Caudal regression syndrome in a fetus of a glucokinase-maturity-onset diabetes of the young pregnancy.

BACKGROUND: Glucokinase-maturity-onset diabetes of the young (GCK-MODY) is a form of diabetes caused by heterozygous inactivating mutations in the GCK gene. Affected individuals maintain their fasting glucose levels at a higher set point (5.4-8.3 mmol/l) than the general population. Hyperglycaemia in women with Type 1 or Type 2 diabetes is known to confer increased risk of fetal congenital abnormalities. The association between GCK-MODY and congenital abnormalities, however, remains uncertain. CASE REPORT: A 35-year-old woman in her third pregnancy was diagnosed with gestational diabetes at 13 weeks' gestation (fasting blood glucose 6.0 mmol/L, 1-h blood glucose 9.2 mmol/l, 2-h blood glucose 7.3 mmol/l). The morphology scan at 19+2 weeks' gestation showed a Type III sacral agenesis. The woman elected to terminate the pregnancy. Her postpartum oral glucose tolerance test was suggestive of GCK-MODY (fasting blood glucose 7.4 mmol/l, 1-h blood glucose 9.3 mmol/l, 2-h blood glucose 7.3 mmol/l). Mutation analysis of the GCK gene identified a novel heterozygous GCK missense mutation, p.V199M, classified as likely pathogenic, providing molecular confirmation of the suspected GCK-MODY diagnosis. DISCUSSION: Sacral agenesis is a rare form of sacral abnormality affecting 0.005% to 0.1% of pregnancies. It is a subtype of the caudal regression sequence, a cardinal feature of diabetic embryopathy. This case raises the question as to whether hyperglycaemia in GCK-MODY may increase the risk of fetal caudal regression syndrome as reported in women with pre-existing diabetes mellitus. Improved diagnostic rates of GCK-MODY, and MODY registers that include pregnancy outcomes, are important to further elucidate risk of congenital abnormalities in GCK-MODY.

GCK monogenic diabetes and gestational diabetes: possible diagnosis on clinical grounds.

AIM: To determine if the previously published clinical criteria for identifying glucokinase monogenic diabetes [GCK gene mutation in maturity-onset diabetes of the young (GCK-MODY)], an elevated antenatal fasting blood glucose of 5.5-8.0 mmol/l, an increment of < 4.6 mmol/l at 2 h in an oral glucose tolerance test and slim are applicable in a large multi-ethnic cohort of women with gestational diabetes. METHODS: We analysed de-identified data from all women with gestational diabetes, diagnosed using the Australasian Diabetes in Pregnancy Society (1998) Australian criteria at our institution between 1993 and 2013, making comparisons among those with complete antenatal data including: diagnostic oral glucose tolerance test results meeting the above criteria; pregestational BMI; birth outcomes; and postpartum oral glucose tolerance test data. We categorized these women into two groups: Group A1 had a BMI ≤ 21 kg/m(2) and Group A2 had a BMI > 21 kg/m(2) and < 25 kg/m(2). RESULTS: Of the 302 women meeting the study entry criteria, we had complete data including a postpartum oral glucose tolerance test result for 171 women: 54 in Group A1 and 117 in Group A2. Ethnicity was significantly different between the groups. The oral glucose tolerance test and postpartum HbA1c results identified few women ( < 14%) in Group A1 and Group A2 who still had 'possible GCK-MODY'. CONCLUSIONS: Our findings indicate that previously recommended clinical criteria for the identification of women likely to have GCK-MODY lack specificity in a cohort of women with multi-ethnic backgrounds. Using these criteria to select women for testing for GCK-MODY in pregnancy would therefore be costly and is likely to yield few women positive for this condition.

Zinc transporter 8 autoantibodies: what is their clinical relevance in gestational diabetes?

AIMS: To investigate the prevalence, clinical significance and antepartum to postpartum trajectory of zinc transporter 8 autoantibodies, a novel marker of islet autoimmunity, in women with gestational diabetes mellitus. METHODS: A total of 302 consecutive women attending a multi-ethnic Australian gestational diabetes clinic were prospectively studied. Zinc transporter 8 autoantibodies were measured at gestational diabetes diagnosis and 3 months postpartum using an enzyme-linked immunosorbent assay, and were correlated with maternal phenotype, antepartum and postpartum glucose tolerance, treatment and perinatal outcomes. RESULTS: Of the 302 women, 30 (9.9%) were positive for one islet autoantibody antepartum. No participant had multiple islet autoantibodies. Zinc transporter 8 autoantibodies were the most prevalent autoantibody [zinc transporter 8 autoantibodies: 13/271 women (4.8%); glutamic acid decarboxylase 7/302 women (2.3%); insulinoma-associated antigen-2: 6/302 women (2.0%); insulin: 4/302 women (1.3%)]. Zinc transporter 8 autoantibody positivity was associated with a higher fasting glucose level on the antepartum oral glucose tolerance test, but not with BMI, insulin use, perinatal outcomes or postpartum glucose intolerance. Five of the six women who tested positive for zinc transporter 8 autoantibodies antepartum were negative for zinc transporter 8 autoantibodies postpartum, which corresponded to a significant decline in titre antepartum to postpartum (26.5 to 3.8 U/ml; P=0.03). This was in contrast to the antepartum to postpartum trajectory of the other islet autoantibodies, which remained unchanged. CONCLUSIONS: Zinc transporter 8 autoantibodies were the most common islet autoantibody in gestational diabetes. Zinc transporter 8 autoantibody positivity was associated with slightly higher fasting glucose levels and, unlike other islet autoantibodies, titres declined postpartum. Zinc transporter 8 autoantibodies may be a marker for islet autoimmunity in a proportion of women with gestational diabetes, but the clinical relevance of zinc transporter 8 autoantibodies in pregnancy and gestational diabetes requires further investigation.

Predictors of large and small for gestational age birthweight in offspring of women with gestational diabetes mellitus.

AIM: To identify predictors of large and small for gestational age in women with gestational diabetes mellitus. METHODS: A retrospective audit of clinical data analysed for singleton births in women diagnosed with gestational diabetes by Australasian Diabetes in Pregnancy Society guidelines from 1994 to 2009. Exclusions were: incomplete data, delivered at < 36 weeks gestation and/or last recorded weight > 4 weeks pre-delivery. We assessed: pre-pregnancy BMI, ethnicity, total maternal weight gain, weight gain before and after treatment initiation for gestational diabetes, HbA(1c) at gestational diabetes presentation and treatment modality (diet or insulin) and smoking. Birthweight was assessed using customized percentile charts (large for gestational age > 90th; small for gestational age < 10th percentile). Multiple regression analyses were undertaken; statistical significance was p < 0.05. RESULTS: There were 1695 women first seen at (mean ± sd) 28.1 ± 5.3 weeks gestation (range 6-39). Ethnic mix was South-East Asian 36.7%, Middle Eastern 27.6%, European 22.4%, Indian/Pakistani 8.6%, Samoan 1.9%, African 1.5% and Maori 1.1%. Therapy was diet 69.1% and insulin 30.9%. Mean total weight gain was 12.3 ± 6.1 kg, the majority (10.6 ± 6.0 kg), gained before dietary intervention. There were 7.9% small for gestational age and 15.2% large for gestational age births. Significant independent large for gestational age predictors were: weight gain before intervention, pre-pregnancy BMI, weight gain after intervention and treatment type, but not HbA1c or smoking. Significant small for gestational age predictors were: weight gain before intervention, weight gain after intervention, but not pre-pregnancy BMI, HbA(1c) or smoking. CONCLUSION: Conventional treatment for gestational diabetes mellitus concentrates on management of blood glucose levels. The trends identified here emphasize the need to also address pregnancy weight gain stratified by pre-pregnancy BMI.

The clinical significance of overt diabetes in pregnancy.

AIM: To explore clinical implications of overt diabetes in pregnancy on antenatal characteristics, adverse neonatal outcome and diabetes risk post-partum. METHODS: Retrospective audit of prospectively collected data for all patients with gestational diabetes mellitus from 1993 to 2010. We defined overt diabetes in pregnancy as an HbA(1c) ≥ 8 mmol/mol (6.5%) or a fasting plasma glucose ≥ 7.0 mmol/l, or a 2-h glucose level ≥ 11.1 mmo/L on a 75-g oral glucose tolerance test as a surrogate for a random glucose ≥ 11.1 mmo/l. RESULTS: Our audit identified 1579 women with gestational diabetes and 254 with overt diabetes in pregnancy. Women with overt diabetes in pregnancy were diagnosed earlier in pregnancy, had a higher number of risk factors for gestational diabetes, higher antenatal HbA(1c), fasting and 2-h glucose levels, higher pre-pregnancy BMI and higher insulin use and dosage requirements than those with gestational diabetes. Overt diabetes in pregnancy was associated with an increased rate of large-for-gestational-age infant, neonatal hypoglycaemia and shoulder dystocia. Of the 133 patients with overt diabetes in pregnancy who attended a follow-up oral glucose tolerance test at 6-8 weeks post-partum, 21% had diabetes, 37.6% had impaired fasting glucose or impaired glucose tolerance, whilst 41.4% returned to normal glucose tolerance. CONCLUSION: In this patient cohort, overt diabetes in pregnancy significantly increased the risk of adverse pregnancy outcomes and post-partum impaired glucose regulation, but should not be regarded as synonymous with underlying diabetes. Two-hour glucose following a 75-g glucose load is a poor predictor of post-partum diabetes.

Evaluation of an enzyme-linked immunosorbent assay for the serological diagnosis of Neospora caninum infection in sheep and determination of the apparent prevalence of infection in New Zealand.

Neospora caninum has recently been shown to be a cause of abortions of sheep in New Zealand. A commercially available enzyme-linked immunosorbent assay (ELISA) was validated for use in sheep with sera from experimentally infected sheep. A cut-off threshold was established that demonstrated sero-conversion between 7 and 14 days post-infection. Higher inocula led to earlier sero-conversion. This ELISA was applied to 640 sera collected from rams across New Zealand and 0.625% (+/-0.61%) (4/640) were shown to be serologically positive. The four positive sera were also demonstrated to be positive by indirect fluorescent antibody test (IFAT). The ELISA evaluated here lends itself more readily to large-scale investigations than IFAT. The low background of N. caninum infection in the New Zealand sheep population suggests that N. caninum abortions could be more easily diagnosed by serological means than in populations with higher background sero-prevalence.

Insulin detemir lowers the risk of hypoglycaemia and provides more consistent plasma glucose levels compared with NPH insulin in Type 1 diabetes.

AIMS: Hypoglycaemia remains a major barrier preventing optimal glycaemic control in Type 1 diabetes due to the limitations of conventional insulin preparations. We investigated whether basal-bolus therapy with insulin detemir (detemir), a new soluble basal insulin analogue, was more effective in reducing the risk of hypoglycaemia compared with NPH insulin (NPH). METHODS: In this multinational, open-label, cross-over trial, 130 individuals with Type 1 diabetes received detemir and NPH twice daily in a randomized order in combination with premeal insulin aspart (IAsp) during two 16-week treatment periods. Risk of hypoglycaemia was based on self-measured plasma glucose (SMPG) and self-reported episodes during the last 10 weeks of each period. RESULTS: Risk of nocturnal and overall hypoglycaemia was, respectively, 50% and 18% lower with detemir than with NPH (P < 0.001). A total of 19 severe hypoglycaemic episodes occurred during treatment with detemir compared with 33 with NPH (NS). HbA(1c) decreased by 0.3% point with both treatments and was comparable at 7.6% (+/- sem 0.06%, 95% confidence interval -0.106, 0.108) after 16 weeks with similar doses of basal insulin. Within-person variation in mean plasma glucose was lower with detemir than with NPH (sd 3.00 vs. 3.33, P < 0.001), as was prebreakfast SMPG (P < 0.0001). CONCLUSIONS: Detemir was associated with a significantly lower risk of hypoglycaemia compared with NPH at similar HbA1c when used in combination with mealtime IAsp. The more consistent plasma glucose levels observed with detemir may allow people to aim for tighter glycaemic control without an increased risk of hypoglycaemia.

An improved immunoblotting technique for the serodiagnosis of Brucella ovis infections.

Two antigen preparations, the routinely used Brucella ovis sodium dodecylsulfate-mercapto ethanol extract and a B. ovis Triton X-114-derived detergent-rich phase, were compared under standard conditions for their use in electrophoretic immunoblotting for confirmafory, serological testing for B. ovis infections, by using 88 sera from ram flocks with a history of freedom from B. ovis infections, 80 sera from chronically infected rams, which were shedding B. ovis in their semen at the time of sampling, and 104 sera from a naturally infected ram flock. Blots with the detergent-rich phase as antigen gave better correlation with the serological results from naturally infected rams, exhibited no non-specific staining with sera from the negative group, gave clearer visualisation of specific bands for positive sera, and were equally sensitive when compared to the standard antigen for sera from chronically infected rams.

Attempted definition by immunoblotting of the causes of reactivity in suspected false-positive sera in the Brucella ovis complement fixation test.

Seventy-nine suspected false-positive sera, obtained over 1 year from routine submissions for Brucella ovis serological testing, were used in this study. These sera, which exhibited titres in the complement fixation test, but which because of their epidemiological history and their reactions in the enzyme-linked immunosorbent assay and gel diffusion test were suspected to be false positives, were further analysed by immunoblotting. In blots, using B. ovis antigens, rough lipopolysaccharide was identified as the major, immuno-reactive bacterial component. Antibodies against this macromolecule were present in 46.8% of the suspected false-positive sera. In order to find out if rough lipopolysaccharides from other bacterial species could be the possible cause for the suspected false positivity, 23 sera with highest complement fixation titres were reacted in blots with cell extracts from Escherichia coli, Yersinia enterocolitica, Yersinia pseudotuberculosis, Bortedella bronchiseptica, Actinobacillus seminis, Campylobacter fetus fetus, Campylobacter jejuni, Mycobacterium paratuberculosis, Mycobacterium phlei, Corynebacterium pseudotuberculosis and pure lipopolysaccharides from Escherichia coli and Salmonella typhimurium. Despite high frequencies of antibody reaction with proteins in most of these bacterial cell extracts, which reflect the presence of infections with these bacteria, immuno-staining in the rough lipopolysaccharide region was not observed.

Why does ethnicity affect prevalence of gestational diabetes? The underwater volcano theory.

To study why gestational diabetes (GDM) is more common in some ethnic groups than others, we tested the hypothesis that GDM is more common in people who are temporally closer to developing non-insulin-dependent (Type 2) diabetes mellitus (NIDDM). The prevalence of GDM and the mean age of affected women in each major ethnic group were determined. From our database of NIDDM 6052 patients, the mean age of onset in each ethnic gorup was calculated and the mean difference between age of developing GDM and age of developing NIDDM derived (NIDDM-GDM age gap). This age gap was used to adjust for the susceptibility to GDM of each group. The overall prevalence of GDM was 6.7% (CI 6.0%-7.4%). In Anglo-Celtic women it was 3.0% (CI 2.3%-3.7%). For the other ethnic groups the prevalence and odds ratio (OR) were: Chinese (15.0% CI 11.8%-18.2% OR 5.6), Vietnamese (9.6% CI 6.6%-12.5% OR 3.6), Indian (16.7% CI 9.8%-23.5% OR 6.4), Arabic (7.3% CI 4.6%-10.1% OR 2.5) and Aborigines (10.1% CI 3.8%-16.4% OR 3.7). The OR for susceptibility to GDM did not change after adjustment for BMI and maternal age and it correlated significantly with the NIDDM-GDM age gap (r = -0.85; p = 0.03). However, it fell substantially after adjustment for NIDDM-GDM age gap. For women of different ethnic origins there is a difference in the time gap between their pregnancies and the time at which they would on average be expected to develop diabetes. This difference may be an important factor underlying the higher prevalence of GDM in some ethnic populations.

Serological crossreactivity between Brucella abortus and Yersinia enterocolitica 0:9 II the use of Yersinia outer proteins for the specific detection of Yersinia enterocolitica infections in ruminants.

Yersinia outer protein (YOP) preparations from Y. enterocolitica and Y. pseudotuberculosis were used as antigens in immunoblots for the detection of Yersinia infections in experimentally and naturally infected ruminants. Sera from 9 groups of animals were used: (1) 51 sera from cattle which were false-positive in the standard brucellosis serological tests, (2) 52 sera from brucellosis-negative cattle, (3) 51 sera from a deer herd in which 16 animals were positive in the brucellosis tests and Yersina species were isolated from 5 animals, (4) 50 sera from a deer herd in which sera from all animals were negative in the brucellosis tests, (5) 107 sera from brucellosis-negative cattle which were received from throughout New Zealand, (6) 30 sera from cattle naturally infected with B. abortus and from which B. abortus was isolated, (7) 55 sera from cattle naturally infected with B. abortus, (8) 26 sera from cattle experimentally infected with B. abortus, with mostly high titres in the conventional brucellosis tests, and (9) sera taken weekly from 3 cattle experimentally infected with Y. enterocolitica 0:9. In all 3 Y. enterocolitica 0:9 experimentally infected animals the antibody reactivity against major YOPs in the Y. enterocolitica and in the Y. pseudotuberculosis YOP preparation correlated well with the strength in the classical brucellosis tests and with the staining of smooth lipopolysaccharides (SLPS) in blots, thus confirming the usefulness of YOPs for the detection of Yersinia infections. Sera from naturally infected cattle and deer herds, regardless of whether they were false positive or negative in the brucellosis tests, showed high frequencies of staining in YOP blots (53-58% in cattle and 80-100% in deer), indicating a high prevalence of field infections with Yersinia species in New Zealand. In two of the three sera groups from B. abortus infected animals, antibodies against YOPs were detected with high frequency, showing that dual infections may be common and may interfere with differential serological testing.

Non-specific seroreactions against Brucella abortus in ruminants in New Zealand and the presence of Yersinia enterocolitica 0:9.

The level of non-specific reactions found in the brucellosis serology of ruminants in New Zealand was very low until July 1992. This changed when, in an export consignment of 1071 deer, 35% reacted in the Brucella abortus tube agglutination test with titres varying from 50 to 200 IU. The reactors were also positive in the Rose-Bengal agglutination test and most of them reacted in the complement fixation test with titres varying from 10 to 80 IU. Yersinia enterocolitica 0:9 was later isolated from one deer of this consignment. It was the first isolate of this serotype recovered in New Zealand from an animal. Shortly after, false reactors occurred more frequently than before in sera from Brucella abortus accredited free cattle herds. As the involvement of Yersinia enterocolitica 0:9 was suspected in these cases, faecal samples from reactors and in-contact animals were cultured for this organism. Yersinia enterocolitica 0:9 was isolated from nine of 19 herds showing one or more false Brucella abortus seroreactions. Prior to 1990, Yersinia enterocolitica serotype 0:9 had not been isolated in New Zealand, despite the recovery of a number of other bio- or serotypes of the organism from humans and animals. From 1990 onward, serotype 0:9 began to be isolated from human faecal samples with increasing frequency. Since the first isolations from deer and cattle in 1992, it has now also been recovered from a cat and an alpaca and from cattle without any association with false positive Brucella abortus reactions. All serotype 0:9 isolates were of biotype 2.

Identification and characterization of immunodominant antigens during the course of infection with Brucella ovis.

The seroresponse against Brucella ovis of 8 intrapreputially and 6 intravenously infected rams and 9 ewes infected through mating was analyzed by electrophoretic immunoblotting. Additionally, 87 sera from chronically infected rams that were shedding B. ovis in their semen, 226 sera from rams belonging to infected flocks, and 324 sera from false-positive complement fixation test (CFT) reactors were examined. In all infected animals, antibody reactivity was predominantly found against 5 B. ovis components of 8-12, 17, 19, 29, and 63 kD, of which the 29-kD antigen was most dominant in the seroresponse. Antibodies to the 29-kD component were present in 93-100% of the infected sheep in each infected group, whereas the frequency of antibodies to the 4 other components varied considerably among and within the different groups. No reactivity against the 29-kD antigen was found in the false-positive CFT reactors. By using monoclonal antibodies against known bacterial macromolecules, the immunodominant antigens were identified as rough lipopolysaccharide (8-12 kD), outer membrane proteins (17, 19, 29 kD), and a heat-shock protein (63 kD).

A sensitive immunoblotting technique for the serodiagnosis of Brucella ovis infections.

A simplified electrophoretic immunoblotting technique based on antigen extracted from Brucella ovis cells with sodium dodecyl sulfate/mercaptoethanol was compared with the complement fixation test (CFT), the enzyme-linked immunosorbent assay, and the gel diffusion test. Sera from 89 chronically infected, semen culture-positive rams, 378 sera from B. ovis-infected flocks, 300 sera from accredited disease-free flocks, and 29 sera from specific-pathogen-free sheep were used. The immunoblotting technique had sensitivity and specificity comparable to those of the standard tests and was able to identify several CFT-negative or -borderline sera as positive. The major immunoreactive antigens of B. ovis had molecular masses of 63, 29, 19 kD (proteins) and 8-12 kD (rough lipopolysaccharide). Antibodies against these antigens were present in 96% of CFT-positive sera from infected flocks and in 100% of sera from semen culture-positive rams. However, immunoblotting also identified antibodies to components other than the major antigens in 1% of CFT-negative sera from infected flocks and in 7.7% of the sera from flocks with a history of freedom from the disease. These reactions probably represent cross-reactivities with other microorganisms and were distinguishable from truly positive reactions.