Histamine intolerance (HIT) is assumed to be due to a deficiency of the gastrointestinal (GI) enzyme diamine oxidase (DAO) and, therefore, the food component histamine not being degraded and/or absorbed properly within the GI tract. Involvement of the GI mucosa in various disorders and diseases, several with unknown origin, and the effects of some medications seem to reduce gastrointestinal DAO activity. HIT causes variable, functional, nonspecific, non-allergic GI and extra-intestinal complaints. Usually, evaluation for HIT is not included in differential diagnoses of patients with unexplained, functional GI complaints or in the here-listed disorders and diseases. The clinical diagnosis of HIT is challenging, and the thorough anamnesis of all HIT-linked complaints, using a standardized questionnaire, is the mainstay of HIT diagnosis. So far, DAO values in serum have not been established to correlate with DAO activity in the gut, but the diagnosis of HIT may be supported with determination of a low serum DAO value. A targeted dietary intervention, consisting of a histamine-reduced diet and/or supplementation with oral DAO capsules, is helpful to reduce HIT-related symptoms. This manuscript will present why histamine should also be taken into account in the differential diagnoses of patients with various diseases and disorders of unknown origin, but with association to functional gastrointestinal complaints. In this review, we discuss currently increasing evidence that HIT is primarily a gastrointestinal disorder and that it originates in the gut.

Histamine intolerance (HIT) is thought to be caused by a disproportionate amount of histamine in the body. The enzyme diamine oxidase (DAO) is considered for the gastrointestinal degradation of histamine. For this open-label interventional pilot study, we identified 28 patients with HIT. For 4 weeks, they were instructed to take DAO capsules before meals. Then, throughout a follow-up period, they were instructed not to take the DAO. We used a questionnaire that included 22 symptoms, which were divided into 4 categories, as well as a symptom severity score. All symptoms improved significantly during the oral supplementation of DAO. During the follow-up period, without DAO supplementation, the symptoms sum scores increased again. The symptom intensity score was reduced for all symptoms. We have demonstrated, a significant reduction of every HIT-related symptom and its intensity due to DAO oral supplements. The ClinicalTrials.gov identifier (NCT number) is NCT03298568.

So far, studies on possible association of plasma lipid levels and depressive disorder are contradictory. This prospective work aimed at assessing a plasma lipid profile in individuals with major depression and healthy controls. In total, 94 patients with major depression and 152 healthy controls were included in this prospective study. After an overnight fasting state of 12 h they underwent blood drawing for triglyzerides (TG), total cholesterol, low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-cholesterol measurements. All participants were evaluated in a clinical interview and filled out the self-rating Beck Depression Inventory (BDI-II) scale to identify depressive symptomatology. Ninety-four patients with major depression showed significantly higher median (interquartile range) plasma TG levels (108.0 [75.8–154.1] vs. 84.0 [63.0–132.2] mg/dL, P = 0.014) and significantly lower HDL-cholesterol levels (55.0 [46.9–123.0] vs. 61.5 [47.4–72.6] mg/dL, P = 0.049) compared to 152 individuals without depression, respectively. Total and LDL-cholesterol concentrations were observed slightly higher in patients with major depression. Significant positive correlation was found between TG, total cholesterol and LDL-cholesterol concentrations and the BDI-II score (p = 0.027, 0.048 and 0.018), and in tendency negative correlation between HDL-cholesterol levels and the BDI-II score (P = 0.091), respectively. Depressive individuals were found with adverse plasma lipid patterns of higher TG and lower HDL-cholesterol levels compared to healthy controls. On this basis, the authors would suggest the implementation of routine lipid measurements in order to stratify these patients by their cardiovascular risk.

Recently several diagnostic manufacturers have launched new 25-hydroxy-vitamin D (25[OH]D) assays, which are aligned to the National Institute of Standards and Technology (NIST) Standard Reference Materials (SRM) (NIST, Gaithersburg, Maryland). The aim of this study was to compare the performance of one liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, one enzyme linked immunosorbent assay (ELISA), and one recalibrated and previous version of a chemiluminescence immunoassay (CLIA). Serum-aliquots of 198 patient samples from routine 25(OH)D analysis were measured by the ClinMass® LC-MS/MS Complete Kit (RECIPE Chemicals+Instruments GmbH, Munich, Germany), the ORGENTEC 25(OH)D3/D2 ELISA (ORGENTEC Diagnostika GmbH, Mainz, Germany), the recalibrated Immunodiagnostic Systems (IDS)-iSYS 25(OH)DS and the previous used IDS-iSYS 25(OH)D CLIA (Immunodiagnostic Systems Ltd, Boldon, United Kingdom). Bland-Altman and Deming regression analyses were calculated for methods comparison of all tested 25(OH)D assays. The LC-MS/MS method was defined as the reference method. Within-run and between-run precision measurements were performed for all methods with three different concentration levels. Compared to the LC-MS/MS method, the new IDS-iSYS 25(OH)DS and ORGENTEC 25(OH)D3/D2 assay demonstrated mean relative biases of 16.3% and 17.8%. The IDS-iSYS 25(OH)D assay showed the lowest mean bias of 1.5%. Deming regression analyses of the recalibrated IDS-iSYS 25(OH)DS and the ORGENTEC 25(OH)D3/D2 assay showed proportional differences, when compared to the reference method. All assays showed a within-run and between-run imprecision of ≤20% at each of the evaluated concentration levels. The evaluated standardized immunoassays and LC-MS/MS are useful methods for measuring 25(OH)D serum-levels in clinical laboratories.

The aim of this study was to evaluate a laboratory-guided therapeutic algorithm of preoperative anemia. 335 patients with elective hip or knee arthroplasty were included in this retrospective before-after study. Group I (n= 101) underwent conventional preoperative procedures before algorithm implementation. Group II (n= 234) underwent algorithm-guided preoperative anemia management. A hemoglobin-level of 13 g/dL was the therapeutic cut-off for men and women. Reticulocyte hemoglobin content (CHr) and soluble transferrin receptor (sTfR)/log ferritin ratio were used in the form of the Thomas plot. Iron deficiency (ID) was substituted with 1000 mg iron intravenous (i.v.) and 10000 international units (I.U.) of erythropoiesis-stimulating agent (ESA) subcutaneous (s.c.) or i.v., anemia of chronic disease (ACD) (without functional ID) with 40000 I.U. ESA s.c. or i.v and additionally 200 mg iron i.v. Substituted anemic patients in Group II (n=32) showed a distinctly higher preoperative (Hb-median 13 versus 11.95 g/dL) (P<0.01) and postoperative (Hb-median 9.75 versus 9.0 g/dL) (P<0.05) Hb level compared with untreated anemic patients in Group I (n=24). In Group II red blood cell (RBC) units (35 units/234 patients) were reduced by 44% compared with Group I (27 units/101 patients). Algorithm-guided preoperative anemia management raises perioperative Hb-level and reduces blood use.