Do elevated serum IgM levels have to be included in probable diagnosis criteria of patients with ataxia-telangiectasia?

Ataxia-telangiectasia (AT) is a rare multisystem, neurodegenerative genetic disorder that is characterised by progressive neurological abnormalities, oculocutaneous telangiectasias and immunodeficiency. Delay in diagnosis or misdiagnosis is probable due to its wide clinical heterogeneity in infancy. Recurrent sinopulmonary infections are often the only presenting symptom and usually patients have decreased immunoglobulins. A total 10% of patients who present with decreased serum immunoglobulin G and A and with normal or elevated immunoglobulin M levels are often misdiagnosed as hyperimmunoglobulin M syndrome. Definitive diagnosis is made if a patient with progressive cerebellar ataxia has a disease causing mutation on the ATM gene. Ataxia-telangiectasia guideline of the European Society for Immunodeficiencies defines the probable diagnosis criteria. We evaluated twenty ataxia-telangiectasia patients (mean age 13.8±4.1 years) retrospectively who were followed-up for a mean of 38.6±27.0 months. Twelve patients had a family history of consanguinity. A total of 80% patients suffered from various infections. Neoplasms occurred in three of them. Patients showed immunological abnormalities as low IgG (45%), low IgA (65%) and elevated IgM (60%) levels. CD3+CD4+ T lymphocyte frequency was low in 45% patients. The mean AFP concentration at the diagnosis was 191.9±140.1 ng/mL and the raised IgM values did not show any statistically significant relationship with high AFP concentrations. Frequency of the elevated IgM concentrations in (60%) patients raises the concerns about thinking this finding has to be accepted as a probable diagnosis criterium.

IgG-anti-IgA antibodies: an autoimmune finding in patients with psoriasis vulgaris.

AIM: Psoriasis is thought to be an autoimmune disease caused by inappropriate activation of the cellular immune system. In this study, we aimed to search out IgG-anti-IgA antibody levels, serum immunoglobulins and antinuclear antibodies (ANA). METHODS: The study enrolled 38 psoriasis vulgaris patients and 40 healthy controls. RESULTS: Mean IgG-anti-IgA levels were significantly higher in psoriasis patients. The frequency of positive ANA testing was 21.1%; however, there was no correlation between IgG-anti-IgA antibody levels and ANA positivity. Only one patient had low IgA levels without high IgG-anti-IgA concentrations. CONCLUSION: The data about high IgG-anti-IgA antibody levels are noteworthy for a new evidence of autoimmune mechanism.

Determination of cut-off titers and agreement between immunofluorescence and immunoblotting methods for detecting antinuclear antibodies in children.

Detection of antinuclear antibodies (ANA) is a diagnostic adjunct in patients with suspected autoimmune connective tissue diseases, and various detection methods are in use. The aim of this study was to analyze the agreement between the ANA immunoflourescence (IF) and immunoblotting (IB) methods and determine cut-off for children subjects in a laboratory setting. We evaluated 729 serum samples that were analyzed by both ANA IF and IB. The results were evaluated by chi(2) test and, for agreement, kappa index was used. Frequencies determined for both 1:40-1:100 cut-off titers of ANA IF in relation to IB testing supported the idea that 1:100 starting dilution should be recommended in children subjects for ANA IF method and antigen specific immunoblot testing was needed, especially for some of the ANA IF negative samples. Agreement between the two methods, especially with homogenous, granular, and nucleolar ANA IF patterns, was statistically significant.

Antioxidant enzymes and paraoxonase show a co-activity in preserving low-density lipoprotein from oxidation.

Oxidative modification of low-density lipoprotein in the artery wall plays a crucial role in the development of atherosclerosis. This physiopathological mechanism is clearly inhibited by high-density lipoprotein possibly via paraoxonase enzyme activity, present in high-density lipoprotein. In this study, we determined the in vitro susceptibility of low-density lipoprotein to oxidation and the effect of various factors, such as paraoxonase phenotypes, on this process. Low-density lipoprotein from healthy volunteers (n=66) was isolated using the precipitant reagent and the oxidation was evaluated by measuring the malonyl dialdehyde and diene levels. Low-density lipoprotein cholesterol and phospholipid, vitamin E, serum cholesterol, high-density lipoprotein and low-density lipoprotein cholesterol levels, and erythrocyte antioxidant enzymes were also determined. There was no difference among the parameters with regard to gender. Low-density lipoprotein samples obtained from subjects with the AA allele were more prone to oxidation, as observed by their higher stimulated conjugated diene (P=0.041) and thiobarbituric acid-related substance (P=0.042) levels, than samples from subjects with AB or BB alleles. The subjects with the BB allele had higher superoxide dismutase (P=0.021) and catalase (insignificant increase) activities, while their conjugated diene (P=0.000) levels were lower. In conclusion, our results revealed that the high low-density lipoprotein oxidation is related to the high low-density lipoprotein cholesterol content and low phospholipid content. The present study demonstrated an increase in superoxide dismutase and catalase activities, as well as PON1 activities, in subjects with the BB allele. Since these enzymes all show activity against low-density lipoprotein oxidation, we propose that future investigations on atherosclerotic processes should address PON1 polymorphism as well as PON1 and other antioxidant enzymes.