Group A streptococcal antibodies in subjects with or without rheumatic fever in areas with high or low incidences of rheumatic fever.

The levels of streptococcal antibody titers in populations with or without rheumatic fever from an area with a relatively high incidence of rheumatic fever and an area with a low incidence of this disease were compared. Streptococcal antibody titers were determined for two populations, each of which included children without rheumatic fever (nonrheumatic children) and rheumatic fever patients. The two populations were derived from two separate geographic areas, one with a high incidence of rheumatic fever (Grenada) and another with a low incidence of this disease (central Florida). The results revealed an absence of consistent differences in the geometric mean antibody titers between the nonrheumatic subjects and the rheumatic fever patients from Grenada. In the population from Grenada, the mean anti-streptolysin O and anti-DNase B titers were higher in the nonrheumatic controls (P of 0.085 and 0.029, respectively). However, the mean titer of the antibody to the group A streptococcal cell wall carbohydrate was higher in the rheumatic fever patients than in the nonrheumatic controls (P = 0.047). This finding contrasted with the finding that the means of all three streptococcal antibody titers in the patients with rheumatic fever were significantly higher than those in the nonrheumatic subjects from Florida (P = 0.01-<0.001). The reason for this paradoxical finding became evident when the streptococcal antibody titers of the nonrheumatic subjects from Grenada and Florida were compared, revealing significantly higher levels of all three antibodies in the nonrheumatic subjects from Grenada than in the nonrheumatic subjects from Florida (P < 0.001). These results suggest that nonrheumatic individuals in an area with a high incidence of rheumatic fever have inordinately elevated levels of streptococcal antibodies in serum. The presence of elevated streptococcal antibody titers in such a population, which probably reflects a high background prevalence of streptococcal infections, should be taken into consideration when evaluating the role of the group A streptococcus in nonpurulent complications of infections.

Angiotensin converting enzyme gene insertion-deletion polymorphism is associated with juvenile rheumatoid arthritis.

OBJECTIVE: To investigate the incidence of angiotensin converting enzyme (ACE) gene insertion-deletion (I/D) polymorphism genotypes in children with juvenile rheumatoid arthritis (JRA), a heterogeneous chronic disease with autoimmune pathology. ACE gene I/D polymorphism influences the plasma and tissue levels of ACE and has an involvement in inflammatory mechanisms. METHODS: The incidence of ACE gene I/D polymorphism genotypes was determined in 82 children with JRA from Kuwait and compared to that in 48 ethnically matched healthy controls using polymerase chain reaction. RESULTS: A considerably higher incidence of II genotype was observed in the JRA patients compared to controls (p < 0.003). In contrast, no statistically significant difference was detected in the incidence of DD and ID genotypes in JRA patients and controls (p = 0.276 and 0.460, respectively). The incidence of ACE gene polymorphism genotypes was also studied in clinical subclasses of JRA patients and controls. There was no significant difference in the incidence of DD and ID genotypes in either of the 3 JRA subclasses (oligoarticular, polyarticular, and systemic) when compared to controls. However, the incidence of II genotype was found to be significantly higher in all the 3 JRA subclasses compared to controls. The strongest association between II genotype and JRA subclasses was detected in systemic JRA, followed by oligoarticular and polyarticular JRA. This was also reflected in a higher prevalence of I-allele in the systemic JRA cases (13/26, 50%) compared to the D-allele (11/26, 42%). In contrast, D-allele of the ACE gene was more prevalent in oligoarticular and polyarticular JRA cases, than the I-allele (61% and 58%, respectively). CONCLUSION: Our data suggest a significant association of the I-allele of the ACE gene I/D polymorphism with the 3 clinical subclasses of JRA in children, and the highest association was observed in systemic JRA cases.

Poststreptococcal reactive arthritis.

Poststreptococcal reactive arthritis (PSRA) refers to a poststreptococcal arthritic condition that does not fulfill the Jones Criteria for diagnosis of acute rheumatic fever. Clinical features include additive rather than migratory arthritis that responds relatively poorly to salicylates and nonsteroidals; persistence for mean of 2 months; elevated acute phase reactants; and laboratory (usually serologic) evidence of recent group A streptococcal infection. PSRA is not associated with HLA-B27 but rather with HLA-DRB1*01. Because up to 6% of PSRA patients develop mitral valve disease, it is recommended that antistreptococcal prophylaxis be administered for 1 year and then discontinued if there is no evidence of cardiac involvement.

Role of Bartonella henselae in the etiology of Henoch-Schönlein purpura.

BACKGROUND: The etiology of Henoch-Schönlein purpura (HSP) has been ascribed to a variety of infectious and noninfectious agents. Because we encountered a patient with HSP who had evidence of Bartonella henselae infection and a prior report of a patient with systemic cat-scratch disease presenting as leukoclastic vasculitis, we investigated the association of B. henselae infection with HSP. METHODS: We determined the antibody titers to B. henselae on the sera of 18 patients with HSP and on 57 controls. All patients presented with the characteristic leukoclastic rash of HSP. About one-half of the patients had joint or abdominal symptoms, and four had hematuria at presentation. An indirect immunofluorescent assay was used to determine serum antibody titers to B. henselae. Sera that were reactive at a dilution of 1/64 were considered positive. RESULTS: Eight of the 57 (14%) control sera and 12 of the 18 (67%) patient sera were positive for B. henselae antibody (P < 0.0001). CONCLUSION: The results of this study indicate a significant association of antecedent B. henselae infection with HSP. The frequency of this association (67%) exceeds that of previously ascribed etiologic agents for this disease, such as the group A Streptococcus.