Reliable analysis of the single nucleotide polymorphism of lactase persistence LPH(-13910) C/T from saliva derived DNA: validation of a standardized saliva collection system.

BACKGROUND: The purpose of this study was to investigate the applicability of the Greiner Saliva Collection System (SCS) to obtain human genomic DNA for the analysis of single nucleotide polymorphisms (SNP) in the clinical routine laboratory. METHODS: Saliva and EDTA-blood were collected pair-wise from 112 participants. DNA was prepared by two automated procedures (MagNA Pure LC or MagNa Pure compact) and analyzed by UV-spectrophotometry and real-time PCR. RESULTS: Mean saliva derived DNA concentration was 52.7 ng/µL ± 36.4 (1000 µL, MagNA Pure LC) and 9.2 ng/µL ± 5.6 (200 µL, MagNA Pure compact) with A260/A280 ratios of 1.9 ± 0.1 and 2.1 ± 0.3 for MagNA Pure LC and MagNA Pure compact, respectively. SNP analysis for caucasian adult type lactase persistence showed a 100% success rate from saliva derived DNA and as reference from blood derived DNA. Matching genotypes were obtained in each sample pair. CONCLUSIONS: Saliva obtained with the standardized SCS yielded sufficient amounts of DNA in high purity and was found to represent a suitable and reliable source of human DNA for SNP analysis in the clinical routine laboratory.

Guidelines and diagnostic algorithm for patients with suspected systemic mastocytosis: a proposal of the Austrian competence network (AUCNM).

Systemic mastocytosis (SM) is a hematopoietic neoplasm characterized by pathologic expansion of tissue mast cells in one or more extracutaneous organs. In most children and most adult patients, skin involvement is found. Childhood patients frequently suffer from cutaneous mastocytosis without systemic involvement, whereas most adult patients are diagnosed as suffering from SM. In a smaller subset of patients, SM without skin lesions develops which is a diagnostic challenge. In the current article, a diagnostic algorithm for patients with suspected SM is proposed. In adult patients with skin lesions and histologically confirmed mastocytosis in the skin (MIS), a bone marrow biopsy is recommended regardless of the serum tryptase level. In adult patients without skin lesions who are suffering from typical mediator-related symptoms, the basal serum tryptase level is an important diagnostic parameter. In those with slightly elevated tryptase (15-30 ng/ml), additional non-invasive investigations, including a KIT mutation analysis of peripheral blood cells and sonographic analysis, is performed. In adult patients in whom i) KIT D816V is detected or/and ii) the basal serum tryptase level is clearly elevated (> 30 ng/ml) or/and iii) other clinical or laboratory features are suggesting the presence of occult mastocytosis, a bone marrow biopsy should be performed. In the absence of KIT D816V and other indications of mastocytosis, no bone marrow investigation is required, but the patient's course and the serum tryptase levels are examined in the follow-up.