Interleukin-2 -330 and 166 gene polymorphisms in relation to aggressive or chronic periodontitis and the presence of periodontopathic bacteria.

BACKGROUND AND OBJECTIVE: As a pro-inflammatory cytokine, interleukin-2 mediates the activation, growth and differentiation of T and B lymphocytes and natural killer cells. Promoter polymorphisms of the interleukin-2 gene have been associated with altered interleukin-2 production or identified as prognostic markers for various infectious diseases. Therefore, the aim of this study was to evaluate two polymorphisms at positions -330 T/G and 166 G/T in patients with generalized chronic periodontitis (n = 58) or generalized aggressive periodontitis (n = 73) in comparison with periodontitis-free controls (n = 69). MATERIAL AND METHODS: Both interleukin-2 polymorphisms were analyzed using the polymerase chain reaction with sequence-specific primers. Distributions of single alleles, genotypes and haplotypes were calculated using the chi-square test. Risk factor analyses were carried out by logistic regression with respect to established cofactors for periodontitis. The presence of subgingival bacteria in an individual were analyzed using a molecular biological method (the micro-Ident test). RESULTS: The interleukin-2 genotype -330 TG occurred less frequently in patients with chronic periodontitis (25.9% vs. 49.3%). Moreover, this genotype decreased the adjusted odds ratio for chronic periodontitis (odds ratio = 0.394), whereas the interleukin-2 genotype 166 TT and the haplotype combination interleukin-2 -330,166 TT : TT were associated with an increased adjusted odds ratio (odds ratio = 2.82 or 2.97). For the latter interleukin-2 combination, a positive association for the subgingival presence of Porphyromonas gingivalis (81.3% vs. 59.5%) and bacteria of the 'red complex' (78.1% vs. 56.0%) was shown. CONCLUSION: The interleukin-2 genotypes -330 TG and 166 TT, as well as the combination genotype interleukin-2 TT : TT, could be putative prognostic factors for chronic periodontitis.

The interleukin-10 promoter haplotype ATA is a putative risk factor for aggressive periodontitis.

BACKGROUND AND OBJECTIVE: Interleukin-10 has been described as an anti-inflammatory cytokine and a B-cell proliferation factor. Promoter polymorphisms of the interleukin-10 gene have been associated with altered interleukin-10 expression. Therefore, the aim of this study was to evaluate three polymorphisms at positions -1082G>A, -819C>T and -590C>A in patients with generalized chronic periodontitis (n = 27) and generalized aggressive periodontitis (n = 32) in comparison with periodontitis-free controls (n = 34). MATERIAL AND METHODS: Interleukin-10 promoter polymorphisms were analyzed by polymerase chain reaction with sequence-specific primers (PCR-SSP). Distributions of single alleles, genotypes and haplotypes were calculated by the chi-square test. Risk factor analyses were carried out by logistic regression. Subgingival bacteria were subjected to molecular biological analyses using the micro-Ident test. RESULTS: The combination ATA/ATA was found only in patients with aggressive periodontitis (15.6 vs. 0.0%, p = 0.023). Taking into account age, gender, smoking and plaque level, an increased odds ratio (3.7, p = 0.04) for aggressive periodontitis was shown for subjects with the haplotype ATA. Prevotella intermedia was found to be decreased in ACC- positive (41.3 vs. 66.7%, p = 0.022), ATA-positive (33.3 vs. 57.1%, p = 0.032) and ACC/ATA-positive (20.0 vs. 55.9%, p = 0.002) individuals. In GCC/GCC-positive subjects, P. intermedia occurred more frequently (86.7 vs. 42.3%, p = 0.002). CONCLUSION: The haplotype ATA, which is known as a 'low interleukin-10 producer' is a putative risk indicator for generalized aggressive periodontitis.

Conserved extended haplotypes of the major histocompatibility complex: further characterization.

Since the complete sequencing of a human major histocompatibility complex (MHC) haplotype, interest in non-human leucocyte antigen (HLA) genes encoded in the MHC has been growing. Non-HLA genes, which outnumber the HLA genes, may contribute to or account for HLA and disease associations. Most information on non-HLA genes has been obtained in separate studies of individual loci. To comprehensively address polymorphisms of relevant non-HLA genes in 'conserved extended haplotypes' (CEH), we investigated 101 International Histocompatibility Workshop reference cell lines and nine additional anonymous samples representing all 37 unambiguously characterized CEHs at MICA, NFKBIL1, LTA, NCR3, AIF1, HSPA1A, HSPA1B, BF, NOTCH4 and a single nucleotide polymorphism (SNP) at HLA-DQA1 as well as MICA, NOTCH4, HSPA1B and all five tumour necrosis factor short tandem repeat (STR) polymorphisms. This work (1) provides an extensive catalogue of MHC polymorphisms in all CEHs, (2) unravels interrelationships between HLA and non-HLA haplotypical lineages, (3) resolves reported typing ambiguities and (4) describes haplospecific markers for a number of CEHs. Analysis also identified a DQA1 SNP and segments containing MHC class III polymorphisms that corresponded with class II (DRB3 and DRB4) lineages. These results portray the MHC where lineages containing non-HLA and HLA variants in linkage disequilibrium may operate in concert and can guide more thorough design and interpretation of HLA-disease relationships.

Are there HLA combinations typical supporting for or making resistant against aggressive and/or chronic periodontitis?

OBJECTIVE AND BACKGROUND: Human leukocyte antigens (HLA)/alleles have been considered as risk factors for periodontal disease. However, data from HLA associations is not consistent. Diversity of HLA antigen combinations and en bloc inherited HLA alleles (haplotypes), as known in systemic diseases, can be variable factors in disease association. Therefore, the aim of this study was to investigate the incidence of HLA homozygosities, heterozygosities and estimated haplotypes in German Caucasian groups with generalized aggressive (N = 50) and chronic (N = 102) periodontitis in comparison to control probands without periodontitis (N = 102). METHODS: HLA-A, -B, -Cw, -DRB1, -DRB3/4/5, -DQB1 typing was carried out using both serologic (microlymphocytotoxicity test) and genomic (PCR-SSP: PCR with sequence specific primers) techniques. Frequencies of all homozygosities, heterozygosities and haplotypes were determined in all patients and controls. RESULTS: In both patient groups, associations to HLA homozygosities and heterozygosities were found. Most striking was the significantly lower frequency of HLA-DRBblank* homozygosity (non-DRB3*/DRB4*/DRB5*) in chronic periodontitis (p < 0.05), whereas HLA-DRB1*15 : DRB5*(DR51) : DQB1*06 showed a slightly higher homozygosity rate in all patients. As the combination HLA-A*02,A*03 was significantly decreased in aggressive periodontitis (p < 0.05), HLA-A*01,A*03 heterozygosity was significantly lowered in chronic periodontitis (p < 0.05). Among others, the known positive associations for HLA-A*68/69 (A28) and HLA-DRB1*04 were confirmed by the haplotypes HLA-A*68/69 : Cw*07 : B*18 in aggressive periodontitis (p < 0.05) and HLA-Cw*08 : B*14 : DRB1*04 in chronic periodontitis (p < 0.05). CONCLUSION: The present study elucidates the variety of HLA associations and therefore the difficulty to assign single HLA markers to periodontal disease. Susceptibility/resistance of both aggressive and chronic periodontitis may rather be influenced by particular HLA marker combinations. Associated HLA haplotypes may be of further importance for unknown gene loci representing a part of the genetic background for periodontitis. The different associations in aggressive and chronic periodontitis indicate different susceptibility/resistance factors for both diseases.

Genetic affinities among Mongol ethnic groups and their relationship to Turks.

The central Asian country Mongolia is home to more than 20 tribes and ethnic groups, some of which are related to neighboring Turkic populations. The main Mongolian people, Khalkha, live in central and eastern Mongolia while the Tsaatan minority lives in the north of the country. The Oold minority is from the western Altai mountain region and live in close proximity with Turkic people. We have typed the HLA-A, -B, -Cw, -DRB1 and -DQB1 loci by PCR-SSP in these three Mongolian populations as well as a sample of the German population. To examine their genetic relationships, a sample of the Turkish population already typed at the HLA-A, -B and -DRB1 loci were used. Altogether five populations were analyzed: Khalkha (n = 100), Tsaatan (n = 72), Oold (n = 52), German (n = 260) and (Anatolian) Turkish (n = 498). Nei's unbiased genetic identity (GI) and genetic distance (GD) were estimated from genotypes using PopGene v1.31, and dendrograms were constructed using phylip. The results suggested a close relationship of the Khalkha to the Tsaatan. The Turks and Germans were equally distant to all three Mongolian populations. These results confirmed the lack of strong genetic relationship between the Mongols and the Turks despite the close relationship of their languages (Altaic group) and shared historical neighborhood. This study has provided useful population data for genetic and anthropologic studies bridging eastern and western populations.

Gender differences in HLA phenotype frequencies found in German patients with generalized aggressive periodontitis and chronic periodontitis.

HLA antigens have been considered as risk factors for periodontitis. Differences in prevalence and in the extent of attachment loss between males and females have suggested that gender-dependent HLA deviations could play a role in individual predisposition to periodontitis. The aim of the present study was therefore to investigate the incidence of gender-dependent HLA associations in 50 patients with generalized aggressive periodontitis (AP) and 102 patients with chronic periodontitis (CP) in comparison to 102 probands without any attachment loss caused by periodontitis. HLA typing was carried out using a microlymphocytotoxic test and a polymerase chain reaction with sequence-specific primers (PCR-SSP). Female AP patients showed an increase in the frequency of HLA-A*68/69 and a decrease in the frequency of DRBblank* (non-DRB3/4/5*) and DQB1*05-positive probands. Only in female CP patients was HLA-DQB1*0303 absent, whereas HLA-DQB1*06 homozygosity increased significantly. With regard to the (AP + CP) periodontitis group as a whole, the increased frequency of HLA-DQB1*06 homozygosity in females was similar to the findings obtained in the AP group. Evidently, gender is a confounding variable, which should be considered in further studies of HLA and periodontitis.

HLA-A, B, Cw, DRB1, DRB3/4/5, DQB1 in German patients suffering from rapidly progressive periodontitis (RPP) and adult periodontitis (AP).

BACKGROUND/AIM: There is growing indication that differences in host response determine susceptibility and resistance to periodontal disease. Particularly, the effect of histocompatibility antigens (HLA) on early onset periodontitis (EOP) has been studied. As most of the results are not conclusive and to date no report has been done on German patients, the aim of this study was to investigate the distribution of HLA alleles in a group of 50 German RPP patients and 102 German AP patients and to compare them to 102 control probands without periodontitis. METHODS: Diagnosis was established according to standardised clinical criteria. HLA typing was performed using serologic and molecular biologic (PCR-SSP) techniques. RESULTS: Compared to the controls, RPP patients had a significantly higher frequency of HLA-DRB1*13 and a significantly lower frequency of HLA-DRBblank*(non-DRB3/4/5). AP patients showed a significantly increased occurrence of HLA-B*14 and -Cw*08 as well as a significantly decreased frequency of HLA-A*03. In both patient groups HLA-A*11 and -A*29 had an increased frequency and HLA-A*31 and -A*30/31 were decreased. These differences were statistical significant in the whole patient group (RPP + AP). CONCLUSIONS: Based on modern DNA techniques the present study shows an association of HLA to both RPP and AP. Certain HLA alleles seem to be associated with susceptibility or resistance to periodontitis in general. However, before this knowledge can be used for differential diagnosis or prognosis, further investigations are necessary.

Increased frequency of homozygosity for HLA class II loci in female patients with chronic lymphocytic leukemia.

The etiology of chronic lymphocytic leukemia (CLL) appears to be influenced by genetic factors which may contribute to its differential, gender- and age-specific incidence. The presented study is the first, which investigated the frequencies of DNA-typed alleles of all relevant human leukocyte antigens (HLA) loci in CLL patients with regard to gender and age at disease onset. The most remarkable result was the higher frequency of homozygosity for MHC class II loci in female patients. Particularly, an increased frequency of overall homozygosity for the DRB3/4/5 loci was observed in female patients compared to gender matched controls (RR = 2.8) and male patients. The previously demonstrated association of DQB1 homozygosity with CLL in general was found to be specific for female patients (RR = 4.4). Considering the lack of an a priori hypothesis which made it virtually impossible to obtain statistical significance it was not unexpected that none of the observed differences remained significant after correction for multiple comparisons. However, these results suggest a recessive, gender-specific susceptibility factor for CLL within or in vicinity of the human MHC class II region and should serve as an a priori hypothesis for future studies focusing on these gene loci. Furthermore, an increased frequency for HLA-Cw*06 was seen in patients with an early onset age (RR = 2.7) but lost significance after correction for multiple comparisons. The previously reported association of HLA-DRB4*0103 with CLL in general was observed in all groups irrespective of gender and age. Conclusively, our study supports the concept, that CLL represents a disease with a complex etiology and genetic susceptibility which appears to be influenced by the human MHC.

Increased heterozygosity for MHC class II lineages in newborn males.

In plants, fungi and marine invertebrates, there are genetic compatibility systems to ensure diversity in the offspring. The importance of genetic compatibility in gametic union and selective abortion in vertebrate animals has also been appreciated recently. There have been suggestions that the major histocompatibility complex (HLA in humans) may be a compatibility system in vertebrates. HLA class II haplotypes often contain a second expressed DRB locus which can be either DRB3, DRB4 or DRB5. These encode the supertypical specificities and mark the ancestral lineages. The members of each lineage have related DNA sequences at the main class II locus HLA-DRB1. We analysed 415 newborns at all expressed DRB loci by PCR analysis to seek evidence for sex-specific prenatal selection events. While there was no significant change in heterozygosity rates between males and females at DRB1, the proportion of males carrying two DRB1 specificities from different ancestral lineages was significantly increased (53.7% in males vs 39.3% in females, P = 0.003). The genotypes consisting of phylogenetically most distinct ones, namely the DRB3 and DRB4 haplotypes, showed the most striking difference between sexes (P = 0.007). These results suggested a more favourable outcome for male concepti heterozygous for supertypical haplotypes. Heterozygosity for most divergent haplotypical families ensures the highest degree of functional heterozygosity at the main HLA class II locus DRB1 while increasing the likelihood of heterozygosity also at other MHC loci. Our observations agree with the previously reported heterozygote excess in male newborn rats and mice. Correlations between MHC class II heterozygosity and advertised male quality in deer and pheasant as well as increased reproductive success in MHC class II heterozygous male macaques are examples of postnatal benefits of heterozygosity in males that may be behind the development of prenatal selection mechanisms. The MHC-mediated prenatal selection of males may also be one of the selective events suggested by the very high primary (male-to-female) sex ratio at fertilization reaching close to unity at birth in humans. These results provide an appealing working hypothesis for further studies in humans and other vertebrates.

Brain glioma and human leukocyte antigens (HLA)--is there an association.

Expression of human leukocyte antigens (HLA) is important for the immune response against infectious agents and malignant cells. Association of single HLA antigens or HLA haplotypes with disease has been investigated previously, and positive correlations between HLA and some cancers, such as cervical or nasopharyngeal carcinomas have been reported. In the present study, HLA antigen frequencies of 65 adult Caucasian patients with low-grade, anaplastic, or malignant astrocytic glioma (WHO grades II-IV) were compared with 157 racially similar, asymptomatic control individuals. Both standard serologic and PCR techniques for HLA typing were employed for all patients and controls. Our results suggest a positive association between single HLA antigens and presence of symptomatic cerebral glioma. Compared with the control population, patients positive for HLA-A*25 had a 3.0-fold increased risk of glioma (p = 0.04), patients positive for HLA-B*27, a 2.7-fold risk (p = 0.03), and patients positive for HLA-DRB1*15, a 2.2-fold risk (p = 0.03), whereas HLA-DRB1*07 was associated with a 0.4-fold decreased risk of glioma (p = 0.02). Occurrence rate of some HLA antigen combinations and estimated haplotypes was also different in glioma patients. Thus, HLA-DRB1*15:DRB5*(51) occurrence in combination with HLA-DRB1*11 was associated with a 13.4-fold increased risk of glioma (p = 0.001), and the incidence of HLA-Cw*6:DRB1*07 with a 0.2-fold decreased risk of glioma (p = 0.03). In conclusion, single HLA antigens and their combinations and estimated haplotypes are possibly significantly more or less frequent in persons developing symptomatic cerebral glioma during their adult life, compared with asymptomatic individuals.

Association of chronic lymphocytic leukemia with specific alleles of the HLA-DR4:DR53:DQ8 haplotype in German patients.

The etiology of chronic lymphocytic leukemia (CLL) remains unknown, though a genetic susceptibility has been suggested. Results of complete DNA typing of HLA alleles in CLL patients are lacking. We compared HLA class I and class II frequencies in 101 German CLL patients and 157 healthy German controls as determined by PCR-SSP/SSO DNA analysis and serologic typing. The most striking difference was the increased frequency of HLA-DRB4*0103 [relative risk (RR) = 2.74, p < 0.0025] among patients. The presence of alleles HLA-DRB1*0401, HLA-DQB1*0302 and HLA-DPB1*0301 as well as of homozygosity for HLA-DQB1 was also associated with a higher risk for CLL, though none of these differences remained significant after correction for multiple comparisons. No association was found for any HLA class I allele. Haplotype analysis revealed a CLL-specific linkage disequilibrium for HLA-DRB1*0401:DRB4*0103 and HLA-DRB4*0103:DQB1*0302. Our results suggest that CLL could be associated with distinct class II alleles of the Caucasian haplotype HLA-DR4:DR53:DQ8, which has also been related to a susceptibility for several auto-immune diseases. The positive, though weak, association of CLL with HLA-DPB1*0301 might represent an independent susceptibility factor since no linkage disequilibrium existed with any of the other CLL-associated alleles. None of the previously reported associations with HLA class I antigens was confirmed. Our results suggest that factors within or close to the human MHC class II region confer susceptibility to CLL.

HLA-A, B, Cw and DRB1, DRB3/4/5, DQB1, DPB1 frequencies in German immunoglobulin A-deficient individuals.

HLA class I and II frequencies and haplotype frequencies were determined in 80 German immunoglobulin (Ig)A-deficient individuals and 157 healthy controls with normal IgA levels using serological and DNA typing methods. For several alleles, significant associations were found, which could be explained mainly in the context of a positive association with three different extended haplotypes (HLA-B*08:DRB1*0301: DQB1*0201, HLA-B*14:DRB1*0102:DQB1*0501 and HLA-B*44:DRB1*0701:DQB1*0202) and a negative association with a fourth haplotype (HLA-B*07:DRB1*1501:DQB1*0602). Furthermore, for the first time this study reports a positive association of IgA deficiency with DPB1 alleles. Homozygosity rate for the gene loci DRB1 and DQB1 was increased in IgA deficiency. Further analysis suggested a different pattern of HLA associations depending on the degree of IgA deficiency and the gender of the IgA-deficient individuals.

Unravelling an HLA-DR association in childhood acute lymphoblastic leukemia.

Genetic and environmental factors play an interactive role in the development of childhood acute lymphoblastic leukemia (ALL). Since the demonstration of a major histocompatibility complex (MHC) influence on mouse leukemia in 1964, an HLA association has been considered as a possible genetic risk factor. Despite extensive efforts, however, no strong evidence comparable to the H-2(k) influence on mouse leukemia has been shown. The number of negative serological studies resulted in a loss of interest and consequently, no molecular HLA-DR association study has been published to date. We reconsidered the HLA-DR association in childhood ALL in 114 patients from a single center and 325 local newborn controls by polymerase chain reaction (PCR) analysis of the HLA-DRB1/3/4/5 loci. With conventional analysis, there was a moderate allelic association with the most common allele in the HLA-DR53 group, HLA-DRB1*04, in the whole group that was stronger in males (P =.0005, odds ratio = 2.9). When the other expressed HLA-DRB loci were examined, homozygosity for HLA-DRB4*01, encoding the HLA-DR53 specificity, was increased in patients (21.1% v 8.3%; odds ratio = 2.9, P =.0005). Consideration of gender showed that all of these associations were reflections of a male-specific increase in homozygosity for HLA-DRB4*01 (32.8% v 4. 0%; odds ratio = 11.7, 95% confidence interval [CI] = 4.9 to 28.0; P = 3 x 10(-8)). This highly significant result provided the long-suspected evidence for the HLA-DR influence on the development of childhood ALL while confirming the recessive nature of the MHC influence on human leukemogenesis as in experimental models. The cross-reactivity between HLA-DR53 and H-2Ek, extensive mimicry of the immunodominant epitope of HLA-DR53 by several carcinogenic viruses, and the extra amount of DNA in the vicinity of the HLA-DRB4 gene argue for the case that HLA-DRB4*01 may be one of the genetic risk factors for childhood ALL.

Early-onset periodontitis in a patient with Ehlers-Danlos syndrome type III.

This case history describes the course of disease in a 17-year-old boy with Ehlers-Danlos syndrome type III and early-onset periodontitis. Flow cytometric tests showed a reduced cell count in the specific immune system. Immunoglobulin concentrations in saliva and serum were within normal limits. Infection with T-lymphotropic viruses was excluded. The phagocytic capacity of the peripheral blood polymorphonuclear leukocytes was unimpaired. The anaerobic infection present in the early-onset periodontitis was treated with systemic antibiotic therapy and closed curettage. Following 14 days of this treatment, signs of acute inflammation subsided, and 18 months after therapy ended, a slight gain in clinical attachment was found, and bone growth was visible via radiology. However, a continuing lack of adequate oral hygiene represents a risk to the success of therapy in the long term.

High-resolution DNA typing in immunoglobulin A deficiency confirms a positive association with DRB1*0301, DQB1*02 haplotypes.

Selective immunoglobulin A (IgA) deficiency, the most common form of primary immunodeficiency, is related to the HLA genes. Previous studies demonstrated associations with particular HLA-DR-DQ haplotypes and a neutral amino acid at position 57 of the DQbeta chain was implicated in the susceptibility to selective IgA deficiency. In this study we reanalyzed the reported findings by high-resolution DNA typing of the loci DRB1, DQB1 and DQA1. We compared the typing results of 74 IgA-deficient individuals, detected by screening of blood donors, with those taken from 111 healthy controls. Results confirmed a strong positive association with DRB1*0301, DQB1*02 and a negative association with DRB1*1501, DQB1*0602. Considering the molecular interactions between HLA class II alleles and the peptides bound we conclude that the amino acid at position 57 of the DQbeta chain may contribute to the susceptibility to selective IgA deficiency, but not determine it. An extended statistical analysis strengthened the hypothesis that selective IgA deficiency might be communicated by the distinct haplotype DRB1*0301, DQB1*02.

Influence of the major histocompatibility complex on age at onset of chronic lymphoid leukaemia.

The major histocompatibility complex is one of the interactive factors in the multifactorial model of carcinogenesis. Its main influence in experimental models is on the age at onset of malignancies. We have previously shown a similar effect of homozygosity for HLA-DR53 in CML. In the present study, we investigated 79 patients with CLL and 329 local controls from Germany. In addition to full serotyping, all patients and 116 of controls were also typed by HLA-DRB PCR analysis. The homozygosity rates for DR53 in patients under and over the median age (60 years) were 18.6% and 2.9%, respectively (p = 0.03). Eight of the 9 homozygous patients were under the median age. The sex ratio in the DR53 homozygous group was reversed in favour of females. The homozygosity rates for DR53 were different in the overall groups of patients and controls, yielding a relative risk (RR) of 2.4 (p = 0.03). This association was stronger in the early-onset group compared to age-matched controls (RR = 4.4; p = 0.008) and for females with an early onset compared to age- and sex-matched controls (RR = 17.9; p = 0.0008). The simultaneous occurrence of the alleles of the haplotype A2B62DR4 showed a strong association with CLL (RR = 4.1; p = 0.002). This was probably the reason behind the association with HLA-DRB1*0401 (RR = 2.4; p = 0.009). Compared to the accelerating effect of HLA-DR53, HLA-DR52 showed a significant delaying effect on the onset of CLL. These findings confirmed the influence of the HLA complex on the development of another leukaemia.

[HLA and selective IgA deficiency]. / HLA und selektiver IgA-Mangel.

A selective deficiency of IgA is developed significantly (p < 0.05) more frequently by HLA-A2-negative than by HLA-A2-positive healthy persons. The frequent combination of A1/A3 is absent. The incidence of HLA-B8-positive persons is increased (p < 0.01). A selective disadvantage is discussed.

[Studies of the antibody heterogeneity in carp (Cyprinus carpio L.). I. Electrophoretic and isoelectric spectra of anti-DNP-antibodies]. / Untersuchungen zur Antikörperheterogenität beim Karpfen (Cyprinus carpio L.). I. Elektrophoretische und isoelektrische Spektren von Anti-DNP-Antikörpern.

Carp IgM as well as carp anti-DNP-antibodies migrate electrophoretically very well as a diffuse band into polyacrylamide gel of large pore size. The isoelectric spectra of the carp anti-DNP-antibodies are heterogeneous and show bands in the pI-range of 4.0 to 6.4. The activity of focused anti-DNP-antibodies could be demonstrated in the pI range between 5.4 to 6.4 even in high antibody dilutions. The investigated structural heterogeneity of the anti-DNP-antibodies of carp is a further proof for the phylogenetically early onset of a large antibody heterogeneity of lower vertebrates.