The distribution of HLA-DRB3 alleles among HLA-DRB1*03:01-positive haplotypes.

HLA-DRB3 allelic polymorphism on HLA-DRB1*03:01-positive haplotypes was investigated among 104 cadaveric donors typed for HLA-A, -B, -DRB1, and -DRB3. Only HLA-DRB3*01:01:02 and -DRB3*02:02:01:01 alleles were detected among HLA-DRB1*03:01-positive individuals and their distribution depended on HLA-B*08 presence: nearly all HLA-B*08-positive samples carried DRB3*01:01:02, while HLA-DRB3*02:02:01:01 was more frequent among HLA-B*08-negative subjects.

The distribution of the DRB4*01:03:01:02N null allele in HLA-DRB1~DQB1 haplotypes in the Croatian population.

The aim of the present study was to investigate frequency and haplotype distribution of DRB4 alleles in the Croatian population. The investigated sample consisted of 288 cadaveric donor samples positive for one of the DR53 alleles. HLA-A, -B, -C, -DRB1, and -DQB1 typing was performed using the polymerase chain reaction-sequence specific primers (PCR-SSP) low resolution method, while HLA-DRB4 and selected HLA class II specificities typing was performed using PCR-SSP at the allelic level. Three different DRB4 alleles were observed among DRB1*04 samples; DRB4*01:02 (2.38%), DRB4*01:03 (91.27%), and DRB4*01:03:01:02N (6.35%). The DRB4*01:03:01:02N allele was predominantly observed among DRB1*04:02-positive samples, while DRB4*01:02 and DRB4*01:03 alleles did not associate preferably with any of the DRB1*04 subtypes. Among DRB1*04~DRB4~DQB1 haplotypes, the predominant DQB1 allele was DQB1*03:02 (69.94%). Seven different DRB4 alleles were found among DRB1*07:01-positive samples. The analysis of DRB1*07~DRB4~DQB1 haplotypes showed that DRB4*01:03 was found in the majority of HLA-DRB1*07:01~DQB1*02:02 (49.09%) haplotypes while DRB1*07:01~DQB1*03:03 haplotypes carried the DRB4*01:03:01:02N allele almost exclusively (98.21%). Among six DRB1*09:01-positive samples, HLA-DRB1*09:01~DRB4*01:03~DQB1*03:03 was the only detected haplotype. The extended haplotype analysis showed a high frequency of HLA-B*15(B62)~C*03(Cw9)~DRB1*04:02~DRB4*01:03:01:02N~DQB1*03:02 and HLA-B*57~C*06~DRB1*07:01~DRB4*01:03:01:02N~DQB1*03:03 haplotypes. In conclusion, the data presented in this study should prompt other population studies focused on DRB3/4/5 genes and be used as a basis for future investigations of the clinical relevance of these genes in transplantation setting.

Carpal spasm in a girl as initial presentation of celiac disease: a case report.

BACKGROUND: Celiac disease is an immune-mediated disorder elicited by ingestion of gluten in genetically susceptible persons. This disorder is characterized by specific histological changes of the small intestine mucosa resulting in malabsorption. This case was written up as it was an unusual and dramatic presentation of celiac disease. CASE PRESENTATION: We report the case of a 3-year-old Albanian girl who presented at our clinic with carpal spasms and hand paresthesia. A physical examination at admission revealed a relatively good general condition and body weight of 10.5 kg (10 percentile). Carpal spasms and paresthesias of her extremities were present. Neuromuscular irritability was demonstrated by positive Chvostek and Trousseau signs. Blood tests showed severe hypocalcemia with a total serum calcium of 1.2 mmol/L (normal range 2.12 to 2.55 mmol/L), ionized calcium of 0.87 (normal range 1.11 to 1.30 mmol/L), and 24-hour urine calcium excretion of 9.16 mmol (normal range female <6.2 mmol/day). Among other tests, screening for celiac disease was performed: antigliadin immunoglobulin A, anti-tissue transglutaminase, and anti-endomysial immunoglobulin A antibodies were positive. A duodenal biopsy revealed lymphocyte infiltration, crypt hyperplasia, and villous atrophy compatible with celiac disease grade IIIb according to the Marsh classification. Following the diagnosis of celiac disease, human leukocyte antigen typing was performed, giving a definite diagnosis of celiac disease. She was started on a gluten-free diet. Due to failure to follow a gluten-free diet, episodes of carpal spasms appeared again. Unfortunately, at the age of 7 years she presents with delayed psychophysical development. CONCLUSIONS: Although hypocalcemia is a common finding in celiac disease, hypocalcemic carpal spasm is a rare initial manifestation of the disease. Therefore, the possibility of celiac disease should be considered in patients with repeated carpal spasms that seem unduly difficult to treat. This should be evaluated even in the absence of gastrointestinal symptoms since hypocalcemia and its manifestation may present as initial symptoms of celiac disease even in young children.

Association of HLA alleles and haplotypes with CYP21A2 gene p. V282L mutation in the Croatian population.

The CYP21A2 mutations that are in linkage disequilibrium with particular HLA-A, -B, -DRB1 alleles/haplotypes, cause deficiency of the 21-hydroxylase enzyme (21-OHD) and account for the majority of congenital adrenal hyperplasia (CAH) cases. The aim of this study was to investigate those associations with the p.V282L mutation linked to the non-classical (NC) form of CAH among Croatians. The study included parents of patients with the NC form of CAH, positive for the p.V282L mutation (N = 55) and cadaveric donor samples (N = 231). All subjects were HLA-A, -B, and -DRB1 typed and tested for the presence of the p.V282L mutation. Among parents of patients, 92.73% of subjects were positive for the B*14:02 allele and almost half of them carried the HLA-A*33:01-B*14:02-DRB1*01:02 haplotype. Among cadaveric samples 77 out of 96 subjects positive for the B*14:02 allele had the p.V282L mutation. Among them, 37 were positive for the HLA-A*33:01-B*14:02-DRB1*01:02 haplotype, 23 had the HLA-A*33:01-B*14:02-DRB1*03:01 haplotype, 8 had the B*14:02-DRB1*01:02 combination and 5 were carrying the HLA-A*68:02-B*14:02-DRB1*13:03 haplotype. Only 4 of these subjects were positive for the B*14:02 allele. HLA-B*14:02 was the only single allele with association that reached statistically significant P value (RR = 12.00; P = 0.0024). Haplotypes B*14:02-DRB1*01:02 (P < 0.001) and HLA-A*68:02-B*14:02-DRB1*13:03 (P < 0.001) as well as HLA-A*33:01-B*14:02-DRB1*01:02 and HLA-A*33:01-B*14:02-DRB1*03:01 showed high relative risks (RR = 45.00, RR = 41.63 and RR = 36.96, respectively). Our data support the previously documented association of the HLA-A*33:01-B*14:02-DRB1*01:02 haplotype with the p.V282L mutation, but also point out a high frequency of the p.V282L mutation among Croatians with HLA-A*33:01-B*14:02-DRB1*03:01 and HLA-A*68:02-B*14:02-DRB1*13:03 haplotypes.

The possible role of the tumour necrosis factor polymorphisms and human leucocyte antigens in the development of prostate cancer.

The cause of prostate cancer (PC), one of the most common cancers found among ageing men, remains unclear, but genetic predisposition is believed to play a major role in its aetiology. The aim of the study was to examine HLA genes polymorphism and TNF polymorphisms in PC development. Patients diagnosed with PC (N = 113) and 150 healthy individuals were tested for HLA-A, HLA-B and HLA-DRB1 genes and for TNFa, TNFb and TNFd microsatellites. The comparison of patients and controls revealed a positive association of HLA-DRB1*12, TNFa2 and TNFb5, and a negative association of HLA-DRB1*13 and TNFb4 with PC. A division of patients into groups according to age, pre-operative PSA level, Gleason score (GS) and involvement of prostatic capsule, seminal vesicles or bladder neck and perineural invasion of PC demonstrated the following: a positive correlation of HLA-DRB1*12 and a negative correlation of HLA-DRB1*13 with younger patients (<65 years), GS > 7 and the positive association of prostatic capsule, seminal vesicles, bladder neck and perineural invasion of PC; TNFb4 allele's negative association with older patients displaying higher PSA levels, higher GS and positive surrounding tissue involvement; positive association of TNFb5 allele for both older and younger patients. Investigation of HLA genes and TNF microsatellites demonstrated a possible role of HLA-DRB1 and TNF regions in PC aetiology.

Identification of the novel HLA-A*01:200 allele by sequence-based typing in a Croatian individual.

The new allele HLA-A*01:200 differs from A*01:12 by four nucleotide substitutions in exon 3.

A case of maternal-foetal chimerism identified during routine histocompatibility testing for hematopoietic stem cell transplantation.

This report describes a case of maternal-foetal chimerism identified in a boy diagnosed with SCID, who underwent HLA testing in preparation for HSCT. The first analysis was carried out on DNA from peripheral blood and included HLA-A, HLA-B, HLA-DRB1 typing using PCR-SSO. The patient's HLA-B typing results were noninterpretable. All samples were re-typed for HLA-B using PCR-SSP, again resulting in noninterpretable typing of patient's HLA-B. In both cases, several weak positive probes/reactions interfered with the interpretation when using commercial software. Next round of HLA typing, using PCR-SSP and PCR-SSO methods, included the patient's bone marrow sample and HLA-C locus, but interpretation was again not possible. The PCR-STR analysis performed on both peripheral blood and bone marrow samples revealed seven STRs for which two maternal and one paternal allele were detected. Retrospective manual interpretation of HLA-B and HLA-C typing revealed that weak positive reactions were indeed owed to paternal HLA-B and HLA-C alleles and that the patient had both maternal and one paternal allele. Retyping of HLA-B and HLA-C loci and STR analysis on the patient's buccal cells sample revealed the expected one maternal/one paternal allele pattern. In summary, the combination of several different typing methods and manual interpretation were necessary to obtain the patient's HLA typing results.

Nonfrequent but well-documented, rare and very rare HLA alleles observed in the Croatian population.

The aim of the study was to evaluate the presence of nonfrequent, rare and very rare alleles among Croats and to estimate whether they are associated with specific alleles at other human leukocyte antigen (HLA) loci. This retrospective study included the typing results from the last 10 years; total number of individuals included was approximately 45,000. Among 17 alleles so far observed only once in our population, 6 (A*24:41, B*07:02:28, B*35:03:03, B*39:40N, DRB1*13:23 and DRB1*14:111) belong to very rare alleles, 2 (B*44:16 and DRB1*01:31) belong to rare alleles according to the 'Rare Alleles Detector' tool ( www.allelefrequencies.net), while for the B*35:101:01 allele published data exist only in the IMGT/HLA database. The remaining eight HLA alleles observed only once among Croats are considered as frequent according to the 'Rare Alleles Detector'. Those 17 HLA alleles are not declared as common well defined (CWD) alleles in the CWD allele catalogue 2.0.0. Haplotype analysis of nonfrequent alleles detected in our sample supports the idea that different populations, although similar in some aspects regarding HLA allele and haplotype distribution, still have some unique characteristics. This is the case for A*01:02, B*39:10 and DRB1*13:32 which form haplotypes unreported to date among our subjects.

HLA-A, HLA-B and HLA-DRB1 allele and haplotype diversity among volunteer bone marrow donors from Croatia.

The determination of human leucocyte antigen (HLA)-A, HLA-B and HLA-DRB1 alleles in the routine procedure of a volunteer hematopoietic stem cell (HSC) donor's registration in the Croatian Bone Marrow Donor Registry (CBMDR) is performed to enhance the odds of finding a suitable HLA compatible donor for patients in need of a HSC transplantation worldwide. However, besides its original purpose, it also provides valuable information about the HLA polymorphism among Croats. The aim of the present study was to analyse the HLA allele and haplotype frequencies in a sample of 4000 donors from CBMDR. The distribution of HLA-A, HLA-B and HLA-DRB1 alleles did not demonstrate significant differences from the data reported for other European populations. The higher frequency of B*40:02 allele in comparison with B*40:01 and DRB1*11:04 in comparison with DRB1*11:01 is interesting because it represents a difference in comparison with the Western and Northern European populations which are a main source of donors for Croatian patients. The haplotype frequencies show a greater variation and difference in comparison with data from other registries and populations; however, due to a lack of high-resolution haplotype data, comparison was possible only with a very limited number of other populations.

Heterogeneity of HLA-DRB1*04 alleles and haplotypes in the Croatian population.

Analysis of allele distribution at the HLA-DRB1*04 gene, as one of the frequent ones among Croatians, and their HLA-A-B-DRB1 haplotypes in the Croatian population was performed in this study. Using LABType® SSO and PCR-SSP method, 11 DRB1*04 subtypes were observed, of which DRB1*04:01 was the most frequent (28.0%) followed by DRB1*04:02 (26.3%), DRB1*04:03 (22.3%), and DRB1*04:04 (14.2%). The significant haplotypes (with highest P value) for given DRB1*04 allele were the following combinations: HLA-B*15:01-DRB1*04:01, HLA-B*38:01-DRB1*04:02, HLA-B*35:03-DRB1*04:03, HLA-B*35:03-DRB1*04:08, HLA-B*14:01-DRB1*04:04, and HLA-B*49-DRB1*04:05. Marked differences in the distribution of our most frequent haplotypes of HLA-B-DRB1*04 (HLA-B*38:01-DRB1*04:02 and HLA-B*15:01-DRB1*04:01) were found in comparison to other European populations investigated so far. Additionally, comparison of HLA-A-B-DRB1*04 haplotypes showed that although there are similarities in the haplotype structure between our and other populations, there are also noteworthy differences. In summary, the identification of conserved and unusual DRB1*04 haplotypes in the present study of Croats should have important clinical implications for donor-recipient matching in the hematopoietic stem cell transplantation program, help in the understanding of HLA polymorphisms in different European populations, and also prove to be very useful in the determination of possible susceptibility genes involved in HLA-DRB1*04-associated diseases.

The investigation of HLA microsatellites influence in predisposition to sarcoidosis among Croatians.

The aim of the present study was to analyze the distribution of HLA alleles (A, B, DRB1, DQB1) and HLA microsatellite alleles (TNFa, TNFb, TNFd, D6S273, D6S1014) in the Croatian patients with acute (N=93), as well as chronic sarcoidosis (N=40), in comparison to healthy controls (N=177), and investigate whether the polymorphism within the HLA region could be associated with different forms of sarcoidosis. Genomic DNA was isolated from peripheral blood. Patients were analyzed for HLA class I loci (A, B) by serology, while PCR-SSP method was used for HLA class II loci (DRB1, DQB1). Five HLA microsatellites were analyzed by PCR and electrophoresis in an automated sequencer. No significant deviation in the distribution of frequencies at HLA class I alleles was observed between the two patients' subgroups and controls. Regarding the HLA class II alleles, a statistically significant increase in frequency of HLA-DRB1*03 and DQB1*0201 allele was found among patients with acute sarcoidosis in comparison to controls as well as in comparison to patients with chronic sarcoidosis. The same finding was observed for HLA-DRB1*03/DQB1*0201 haplotype (Pcorr=0.0168; OR=2.83). In the group of patients with chronic sarcoidosis DRB1*11 (P=0.0219; OR=2.44), DRB1*15 (P=0.0414; OR=2.47) demonstrated statistically significant difference in comparison to controls only, while a lower frequency of DRB1*13 (P=0.0156; OR=0.24) in this group was statistically significant when compared to both patients with acute sarcoidosis and controls. None of the alleles at TNFa microsatellite showed significant difference in distribution among both subgroups of patients and controls. Significant difference between patients with acute form of disease and controls was found for the following alleles: TNFd-2 (Pcorr=0.00007; OR=4.89), D6S273-7 (Pcorr=0.0213; OR=2.96), and D6S1014-7 (Pcorr=0.0028; OR=3.97). On the other hand, patients with chronic sarcoidosis differed from control subjects for D6S1014-8 (Pcorr=0.0296; OR=8.35) allele. This study suggests the existence of an association of non-HLA markers with sarcoidosis and the involvement of the region between HLA-DQB1 and D6S273 loci in its pathophysiology.

The study of the extended haplotypes of rare HLA-B*2730 allele using microsatellite loci.

The aim of the present study was to compare haplotypes of the most frequent B*27 alleles among Croatians (B*2702 and *2705) and the rare B*2730 allele. For this purpose, 37 families with members carrying human leukocyte antigen (HLA)-B27 were selected. All individuals were analysed for eight microsatellites (Msats): D6S2927, short tandem repeat - MHC class I-related gene (STR_MICA), D6S2793, D6S2811, tumor necrosis factor a (TNFa), tumor necrosis factor d (TNFd), D6S273 and D6S1014, while individuals carrying the HLA-B27 specificity were subtyped. Of 39 analysed haplotypes, 20 individuals had B*2702, 15 subjects were positive for the B*2705 allele, the B*2730 allele was found in three haplotypes from different families, while one individual carried the B*2703 allele. HLA-A3 and -DRB1*16 were shared by all three B*2730 haplotypes. The DRB1*16 allele was also observed in the majority of B*2702 haplotypes (76.5%), while HLA-A3 was, after HLA-A2, the second most frequent HLA-A specificity in B*2702 haplotypes. No such correlation was found for the B*2705 haplotypes. Msat analysis showed that B*2730 haplotypes also share the same allele at all tested Msats. The D6S2927, D6S2793, MICA and TNFd Msats were not useful in distinguishing B*2702 and B*2705 alleles because D6S2927-213bp, STR_MICA-179bp, D6S2793-206bp, D6S2811-83bp and TNFd-130bp were detected in almost all cases. Conversely, for the TNFa, D6S273 and D6S1014 loci, haplotypes carrying B*2702 and B*2730 shared a single Msat allele in the majority of cases (TNFa-113bp, D6S1014-134bp and D6S273-134bp), which was not observed for B*2705 haplotypes. In conclusion, the similarity between B*2702 and B*2730 DNA sequences as well as their sharing of the same haplotypic combinations corroborates the proposed mechanism of B*2730 evolution from B*2702 by interallelic recombination.

HLA class I and class II frequencies in patients with sarcoidosis from Croatia: role of HLA-B8, -DRB1*0301, and -DQB1*0201 haplotype in clinical variations of the disease.

Sarcoidosis is an immune-mediated, multiorgan, granulomatous disease triggered by a combination of environmental and genetic factors. Numerous studies have reported about an association of human leukocyte antigen (HLA) alleles with sarcoidosis, with variation of alleles in different ethnic groups. Therefore, we investigated 142 Croatian sarcoidosis patients treated at the University Hospital for Lung Diseases Jordanovac, Zagreb, Croatia. Diagnosis was based on the presence of typical clinical features, chest X-ray findings and biopsy evidence of granuloma. Patients and control subjects (n = 190) were typed for HLA class I antigens by serology, while for HLA class II, they were tested by the polymerase chain reaction-sequence specific primers (PCR-SSP) method. Results indicated that HLA-B8, -DRB1*0301, and -DQB1*0201 positive patients have a significantly higher risk of acute onset of the disease (AOD), radiological stage I erythema nodosum (EN), Löfgren's syndrome, no-medicament therapy, and pulmonary sarcoidosis. On the other hand, the group of non-treated patients (corticosteroids and/or immunosuppressive) showed a significantly lower presence of HLA-B15 antigen in comparison to controls and treated patients (P = 0.0490 and P = 0.0379, respectively) and for DRB1*04 specificity (P = 0.0078 and P = 0.0065, respectively). In the group of patients with AOD, those who were positive for DRB1*16 specificity have a statistically significant chance to develop EN, as opposed to those who are positive for DRB1*15 specificity.

Linkage disequilibria between human leucocyte antigen-B and closely linked microsatellites in the Croatian population.

The aim of the present study was to investigate polymorphism of D6S2927, STR_MICA, D6S2793, TNFa (D6S2792), TNFb and TNFd (D6S2789) microsatellites and linkage disequilibria between these loci and human leucocyte antigen (HLA)-B (previously tested) for better characterisation of extended HLA haplotypes. A total of 176 healthy unrelated Croatians were studied using polymerase chain reaction amplification and electrophoresis on 6% polyacrylamide gel in ALFexpress sequencer. Eight HLA-B/D6S2927 haplotypic associations (B*07/D6S2927-4, B*08/D6S2927-3, B*18/D6S2927-3, B*27/D6S2927-1, B*35/D6S2927-5, B*38/D6S2927-4, B*51/D6S2927-2 and B*61/D6S2927-1) showed strong association (P < 0.001, D > 0.5). Among 88 different HLA-B/STR_MICA haplotypic associations, seven combinations (B*07/STR_MICA-A5.1, B*08/STR_MICA-A5.1, B*15/STR_MICA-A5, B*18/STR_MICA-A4, B*27/STR_MICA-A4, B*38/STR_MICA-A9 and B*51/STR_MICA-A6) demonstrated high linkage (D> or = 0.3) with significant P value (P < 0.001). Strong associations were also observed for five HLA-B/D6S2793 haplotypes (B*07/D6S2793-CA17, B*08/D6S2793-CA24, B*13/D6S2793-CA18, B*14/D6S2793-CA14 and B*27/D6S2793-CA14). HLA-B*08/TNFb3 and HLA-B*50/TNFb7 were the strongest associations for HLA-B/TNFb. Nine HLA-B/TNFa combinations were observed with significant P value (B*07/TNFa11, B*08/TNFa2, B*13/TNFa7, B*18/TNFa10, B*27/TNFa6, B*37/TNFa9, B*38/TNFa10, B*39/TNFa13 and B*44/TNFa4). Out of six HLA-B/TNFd haplotypic associations with strong D value, HLA-B*08/TNFd2 and B*37/TNFd3 showed the highest statistical significance (P < 0.0001). These results provide data on the region around the HLA-B that is very attractive because of its contribution to genetic susceptibility for many HLA-associated diseases and therefore this information will help in all further HLA-B locus-associated disease studies.

Pregnancy outcomes in women with classical congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

OBJECTIVE: Despite earlier detection, treatment, and surgical advances, fertility prognosis in women with classical 21-hydroxylase deficiency (21-OHD) is still low, especially in the salt-wasting (SW) form. PATIENTS AND METHODS: We analysed the course and outcome of four pregnancies in two simple virilizing (SV) and one SW patient. RESULTS: The evaluation of carrier status indicated that all three fathers had two normal CYP21 genes. During the pregnancy, the dose of prednisolone was increased in one of the SV patients and the SW patient. In the SW patient who developed pre-eclampsia, the dose of fludrocortisone was also increased. Three patients gave birth to a total of four healthy girls who were heterozygotes for 21-OHD with normal genitalia (one by vaginal delivery and three by Caesarean section). Family studies revealed that the mother of the SW patient has nonclassical 21-OHD. CONCLUSION: Improving a low birth rate in females with SW 21-OHD remains a problem and new approaches are required. If the mother has 21-OHD (even nonclassical 21-OHD), pre-conception counselling and paternal genotyping are advisable and prenatal dexamethasone therapy should be considered.

Evaluation of mixed chimerism in bone marrow transplantation program in Croatia.

In this study we monitored mixed chimerism in 36 patients with various hematologic disorders. All of them underwent a classic conditioning regimen, 31 patients for related bone marrow transplantation (BMT) and 5 patients for unrelated BMT. DNA was isolated from peripheral blood, and samples were polymerase chain reaction (PCR) amplified for 5 short tandem repeat (STR) loci (TH01, VWA31, FES/FPS, F13A01, and SE33) and for one variable number of tandem repeats locus (D1S80). Samples were run on a 6% polyacrylamide gel in an automated ALFexpress sequencer. In all 36 donor-recipient pairs we found differences for at least two STR loci. In most cases the difference was observed for SE33 and D1S80 loci. Mixed chimerism (MC) was detected in 18 patients: 4 with unrelated BMT and 14 with related sibling donors. In 11 patients MC was detected in the early period after BMT, but was soon followed by full donor chimerism (FDC) in peripheral blood. In 5 cases patients MC appearing after FDC was established, and was predictive for the relapse. One patient showed alternating MC and FDC, but at the end showed only recipient cells and graft rejection. In conclusion, the PCR-STR analysis is a highly informative, fast, and simple screening method for monitoring chimerism in a BMT program.

The MICA-A4 triplet repeats polymorphism in the transmembrane region confers additional risk for development of psoriatic arthritis in the Croatian population.

The aim of this study was to investigate possible differences in the frequencies of alleles at the HLA loci and at microsatellite loci within the HLA region among patients suffering from psoriatic arthritis (PsA) and healthy controls. Fifty-eight Croatian PsA patients (28 male and 30 female) and 157 healthy unrelated controls were typed for HLA alleles (A, B, Cw and DRB1) by the polymerase chain reaction-sequence-specific primers (PCR-SSP) method, while microsatellite alleles (D6S265, D6S273, MHC class I chain-related gene (MICA) and MIB) were analysed by electrophoresis in an ALFexpress sequencer (Pharmacia Biotech, Uppsala, Sweden). The findings from this study were: (1) the frequencies of B*39 and B*57 were significantly increased in PsA patients; (2) differences in the frequencies of B*13 and B*27 were not statistically significant after correction; (3) the B*0702, B*18, and B*38 alleles were decreased in patients only before correction; (4) none of the alleles at other HLA loci tested were associated with PsA in Croatia; (5) polymorphism at D6S265, D6S273, and MIB microsatellites in patients did not show any statistically significant differences when compared to controls; (6) the increase in the MICA-A4 allele frequency in PsA patients was independent of the B*39 and B*57 alleles.

HLA class II haplotypic association and DQCAR microsatellite polymorphisms in Croatian patients with psoriasis.

The purpose of the present study was to investigate polymorphism of HLA class II haplotypic associations (HLA-DRB1, -DQA1, -DQB1) and DQCAR alleles in 78 Croatian patients with psoriasis. Patients were divided into two groups according to a family history of disease and age of onset: type I (positive family history and early onset) and type II (negative family history and late onset). The difference in frequency of HLA class II haplotypic associations between type I patients and controls was observed for the following combinations: HLA-DRB1*0701, -DQA1*0201, -DQB1*02 (23.6% vs. 7.2%; p < 0.001), HLA-DRB1*0701, -DQA1*0201, -DQB1*0303 (8.5% vs. 1.3%; p = 0.0018) and HLA-DRB1*1601, -DQA1*0102, -DQB1*0502 (2.8% vs. 9.3%; p = 0.06). The difference between type II psoriasis and controls for association: HLA-DRB1*1501, -DQA1*0102, -DQB1*0602 is not significant (20.0% vs. 8.9%; p = 0.06). The significantly higher frequency of DQCAR 113bp and 119bp alleles in patients with type Ipsoriasis is a result of linkage disequlibrium of these alleles with both HLA-DRB1*0701 haplotypic associations. Analysis ofDQCAR alleles in the HLA-DRB1*0701 haplotypic associations in patients with psoriasis vulgaris and matched controls did not reveal any difference in polymorphism of DQCAR alleles. These data suggest that HLA-DRB*0701 haplotypic combinations are associated with type I but not for type II psoriasis in the Croatian population. DQCAR polymorphism is not useful genetic marker to distinguish susceptible HLA class II haplotypic association.