Endothelial nitric oxide synthase gene haplotype association with systemic lupus erythematosus.

Endothelial nitric oxide synthase (eNOS) catalyses the production of nitric oxide, which has been shown to participate in the pathogenesis of systemic lupus erythematosus (SLE). eNOS gene polymorphism may have an effect on eNOS gene expression, eNOS protein synthesis and enzymatic activity. We investigated the influence of eNOS gene polymorphisms on susceptibility to SLE. eNOS T-786C, G894T and intron 4 27-base pair tandem repeat (VNTR4) polymorphisms were investigated in 152 SLE patients and 184 controls using RFLP-PCR, direct sequencing and fragment analysis. Allele, genotype and haplotype frequency comparisons, Hardy-Weinberg equilibrium and linkage disequilibrium (LD) analysis were performed. No significant association was detected between SLE and single-nucleotide polymorphisms (SNPs) T-786C and G894T. VNTR4 allele 4b was associated with susceptibility to SLE (OR 1.89, p = 0.023), as was the genotype 4bb (OR 2.41, p = 0.007). However, allele 4a was protective (OR 0.53, p = 0.023), as was genotype 4ab (OR 0.41, p = 0.007). T-786C and VNTR4 were in high LD (r (2 )= 0.34). Haplotypes T4bC and C4aG of the three tested polymorphisms had a susceptibility effect on SLE (OR 1.89 and 4.23 at p = 0.005 and 0.001, respectively), while haplotypes T4aG and C4bG had a protective effect (OR 0.06 and 0.11 at p = 0.000001 and 0.0005, respectively). The novel finding in our study is that individual eNOS polymorphisms probably do not exert a major influence on susceptibility to SLE, but they have significant effects when combined within a specific haplotype.

Comparison between familial and sporadic systemic lupus erythematosus in Kuwaiti patients.

To validate the use of multiplex case families in studying the pathogenesis of systemic lupus erythematosus (SLE), we investigated the pattern of familial SLE in relation to sporadic SLE in the highly consanguineous Kuwaiti population. We sought to determine whether familial and sporadic SLEs have the same clinical and serological features. We compared 21 cases of familial SLE in 21 families with 42 non-familial SLE controls matched for age, sex and duration of disease. Twenty-one families, in which the diagnosis of SLE was verified in at least two relatives, were included in the study. The diagnosis was made according to the revised 1982 American College of Rheumatology criteria. There were no significant differences in clinical features or serological manifestations between familial SLE cases and their matched controls. However, our results showed that the frequency of La/SSB antibodies was higher in the sporadic group (P = 0.048), although this was not significant after application of Bonferroni's correction for the number of comparisons. Familial cases of SLE were more likely to present at younger age of 20 years and sporadic cases at 26 years (P = 0.006). The prevalence of familial SLE was 27.4%. We have found that familial and sporadic cases of SLE are broadly similar, and it is justified to include multiple case families in genetic studies.

The prevalence of human leukocyte antigen (HLA) DR/DQ/DP alleles in Kuwaiti children with oligoarticular juvenile idiopathic arthritis.

We have determined the prevalence of human leukocyte antigen (HLA)-DR, DQ and DP alleles in Kuwaiti children with oligoarticular juvenile idiopathic arthritis (OA-JIA) and healthy controls using the PCR-SSP (sequence specific primers) method. The analysis took into account the presence of antinuclear antibodies and chronic anterior uveitis. DRB1*03 (RR 2.20, P<0.001), DRB1*08 (RR 5.280, P<0.026), DQA1*0501 (RR 1.930, P<0.001), DQB1*0304 (RR 7.920, P<0.002), DQB1*0501 (RR 3.080, P<0.007) and DPB1*0101 (RR 8.8, P<0.001) were the main HLA alleles associated with OA-JIA in Kuwaiti Arabs in this study. DRB1*03 was detected in 71% of children with positive ANA, and in 50% of children with anterior uveitis. DQA1 alleles *0501, *0103 and *0105 (P<0.001; 0.029 and 0.024 respectively) were found to be associated with OA-JIA. In contrast, DQA1*0301 and DQA1*0302 alleles appear to be protective in Kuwaiti children (RR 0.153, P<0.001 and RR 0.278, P<0.016 respectively). The DQB1 alleles *0304 and *0501 were associated with OA-JIA (P<0.002 and P<0.007 respectively). In the case of DPB1, only one allele (*0101) was associated with OA-JIA (P<0.001). Most Kuwaiti Arab patients with OA-JIA who carried a DQ or DP susceptibility allele also had an accompanying DRB1*03 or *8 allele.

Systemic lupus erythematosus in Kuwaiti children: organ system involvement and serological findings.

The course and severity of systemic lupus erythematosus (SLE) in children is generally similar to the adult form with potential serious organ system involvement, there are, however, factors that influence the prevalence and clinical behavior of the disease. Our objective was to analyse the organ system involvement and immunological findings in Kuwaiti children with SLE in relation to gender and age of onset and compare these findings to that in published reports. Organ system involvement and serologic profiles were analysed in 35 children with SLE. The major organ systems studied were: renal, hematological, cardiac, pulmonary, hepatic and the central nervous system. The prevalence of ANA, anti-dsDNA, anti-Sm, SSA, SSB and anti-cardiolipin antibodies were studied in addition to complement C3 and C4 levels. The results showed that a high percentage of children had hematological involvement (34%); thrombocytopenia (23%) and hemolytic anemia (20%). Renal involvement was proven by biopsy in only 10 children (29%). Neuropsychiatric manifestations were seen in five (14%) of patients. Males had a tendency for major organ involvement relative to females. All patients had positive ANA tests. All males had positive anti-dsDNA tests compared to 86% of female patients. The most significant finding in this study is the high frequency of hematological manifestations and the relatively low incidence of renal disease and neuropsychiatric abnormalities in Kuwaiti children with SLE.

Birthweight percentiles by gestational age in Kuwait.

Our aim is develop a curve for singleton birthweight based on accurately calculated gestational age. A retrospective analysis of all singleton live births from 22-44 completed weeks of gestation during the period from September 1998 to December 2000 in the two largest birth birth centers in Kuwait was conducted. Neonates with major congenital anomalies and those with unrecorded gestational age were excluded from the study population. Total population and gender-specific birthweight percentiles according to gestational age were developed after smoothening of growth curves. A total of 35768 births were included in the development of the birthweight curve. Percentiles of birthweight for all population and by gender are presented. There was significant difference in birthweight among different ethnic groups in this population. At term, 9.8% of births are smaller than the 10th percentile and 10.0% are larger than the 90th percentile. Plotting birthweight in our population on percentile curves derived from the United States or United Kingdom would generally overestimate small for gestational age newborns and underestimate large for gestational age newborns. We conclude that the diagnosis of clinically significant birthweight abnormalities depends on the fetal growth curve used. A population specific curve of fetal growth dated by ultrasonography would provide a reliable reference for birthweight distribution.

Ethnic variations in birthweight percentiles in Kuwait.

The objectives of this retrospective study were to assess the effect of ethnicity on birthweight percentiles and to compare ethnic-specific percentiles with other references. Analysis was made of 35 768 singleton live births from 22 to 44 completed weeks of gestation at two major obstetric hospitals in Kuwait, after exclusion of data with inaccurate gestational age, major congenital abnormalities, stillbirths, and outlying birthweights. The population included four major ethnic groups: Gulf Arabs, Mediterranean Arabs, Egyptians, and a group combining Indians and Southeast Asians. Total population and ethnic-specific smoothed birthweight percentiles according to gestational age were developed. Indians-Asians had the smallest birthweights, the highest prevalence of small-for-gestational-age (SGA) birthweights and the lowest prevalence of large-for-gestational-age (LGA) birthweights. On the contrary, Egyptians had the largest birthweights, the lowest prevalence of SGA birthweights and the highest prevalence of LGA birthweights. Plotting our birthweights on a reference from Canada resulted in a low prediction rate for SGA and a low sensitivity in identifying LGA of all ethnic groups. We conclude that interpretation of fetal growth and birthweight should involve locally derived and ethnically specific percentiles based on accurately calculated gestational age.

Role of human leukocyte antigen DRB1*0307 and DRB1*0308 in susceptibility to juvenile rheumatoid arthritis.

OBJECTIVE: To study the prevalence of Human Leukocyte Antigen (HLA) DR alleles in children with juvenile rheumatoid arthritis (JRA). METHODS: DNA samples from 64 children with oligoarticular and seronegative polyarticular JRA and 64 controls of the same ethnic background were analyzed using PCR-sequence specific primers (PCR-SSP) method. Analysis took into account the onset subtype, the presence of antinuclear antibodies (ANA) and the presence of chronic anterior uveitis, a recognised serious complication of JRA. RESULTS: A high prevalence of DR3 alleles were detected in children with oligoarticular JRA compared to controls (p < 0.05). DR3 alleles were the commonest also in patients with positive ANA as well as those with chronic anterior uveitis. The interesting finding in this study is the absence of two DR3 alleles, namely DRB1*0307 and DRB1 *0308 in the control group while present in significant proportion in children with JRA. DRB1*0307 was present in 16% of children with oligoarticular subtype and 15% of those with polyarticular JRA. DRB1*0308 was only detected in children with oligoarticular JRA, none of the children with polyarticular JRA or the controls had this allele. CONCLUSION: These findings support earlier observations linking these two DR3 alleles, namely 0307 and 0308, to the genetic susceptibility to JRA.

High frequency of HLA-DQB1 non-Asp(57) alleles in Kuwaiti children with insulin-dependent diabetes mellitus.

The prevalence of polymorphic amino acids at position 57 of the HLA DQB1 in Kuwaiti children with insulin-dependent diabetes mellitus (IDDM) and nondiabetic controls has been determined using a polymerase chain reaction-sequence-specific primers (PCR-SSP) method. Using this approach, 34/55 (62%) IDDM children were found to be homozygous Ala/Ala and 19/55 (35%) were heterozygous with various combinations. Amongst the IDDM children with heterozygous genotype at codon 57 of HLA DQB1, 6/55 (11%) had Asp/Ala, 8/55 (15%) had Ala/Val, 4/55 (7%) had Ala/Ser and 1/55 had Asp/Val allelic combinations. When considered collectively, the nonaspartate (NA) alleles were represented in 87% of the IDDM cases and only 13% cases had Asp(57) allele in different heterozygous combinations, while none of the IDDM subjects had a homozygous Asp genotype. In nondiabetic controls, homozygous non-Asp (NA) alleles were represented in 44% subjects, 37% of the controls were heterozygous (NA/A) and 19% had a homozygous (A/A) genotype. These differences between the IDDM group and the control group were found to be statistically significant. Our data report one of the highest frequency of NA/NA residues at this locus compared with that from different world populations (Sardinians, Norwegians, US Caucasians, US Blacks and Chinese).

Lipoprotein A profiles in Arab newborns.

BACKGROUND: Lipoprotein A (LpA) is an intriguing lipoprotein with unquestionable genetic determination which is expressed early in life. The increasing interest in LpA is due to its established recognition as an important independent risk factor for premature atherosclerosis in cardiovascular diseases. Coronary heart disease is a major cause of morbidity and premature mortality in Kuwait. The present study was designed to measure serum LpA concentrations in Arab newborns to establish reference values for LpA in newborns and its relationship to factors present in the mother and baby. METHODS: Serum LpA concentration was analyzed in the cord blood of 107 Arab newborns by an enzyme-linked immunosorbent assay. RESULTS: The mean and median LpA were 54.8 mg/L and 33 mg/L, respectively (range 1-500 mg/L). The frequency distribution of LpA in cord blood was skewed to the right, with the highest frequencies of LpA below 100 mg/L. Mean LpA levels were significantly higher in female infants compared with male infants at birth (77.27 +/- 108.12 mg/L vs 40.2 +/- 41.43 mg/L, P < 0.05). Lipoprotein A concentrations in newborns were not influenced by material characteristics or type of delivery. Moreover, neonatal LpA concentration did not correlate with birthweight (BW) or body mass index (BMI). CONCLUSIONS: Lipoprotein A concentration at birth is low and is not related to maternal characteristics. Additionally, the development of circulating LpA in serum at birth was independent of BW and BMI.

Prevalence of human leukocyte antigen DQA1 and DQB1 alleles in Kuwaiti Arab children with type 1 diabetes mellitus.

The prevalence of human leukocyte antigen (HLA) DQB1 and DQA1 alleles has been determined in 78 Kuwaiti Arab children with insulin-dependent diabetes mellitus (IDDM) and in 57 normal healthy controls with similar ethnic background. The typing of HLA-DQ alleles was carried out using an allele-specific DNA-based polymerase chain reaction (PCR) SSP method. DR typing was also performed in 212 control subjects using PCR-SSP (sequence specific primer) method. A significantly higher frequency of DQB1*0201 allele was found in IDDM cases compared to the controls (p<0.001). There was no significant difference in the prevalence of DQB1 alleles *0302, *0501, and *0602 between IDDM cases and the controls. In contrast, DQB1 alleles *0301, *0402, *0502, *0602, and *0603 were represented at a somewhat higher frequency in controls compared to the IDDM cohort. The frequency of DQA1 allele *0301, which encode for an Arg at codon 52, was significantly higher in the IDDM patients compared to the controls (p<0.001). The frequency of DQA1 allele *0302 was also higher in IDDM cases than controls (p = 0.034) but the difference was less pronounced than DQA1*0301. Amongst the Arg52 alleles, no significant difference was detected in the frequency of *0401 between IDDM cases and the controls and the allele *0501 was detected only in controls. For non-Arg52 alleles *0103, *0104, and *0201, the differences in the two groups were not significant, with the exception of allele *0104 (p = 0.024). DR3 was the most common type in the Kuwaiti general population (28%) and DRB1*0301 was detected in 41% of the individuals with DR3 specificity. Analysis of HLA-DQBI/DQA1 haplotypes from IDDM cases and controls revealed a significantly high frequency of haplotype DQA1*0301/DQB1*0201 between Kuwaiti IDDM cases (49/78, 63%) and the controls (8/57, 14%).

Serum lipoprotein (a) concentrations among Arab children: a hospital-based study in Kuwait.

Elevated lipoprotein (a) [Lp(a)] is an independent risk factor for premature atherosclerosis and coronary heart disease, both of which are prevalent among Kuwaitis. Our objective was to measure serum lipids, including Lp(a), in Arab children and compare them with values reported for other ethnic groups. To that end, serum concentrations of Lp(a), total cholesterol [T-CHOL], high density lipoprotein [HDL], low density lipoprotein [LDL], and triglyceride [TG] were assessed in 103 Arab children. The mean and median Lp(a) were 140.4 mg/l and 95 mg/l, respectively. The Lp(a) frequency distribution was skewed to the right with the highest frequencies appearing at low levels. Serum Lp(a) correlated positively with T-CHOL and LDL but did not correlate with age, HDL and TG. Only nine children (8.7%) had serum Lp(a) levels associated with increased cardiovascular risk, namely > or = 300 mg/l.

Prevalence of antibodies to human caliciviruses (HuCVs) in Kuwait established by ELISA using baculovirus-expressed capsid antigens representing two genogroups of HuCVs.

Baculovirus recombinant-expressed antigens of Norwalk viruses (rNV) and a Mexico strain (rMX) of the Snow Mountain serogroup of human caliciviruses (HuCVs) were used in enzyme immunoassays to study the antibody prevalence among the Kuwaiti population and foreign workers employed in Kuwait. The antibody titers in 16 different age groups which ranged from neonates to centenarians were investigated by testing eight different dilutions of each serum (1:200-1:25,600). The results indicate that NV infection is widespread in Kuwait and affects all age groups Ninety-eight percent of the 433 serum samples tested had antibodies to rNV. In the 50-79-year, old age group, the antibody levels to rNV were higher and significantly different from those in children 0-7 years old. In infants, the rNV antibodies did not diminish by 4 months of age and their titer steadily increased with age. When 414 of these sera samples were tested for antibodies to rMX, 96% positive serological responses were observed. Antibody titers to rMX were reduced in infants from 4 to 11 months; however, 95% of the samples were positive. These data indicate that children born in Kuwait are infected with Norwalk-like viruses at a very early age. Finally, antibodies to rNV and rMX were found in 98% of 151 and in 95% of 148 foreign workers, respectively.

Seroprevalence of human parvovirus B19 in children of a desert region.

A seroepidemiological study was conducted in Kuwait to evaluate the pattern of acquisition of human parvovirus B19 by children in Kuwait and to compare it with patterns described in other regions in different climatic zones. A total of 218 serum samples from children less than 16 years of age were tested for the presence of anti-B19 IgG by enzyme immunoassay. The overall seroprevalence was 17.4%. Infants in Kuwait had low levels of maternally-acquired anti-B19 IgG (8.6%). The age of peak exposure to parvovirus B19 was 10-15 years compared with less than 10 years in England and Wales and more than 20 years in Singapore. The results of this study indicate an influence of geographic differences on transmission of parvovirus B19.

Juvenile rheumatoid arthritis--clinical manifestations.

Chronic inflammatory arthritis in childhood could be due to an obvious cause (e.g. sepsis, rheumatic fever, systemic lupus erythematosus etc.), or it could be idiopathic. After excluding those with obvious cause there still remains a large group of chronic inflammatory arthritis in childhood. This category has been variously called 'juvenile rheumatoid arthritis', 'juvenile arthritis', 'juvenile chronic arthritis', and more recently, 'idiopathic arthritis of childhood', The present article reviews the various classification criteria used for defining this group of disorders with emphasis on the common features as well as the major differences between these criteria. The major classes within this group with their characteristic clinical and laboratory features are also discussed.