HIV-specific IgA antibodies in tears of children with AIDS or at risk of AIDS

To improve on the diagnosis of human immunodeficiency virus (HIV) infection, 14 children with clinical evidence of AIDS, 86 children less than 15 months old and born to seropositive mothers, and 29 controls were tested for the presence of IgA antibody in tears directed against HIV antigens on Western blots. IgA antibodies in tears against env- and pol-encoded proteins were present in 13 of 14 children with AIDS and in 13 of 86 children born to seropositive mothers. No HIV-specific IgA was observed in tears of the 29 controls. Among the 86 children less than 15 months old, 11 had clinical evidence of AIDS and 7 of them (64%) had HIV-specific IgA in tears. Results show that the demonstration of lacrimal HIV-specific IgA may help to distinguish between truly infected children and those whose HIV antibodies are passively transferred from the mother. Therefore, this simple method is a good tool for laboratory diagnosis of paediatric AIDS.

Simple gas chromatography analysis of faecal butyrate: application to patients at risk of pouchitis

In spite of the fact that pouchitis is the most frequently occurring and troublesome complication found in patients treated by ileo-anal anastomosis for ulcerative colitis, no biological marker currently exists to monitor the outcome of the disease. Since it has been noted faecal butyrate is reduced in patients with pouchitis, we developed a simple gas chromatography method to quantify butyrate in faecal water. This test is based on diethyl ether extraction with the use of methacrylic acid as an internal standard. We demonstrated that butyrate was effectively measured when this technique was applied to eleven patients with ileal-pouch anal anastomosis within the first year after the closure of their ileostomy. We also observed a noticeable reduction in the concentration of butyrate in patients who went on to develop a pouchitis.

High levels of anti-Campylobacter-flagellin IgA antibodies in breast milk

Several studies have shown the beneficial role of immunity against enteric Campylobacter sp. Circulating antibodies against flagellin and possibly maternal antibodies seem to protect against intestinal colonization by Campylobacter. Milk from women in Central Africa (n = 120) and in France (n = 31) were investigated for the presence of anti-flagellin antibodies. Results showed that most French and all African milk possessed anti-flagellin IgA but not IgG. The titres of anti-flagellin IgA were elevated in colostrum and decreased in later milk. Specific activities were constant during lactation, suggesting constant antigenic stimulation. The fact that IgA but not IgG are elicited against flagellin could be due to an infection limited to the mucosal surface.

Detection of anti-HIV IgA in tears of children born to seropositive mothers is highly specific

In order to improve the diagnosis of HIV infection in children born to seropositive mothers, 86 children were previously tested by Western blotting for anti-HIV IgA in tears and IgG in serum, at a median age of 9.2 months. To determine the exact value of the assay, 68/86 children of the same cohort were retested 9 months later. Nine children (13.4%) were seropositive and all had anti-HIV IgA in tears. Eight of them had possessed lachrymal antibodies 9 months earlier. The ninth child was seronegative when 9 months old and then seroconverted. Four children (6%), known to be seronegative, had an indeterminate Western blot pattern and no HIV IgA in tears. Fifty four (80.6%) were seronegative at 18 months; none of them had ever had anti-HIV IgA in tears. This highlights the fact that only the children without lachrymal HIV IgA at the age of 9 months became seronegative at the age of 18 months. Our results clearly show that the detection of anti-HIV IgA in tears is a highly specific and reliable diagnostic test in children aged less than 15 months, born to seropositive mothers.

Major ketogenesis and the absence of an osmolar gap in an atypical case of alcoholic ketoacidosis

A new case of alcoholic ketoacidosis (AKA) is presented because of unusual clinical and biochemical features. Although it shares some similarities with typical cases of AKA, it appears as unique because of predominantly neurological, rather than abdominal symptoms, major ketogenesis with normal ketone body ratio, the presence of large amounts of propanediol and the absence of an osmolar gap.

N-benzoyl, L-glutamic acid as a suitable internal standard for the analysis of trans,trans-muconic acid in human urine by liquid chromatography

Urinary trans,trans-muconic acid is a sensitive biomarker for low level benzene exposure. The method described by Ducos et al. (Int Arch Occup Environ Health 1990; 62:529-34) is commonly used for its determination. In this study, we demonstrate that N-benzoyl, L-glutamic acid added to urine samples is a suitable internal standard to control trans,trans-muconic acid recovery after solid phase extraction of urine and to compensate for variations which might occur during high-performance liquid chromatography analysis.

[Discordant Down syndrome risk calculation with low maternal serum markers: About five cases of digynic triploidies]

OBJECTIVE

We compare the risk of Down syndrome among five patients carrying a foetus with digynic triploidy and suggest a course of action for these particular serological profiles.

METHODS

The concentrations of the different markers used are transformed into multiples of the median by using each of the three software types present on the French market which then determine the risk of Down syndrome.

RESULTS

For comparable biochemical and ultrasound profiles, the risk of Down syndrome turns out to be vastly different depending on the type of software employed. The relevance of an immediate diagnostic procedure, of a cell free DNA test or of a basic ultrasound follow-up then arises, leading to a potentially variable care pathway for the patient.

CONCLUSIONS

This study confirms that for this type of biochemical profile, the laboratory's advisory service is fundamental, that a control ultrasound is essential and that an invasive procedure must be used almost invariably due to the extremely substantial risk factors.