian. They underwent G-CSF (filgrastim, Neupogen, Amgen) stimulated HPC collection by leukapheresis from April 1999 to May 2013. G-CSF dose ranged from 10-16 mcg/kg, given daily for 5 days. An unstimulated leukapheresis procedure for lymphocyte collection was performed in the 7 days preceding G-CSF in 336 subjects. Apheresis procedures were performed on the CS-3000 Plus or COBE Spectra device. Baseline lab data included CBC, serologic blood group antigen typing, and Hb electrophoresis in AA donors. CD34+ cell counts were performed on peripheral blood immediately pre-apheresis (2 hours after the 5th dose of G-CSF) and on the apheresis product. Values are given as mean ± SD.All AA (n=215) and Caucasian donors (n=881) with complete data sets were included. Sex ratio was similar among the groups (45 vs 52% male; p=0.09). AAs were younger (39 vs 43 yrs, p=0.001) and had greater weight (86 vs 81 kg, p=0.001) and BMI (30 vs 27; p<0.0001) than Caucasians. G-CSF dose/kg was similar in the 2 groups, but total daily dose of G-CSF was greater in AAs than Caucasians (920 vs 850 mcg, p<0.0001). After adjusting for age, sex, height, weight, and total daily G-CSF dose, peak CD34+ cell mobilization immediately pre-apheresis was higher among AAs than Caucasians (123 ± 87 vs 75 ± 47 cells/uL; p<0.0001) (Figure). When laboratory parameters such as baseline WBC, MNC, and platelet counts were included in the stepwise regression model, AA race remained a significant predictor of higher peak CD34 cell counts. At higher G-CSF doses (16 mcg/kg/d), the difference in mobilization responses between the 2 groups was less apparent (peak CD34 counts 123 vs 93 cells/uL, AA (n=33) vs Caucasian (n=73), p=0.07) than at lower doses (10 mcg/kg/d), where peak CD34 counts were 123 vs 74 cells/uL, AA (n=182) vs Caucasian (n=808), p<0.0001. AAs had lower baseline ANC (3.4 vs 4.0 x 103 cells/uL, p<0.001) than Caucasians, but demonstrated significantly higher peak WBC and MNC counts after G-CSF. In AA donors with known HbS status, presence of sickle cell trait had no effect on CD34 mobilization (peak CD34 counts 123 ± 91 vs 107 ± 72 cells/uL, HbAS (n=41) vs HbAA (n=84), p=0.34). Similarly, in AA donors with known Duffy phenotype, Duffy expression did not affect CD34 mobilization (peak CD34 counts 114 ± 81 vs 134 ± 85 cells/uL, Fya-b- (n=49) vs Fya+ &/Fyb+ (n=20), p=0.4). Lymph-apheresis prior to starting G-CSF was associated with significantly improved CD34+ cell mobilization; however the effect did not differ by race. CD34 apheresis yield was also greater in AAs than Caucasians (51 ± 35 vs 32 ± 21 x 106 cells per liter processed, p <0.0001), consistent with higher pre-apheresis counts.African Americans demonstrated significantly more robust CD34 mobilization responses to G-CSF than Caucasians. The effect was independent of age, BMI, HbS and other variables, and occurred despite physiologically lower neutrophil counts among AAs. A ceiling effect in response to increased doses of G-CSF (>10 mcg/kg) was seen in AAs but not in Caucasians, suggesting that dose titration based on race might be used to optimize HPC yields. Further evaluation of race-associated genetic polymorphisms in relation to G-CSF pharmacokinetics may help improve G-CSF dosing strategies. [Display omitted] Disclosures:No relevant conflicts of interest to declare.