Genetic polymorphisms of the TNFB and HSP70 genes located in the human major histocompatibility complex in sarcoidosis

Heat Shock Protein 70 and The Risk of Multiple Sclerosis in The Iranian Population

Multiple sclerosis (MS) is a chronic disease of the central nervous system and one of the most common causes of neurological disability among those aged 20-40 years, particularly in women. Major histocompatibility complex (MHC) Class II genes are known to be involved in the development of MS. One of the important groups of this complex is the HSP gene family, especially HSP70, which is induced under stress conditions. The aim of the present case-control study was to determine the association between the heat shock protein 70 (HSP70) and risk of MS in Iranian patients by genotyping the rs1061581 gene polymorphism. A total of 50 relapsing-remitting MS (RRMS) patients and 50 healthy control subjects were considered for this study. Genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR- RFLP) method. PCR-RFLP results of twenty-five randomly selected samples were confirmed by DNA sequencing. Genotypic and allelic distributions were compared between the case and control groups. We observed no significant difference in the distribution of rs1061581 genotype and allele frequencies between RRMS patients and controls. In addition, there was no association between the HSP70 gene polymorphism and the clinical variables in the case group. Our data indicate that HSP70, in particular rs1061581, is unlikely to be involved in the susceptibility to or the severity of RRMS in Iranian patients. Further large prospective studies are required to confirm these findings.

Pneumonia

The lung is constantly exposed to airborne infectious agents due to the large surface area of approximately 100 m². Therefore pneumonia is one of the most common lung diseases. Understanding infection requires understanding the routes of infections, the way invading organisms infect epithelial cells, as well as defense mechanisms of the lung tissue acquired during evolution.

 Different variants of infectious and non-infectious pneumonias are discussed; special types of pneumonias such as granulomatous and fibrosing pneumonias are presented under separate sections. Causing organisms and other causes of pneumonias are included, and their mode of action is included as far as understood.

Analysis of heat shock protein 70 gene polymorphisms Mexican patients with idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease of unknown etiology. Genetic variation within different major histocompatibility complex (MHC) loci contributes to the susceptibility to IPF. The effect of 70 kDa heat shock proteins (HSP70) gene polymorphisms in the susceptibility to IPF is unknown. The aim of this study was to explore the association between HSP70 polymorphisms and IPF susceptibility in the Mexican population.

Methods

Four HSP70 single nucleotide polymorphisms (SNPs) were evaluated using real time PCR assays in 168 IPF patients and 205 controls: +2763 C>T of HSPA1L (rs2075800), +2437 of HSP HSPA1L A>G (rs2227956), +190 of HSPA1A G>C (rs1043618) and +1267 of HSPA1B G>A (rs1061581).

Results

The analysis of the recessive model revealed a significant decrease in the frequency of the genotype HSPA1B AA (rs1061581) in IPF patients (OR = 0.27, 95 % CI = 0.13–0.57, Pc = 0.0003) when compared to controls. Using a multivariate logistic regression analysis in a codominant model the HSPA1B (rs1061581) GA and AA genotypes were associated with a lower risk of IPF compared with GG (OR = 0.22, 95 % CI = 0.07–0.65; p = 0.006 and OR = 0.17, 95 % CI = 0.07–0.41; p = <0.001). Similarly, HSPA1L (rs2227956) AG genotype (OR = 0.34, 95 % CI = 0.12–0.99; p = 0.04) and the dominant model AG + GG genotypes were also associated with a lower risk of IPF (OR = 0.24, 95 % CI = 0.08–0.67; p = 0.007). In contrast, the HSPA1L (rs2075800) TT genotype was associated with susceptibility to IPF (OR = 2.52, 95 % CI = 1.32–4.81; p = 0.005).

Conclusion

Our findings indicate that HSPA1B (rs1061581), HSPA1L (rs2227956) and HSPA1 (rs1043618) polymorphisms are associated with a decreased risk of IPF.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-015-0127-7) contains supplementary material, which is available to authorized users.

Genetic polymorphisms of HSP70 in age-related cataract

Polymorphisms have been identified in several HSP70 genes, which may affect HSP70 repair efficiency. We investigated the association of the polymorphisms in HSPA1A, HSPA1B, and HSPA1L genes in the HSPs repair pathway with the risk of cataract in a Chinese population. The study included 415 cataract patients and 386 controls. Genotyping was done by the polymerase chain reaction-restriction fragment length polymorphism method. HSPA1B 1267 A/A genotype seems to have a protective role against cataract (p = 0.014, odds ratio (OR) = 0.664, 95 % confidence intervals (CI) = 0.480-0.919), and the G allele (p = 0.057, OR = 1.216, 95 % CI = 0.999-1.479) does not seem to have a deleterious role in the development of cataract. Haplotypes with frequencies of GAT were significantly different than those of controls (p = 0.005). In HSPA1A G190C and HSPA1L T2437C polymorphisms, there were no significant differences in frequencies of the variant homozygous in patients compared to controls. We conclude that the A/A genotype of HSPA1B A1267G polymorphism seem to have a protective role against age-related cataract.

[Sarcoidosis and genetics]

Familial features of sarcoidosis and observations in monozygotic twins affected by the condition suggest the presence of a genetic predisposition. Various genetic associations have been described with genes coding for proteins involved in immune regulation in particular at the level of interaction between T-lymphocyte and antigen presenting cell. We review the various genetic targets described with techniques ranging from classic human lymphocyte antigen genotype to genome wide linkage scans. The 6p21 region has been highlighted, which includes relevant genes such as MHC class II, BTNL2 and TNFα. These studies show that the genetics of sarcoidosis are complex, that patient sub-groups exist, which may explain some of the heterogeneity in the results of genetic studies and that the interactions between genetic and environmental factors remains to be elucidated.

The relationship between three heat shock protein 70 gene polymorphisms and susceptibility to lung cancer

BACKGROUND

Heat shock protein 70 (Hsp70) has been shown to act as a chaperone and be associated with a variety of tumors. We investigated HSP70-1 G+190C, HSP70-2 A+1267G, and HSP70-hom T+2437C polymorphisms to assess whether genetic variation in HSP70 plays a role in the occurrence and development of lung cancer.

METHODS

A case-control study was conducted using 159 patients with lung cancer and 202 control subjects. Genomic DNA was typed for HSP70 polymorphisms using polymerase chain reactions with restriction fragment length polymorphism (PCR-RFLP). Unconditional logistic regression was used to estimate the relative risks of lung cancer.

RESULTS

There were significant differences in genotype and allele distributions between patients and controls for the HSP70-1 G+190C polymorphisms with and without adjustment for age, gender, smoking history, drinking history and family history of cancer (p<0.05). No significant differences were found in the polymorphisms of HSP70-2 A+1267G and HSP70-hom T+2437C. The haplotype analysis showed that the G/A/C and C/G/T haplotypes were associated with a significantly increased risk of lung cancer compared to the G/G/T haplotype. After adjustments for other risk factors, such as age, gender, drinking history and family history of cancer, the interactions between the HSP70-1 and HSP70-hom genotypes and smoking were confirmed [I(AB), 2.56 and 5.12, respectively].

CONCLUSIONS

HSP70-1 G+190C may be a functional polymorphism and affect susceptibility to lung cancer, and homozygous C/C genotype may enhance the risk of lung cancer. In addition, smoking along with HSP70-1 G+190C and HSP70-hom T+2437C, may increase the risk of lung cancer.

Crystal structures of the ATPase domains of four human Hsp70 isoforms: HSPA1L/Hsp70-hom, HSPA2/Hsp70-2, HSPA6/Hsp70B', and HSPA5/BiP/GRP78

The 70-kDa heat shock proteins (Hsp70) are chaperones with central roles in processes that involve polypeptide remodeling events. Hsp70 proteins consist of two major functional domains: an N-terminal nucleotide binding domain (NBD) with ATPase activity, and a C-terminal substrate binding domain (SBD). We present the first crystal structures of four human Hsp70 isoforms, those of the NBDs of HSPA1L, HSPA2, HSPA5 and HSPA6. As previously with Hsp70 family members, all four proteins crystallized in a closed cleft conformation, although a slight cleft opening through rotation of subdomain IIB was observed for the HSPA5-ADP complex. The structures presented here support the view that the NBDs of human Hsp70 function by conserved mechanisms and contribute little to isoform specificity, which instead is brought about by the SBDs and by accessory proteins.

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Role of genetic polymorphisms in ACE and TNF-alpha gene in sarcoidosis: a meta-analysis

A great number of association studies have been performed to identify the genes involved in the etiology and prognosis of sarcoidosis. We performed a systematic review of case-control studies through the PubMed database and evaluated them for a possible inclusion into a meta-analysis in order to assess whether the reported genetic polymorphisms are the risk factors of sarcoidosis. Case-control studies with clear diagnostic criteria and interventions were included. Only investigations of a single polymorphism/gene involvement in sarcoidosis reported more than five times were selected. Aggregating data from 12 studies on ID/ACE polymorphisms, the odds ratio (OR) for sarcoidosis, if the polymorphism was considered under the dominant genetic model, was not significantly increased: 1.19 (95% CI 0.98-1.43); OR under the recessive model was 1.20 (95% CI 0.98-1.46). In seven case-control studies on -308/TNF-alpha polymorphism, the OR for sarcoidosis if the polymorphism considered under the dominant genetic model was significantly increased at 1.47 (95% CI 1.03-2.08); the OR under the recessive model was 1.39 (95% CI 0.67-2.90). In conclusion, the results showed that the TNF-alpha genotype could be a significant risk factor for sarcoidosis, whereas the risk of sarcoidosis due to the ACE genotype was not substantially elevated.

Effects of polymorphisms of heat shock protein 70 gene on ischemic stroke, and interaction with smoking in China

BACKGROUND

Heat shock protein 70 (HSP70) plays a key role in up-regulating stress responses, and it may be involved in the pathogenesis of ischemic stroke (IS). However, whether HSP70 polymorphisms are a risk factor for IS is still controversial.

METHODS

Three polymorphisms of HSP70 gene (+190G/C, +1267A/G, and +2437T/C) were analyzed by PCR-RFLP in Chinese patients with IS (n=116) and elderly subjects without IS (n=116).

RESULTS

The genotype distribution of HSP70-2 and HSP70-hom was not different significantly, but the genotype distribution of HSP70-1 at +190 was different significantly between the patients and controls. The allele frequency of HSP70-1 b2 was significantly higher in the patients (36.64%) than the controls (21.99%, P<0.001). The frequency of HSP70-1 b1b2 genotype was higher in the patients (64.66%) than the controls (37.07%; OR, 3.62). Conditional logistic regression revealed that +190 b2b2+b1b2 genotypes was an independent risk factor for IS (OR, 5.41). After adjustment for other risk factors, the interaction between the HSP70-1 genotype and smoking was confirmed (I(AB),2.78).

CONCLUSIONS

HSP70-1+190G/C may affect susceptibility to IS and smoking along with HSP70-1+190G/C may increase the risk of IS.

Genetics of sarcoidosis: candidate genes and genome scans

Human leukocyte antigen class II allele associations and T-cell receptor beta chain bias in sarcoidosis suggest a specific disease-triggering antigen exposure in a genetically susceptible host. The cause of sarcoidosis has been elusive, but genetics provides one of the few promising avenues to further our understanding. We review the association studies and genome scans used to identify the genes involved in sarcoidosis.

HSP70-hom gene single nucleotide (+2763 G/A and +2437 C/T) polymorphisms in sarcoidosis

In the present study, two coding polymorphisms within the heat shock protein 70-hom gene (HSP70-hom) were analysed. One hundred and thirty-eight individuals were studied, including 42 Polish patients with sarcoidosis, 13 of which presented with Löfgren's syndrome (LS), and 94 control subjects. Dimorphisms at positions +2763 (A/G) and +2437 (C/T) of the HSP70-hom gene were typed using amplification refractory mutation system and polymerase chain reaction-restriction fragment length polymorphism technique, respectively. A significant prevalence of the HSP(+2437)-C allele and the HSP(+2437)-CC homozygous genotype was observed in patients with sarcoidosis and in those presenting with LS as compared to controls (P < 0.001 in all comparisons made). A majority of HLA-DRB1*03-positive patients with LS were carrying both HSP(+2437)-C and (+2763)-G alleles, and the concomitant presence of these three genetic factors was more frequent among patients with LS as compared to patients without LS (0.54 vs. 0.17, P < 0.05) and controls (0.54 vs. 0.01, P < 0.001). The association of the HSP(+2437)-C allele with sarcoidosis and LS appeared to be independent of the presence of DRB1*03, although this HLA specificity was associated with LS manifestation. The HSP(+2763)-G allele was independently associated with neither sarcoidosis nor LS. However, this HSP(+2763)-G allele was present with either DRB1*03 or HSP(+2437)-C within the same haplotypes in the patients and this might explain the observed prevalence of DRB1*03, HSP(+2437)-C and (+2763)-G in patients with LS. In conclusion, HSP(+2437)-C allele was found as a factor associating with susceptibility to sarcoidosis and LS.

Sarcoidosis

There have been several new insights into the cause and treatment of sarcoidosis. Studies of genetic variation have shown that specific genetic polymorphisms are associated with increased risk of disease or affect disease presentation. These polymorphisms include variation of MHC and cytokines such as tumour necrosis factor (TNF). Not all investigators have come to the same conclusion, suggesting an interaction of various factors, including the patient's ethnic origin. Treatment of sarcoidosis varies considerably. Patients with symptomatic disease for more than 2-5 years have been of particular interest. Corticosteroids remain the standard of care in such cases, but immunosuppressive drugs have proved steroid-sparing in many patients. New agents, including pentoxifylline, thalidomide, and infliximab have proved useful in selected cases. The effectiveness of these agents seems to lie in their ability to block TNF, especially in the treatment of chronic disease.

Surfactant gene polymorphisms and interstitial lung diseases

Pulmonary surfactant is a complex mixture of phospholipids and proteins, which is present in the alveolar lining fluid and is essential for normal lung function. Alterations in surfactant composition have been reported in several interstitial lung diseases (ILDs). Furthermore, a mutation in the surfactant protein C gene that results in complete absence of the protein has been shown to be associated with familial ILD. The role of surfactant in lung disease is therefore drawing increasing attention following the elucidation of the genetic basis underlying its surface expression and the proof of surfactant abnormalities in ILD.

Heat shock protein 70 gene polymorphisms in Mexican patients with spondyloarthropathies

OBJECTIVE

To investigate the role of HSP70 genes as contributors to genetic susceptibility of the spondyloarthropathies (SpA) in the Mexican population.

METHODS

The study included 150 patients with SpA (undifferentiated spondyloarthropathy (uSpA) 68, ankylosing spondylitis (AS) 60, and reactive arthritis 22) and 158 healthy controls. HSP70-1, HSP70-2 and HSP70-hom genotypes were analysed by the polymerase chain reaction-restriction fragment length polymorphism technique. Statistical methods included the Mantel-Haenzel, chi(2), Fisher's exact test, and Woolf's method for odds ratio (OR).

RESULTS

HSP70-2 B/B genotype frequency was increased in the whole group of patients with SpA (pC<0.05, OR=4.3), as well as in the different clinical subgroups (pC<0.05, OR=4.2 for AS; pC<0.05, OR=4.4 for uSpA; and pC<0.05, OR=4.1 for ReA). This frequency remained significantly increased when the patients with B27 negative SpA were analysed. On the other hand, HSP70-hom locus analysis showed significantly increased frequency of A allele in the whole group of SpA (pC<0.05, OR=3.4), as well as in the groups with AS (pC<0.05, OR=5.6) and with uSpA (pC<0.05, OR=3.1), when compared with healthy controls. In this case, also, the genotype A/A was increased in the whole group of SpA (pC<0.05, OR=4.5), as well as in patients with AS (pC<0.05, OR=6.4) and with uSpA (pC<0.05, OR=3.7). When the patients with B27 negative SpA were analysed the frequencies of HSP70-hom A allele and A/A genotype remained significantly increased in the whole group of SpA (pC<0.05, OR=3.2 for the A allele and pC<0.05, OR=4.2 for the A/A genotype) and in the uSpA subgroup (pC<0.05, OR=3.8 for the A allele and pC<0.05, OR=4.3 for the A/A genotype).

CONCLUSION

In addition to the association of SpA with HLA-B27, there is a significant association of HSP70-2 and HSP70-hom alleles with SpA in Mexicans. This association seems to be independent of the susceptibility conferred by HLA-B27 in the group of patients with uSpA.

Heat shock protein 70 gene polymorphism in Japanese patients with multiple sclerosis

Despite the strength of the association of multiple sclerosis (MS) and human leukocyte antigen (HLA)-DR2, other genetic elements could have a role in the pathophysiology of MS. We investigated possible associations with polymorphic susceptibility genes located within the HLA complex, i.e., heat-shock protein (HSP)70-1, HSP70-2, and HSP70-hom in Japanese patients with MS. Furthermore, we analyzed the influence of HSP70 gene polymorphisms on the severity of the disease, clinical course, magnetic resonance imaging findings, and oligoclonal bands in the cerebrospinal fluid, and HLA in MS patients. The results of the present study indicated that there were no significant differences in the distribution of all HSP70 genotypes and allele frequencies between Japanese MS patients and controls. In MS patients, there were no associations between HSP70 gene polymorphisms and the clinical data. Moreover, there were no significant differences in HSP70 genotype or allele frequencies between MS patients positive for HLA-DRB1*1501 alleles and matched controls. Our data indicate that HSP70 gene polymorphisms are not relevant in the susceptibility to or the severity of Japanese MS patients.

Beryllium disease

Berylliosis is an environmental chronic inflammatory disorder of the lung caused by inhalation of insoluble beryllium (Be) dusts and characterized by the accumulation of CD4+ T cells and macrophages in the lower respiratory tract. In response to Be inhalation, noncaseating granuloma formation and, eventually, fibrosis. The immunopathogenic process is maintained by Be-specific lung CD4+ T-lymphocytes. Consistent with the disease immunopathology, these Be-specific T cells have a T-helper 1 phenotype producing interleukin-2 and interferon-gamma, the macrophage-activating cytokine driving the granulomatous reaction. Previous studies have demonstrated that the glutamic acid in position 69 of the human leukocyte antigen class II b chain is strongly associated with increased susceptibility to Be in exposed workers, suggesting that human leukocyte antigen gene markers may be used as epidemiological probes to identify population groups at higher risk.

Polymorphisms at position -308 in the promoter region of the TNF-alpha and in the first intron of the TNF-beta genes and spontaneous and lipopolysaccharide-induced TNF-alpha release in sarcoidosis

TNF-alpha is a potent pro-inflammatory cytokine. Previous studies have proved that biallelic polymorphisms in the TNF-alpha (-308, TNFA) and TNF-beta genes (intron 1, TNFB) influence TNF-alpha production. In sarcoidosis, a chronic granulomatous disease, as a result of an unknown in vivo activation bronchoalveolar lavage (BAL) cells release high amounts of TNF-alpha, spontaneously and after in vitro stimulation. Thus, sarcoidosis could serve as a model to test the in vivo effect of TNF gene polymorphisms. We determined the TNFA and TNFB polymorphisms of 44 patients with sarcoidosis and found the following allele frequencies: 0.80, 0.20, 0.38 and 0.62 for TNFA1, TNFA2, TNFB1 and TNFB2, respectively. To examine the in vivo effect of the named polymorphisms on the TNF-alpha production, the spontaneous and LPS-induced TNF-alpha release of BAL cells and peripheral blood mononuclear cells were also determined in patients with sarcoidosis. Statistical analysis did not reveal any significant difference between sarcoidosis patients with different genotypes. The results show that TNFA and TNFB polymorphisms do not determine the level of TNF-alpha release of mononuclear cells activated during the course of sarcoid inflammation.

Genetics of rheumatoid arthritis (RA): two separate regions in the major histocompatibility complex contribute to susceptibility to RA

We analyzed HLA-DR antigens and microsatellite Bat2 alleles in 97 adult caucasian patients with classical seropositive rheumatoid arthritis (RA) and 95 normal healthy controls. The results demonstrate that the prevalence of microsatellite Bat2 138 allele was significantly higher in RA-susceptibility DRB1 QKRAA/QRRAA epitope-negative patients as compared with normal controls. Analysis of the data suggested that Bat2 138 allele has primary association with RA-susceptibility in QKRAA/QRRAA epitope-negative patients. The Bat2 138 allele thus provides an additional risk in RA-susceptibility. In addition, microsatellite Bat2 138 allele showed a highly significant positive association with microsatellite D6S273 138 allele, which has similar (identical) association with RA development in DRB1 QKRAA/QRRAA epitope-negative patients. The present data demonstrate that DRB1 QKRAA/QRRAA epitope and microsatellite Bat2 138/D6S273 138 alleles more completely define the risk for development of RA. The results in the present study therefore suggest that two regions in MHC, class II (DRB1) and class III (Bat2 and D6S273 in HSP70-Bat2 region), contribute to susceptibility to RA.

D6S273 microsatellite polymorphism and susceptibility to rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic articular inflammatory disease associated with HLA-DR genes that share a five amino acid sequence motif, QKRAA or QRRAA, from position 70 to 74 in the third hypervariable region of the DRB1 molecule. Since these associations between DRB1 genes and susceptibility to RA are incomplete, we examined the role of a CA repeat polymorphic microsatellite marker, D6S273, located between HSP70 and Bat2 genes in the class III region of MHC, in susceptibility to RA. Ninety-seven adult patients with seropositive RA and 100 normal healthy subjects were studied. Two D6S273 alleles (132 and 138) showed significant differences in their prevalence in RA patients as compared to normal controls; allele 132 was significantly higher in total patients and in DRB1 QKRAA/QRRAA epitope-positive patients, and allele 138 was significantly higher in QKRAA/QRRAA-negative patients. Analysis of data suggested that the association of D6S273 132 allele with RA was secondary to that of DRB1 genes. On the other hand, D6S273 138 allele showed primary association with RA susceptibility in QKRAA/QRRAA epitope-negative patients. The D6S273 138 allele thus provides an additional risk in RA susceptibility. The results in the present study therefore suggest that two regions in MHC, DRB1 and D6S273, contribute to susceptibility to RA.

Tumor necrosis factor alpha production by oral leukocytes: influence of tumor necrosis factor genotype

Tumor necrosis factor alpha (TNF-alpha) is a proinflammatory cytokine that is thought to play a role in the pathogenesis of periodontal disease. TNF-alpha production is regulated by many factors, including certain alleles of TNF gene polymorphisms. In the present study, TNF genotypes of 3 bi-allelic polymorphisms were determined in 32 Caucasian patients with adult periodontitis and 32 orally-healthy matched controls, and correlated with TNF-alpha production by oral polymorphonuclear leukocytes (PMN). No differences in distribution of TNF alleles of the -238, -308, or +252 gene polymorphisms were observed between patients and controls or between patients with different disease severity. However, the level of TNF-alpha production by oral PMN correlated with the TNF-alpha 308 genotype in patients with adult periodontitis, with increased production found in patients with the T1,2 genotype (t-test; P=0.037). When cytokine production was examined in patients according to disease severity, an association between the T1,2 genotype and increased production was observed only in patients with advanced disease (t-test; P=0.05). These findings suggest that further studies are warranted to determine if the TNF genotype is a risk factor for severity of disease in adult periodontitis.

Genetic influences on sarcoidosis

To investigate the genetic influences underlying the development of sarcoidosis, HLA class II genotyping was performed in Japanese patients with sarcoidosis and healthy controls using the PCR-RFLP method. The frequencies of both DR52 group antigen-associated alleles (HLA-DRB1*11, -DRB1*12 and -DRB1*14) and DRB1*08 alleles were higher in the patient group, suggesting that the common, specific amino acid residue on the DRB1 molecule of these alleles may determine susceptibility to sarcoidosis. Alternatively, it is possible that another susceptibility gene, linked to these DRB1 alleles, exists within the MHC region. We screened the TNFA, TNFB, HSP70-1 and Hum70t genes around the class III region, as well as the HLA-DMA and -DMB genes in the class II region, for genetic polymorphism in sarcoidosis. None of these genes suggested a susceptibility to sarcoidosis. These studies support the thesis that one of the major genetic factors controlling the development of sarcoidosis is located within the DRB1 locus in the HLA class II region.

Heat shock protein 70 gene polymorphisms in rheumatoid arthritis

A role for heat shock proteins (hsp) in rheumatoid arthritis has been suggested. In addition, the specific binding of human HSP70 protein to QKRAA and RRRAA motifs within the HV3 region of disease-associated DRB1*0401 and DRB1*1001 molecules, respectively, has been proposed as being relevant to rheumatoid arthritis. The purpose of this work was to analyze the influence of HSP70 gene polymorphism on the susceptibility to or severity of rheumatoid arthritis and to investigate the possible contribution of these HSP70 polymorphisms in determining HLA-DRB1*0401/*1001 disease association. The frequencies of the HSP70-1, HSP70-2 and HSP70-hom genotypes were analyzed by PCR-RFLP using BsrBI, PstI and NcoI enzymes, respectively, in patients with rheumatoid arthritis and in healthy controls. No significant differences were observed when HSP70 allele distribution between the groups under study were compared. Moreover, we did not observe any significant difference in HSP70 allele frequencies between patients positive for HLA-DRB1*0401/*1001 alleles and matched controls. Our data indicate that HSP70 gene polymorphisms do not appear to be relevant in the susceptibility to or severity of rheumatoid arthritis.