Validation and application of a SEC-HPLC method for the determination of total protein in therapeutic immunoglobulins as an alternative to the European Pharmacopoeia methods.

Several analytical procedures are described in the European Pharmacopoeia (Ph. Eur.) to determine total protein content. However, the method for the determination of protein content in therapeutic immunoglobulins prescribed in the Ph. Eur. monographs is the Kjeldahl method. The Kjeldahl method is time-consuming and requires the use of large amounts of hazardous reagents, which also results in the production of a large amount of hazardous chemical waste. The purpose of this work was to validate an alternative chromatographic method that requires no hazardous reagents and saves time, using the same instrumental conditions specified in the Ph. Eur. for the human immunoglobulin size-exclusion high-performance liquid chromatography (SEC-HPLC) molecular-size distribution assay. The chromatographic separation was achieved with a TSKgel G3000SW (600 × 7.5 mm, 10 µm) column, using an isocratic elution, with detection at 280 nm wavelength. The mobile phase consisted of an aqueous solution of 0.03 M disodium hydrogen phosphate dehydrate, 0.01 M sodium dihydrogen phosphate monohydrate, 0.2 M sodium chloride and 1 mM sodium azide. The protein content of the test samples was determined referring to a standard with a known protein concentration (i.e. Human immunoglobulin (molecular size) Biological Reference Preparation). The method was validated evaluating the characteristics precision and trueness according to the ICH Q2 guideline, and the goodness of linear fit for the signal response was assessed (given for information only). In addition, the equivalence of methods was evaluated with two one-sided t-tests (TOST) analysis with the Kjeldahl method mentioned in Ph. Eur. monographs on therapeutic immunoglobulins, and with Bland-Altman analysis of SEC-HPLC and manufacturers' data (Kjeldahl and biuret methods). The uncertainty of measurement was also calculated in order to evaluate the accuracy and quality of the results, thus facilitating a reliable compliance/non-compliance decision. Based on the outcome, the method is proposed as a suitable and convenient alternative for the determination of protein content in human immunoglobulins.

Syphilis with HIV in Florence, 2003-2009: a 7-year epidemiological study.

The aims of this study were to describe the trend of acquired syphilis in the city of Florence and its province over a 7-year period, to investigate sexual behaviours in the syphilis-infected population and to analyse syphilis/HIV co-infection. A total of 259 patients were classified according to age, sex and HIV infection. We estimated that from 2004 to 2008 cases increased by 248%. Most patients with concurrent HIV infection were male (31-45 years), but 40- to 60-year-old men who had sex with men predominated in both male and HIV-positive patients. Oral sex was identified as the most significant route of transmission, although most patients did not consider it so. Late-presenters with HIV accounted for 33% of HIV-positive patients: they were unaware of their HIV status and showed syphilis lesions only. In these cases, syphilis heralded the presence of HIV infection and allowed earlier diagnosis.

Use of patch testing for the diagnosis of abacavir-related hypersensitivity reaction in HIV patients.

BACKGROUND: The use of antiretroviral drug abacavir (ABC) has been often associated with cutaneous hypersensitivity reactions, the majority being severe. OBJECTIVE: The present study discusses the issues of patch testing associated with pharmacogenetic screening in light of the development of abacavir hypersensitivity reactions (HSRs). METHODS: The present authors classified 100 patients into three groups: 20 patients (group A) had experienced a hypersensitivity reaction when treated with highly active antiretroviral therapy (HAART) including ABC; 60 HIV-positive patients (group B) were receiving HAART scheme including ABC; 20 HIV-negative patients acted as control group (group C). Patients of group A and B were patch tested with ABC as such, then with an ABC extract diluted to 1 and 10% in petrolatum. Group C patients underwent patches with petrolatum only. A biopsy of the lesion was performed in those patients who showed a positive skin reaction. All patients had been tested for HLA-B5701. RESULTS: A correlation between positive ABC-patch testing and HLA-B5701 was found in 50% of patients enrolled in group A, while in group B and C, all patients tested negative for both genetic marker and ABC-patch testing. Histopathology findings confirmed a vigorous CD4+ and CD8+ cellular response that is compatible with HSR. CONCLUSIONS: Patch testing is a safe and sensitive method that can be used for to confirm or exclude any correlation between abacavir and hypersensitivity skin reactions in patients who have been previously treated with abacavir during HAART. Correlation between patch test, immunohistochimical, and genetic tests results shows that genetic testing increases the possibility to identify patients with a true reaction.

First case of Mycobacterium haemophilum infection in an AIDS patient in Italy.

Mycobacterium haemophilum, a strongly acid- and alcohol-fast bacillus belonging to the group of non-tuberculous mycobacteria was first described in 1978 as the cause of cutaneous ulcerating lesions in a woman with Hodgkin's disease. Infection due to M. haemophilum is rare but increasing in prevalence in immnunosuppressed subjects, particularly in patients with acquired immunodeficiency syndrome (AIDS) patients. The skin is the most common site of infection with erythematous or violaceous papules and/or nodules that are usually painless at first, but some elements develop into abscesses or ulcers that can become very painful. The incidence of M. haemophilum is unknown, but cases of infection have been reported in Australia, Canada, the United States, France, Israel, the United Kingdom and Taiwan; to date no cases have been reported in Italy, thus the case reported here is apparently the first one observed in our country.

Facile entry to (-)-(R)- and (+)-(S)-mexiletine.

The title compounds, 1a and 1b, have been synthesized in a three-step sequence starting from (-)-(S) and (+)-(R)-propylene oxide, respectively, in acceptable overall yields. The enantiomeric excess values for 1a and 1b were 96% and 93% respectively, as assessed by HPLC analysis on a chiral stationary phase of the corresponding N-acetyl derivatives. The synthetic route herein presented may represent a facile entry to highly enriched mexiletine enantiomers, alternative to those previously reported in the literature.

Human parvovirus B19 infection within a family and risk for pregnant women.

During an outbreak of parvovirus B19 infection among four related families at least 70% of the household contacts, including a woman at the 33rd week of pregnancy, became infected. Twins were born at the 39th week of pregnancy, both with B19 infection. B19 DNA was detected in their sera by a nested PCR, anti-B19 IgM was detectable only by an immunofluorescence assay, and low levels of maternal anti-B19 IgG were demonstrable by an immunoenzymatic test in the serum of both children. All the haematological parameters were normal at birth and 6 months later, when B19 DNA and anti-B19 antibody were no longer detectable in serum samples. This observation emphasizes the high risk of B19 infection among household contacts and the possibility of a favourable outcome of the foetal infection, possibly related to infection late in the pregnancy.