Rheumatic manifestations of tropical diseases

It is becoming increasingly recognized that a variety of tropical infectious diseases may be associated with a wide range of rheumatic infections. These include viral arthropathies such as O'nyong-nyong, chikungunya, and dengue. Parasitic infections such as filariasis, schistosomiasis, and amoebiasis can be associated with various joint problems. Diseases such as tuberculosis, rheumatic fever, leprosy, and brucellosis, although more common in the tropics, continue to present with rheumatic features in Western countries. Thus, with increasing world travel and migration, there is a need for increasing awareness and further study of tropical diseases and their rheumatic manifestations.

IgG glycosylation in association with tropical infections and rheumatoid arthritis in the tropics

Studies conducted in Europe suggest an association between IgG glycosylation abnormalities and rheumatoid arthritis (RA). Glycosylation abnormalities have been shown in other inflammatory diseases such as tuberculosis, systemic lupus erythematosus (SLE) and Crohn's disease. These observations led us to study glycosylation abnormalities among patients with RA and healthy controls in the tropics (sub-Saharan Africa). Using a lectin binding assay, we found that glycosylation differences were present in both groups when compared with British rheumatoid and healthy controls. This suggests that IgG glycosylation abnormalities may occur in association with chronic infections in the tropics.

Antibodies to the 65 kDa mycobacterial stress protein in west Africans with rheumatoid arthritis, tuberculosis and malaria

We have studied IgG antibodies to recombinant mycobacterial 65 kDa heat-shock protein in West African rheumatoid arthritis (RA) patients and local control groups, including those with tuberculosis or malaria. Mean levels were higher among the patients with RA than among healthy controls, but did not achieve statistical significance. Our findings may relate to the level of mycobacterial exposure in West Africa.

Osteoarthritis

There are few studies on the prevalence, pattern or clinical course of osteoarthritis (OA) in the tropics. The studies that have been carried out, however, indicate that on the whole there is a lower prevalence of OA than found in Western countries. In addition, the pattern of joint involvement may be different with less common involvement of the hip relative to the knee and polyarticular OA is uncommon in many parts of the tropics. It also seems likely that a significant number of these patients in the tropics have OA secondary to various infections including pyogenic, tuberculous and parasitic infections. There is an urgent need to confirm these observations and to identify possible genetic, developmental or environmental factors influencing the expression of OA in the tropics. In addition degenerative arthropathies, such as Mseleni's disease, present in some parts of the tropics, merit further study. With increasing life-expectancy and improved health-care in many parts of the tropics, OA will become an increasingly prevalent and important condition with associated morbidity and socio-economic implications for these countries.

Tropical rheumatology. Epidemiology and community studies: Africa

There is still far too little information available on the rheumatic diseases in Africa. Epidemiological studies are required in order to determine the burden of illness from rheumatic diseases on the African continent as well as to identify local risk factors for certain diseases. Such studies will also serve to enable the development of preventative and rehabilitation strategies. Functional disability has to be assessed in relation to the prevailing sociocultural lifestyle on the continent. Measures of disability that reflect this await development whilst regional diagnostic criteria also need to be worked out. The validity of tests and the stability of test reagents in a tropical climate require analysis. Continuing assessment of rheumatological services is essential to ensure their effectiveness and efficiency in the community and in particular to determine health care priorities and the best forms of therapeutic intervention. This will enable judicious use of limited resources. Community surveys in Africa are fraught with constraints and are difficult to undertake owing to a shortage of manpower and financial resources. For this reason, most studies hitherto have been hospital based. Hospital studies though useful lack applicability to the population as a whole and consequently more emphasis on cross-sectional and longitudinal community studies are required. It is hoped that despite the restraints, these studies will be performed.

Tropical rheumatology. Immunological aspects

The presence of auto-antibodies in infectious diseases continues to puzzle and provoke. It is hoped that sequencing studies in particular will yield further clues as to the role and mechanism of production of autoantibodies in infectious diseases. This, in turn, may also provide further insights into the role of auto-antibodies in auto-immune diseases. From a practical clinical viewpoint, the search for improved auto-antibody tests and new diagnostic markers with improved sensitivity and specificity must continue in the tropics. Until this is achieved, the results of auto-antibody tests in persons living in the tropics, persons from the tropics or patients with tropical infections, must be interpreted with caution.

Specificity of IgM antiglobulins produced in rheumatoid arthritis and tropical infections

The measurement of rheumatoid factors is of limited value in West Africa due to the low rheumatoid factor seroprevalence among patients with rheumatoid arthritis and the increased seroprevalence among healthy individuals and those with infectious diseases in the region. Using ELISA methods, we have been able to increase the specificity of rheumatoid factor measurement although the sensitivity of this test remains low. Furthermore, among the infectious diseases studied, there was no preferential binding of rheumatoid factors to the Fab gamma portion of immunoglobulin over the Fc gamma portion.

High levels of anti-type II collagen IgG in west African patients with rheumatoid arthritis

OBJECTIVE

To compare levels of antitype II collagen IgG in West African and British patients with rheumatoid arthritis (RA).

METHODS

IgG levels to native and denatured type II collagen were measured by ELISA:

RESULTS

Serum levels of antinative type II collagen IgG were raised in 17 of 58 (29%) West African patients with RA. In contrast, 14 of 89 (16%) British RA patients had raised levels of antinative type II collagen IgG. Levels of antinative type II collagen IgG were also higher in West African patients with RA than in the British patients.

CONCLUSION

Our results suggest that type II collagen autoimmunity plays a more prominent role in RA in West Africa than in Britain.

DC-ART: preventing or significantly decreasing the rate of progression of structural joint damage

Progressive joint damage, increasing deformity, and declining function characterize rheumatoid arthritis (RA). The evidence suggests structural joint damage is the predominant cause of functional impairment. Structural changes of joints are evaluated by imaging methods. Plain joint radiographs remain the best method for determining the extent and nature of structural changes at present. Newer technologies such as magnetic resonance imaging may eventually replace them. Clinical studies of antirheumatic drugs involving the assessment of prevention or significant decrease in the rate of progression of structural joint damage in RA should meet several standards. All patients who enter a study, whether they continue medication or not, must be assessed on its completion. Studies require sufficient power to determine realistic differences due to therapy. They should last long enough for a reliable analysis of the effects of joint damage; 1 year would be the minimal period for such a study, and 2 years would be preferable. Evaluation should concentrate on erosions and related structural changes in juxtaarticular bone; mapping osteoporotic areas in early disease may be a sensitive and objective measure. Assessments ought to use changes within the hands and wrists to indicate overall progression, with the feet included in evaluating early disease. There should be different therapeutic aims at various stages of RA, focussing on preventing new erosions developing in early disease (< 2 years from diagnosis), preventing new erosions occurring in established disease (2-5 years from diagnosis), reducing the rate erosions develop in established disease (< 5 years from diagnosis), and reducing the rate of joint destruction in late disease (> 5 years from diagnosis).

Antibodies to synthetic peptide P62 corresponding to the major epitope of rheumatoid arthritis nuclear antigen in a west African population with rheumatoid arthritis

Using a synthetic peptide (P62) we have investigated antibodies to rheumatoid arthritis nuclear antigen (RANA) in 58 West African patients with RA, 51 with malaria, 111 with tuberculosis (TB) and 166 healthy controls by ELISA using a synthetic peptide (P62). As in Western populations the RA sera showed significantly increased levels of anti-P62 antibodies though in our study the mean titres were only elevated twofold above the controls. The levels in malaria and TB were normal. Our data extend previous work by showing that raised anti-P62 antibodies is a consistent finding in RA world-wide including indigenous West African patients.

Seroepidemiological associations between tuberculosis, malaria, hepatitis B, and AIDS in West Africa

Serum samples from 51 patients with malaria, 35 patients with hepatitis B virus infection, 111 patients with tuberculosis, and 166 healthy controls were studied to determine any associations between tuberculosis, malaria, hepatitis B, and AIDS in Nigeria, West Africa. All serum samples were examined for the presence of HIV-1/HIV-2, hepatitis B virus surface antigen (HBsAg), and malaria antibodies. Only one patient was HIV-1 antibody-positive and none HIV-2 antibody-positive. Statistical associations were found between the presence of malaria antibody titres on the one hand and a diagnosis of hepatitis B virus infection (P < 0.05) or tuberculosis (P < 0.05). A stronger association (P < 0.001) was found between the presence of HBsAg and tuberculosis suggesting that HBsAg carriers are at higher risk of contracting tuberculosis.

High prevalence of joint laxity in West Africans

Previous surveys have suggested marked ethnic and geographical variation in the occurrence of joint hypermobility. We investigated the prevalence of joint hypermobility and the influences of age, sex, body mass and occupation in a rural Yoruba population in Nigeria. The study sample consisted of 204 individuals aged 6-66 yr from the townships of Igbo-ora and Eruwa in south western Nigeria. Sixty-eight had reported joint pain as part of a population survey of arthritic disorders and each was age and sex matched with one household and one neighbour control. Joint hypermobility was assessed, at four peripheral sites bilaterally and forward flexion of the trunk, by a single observer using the Beighton score. Each subject had weight and height recorded, answered a brief questionnaire about occupation and joint symptoms and was examined for peripheral joint disease. Only 11 (5%) of the subjects were negative at all five sites whereas 111 (54%) were hypermobile at three or more sites including 23 (11%) positive at all five. Using a score of 4/9 or greater as a cutoff, 88 (43%) were positive, including 35% of males and 57% of females. There was a linear decline with age in females but a more rapid decline only to age 35 yr in males. There was no relation to body mass or occupation. We conclude that joint hypermobility amongst this population is substantially greater than that recorded for other groups but is not associated with joint pain.

The absence of antibodies to malaria and human immunodeficiency virus, and the presence of hepatitis B surface antigen as diagnostic markers of rheumatoid arthritis

Rheumatoid factor is of limited value in the diagnosis of rheumatoid arthritis (RA) in West Africa. Consequent upon previous findings, we have studied the role of the absence of antibodies to malaria and human immunodeficiency virus (HIV) as well as the presence of the hepatitis B surface antigen (HBsAg) as diagnostic markers of rheumatoid arthritis in West Africa. We have found a significant association (p < 0.001) between RA and titre of HBsAg, but only between RA and malaria (p < 0.05) when sera with low malaria antibodies were studied. No correlation between either HBsAg or malaria and rheumatoid factor was found and no RA patient was either HIV-1 or HIV-2 positive.

A double-blind study of the effectiveness of low level laser treatment of rotator cuff tendinitis

Thirty-five patients with rotator cuff tendinitis were randomly allocated to active (CB Medico Master III 830 nm Ga As AL diode) laser or dummy laser treatment twice weekly for 8 weeks. Movement range, painful arc score, resisted movement score and responses to visual analogue scales for night pain, rest pain, movement pain and functional limitation were measured second weekly. All responses improved from baseline but there was no difference between the two groups. These results fail to demonstrate the effectiveness of laser therapy in rotator cuff tendinitis.