Comparison of techniques of detecting immunoglobulin-binding protein reactivity to immunoglobulin produced by different avian and mammalian species

The rationale of this study was to use several immunological assays to investigate the reactivity of immunoglobulin binding protein (IBP) to immunoglobulins from various avian and mammalian species. The IBP studied were Staphylococcal protein A (SpA), Streptococcal protein G (SpG), Peptostreptococcal protein L (SpL) and recombinant protein LA (SpLA). The various immunological techniques used were double immunodiffusion (Ouchterlony technique) that tested positive high protein reactivities, direct and competitive enzyme-linked immunosorbent assays (ELISAs) that tested moderate and low positive protein binding capacities, respectively. In addition to sandwich ELISAs, immunoblot analyses and Ig-purification by SpA-affinity chromatography, which were sensitive tests and helpful in the screening and confirmatory tests were also used. The Ouchterlony technique showed that compared to the other proteins, SpLA had the highest range of reactivity with animal sera and purified immunoglobulins while SpL was least reactive. With the direct ELISA, SpL reacted with the raccoon sera, rabbit IgG and with IgY from bantam hens and pigeons. While with the direct ELISA, SpA reacted with sera from skunk, coyote, raccoon, mule, donkey and human. The sandwich ELISA revealed high reactivity of both SpG and SpLA with mammalian sera titres ranging from 1:32 (raccoon serum) to 1:1024 (mule and donkey sera). These results suggest that IBP can be used for the detection of immunoglobulin using various immunological assays and this is important for the diagnosis of infectious diseases in animal and bird populations studied and in the purification of immunoglobulins.

Molecular epidemiology of dengue in Jamaica dengue virus genotypes in Jamaica, 2007

The genotypes of dengue viruses (DENV) isolated from patients with dengue in Jamaica during 2007 were determined using DNA sequencing and phylogenetic analysis of the C-prM gene junction. The 17 DENV analysed included strains of DENVserotypes 1 (DENV-1, n = 3), DENV-2 (n = 7) and DENV-4 (n = 7). All strains ofDENV-1 were classified as genotype III, while 1 of 7 strains of DENV-2 belonged to the Asian American/Asian genotype, genotype I/III (Jamaica genotype), 2 were genotype V, the American genotype and 4 strains clustered with reference strains belonging to genotype IV. The 6 DENV-4 strains from Jamaica and the control strain clustered together in a separate clade from Caribbean/American reference strains, which belong to genotype II and Asian strains, classified as genotypes I and III. There has been little evolution in the DENV-1 strains circulating in Jamaica over the years and this might reduce the risk of outbreaks due to this serotype. In contrast, the high genetic diversity in strains of DENV-2 viruses in circulation, the presence of more recently introduced genotypes and a new clade of DENV-4 might contribute to the epidemic potential of these DENV serotypes. These preliminary data clearly indicate the need to maintain laboratory surveillance, and other control measures against hyperendemicity of dengue in Jamaica.

Dengue virus serotypes in Jamaica, 2003-2007

BACKGROUND

Dengue virus (DENV) infection is increasing in prevalence and severity globally. The severity of dengue is influenced by several factors including the immune response, viral and host genetic factors.

METHOD

The DENV serotypes were determined in 770 serum samples from dengue immunoglobulin (Ig) M antibody positive (n = 469), dengue IgM negative (n = 185) and dengue antibody negative (n = 116) patients with suspected dengue who presented during (n = 150) or after (n = 620) the acute phase of illness during 2003-2007. Dengue antibodies were detected by enzyme-linked immunosorbent assays and DENV RNA by reverse transcriptase-polymerase chain reaction (RT-PCR) performed on serum and cell culture supernatants of C6/36 mosquito cells inoculated with acute phase serum (n = 150).

RESULTS

Based on serological profiles, 41% of acute phase sera and 66% of post acute sera were from patients with current primary or secondary dengue, while 41% and 35% of acute and post-acute phase sera, respectively, were from patients with secondary dengue or past exposure only. Dengue virus RNA was found in 20/770 samples (2.6%). Only 1.5% (9/620) of sera collected after the acute phase of illness tested positive for DENV RNA compared with 2.6% (4/150) of sera collected during the acute phase and 7.3% of cell culture supernatants inoculated with acute phase serum (11/150, p = 0.001). All four serotypes including DENV-1 (3/20, 15%), DENV-2 (7/20, 35%), DENV-3 (3/20, 15%) and DENV-4 (7/20, 35%) were identified over the five-year period. These results also showed that DENV-1, 2 and 4 were present during 2007 and that DENV-2 and DENV- 4 were the likely causative viruses of the 2007-2008 dengue outbreak in Jamaica. The three strains of DENV-3 were isolated from infants less than three years of age with primary infection during 2006.

CONCLUSION

This study highlights the increasing threat of dengue and severe dengue disease to the Jamaican population. Preventative measures including laboratory surveillance and vector control should be strictly maintained at the highest level.

Dengue HLA associations in Jamaicans

BACKGROUND

Polymorphisms in the human leukocyte antigen (HLA) genes might predispose certain individuals to dengue fever (DF) and the severe forms of the disease: dengue haemorrhagic fever/ dengue shock syndrome (DHF/DSS).

SUBJECTS AND METHOD

A DNA-based HLA typing method was used to determine the HLA class I and II alleles in 50 patients with dengue, including 45 cases of DF 5 cases of DHF and 177 healthy individuals in Jamaica.

RESULTS

HLA-A*24 and - DRbeta5*01/02 were significantly associated with dengue infection while possession of HLA-A*23, -CW*04, -DQbeta*02, -DQbeta*03 and DQbeta*06 were protective. No other significant associations were found after correction for the number of alleles tested at each HLA-locus.

CONCLUSION

This is the first study to report a significant association with HLA-A*24 and DF although this allele is associated with DHF and DSS in Vietnamese patients. The other HLA associations observed in the Jamaican cohort also are different from those reported in other ethnic groups. Further studies which involve larger numbers of patients with DHF and explore functional aspects of HLA allelic associations with dengue in Jamaicans are necessary.

Clinical and laboratory features of youth onset type 2 diabetes in Jamaica

OBJECTIVES

To assess the frequency of youth onset Type 2 diabetes mellitus (T2D) in Jamaica and the characteristics of youth with this form of diabetes.

METHODS

Patients from two major referral hospitals, diagnosed with diabetes before age 25 years and < 6 years prior to the study, were evaluated. Classification was based on the presence of GAD-65 and IA-2 diabetes autoantibodies (AB), fasting (FCP) and stimulated C-peptide (SCP) measurements, serum leptin and clinical phenotype as follows: (i) Type IA diabetes--AB+, (ii) Type lB diabetes--AB- and FCP < 230 pmol/l and/or SCP < 660pmol/l, (iii) Type 2 diabetes - AB- and FCP > 500 pmol/L and or SCP 2 1160 pmol/l (iv) Untypeable diabetes--AB- and FCP 230-500 pmol/l and or SCP 660-1160 pmol/l and (v) Lipoatrophic diabetes--clinical phenotype and serum leptin.

RESULTS

Fifty-eight participants (21M, 37F, age 20-8 years, duration of diabetes 2.6-2 years) were enrolled in the study. Using the classification criteria, Type 1 diabetes was the most common form of diabetes: 18 (31%) Type 1A, 18 (31%) Type IB. Overall 22% (13 patients) had T2D. Patients with T2D were more likely to be female, older at diagnosis, obese and have a higher blood pressure when compared to those with Type 1 diabetes. In logistic regression analysis, age of diabetes onset, gender BMI, systolic and diastolic blood pressure were significantly associated with T2D. Obesity measured by BMI was the strongest predictor of T2D.

CONCLUSIONS

While Type 1 diabetes was the predominant form of diabetes in this study, a significant proportion of Jamaicans with youth onset diabetes may have T2D. Obesity is the strongest clinical predictor of Type 2 diabetes in the young diabetic patient.

Cardiovascular risk profile in Caribbean youth with diabetes mellitus

OBJECTIVE

To assess the effect of diabetes mellitus type on conventional and novel cardiovascular risk factors in patients, diagnosed with diabetes from two major referral hospitals in Jamaica, before age 25 years and with diabetes duration < 6 years.

METHODS

Participants were classified based on the presence of GAD-65 and IA-2 autoantibodies, C-peptide, leptin and clinical phenotype. Trained observers obtained anthropometric measurements and sitting blood pressure. Fasting blood was taken for glucose, A1c, lipids, high sensitivity C-reactive protein and lipoprotein profile.

RESULTS

Fifty-eight participants (21M; 37F age 20 +/- 8 [Mean +/- SD] years, diabetes duration 2.6 +/- 2 years) were enrolled. Thirty-six had Type 1 diabetes (T1D), thirteen Type 2 diabetes (T2D), six were not typed and three had lipoatrophic diabetes. Patients with Type 2 diabetes (T2D) were more obese with a higher systolic blood pressure but a lower A1c than those with Type 1 diabetes (T1D). Total cholesterol, LDL-cholesterol, triglycerides, VLDL, LDL and HDL particle numbers were similar in patients with T1D and T2D. HDL-cholesterol and LDL and HDL particle sizes were lower in patients with T2D but differences were no longer significant after adjusting for BMI.

CONCLUSIONS

Risk factors for cardiovascular disease are common in patients with all forms of youth onset diabetes. Clinicians should therefore investigate these risk factors in their patients regardless of diabetes type.

High genetic diversity in human immunodeficiency virus-type 1 in Jamaica

The subtypes of the human immunodeficiency virus - type 1 (HIV-1) strains from 54 HIV-1 - infected persons including 44 strains which were typed previously by heteroduplex mobility assay (HMA) were determined by DNA sequencing and phylogenetic analysis. Of 54 HIV- infected persons, 92.5% were infected with HIV-1 subtype B and 7.5% with other HIV-1 subtypes including subtypes D (3.7%), A (1.9%) and J (1.9%). In the phylogenetic analysis, the subtype A virus found in the sample clustered with subtype A reference strains and a circulating recombinant form (CRF) reference strain which originates in Central Africa and is circulating in Cuba indicating a close relationship between these viruses. There was 86% concordance between HMA and DNA sequencing in assigning subtype B viruses. For the non-B subtype viruses, there was less concordance between the two methods (67%). The results confirm the predominance of HIV-1 subtype B strains and the high genetic diversity of HIV-1 strains in circulation in Jamaica. The efficacies and some limitations of the HMA as a method of HIV-1 subtyping also were noted. It is important that the HIV/AIDS epidemic in Jamaica be monitored meticulously for possible expansions in non-B subtypes and the emergence of inter-subtype recombinant forms. We recommend that the more expensive DNA sequencing and phylogenetic analysis, including HIV-1 genotyping for antiretroviral drug resistance testing, be used as an adjunct to the more cost-effective HMA to track the HIV/AIDS epidemic in Jamaica.

Effectiveness of antiretroviral therapy in treating paediatric HIV/AIDS in Jamaica

BACKGROUND AND PURPOSE

Paediatric HIV/AIDS remains a significant challenge in developing countries. We describe the effectiveness of interventions in HIV-infected children attending Paediatric Infectious Diseases Clinics in Jamaica.

METHODS

One hundred and ninety-seven HIV-infected children were followed prospectively in multicentre ambulatory clinics between September 1, 2002 and August 31, 2005, in the Kingston Paediatric and Perinatal HIV/AIDS Programme, Jamaica, and their outcomes described.

RESULTS

Median follow-up was 23 child-months (interquartile range [IQR] 12-31) with 12 children (6.0%) lost to follow-up and deaths (n=13) occurred at 4.64 per 100 child-years of follow-up. Median age was 5.0 years (IQR 2.2-8.1) and 32.1% had Centers for Disease Control and Prevention (CDC) category C disease at enrollment; 62% were ever on antiretroviral therapy (ART) with median duration of 15.4 months (IQR 5.5-25.5); 85% initiated ART with zidovudine/lamivudine/nevirapine. Mean weight-for-height 0.13 +/- 1.02 (mean difference -1.71 [95% Confidence interval (CI) -2.73, -0.69]; p = 0.001) and body mass index-for-age 0.05 +/- 1.11 (mean difference -1.11, [CI -1.79, -0.43]; p = 0.002); z scores increased after 24 months on ART; however, children remained stunted. Reductions in the incidence of hospitalizations (mean diff 30.95, [CI 3.12, 58.78]; p = 0.03) and in episodes of pneumonia, culture-positive sepsis and tuberculosis occurred in those on ART.

CONCLUSIONS

A successfully implemented ambulatory model for paediatric HIV care in Jamaica has improved the quality of life and survival of HIV-infected children.

Paediatric and perinatal HIV/AIDS in Jamaica an international leadership initiative, 2002-2007

BACKGROUND

Paediatric and Perinatal HIV/AIDS remain significant health challenges in the Caribbean where the HIV seroprevalence is second only to Sub-Saharan Africa.

METHOD

We describe a collaborative approach to the prevention, treatment and care ofHIVin pregnant women, infants and children in Jamaica. A team of academic and government healthcare personnel collaborated to address the paediatric and perinatal HIV epidemic in Greater Kingston as a model for Jamaica (population 2.6 million, HIV seroprevalence 1.5%). A five-point plan was utilized and included leadership and training, preventing mother-to-child transmission (pMTCT), treatment and care of women, infants and children, outcomes-based research and local, regional and international outreach.

RESULTS

A core group of paediatric/perinatal HIV professionals were trained, including paediatricians, obstetricians, public health practitioners, nurses, microbiologists, data managers, information technology personnel and students to serve Greater Kingston (birth cohort 20,000). During September 2002 to August 2007, over 69 793 pregnant women presented for antenatal care. During these five years, significant improvements occurred in uptake of voluntary counselling (40% to 91%) and HIV-testing (53% to 102%). Eight hundred and eighty-three women tested HIV-positive with seroprevalence rates of 1-2% each year The use of modified short course zidovudine or nevirapine in the first three years significantly reduced mother-to-child transmission (MTCT) of HIV from 29% to 6% (RR 0.27; 95%0 CI--0.10, 0.68). During 2005 to 2007 using maternal highly active antiretroviral therapy (HAART) with zidovudine and lamivudine with either nevirapine, nelfinavir or lopinavir/ritonavir and infant zidovudine and nevirapine, MTCT was further reduced to an estimated 1.6% in Greater Kingston and 4.75% islandwide. In five years, we evaluated 1570 children in four-weekly paediatric infectious diseases clinics in Kingston, St Andrew and St Catherine and in six rural outreach sites throughout Jamaica; 24% (377) had HIV/AIDS and 76% (1193) were HIV-exposed. Among the infected children, 79% (299 of 377) initiated HAART resulting in reduced HIV-attributable childhood morbidity and mortality islandwide. An outcomes-based research programme was successfully implemented.

CONCLUSION

Working collaboratively, our mission of pMTCT of HIV and improving the quality of life for families living and affected by HIV/AIDS in Jamaica is being achieved.

Evolving care of HIV-infected pregnant women in Jamaica--from nevirapine to HAART

BACKGROUND

The Ministry of Health, Jamaica, is scaling-up programmes to improve the health of HIV-positive pregnant women according to the modified WHO recommended preventative mother to child transmission (pMTCT) regimens of therapy based upon the mother's clinical and immunological status. Highly-active antiretroviral drugs (HAART) can result in successful pMTCT to < 1%. We report the clinical and immunological characteristics of HIV/AIDS in an era of evolving treatment and care of HIV-infected pregnant Jamaican women.

SUBJECTS AND METHOD

Clinical records were reviewed of patients registered in antenatal clinics in Greater Kingston and St. Catherine, Jamaica (annual birth cohort--20,000) between September 2002 and August 2006. Disease status was determined using the Centers for Disease Control and Prevention (CDC) classification system for adult HIV/AIDS. Demographic, clinical and laboratory data were documented and analyzed.

RESULTS

During the four-year period, 571 HIV-infected women were enrolled; 62% from Victoria Jubilee Hospital, 25% from Spanish Town Hospital and 13% from the University Hospital of the West Indies. Mean age was 27-29 (range 15-41) years, median parity was 2 (range 0-9) and 68-70% were unemployed. Ninety-five per cent had live births. CDC categories of illnesses were A--mild disease in 82% (n=473), B--moderate disease in 4.4% (n=24) and C--severe disease in 1.4% (n=8) while 12% (n=66) had insufficient data. During the first three years, CD4+ cell counts were evaluated in only 2.5% (10 of 406) of patients with median of 344 cells/microL, compared to CD4 evaluation in 50% (83 of 165 women) in the last year with median of573 cells/uL. Antiretroviral (ARV) medications primarily for pMTCT were given to 89% (n=506) ofwomen. Of these, uptake of HAART increased during years 1-3 from 2-3% to 62% in year four Within two years post-partum, 24 women died, 92% (n=22)from the direct complications of HIV/AIDS.

CONCLUSION

A comprehensive system of care of HIV in the peripartum period has been developed in Jamaica. Detailed medical evaluation during pregnancy is performed with modern guidelines and increasing laboratory availability of CD4+ cell counts and viral loads. We believe declining HIV infection rates in Jamaican infants and healthier mothers are a direct consequence of increased testing in pregnancy with early diagnosis and initiation of HAART-based pMTCT regimens in pregnant women.

Autoantibodies in Caribbean youth with diabetes mellitus

The prevalence of diabetes and other autoantibodies in patients with recently diagnosed youth onset diabetes was evaluated. Fifty-seven patients (95% black, age 19 +/- 5 years, 36% male, diabetes duration 2.6 +/- 2.2 years) were clinically diagnosed as having type 1 (n = 35), type 2 (n = 13) and lipoatrophic diabetes (n = 3) while 6 remained untyped. GAD65 was the most common diabetes-associated autoantibody in patients with type 1A diabetes (12/17; 71%). The prevalence of any diabetes-associated autoantibodies decreased with diabetes duration (OR[95%CI]/yr after diagnosis 0.50[0.31,0.82]) and was not associated with age of onset, duration or gender. Rheumatoid factor (13/57; 23%), smooth muscle (6/57; 11%), gastric-parietal cell (5/57; 9%) and thyroid microsomal antibodies (5/57; 9%) were the most frequent non-diabetes associated autoantibodies and were more common in patients with type 1A diabetes. Only one patient had clinical autoimmune disease (hypothyroidism). Type 1A diabetes may constitute up to half the cases of newly diagnosed type 1 diabetes in Jamaican youth and is associated with a higher prevalence of other organ-specific autoantibodies.

Immunological evidence supporting the use of extracts from Boehmeria jamaicensis Urb for treating the common cold and sinus infections

Mixed lymphocyte responses assays were conducted at 25.0 and 250.0 microg/mL of the crude ethanolic extract of Boehmeria jamaicensis Urb (coded as BJE) using peripheral lymphocytes obtained from individuals suffering from the common cold after four days of infection and from healthy individuals (without the common cold infection). At a concentration of 25 ug/mL, gamma interferon (IFN-gamma) was increased by 24.03 fold and interleukin 4 (IL-4) by 1.71 fold for the cells obtained from individuals with the common cold (Group A). The extract suppressed IFN-gamma by 8.3% while IL-4 was stimulated by 9.90 fold from peripheral lymphocytes obtained from healthy individuals (Group B). Gamma interferon was suppressed at 250 microg/mL while IL-4 was elevated by 1.86 fold for cells obtained from individuals suffering from the common cold (Group A). In conclusion, BJE could have implications for the treatment of the common cold.

Antinuclear antibodies and HLA class II alleles in Jamaican patients with systemic lupus erythematosus

OBJECTIVE

The relationship between human leukocyte antigens class II (HLA) and antinuclear antibodies was investigated in Jamaican patients with Systemic Lupus Erythematosus (SLE).

METHODS

Samples of blood of 82 patients with SLE and 75 healthy controls were tested for antinuclear antibodies using the fluorescent antinuclear antibody (FANA) test, counterimmunoelectrophoresis (CIEP) and the Crithidia luciliae immunofluorescence test (CL-IFT). A DNA-based HLA typing method was used to determine the frequencies of alleles of HLA-DRB1, DRB3, DRB4 and DRB5 in patients and healthy controls.

RESULTS

The FANA test was positive in all of the sera from patients with SLE. Anti-dsDNA antibodies were present in 49% (40/82), anti-Sm/RNP 44% (36/82) and anti-Ro/La 43% (35/82) of the sera from SLE patients. The frequency of HLA-DR4 was significantly lower in SLE patients than in healthy controls (2/82, 2% vs 15/75, 20%; RR = 0.12; p = 0.0004; CP = 0.005) but no other HLA-DRB1 SLE associations were found. A positive HLA-DR3 anti-Ro/La antibody association was found in the patients with SLE (9/21, 43% vs 5/55, 9%; odds ratio (OR) = 7.5; CP = 0.01). In contrast, possession of HLA-DR6 was negatively associated with the absence of anti-dsDNA antibodies (9/32, 28% vs 27/44, 61%; OR = 0.2; CP = 0.05).

CONCLUSION

The HLA-DR6 allele is associated with the absence of antinuclear antibodies and HLA-DR3 with the presence of anti-Ro/La antibodies in Jamaican patients with SLE. However, these results and those of previous studies of Jamaican patients suggest that the HLA-DR3 association with the development of SLE reported in other populations might in fact reflect the association of HLA-DR3 with anti-Ro/La antibodies. Further investigations are needed to determine whether HLA-DRB antinuclear antibody associations define clinical subsets of SLE in Jamaican patients.

Clinical and epidemiological characteristics of adult and adolescent patients newly diagnosed with the human immunodeficiency virus at a Jamaican clinic for sexually transmitted infections

Persons infected with the human immunodeficiency virus (HIV) may have protean clinical manifestations. These characteristics have not been described for adult patients in Jamaica. This study was conducted to determine the clinical and epidemiological characteristics of adult and adolescent persons newly diagnosed with HIV presenting at a specialized clinic for sexually transmitted infections (STI). A retrospective analysis of the medical records of adult and adolescent patients newly diagnosed with HIV was undertaken over a 12-month period. The results showed that most patients (64%) were between 20 and 39 years old (age range 14-68 years, M:F ratio 1.4:1). Heterosexual practice was admitted to by 77% of patients. At the time of presentation most patients (53%) were asymptomatic while 24% had some symptoms and 21% had acquired immunodeficiency syndrome (AIDS). The most common presentation was generalized lymphadenopathy (67%) which was significantly higher than skin rash (27%), oral candidiasis (24%), cough (24%), weight loss (24%) and pallor of mucous membranes (19%, p < 0.001). This study affirms that young people account for the majority of new cases of HIV infection. The heterosexual route was the predominant mode of transmission. Generalized lymphadenopathy was the commonest presenting feature of persons newly diagnosed with HIV infection.

The immunomodulatory effect of antibiotics on the secretion of tumour necrosis factor alpha by peripheral blood mononuclear cells in response to Stenotrophomonas maltophilia stimulation

Some antibiotics have been shown to modify the host immune response. Infection with Stenotrophomonas maltophilia, is often difficult to treat due to multiresistance to antibiotics. The authors examined the effect of four commonly used antimicrobial agents (ciprofloxacin, ceftazidime, cotrimoxazole and piperacillin-tazobactam) on tumour necrosis factor alpha (TNF alpha) production by human peripheral blood mononuclear cells (PBMC) stimulated with heat-killed S maltophilia. Cotrimoxazole was the only antibiotic that suppressed TNFa secretion at clinically achievable concentrations. This may explain its use with good effect in the treatment of S maltophilia infections. However at supratherapeutic concentrations, ceftazidime and ciprofloxacin, but not piperacillin-tazobactam, also inhibited significantly the production of TNF alpha. Cotrimoxazole, in addition to its antimicrobial effect against S maltophilia, has an immunomodulatory effect on peripheral blood mononuclear cells stimulated by S maltophilia.

Epidemiology of coagulase-negative Staphylococci isolated from clinical blood specimens at the university hospital of the West Indies

The prevalence and significance of coagulase negative staphylococci (CoNS) isolated from blood cultures at the University Hospital of the West Indies (UHWI) during a six-month period were investigated. Standard and automated microbiological procedures were used to process 3001 blood culture specimens received from 2363 patients and 658 (21.9%) of the blood cultures yielded 854 bacterial isolates. The highest prevalence of positive blood cultures (60%) and the lowest prevalence of blood isolates of CoNS (12%) were found in the intensive care unit (ICU). The blood isolates of CoNS were most frequent in the surgical wards (13%) and lowest in obstetrics and gynaecology (2%). High rates of resistance to methicillin, other anti-staphylococcal penicillins, and cephalosporins used in the treatment of CoNS were observed All blood isolates of CoNS (100%) were susceptible to vancomycin. In conclusion, the results show that coagulase-negative staphylococci are the most prevalent bacterial isolates in blood cultures at the UHWI occurring mostly as contaminants. The practice of proper venepuncture and hand-washing techniques by medical staff are recommended to facilitate appropriate antibiotic usage.

Human immunodeficiency virus type-1 (HIV-1) subtypes in Jamaica

The subtypes of 141 isolates of human immunodeficiency virus type-1 (HIV-1) from Jamaica were determined by a combination of env and gag heteroduplex mobility analysis (HMA) genotyping. The majority of HIV-1 isolates were subtype B (131/141, 93.0%); one (0.8%) isolate each of subtypes C, D and E was found and 7 (4.9%) were indeterminate. These results and the failure of the sets of primers used to amplify some of the HIV-1 isolates provide strong evidence of genetic diversity of the HIV/AIDS epidemic in Jamaica. Surveillance of the circulating HIV-1 genetic subtypes is a pre-requisite for developing regional vaccine strategies and understanding the transmission patterns of the virus. This is the first study of its kind in Jamaica and the findings complement data from other Caribbean countries. This work supports the view of colleagues from the French and Spanish-speaking Caribbean that an epidemiological network supported by regional laboratories will help track this epidemic accurately with positive outcomes for the public.

Antibiotic sensitivity of Helicobacter pylori in Jamaica

Helicobacter pylori infection is one of the commonest chronic infections worldwide. Eradication regimes usually contain two antibiotics, however resistance is increasing and this decreases treatment success. This study reports on the sensitivity and resistance of H pylori to several antibiotics in patients undergoing upper gastrointestinal endoscopy in Jamaica. The rapid urease test (CLO) was positive in 128 (38%) of 336 patients. Fifty patients (39%; 50/128) with positive CLO tests had positive cultures for H pylori. Two-thirds (32/48) of islolates were sensitive to metronidazole and one-third (16/48) were resistant. Ninety-seven per cent of isolates (31/32) were sensitive to erythromycin. The sensitivity for clarithromycin was 92% (11/12) with one isolate (8%) resistant. All strains of H pylori (48/48) were sensitive to ampicillin and amoxicillin - clavulanate. Metronidazole resistance is present in one-third of H pylori isolates and resistance to macrolides is relatively low in Jamaican patients. It is important to monitor antibiotic resistance in order to provide clinicians with data on the most appropriate and cost effective eradication regimes for H pylori.

HIV seroprevalence, uptake of interventions to reduce mother-to-child transmission and birth outcomes in greater Kingston, Jamaica

BACKGROUND

The seroprevalence of HIV among pregnant women in the Caribbean is 2-3% and increasing. The Kingston Paediatric and Perinatal HIV Programme is developing and implementing a unified programme to eliminate mother-to-child transmission (MTCT) of HIV in Kingston, Jamaica.

METHODS

Pregnant women presenting to Kingston Metropolitan Antenatal Clinics, Victoria Jubilee Hospital, Spanish Town Hospital and the University Hospital of the West Indies had HIV serology performed by ELISA, or by the new Determine Rapid Test after receiving group counselling. HIV-positive women were referred to High Risk Antenatal Clinics. Antiretroviral prophylaxis with zidovudine (AZT), or nevirapine was given. Care was administered using a standard protocol by a multi-disciplinary team of public and academic healthcare personnel.

RESULTS

In year one, 19,414 women delivered Among 14,054 women who started antenatal care for this period, 5,558 (40%) received group counselling and 7,383 (53%) received HIV-testing. During the fourth quarter of follow-up, these comparative rates were 66% (2049/3 118) and 72% (2260/3118) respectively. HIV seroprevalence overall was 2.1% (152/7 383). One hundred and seven HIV+ women at varying gestational ages were identified in the programme, 72 had so far received AZT and nine nevirapine (76%). 0f 84 deliveries, birth outcomes were 75 live births (89%), six neonatal deaths and four maternal deaths (all from HIV/AIDS). Major challenges include repeat pregnancies of 36% despite prior knowledge of HIV seropositivity and poor partner notification with only 30% (32) having a HIV-test. Although rates of HIV testing in pregnant women in Greater Kingston are increasing, rates of testing overall remain sub-optimal. On the labour ward, there was sub-optimal identification of the HIV+ pregnant woman and administration of AZT chemoprophylaxis, along with issues of patient confidentiality and stigma.

CONCLUSION

This programme needs strengthening in order to reduce maternal-fetal transmission of HIV in Greater Kingston, Jamaica "pMTCT-PLUS, or comprehensive family-centred care, is the next step".

CDC-defined diseases and opportunistic infections in Jamaican children with HIV/AIDS

OBJECTIVE

To document the frequency of Centers for Disease Control and Prevention (CDC)-defined clinical conditions, opportunistic and co-infections among children with HIV/AIDS.

METHODS

This prospective, observational study reports the findings of 110 HIV-infected children followed in multicentre ambulatory clinics during September 1, 2002, to August 31, 2003, from the 239 children enrolled in the Kingston Paediatric and Perinatal HIV/AIDS Programme, Jamaica. We describe the clinico-pathologic characteristics of these children with HIV/AIDS, using the CDC criteria.

RESULTS

The client distribution by clinic site was as follows: the University Hospital of the West Indies, 71 (64.6%), Bustamante Hospital for Children, 23 (20.9%), Comprehensive Health Centre 13 (11.8/%) and Spanish Town Hospital, 3 (2.7%). The median age of the 110 children with HIV/AIDS was 6.0 years (range 0.9-17.5). Mode of transmission was primarily mother-to-child (88.0%) and only 4% maternal/infant pairs received antiretroviralprophylaxis. Grouped by CDC category: 17 (15.4%) were asymptomatic (N), 22 (20.0%) mildly symptomatic (A), 30 (27.3%) moderately symptomatic (B) and 41 (37.3%) severely symptomatic (C). The most common CDC-defining symptoms were lymphadenopathy (12, 42.8%) and asymptomatic (6, 21.4%) in category N; lymphadenopathy (30, 29.7%), dermatitis (20, 19.8%) and persistent or recurrent upper respiratory tract infections (20, 19.8%) in category A; bacterial sepsis (18, 34.6%) and recurrent diarrhoea (11, 21.2%) in category B; and wasting (28, 30.0%), encephalopathy (26, 27.9%), and serious bacterial infections (15, 16.1%) in category C; Pulmonary tuberculosis (7, 7.5%) and Pneumocystis (jiroveci) carinii pneumonia; (5, 5.4%) were the most frequent opportunistic infections. Streptococcus pneumoniae (10, 30.3%) was the most common invasive bacterial pathogen causing sepsis and Escherichia coli (14, 34.2%) was the most common bacterial pathogen causing urinary tract infections, among the cohort. Thirty-three per cent commenced antiretroviral drugs (ARVs). There were 57 hospitalizations and five deaths.

CONCLUSIONS

The study is an important step toward documentation of the natural history of paediatric HIV/AIDS in a primarily ARV-naive population from a developing country. It promotes training in paediatric HIV management as we move toward affordable access to antiretroviral agents in the wider Caribbean and the implementation of clinical trials.

Uptake of interventions, outcomes and challenges in caring for HIV-exposed infants in Kingston, Jamaica

BACKGROUND

In a few Caribbean islands, prevention of mother-to-child transmission (pMTCT) of HIV with zidovudine prophylaxis has reduced transmission rates from 27 - 44% to 5.5 - 9 %.

OBJECTIVES

To highlight the uptake of interventions, preliminary outcomes and challenges in caring for HIV-exposed infants in a pMTCT HIVprogramme in a resource-limited setting.

METHOD

A cohort of HIV-infected pregnant women were identified at the leading maternity centres in Greater Kingston through HIV counselling and testing and enrolled in the Kingston Paediatric and Perinatal HIV/AIDS Programme. Antiretroviralprophylaxis with zidovudine or nevirapine was given to the HIV-positive women and their newborns along with formula feeding. Some infants were enrolled retrospectively and followed irrespective of whether they had or had not received antiretroviral prophylaxis. A multidisciplinary team at the paediatric centres supervised protocol-driven management of the infants. Infants were followed for clinical progress and definitive HIV-infection status was to be confirmed at 18 months of age by ELISA or the Determine Rapid Test.

RESULTS

During September 1, 2002 through August 31, 2003, 132 HIV-exposed infants were identified. For those infants prospectively enrolled (78), 97% received antiretroviral prophylaxis and 90% were not breastfed For all HIV-exposed children, 90% received cotrimoxazole prophylaxis and 88% continued follow-up care. Ninety-two per cent of all the infants remained asymptomatic and five died; of these deaths one is possibly HIV-related (severe sepsis at 11 weeks). This infant was retrospectively identified, had received no antiretroviral prophylaxis and was breastfed The main programme challenges, which were overcome, included the impact of stigma, compliance with antiretroviral chemoprophylaxis, breast-milk substitution and follow-up care. Financial constraints and laboratory quality assurance issues limited early diagnosis of HIV infection.

CONCLUSION

Despite the challenges, the expected outcome is to prevent 50 new cases of HIV/AIDS in children living in Greater Kingston per year (300 over six years).

A survey of chronic renal failure in Jamaica

The prevalence of chronic renal failure (CRF)/end stage renal disease and the accessibility of long term renal replacement therapy in Jamaica were evaluated. The study was conducted at six Jamaican healthcare facilities between July 1998 and December 1999 and included 605 patients with CRF. Men with CRF (57% of patients, mean age of 56.7 years) were significantly older than women (mean age 53.2 years). Hypertension was the most commonly associated medical condition (60.8% of patients) followed by diabetes mellitus (31.4% of patients). The estimated crude point prevalence of CRF in persons 20 years and over at the end of 1999 was 327 per million population. More than one-third of patients with CRF (39%) were receiving renal replacement therapy, the most common modality being haemodialysis, and only 1.8% of patients had received kidney transplantation. The prevalence of chronic renal failure was not increased in areas known to have high soil cadmium levels. Chronic renal failure is a significant public health problem in Jamaica and is placing an increasing financial burden on the healthcare sector.

Prevalence of chronic renal failure in the diabetic population at the University Hospital of the West Indies

The prevalence of chronic renal failure (CRF) in 460 patients with diabetes mellitus attending the diabetic outpatient clinic at the University Hospital of the West Indies in Jamaica was determined from a review of medical records. The prevalence of CRF was 10% (39/386) in the diabetic clinic population. Significant positive associations with CRF were found with male gender (20/98, 20% vs 19/287, 7%; odds ratio (OR), 3.24; p = 0.001); age 60 years and older (22/162; 14% vs 17/221, 8%; OR, 2.01; p = 0.04); fasting blood glucose concentrations exceeding 8.0 mmol/L (22/162, 13% vs 12/182, 7%; OR, 2.08; p = 0.05); the presence of significant proteinuria as a marker for outcome (13/39, 33% vs 48/346, 14%; OR, 3.60; p = 0.02) and peripheral vascular disease (6/20, 30% vs 139/386, 10%; OR, 4.75; p = 0.005). The prevalence of CRF did not differ significantly between patients with Type 1 and Type 2 diabetes mellitus. Also, the presence of CRF was not significantly associated with duration of diabetes mellitus, type of hypoglycaemic agents used, or history of hypertension. However, the presence of persistent proteinuria was significantly associated with duration of diabetes mellitus exceeding five years (46/255, 17% vs 11/149, 7%; OR, 2.52; p = 0.005) and a history of hypertension (41/235, 17% vs 20/198, 10%; OR, 1.88; p = 0.03) but not with age or gender. This study emphasizes the need to evaluate patients with diabetes mellitus for renal impairment so that intervention strategies may be adopted early to delay progression to endstage renal disease.

A serosurvey of hepatitis B virus, hepatitis C virus, human T lymphotropic virus type-1 and syphilis in HIV-1-infected patients in Jamaica

The seroprevalences of hepatitis B virus (HBV), hepatitis C virus (HCV), human T lymphotropic virus type-1 (HTLV-1) and syphyilis were determined in 129 HIV-1-infected patients using commercially prepared reagents. The seroprevalences were HCV, 0% (0/129); HBV, 37% (48/129); HTLV-1, 5% (6/129) and syphilis, 20% (26/129). Fifteen per cent (19/129) of the patients had active/chronic HBV infection. The seroprevalence of HBV was statistically significantly higher in HIV-1 infected men (24/49, 50% versus 17/80, 21%; p = 0.005), while the seroprevalence of syphilis was statistically significantly increased in HIV-1 infected patients in the over-40 age group (10/31, 32% versus 6/53, 11%; p = 0.05). These findings throw the spotlight on HBV infection and syphilis and suggest that these two sexually transmitted infections should be carefully surveyed in patients with HIV/AIDS in Jamaica. It is essential for management protocols in Jamaica to include screening for evidence of these co-infections.

Autoantibodies, human T lymphotropic virus type 1 and type 1 diabetes mellitus in Jamaicans

The clinical characteristics, autoantibody profiles and seroprevalence of human T lymphotropic virus Type 1 (HTLV-1) were assessed in 30 Jamaican patients with Type 1 diabetes mellitus. Two hundred and fifty-two blood donors and 108 patients with Graves' disease were included as controls for the HTLV-1 component of the study. The mean age of onset of diabetes mellitus was 20.5 +/- 9.2 years and the mean duration of diabetes mellitus was 10.5 +/- 6.1 years. The remarkable clinical data included an absence of other associated organ-specific autoimmune diseases, and clinical evidence and history of congenital rubella in one patient. Islet cell cytoplasmic antibodies (ICA) were absent but 17% (5/30) of the diabetic patients tested positive for glutamic acid decarboxylase (GAD) antibodies. No other organ-specific autoantibodies were detected but non-organ-specific autoantibodies were present in 9 (30%) of the sera of diabetic patients. The seroprevalence of HTLV-1 in the patients with diabetes mellitus was significantly higher than that in the healthy controls (17% (5/30) versus 4% (11/252), p = 0.05). Autoantibodies were found in the sera of 4/5 (80%) of the diabetic patients who were positive for HTLV-1. None of the patients with onset of diabetes mellitus below age 15 years was HTLV-1 positive. The likely polyaetiological nature of Type 1 diabetes mellitus in Jamaicans is being further investigated at the molecular level.

Anticardiolipin antibodies and risk of thromboembolic disease in young Jamaican women

BACKGROUND

Anticardiolipin antibodies (aCL) are a heterogeneous group of antiphospholipid antibodies that are associated with arterial and venous thrombosis. We measured aCL in women, aged 15-49 years, to determine if they are an independent risk factor for thromboembolic disease.

STUDY DESIGN

Case--control study

METHODS

Fifty cases were studied including venous thromboembolism (n=29), stroke and myocardial infarction (n=21), along with 148 age-matched controls. Serum samples were assayed for aCL and anti-beta2 glycoprotein 1 antibodies using the enzyme-linked immunosorbent assay (ELISA). Information on other risk factors was obtained by a standardized questionnaire.

RESULTS

aCL were present in 16/50 (32%) of cases compared with 25/148 (17%) of controls (P[?]=[?]0.02). Unadjusted odds ratio (OR) and 95% confidence interval (95% CI) for thromboembolic disease associated with aCL was 2.32 (1.10--4.87). Other risk factors were hypertension, 2.93 (1.20--7.17) and a history of other heart diseases, 12.78 (1.32--123.60). Adjustment for hypertension, diabetes, oral contraceptive use, smoking, alcohol use, varicose veins, a family history of cardiovascular disease and a history of other heart diseases yielded OR (95%CI) 2.99 (1.32--6.80). beta2 glycoprotein 1-dependent aCL were also an independent risk factor, OR 4.56 (1.76--17.83). Subgroup analysis was carried out separately for cases of MI and stroke and for venous thrombosis. Adjusted OR (95% CI) associated with aCL in cases of MI and stroke was 1.76 (0.46--6.73) and 3.32 (1.15--9.54) for venous thromboembolism.

CONCLUSION

aCL are a risk factor for thromboembolic disease in young Jamaican women. They confer a strong independent risk for venous thromboembolism.

Antibodies to hepatitis B virus and hepatitis C virus in residential detoxification clients in Jamaica

The role of non-injecting drug abuse in viral hepatitis has not been studied widely and is not well understood. A total of 301 substance abusers, residents of a detoxification/rehabilitation unit, were investigated for exposure to hepatitis B virus (HBV) and hepatitis C virus (HCV). Samples of serum were tested for anti-HCV and anti-HBc antibodies and HBsAg. All of the patients were non-injecting drug users (non-IDUs). The prevalence of anti-HCV was 1.7%; anti-HBc was found in 28.7% and HbsAg in 0.6% of patients. Anti-HCV positivity correlated with the presence of elevated aminotransferases (80%). Exposure to HBV correlated significantly with gender (p < 0.05); age (p < 0.05); and duration of substance abuse (p < 0.05). No significant correlations were found between HCV and/or HBV infection, the drug of abuse, HIV, HTLV-1 or syphilitic infection. Residential detoxification/rehabilitation provides an opportune moment to identify and treat HCV positive substance abusers in the attempt to avert the severe hepatic sequelae. Measures which exclude substance abusers from volunteer blood donation should be considered.

HTLV-1 associated polymyositis in Jamaica

The clinical, laboratory and epidemiological characteristics of 38 adult Jamaican patients with polymyositis were evaluated. Twenty-four patients (63%) were human T-lymphotropic virus 1 (HTLV-1) seropositive and 14 patients (37%) were HTLV-1 seronegative. Polymyositis runs a more protracted course in seropositive patients who had more frequent hospital admissions and a significantly longer duration of symptoms prior to presentation. Joint swelling, chest pain and dyspnoea were more frequent complaints among the seronegative patients. There was no significant difference between the two serological groups in muscle enzyme levels, antinuclear antibody positivity or frequency of Jo-1 antibodies. HTLV-1 infection may define a subgroup of polymyositis patients with a more insidious presentation and poorer response to corticosteroid therapy.

Risky behaviour in Jamaican adolescent patients attending a sexually transmitted disease clinic

The prevalence of sexually transmitted diseases (STD) and risky behaviour patterns were studied in 165 adolescents attending a STD clinic in Jamaica. A standardised structured questionnaire, clinical algorithms for STD and serological tests for HIV and syphilitic infection were applied. High prevalences of risky behaviour including young age at onset of sexual activity, especially in boys, (mean age 12.5 +/- 2.5 years); unprotected sexual intercourse (only 4% used condoms consistently); multiple sexual partners (mean 3.8 +/- 2.4 and 1.8 +/- 1.2 for boys and girls, respectively) were found. Marijuana, used by 60% of the boys, was an independent risk factor for dysuria (adjusted Odds Ratio (OR), 2.0; 95% CI, 1.6-3.4). Repeated episodes of STD (33%), coinfection with HIV (1.2%), syphilis (1.2%) and teenage pregnancy (13%) were prominent findings. Educational strategies which promote behaviour intervention at an early age, frequent and consistent use of condoms, abstinence or delayed onset of sexual activity are essential to reducing the HIV/AIDS and STD risk in adolescents in Jamaica.

Limited usefulness of antithyroperoxidase and antithyroglobulin assays in Jamaicans with Graves' disease

The clinical usefulness of commercially prepared haemagglutination kits for thyroperoxidase (TPO) antibody and thyroglobulin (TG) antibody was evaluated in 145 consecutive Jamaicans with Graves' disease. Sixty two (43%) of the patients were newly diagnosed, 12 (8%) were in remission and 71 (49%) had relapsed. Sera from 65 (45%) patients were positive for thyroid antibodies. The TPO antibodies were found in 43% (63/145), thyroglobulin antibodies in 12% (17/145) fifteen (10%) patients had both anti-TPO and TG antibodies. Similar prevalences of TPO antibody were found in newly diagnosed patients and those who had relapsed (44% v. 41%) but the prevalence in the patients in remission was significantly higher (75%; X2 = 4.8, P < 0.05). The prevalence of TPO antibody increased significantly with age at onset before age 35 years compared to later onset (56% v. 32%; X2 = 8.09, P < 0.005). The presence of both TPO antibody (64% v. 31%; X2 = 13.1, P < 0.001) and TG antibody (22% v. 6%; X2 = 8.8, P < 0.005) correlated positively with Graves' ophthalmopathy. Neither of the tests was adequately sensitive in detecting GD in Jamaicans but we recommend testing for TPO antibody without TG antibody as a cost-effective approach. The presence and titres of TPO antibody and TG antibody do not correlate with disease activity and are not reliable enough for monitoring antithyroid drug therapy in GD. There is a need for antibody tests which are efficacious in diagnosing and monitoring antithyroid drug therapy in GD, and suitable for use in developing countries.

The prophylaxis of acute rheumatic fever in a pair of monozygotic twins. The public health implications

Recurrent acute rheumatic fever and rheumatic heart disease can be prevented by antibiotic intervention. We report the case of genetically identical twins, one of whom had overt rheumatic fever, received penicillin prophylaxis and did not have rheumatic heart disease. The other must have had inapparent rheumatic fever, received no chemotherapy prophylaxis and proceeded to develop rheumatic heart disease. A greater clinical and laboratory vigilance is required for the diagnosis of acute rheumatic fever in the asymptomatic identical twin of a patient with rheumatic fever. This case provides further evidence of a genetic predisposition to rheumatic fever and demonstrates the continued value of penicillin in the prophylaxis of acute rheumatic fever. It emphasises the need to maintain the integrity of preventive programmes against rheumatic fever worldwide. Studies which explore the HLA and other genetic linkages with rheumatic fever should be encouraged.

The significance of immune disorder in tropical spastic paraparesis

The reports of the occurrence of HTLV-1 infection and/or HTLV-1 associated myelopathy (HAM/tropical spastic paraparesis (TSP) in patients with certain organ-specific and nonorgan-specific autoimmune diseases prompted us to assess the relationship between TSP and humoral autoimmunity. Blood samples from 76 TSP patients, 60 asymptomatic HTLV-1 carriers and 100 HTLV-1 seronegative blood donors were examined for the presence of organ-specific and nonorgan-specific autoantibodies, reactive serological tests for syphilis, immunoglobulin and complement concentrations as well as immunecomplexes. High prevalences of autoantibodies (39/76, 51%), reactive serological tests for syphilis (23/76; 30%), hypergammaglobulinaemia (69/76, 90%) and complement fixing immune complexes (44/76, 58%) were found in the TSP patients. These indicators of immunological disorder were found in statistically significantly lower prevalences in asymptomatic HTLV-1 carriers (12/60, 20%; p < 0.001; 6/60, 10%; p < 0.05; 32/60, 53%; p < 0.001 and 8/60, 13%; p < 0.001, respectively) and HTLV-1 seronegative blood donors (8/100, 8%; p < 0.001; 3/100, 3%; p < 0.001; 15/100, 15%; p < 0.001 and 5/100, 5%; p < 0.001, respectively). The profiles of autoimmune phenomena observed in the patient and control groups revealed that they were associated with TSP rather than mere HTLV-1 infection and consequently pathogenetic significance. The array of immunological features present in TSP was suggestive of autoimmune disease resulting from immune dysfunction. Studies which explore the possible existence of HTLV-1 induced autoantibodies with specificity for antigens of the spinal cord in TSP might be useful in elucidating its pathogenesis.

Prevalence of viral and bacterial sexually transmitted pathogens in Jamaican pregnant women

In this study we investigated the prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum, human immunodeficiency virus type I (HIV-I), human T cell lymphotropic virus type 1 (HTLV-1) and hepatitis B virus (HBV) infections in 200 pregnant women attending antenatal clinics at the University Hospital of the West Indies. 19% of the women had at least one pathogen: C. trachomatis was found in 16%, HTLV-1 in 2%, HIV-1, HBV and N. gonorrhoeae each in 0.5% C. trachomatis infection was more prevalent in women less than 20 years of age (31%) than in those 20 years and older (16%; OR = 0.43; chi 2 = 5.66; p < 0.05). The study demonstrates the need for identification of sexually transmitted pathogens in antenatal women for syndromic management of genital infections as part of the strategy for prevention and control of HIV/AIDS (acquired immunodeficiency syndrome) in Jamaica.

Photosensitivity and antinuclear antibodies in black patients with systemic lupus erythematosus

Black patients with systemic lupus erythematosus (SLE) have a lower prevalence of photosensitivity rashes than white patients. The reasons for this are unknown, but some studies suggest a correlation between the presence of antinuclear antibodies and protection from photosensitivity. In our study, we determined serum antinuclear-antibody profiles, including anti-dsDNA, anti-Sm, anti-RNP, anti-Ro/SS-A, and anti-La/SS-B antibodies, in 91 black Jamaican patients with SLE. All 91 serum samples from SLE patients (100%) were positive in the fluorescent antinuclear-antibody test. Using the crithidia luciliae immunofluorescence test, anti-dsDNA was found in 27.5% of the samples. By a double immunodiffusion method, anti-Sm antibodies were found in 15.4%, anti-RNP in 18.7%, anti-Ro/SS-A in 9.9%, and anti-La/SS-B in 11.0%. However, no statistically significant differences were observed in the seroprevalence of these antinuclear antibodies when sera from patients of the following groups were compared: only photosensitivity rashes (n = 17), photosensitivity and other rashes (n = 23), other rashes without photosensitivity (n = 27), and patients with no skin rash of any type (n = 24). These results suggest that photosensitivity in black Jamaican patients with SLE is not associated with antinuclear-antibody specificity.

Systemic lupus erythematosus, rheumatoid arthritis and HLA phenotypes in Jamaicans

The HLA phenotypes were investigated in 30 Jamaican patients with Systemic Lupus Erythematosus (SLE), 30 with Rheumatoid Arthritis (RA) and 40 healthy controls. HLA phenotypes were determined by the microcytoxicity technique, using commercially prepared typing trays. In this study, the HLA phenotypic associations with SLE (HLA-B14, RR 4.3: HLA-A28, RR 4.3) were not statistically significant. However, a statistically significant lack of HLA-A9 (p < 0.01; CP < 0.1) was observed in SLE patients compared to healthy controls. In RA patients, a statistically significant association was noted with HLA-A2 (RR 5.1; CP < 0.01). No HLA class II associations were noted with SLE. Class II associations with RA did not achieve statistical significance but included those previously established in other populations. The preliminary data obtained from this study indicate differences in the patterns of HLA phenotypes in Jamaican patients with SLE and RA compared to those observed in such patients elsewhere. Further studies involving larger groups of patients and typing at the serological, cellular and molecular levels are clearly warranted.

Asymptomatic cardiac involvement in systemic lupus erythematosus

Cardiologic and laboratory parameters were studied in 21 patients with systemic lupus erythematosus (SLE) with cardiopulmonary symptoms (CPS), 20 SLE patients without CPS and 45 age- and sex-matched healthy controls. The most frequent cardiac abnormalities in patients with CPS included pericardial effusion (24%), ventricular enlargement (20%), mitral regurgitation (19%) and tricuspid regurgitation (14%). No structural abnormalities were observed in SLE patients without CPS. Mean calculated and derived echocardiographic values in both groups of SLE patients differed significantly from those observed in normal controls (p < 0.004). Patients with CPS had significantly lower mean values of ejection fraction (p < 0.05) and fractional shortening (p < 0.03). However, the frequencies of functional abnormalities in patients with CPS did not differ significantly from those observed in patients without CPS. There were no remarkable laboratory findings in SLE patients with CPS compared to those without. The finding that some SLE patients may have functional cardiac abnormalities in the absence of CPS is an important one. It raises the question as to whether asymptomatic cardiac involvement in SLE is a separate entity or whether it heralds symptomatic cardiopulmonary involvement.

Seroprevalence of HTLV-1 in chronic disease patients in Jamaica

A high seropositivity rate of human T cell lymphotropic virus type 1 (HTLV-1) infection was found in Jamaican patients with chronic diseases. However, except for tropical spastic paraparesis, polymyositis, adult T cell leukaemia/lymphoma and polyneuropathies of undetermined cause, HTLV-1 seropositivity rates in chronic disease patients were not significantly different from that found in healthy Jamaicans. These results indicate that there is no increased risk of HTLV-1 infection or HTLV-1 associated disease in patients with chronic diseases compared to the general Jamaican population. The association of unclassified polyneuropathies with HTLV-1 reported herein is a novel one which requires further studies to elucidate its nature.

Seroprevalence of autoantibodies in selected and unselected populations in Jamaica

Various serological techniques were used to investigate the prevalence and distribution of autoantibodies in healthy Jamaicans and patients with autoimmune and non-autoimmune disease. Low concentrations of autoantibodies were found in healthy Jamaicans, including thyroid (1.5%), gastric parietal cell (1.4%) and smooth muscle (11.3%). There was no significant age or sex predominance in the distribution of autoantibodies in the healthy population though autoimmune disease was more prevalent in females. Serological overlaps occurred but the comparative distributions and concentrations of autoantibodies in patients with autoimmune disease and non-autoimmune disease, and healthy subjects indicate that currently available methods of autoantibody determination may be used successfully in diagnosis in Jamaica. Failure to detect circulating pancreatic islet cell antibodies in insulin-dependent diabetic patients as well as in healthy Jamaicans questions the pathogenicity of these antibodies and diminishes their diagnostic usefulness in this population.

Reactive serological tests for syphilis in tropical spastic paraparesis: a dilemma

The prevalence of reactive serological tests for syphilis (STS) was investigated in 183 Jamaican patients with tropical spastic paraparesis (TSP) and 200 age and sex matched controls. A significantly higher prevalence of reactive STS was found in TSP patients (34.9%) compared with controls (14.0%, P < 0.001). The biological false positive (BFP) rate was also significantly higher in TSP patients (P < 0.01) as well as controls (P < 0.001) over 40 years of age. However, these findings do not imply a pathogenetic role for treponemal disease in TSP. The high prevalence of reactive STS in Jamaican TSP patients may be multifactorial, and include biological false positives (BFP), previous childhood yaws and concurrent syphilis.

Seroprevalence of cytomegalovirus infection in a selected population in Jamaica

The prevalence of antibodies to cytomegalovirus (CMV) was determined by the indirect enzyme-linked immunosorbent assay in a selected population of 2655 in Jamaica. The overall prevalence rate was 95%, increasing from 56.2% in children 1-4 years of age to 90% in the 15-19 years age group and by 25 years of age 97% of subjects had been exposed to CMV. The prevalence rate in children (58.4%) was significantly lower than that in blood donors (84%), sexually transmitted disease clinic attendants (95%) and antenatal women (97%) (p < 0.001). The prevalence rate in STD clinic attendants and pregnant women was also significantly higher than in blood donors (p < 0.05). The prevalence of CMV infection in the selected population, the clinical implications, routes of transmission and socioenvironmental factors are discussed.

Thymectomy in myasthenia gravis. The Jamaican experience

Forty-five patients with myasthenia gravis (MG) were subjected to thymectomy by the median sternotomy technique and were followed up for 4,380 patient months. No operative deaths occurred and 93.3% of the patients benefited from surgery with 28.8% achieving remission. Forty patients (88.5%) showed improvement within one month, and 73% of those who achieved remission did so in the first 2 years. Outcome was not affected by thymic pathology except in one patient who had a thymoma removed. These results confirm the value of thymectomy in the management of MG patients with generalised disease and the efficacy of the simple median sternotomy procedure.

Myasthenia gravis in Jamaica. Clinical, immunological and genetic studies

Clinical, immunological and genetic parameters were studied in 73 Jamaican patients with myasthenia gravis (MG). The reported bimodal clinical distribution of females with early onset of disease and males with late onset was not observed. The female to male ratio was 2:1. The most frequent manifestations of disease were ptosis (84.9%), general muscle weakness (68.5%), bulbar symptoms (41.1%) and diplopia (32.9%). Unusual presenting features such as unilateral ptosis, recurrent chest infection and stumbling while walking resulted in diagnosis being missed in 5.8% of cases. The sensitivity of radioimmunoassay in detecting acetylcholine receptor antibody (AchR-Ab) in sera from a subgroup of 35 MG patients was 71.4% whilst that of the ELISA was only 14.2%. There was no correlation between concentration of AchR-Ab and severity of disease. Similarly, there was no association between HLA-type, thymic pathology and course of disease. HLTV-I could not be implicated in the pathogenesis of this disease. There was a paucity of other associated autoimmune conditions among MG patients. Thymectomy was an important therapeutic modality in that improvement was observed in 22 cases and remission in 11.