Monitoring of complement activation biomarkers and eculizumab in complement-mediated renal disorders

Various complement-mediated renal disorders are treated currently with the complement inhibitor eculizumab. By blocking the cleavage of C5, this monoclonal antibody prevents cell damage caused by complement-mediated inflammation. We included 23 patients with atypical haemolytic uraemic syndrome (aHUS, n = 12), C3 glomerulopathies (C3G, n = 9) and acute antibody-mediated renal graft rejection (AMR, n = 2), treated with eculizumab in 12 hospitals in Germany. We explored the course of complement activation biomarkers and the benefit of therapeutic drug monitoring of eculizumab. Complement activation was assessed by analysing the haemolytic complement function of the classical (CH50) and the alternative pathway (APH50), C3 and the activation products C3d, C5a and sC5b-9 prior to, 3 and 6 months after eculizumab treatment. Eculizumab concentrations were determined by a newly established specific enzyme-linked immunosorbent assay (ELISA). Serum eculizumab concentrations up to 1082 μg/ml point to drug accumulation, especially in paediatric patients. Loss of the therapeutic antibody via urine with concentrations up to 56 μg/ml correlated with proteinuria. In aHUS patients, effective complement inhibition was demonstrated by significant reductions of CH50, APH50, C3d and sC5b-9 levels, whereas C5a levels were only reduced significantly after 6 months' treatment. C3G patients presented increased C3d and consistently low C3 levels, reflecting ongoing complement activation and consumption at the C3 level, despite eculizumab treatment. A comprehensive complement analysis together with drug monitoring is required to distinguish mode of complement activation and efficacy of eculizumab treatment in distinct renal disorders. Accumulation of the anti-C5 antibody points to the need for a patient-orientated tailored therapy.

[Value of fine needle aspiration cytology and core needle biopsy in the head and neck region]

BACKGROUND

Fine-needle aspiration cytology (FNAC) and core-needle biopsy (CNB) represent 2 minimal invasive methods for further assessment of suspect lesions of the head and neck area. However, only limited data on the direct comparison of both methods has been published. The aim of this retrospective study was to evaluate the diagnostic value of FNAC and CNB and to compare their sensitivity and specificity.

MATERIAL AND METHODS

Between 2005 and 2012, CNB was performed in 86 patients and FNAC in 408 patients. 52 of 86 CNB-patients and 224 of 408 FNAC-patients underwent surgery afterwards and were included into the study (n=276). In order to compare the results of both methods the corresponding final histopathological finding from surgery was considered.

RESULTS

The sensitivity of the FNAC-group was higher (85%) compared to the CNB-group (80%), the specificity (87 vs. 94%) as well as the positive predictive value (64 vs. 97%) was lower. The negative predictive value (92 vs. 71%) and also the false negative value of the FNAC (5 vs. 13%) were superior to the results of the CNB-group. Concerning the false positive value the CNB-group showed better results (2 vs. 15%).

CONCLUSION

Both methods are well suited to clarify the dignity of lesions in the head and neck region. In the current case series, FNAC seemed particularly suitable for diagnosis of hematologic diseases and the exclusion of malignancy in suspicious lymph nodes. The GNP has proven to be valid in the detection of tumor recurrences in irradiated or previously operated tissue, furthermore the definitive oncological treatment can be planed, based on the histopathological results obtained by GNP.

[Pronounced pancytopenia with concomitant jaundice in a 66-year-old woman]

HISTORY AND ADMISSION FINDINGS

A previously healthy 66-year-old women presented with onset of general weakness, shortness of breath and significant weight loss. Due to appearance of jaundice, biliary obstruction had been ruled out by a CAT scan previous to the patients presentation in our practice.

INVESTIGATIONS

The laboratory tests already arranged by the patients general practitioner showed a pronounced pancytopenia with megaloblastic anemia and hyperbilirubinemia. The bone marrow aspiration revealed a hypercellular bone marrow with megaloblastic erythropoiesis. The diagnosis of pernicious anemia was confirmed by the low cobalamin (vitamin B12) serum level and the presence of atrophic gastritis.

TREATMENT

Pernicious anemia was treated with intramuscular injection of Cyanocobalamin (1000 µg) which resulted in an immediate reticulocytosis and a widely normalized blood cell count and bilirubin level four weeks after initiation of treatment.

CONCLUSION

The differential diagnosis of megaloblastic anemia covers a wide spectrum of diseases with different etiology. This case report demonstrates an example of a pernicious anemia with atypical and foudroyant clinical course.

Severe agranulocytosis as a rare side effect of pegylated interferon therapy for chronic hepatitis B

We report on a 19-year-old male patient with chronic HBeAg-positive hepatitis B-infection and agranulocytosis as a severe side effect of pegylated interferon alpha therapy. Within the first six months of therapy the hepatitis B virus DNA became undetectable in parallel with a significant decrease of the HBsAg serum concentration. After a six-month course of therapy the patient was admitted to our emergency unit. He appeared significantly ill and reported that he had fever for two days, painful oral mucosa, throat pain and general fatigue and discomfort. A complete blood cell count was performed and revealed a complete agranulocytosis with no detectable neutrophilic granulocytes in the blood smear. Antiviral therapy was immediately stopped and he was admitted to our clinic where a supportive therapy and an empirical course of broadband antibiotics were initiated. A few days later an additional treatment with intravenous prednisolone was started. Within the next week the agranulocytosis resolved and the neutrophil count was completely restored. In parallel, the clinical status improved quickly. This case demonstrates the need for our awareness of agranulocytosis as a rare but severe and potentially life-threatening side effect of interferon alpha therapy.

Prevalence and risk factors of focal sparing in hepatic steatosis

PURPOSE

The prevalence, localization and potential risk factors for focal sparing were prospectively assessed in subjects with sonographically detectable hepatic steatosis as part of a population-based cross-sectional study.

MATERIALS AND METHODS

A total of 1,624 persons (n = 906 women; n = 718 men) were evaluated using ultrasonography, laboratory testing and a standardized questionnaire. The following were excluded from the analysis: subjects with reported alcohol consumption > 40 g/day (males) or > 20 g/day (females), those with known chronic hepatitis B or C infection, elevated serum transaminases (AST: m > 44 U/l, f > 33 U/l; ALT: m > 45 U/l, f > 35 U/l) and prior right nephrectomy.

RESULTS

The prevalence of focal sparing in patients with hepatic steatosis (grade I) was 25.6 % for men and 13.0 % for women. In patients with grade II/III disease, the prevalence was 70.9 % for men and 77.6 % for women. The most common site of focal sparing was in segment IV. The average diameter was 22.3 mm (range 7 - 84 mm). No correlation was found for postulated risk "age" (p = 0.09) or "status post cholecystectomy" (p = 0.09). Male sex (p = 0.02) and metabolic syndrome (odds ratio, 2.1; 95 % confidence interval, 1.1 - 4.1; p = 0.02) were confirmed as risk factors.

CONCLUSION

Sonographic evidence of focal sparing in subjects with hepatic steatosis is associated with an increased risk for metabolic syndrome and may be an easily obtained diagnostic criterion in routine clinical settings.

CMV monitoring using blood cells and plasma: a comparison of apples with oranges?

Quantitative cytomegalovirus (CMV) monitoring is still far from being standardized between transplant centers. In the present study, we compared assays for quantitative CMV monitoring using blood cells and plasma. Four hundred and thirty-five consecutive samples from 29 patients with active CMV infection after allogeneic T-cell-depleted hemopoietic stem cell transplantation were tested in parallel using pp65 antigenemia and quantitative CMV polymerase chain reaction (PCR) in blood cells and plasma (COBAS AMPLICOR CMV MONITOR). Although only 142 (53.1%) of 253 positive samples were concordantly identified by all three assays, the number of positive samples detected by each assay was not different and the quantitative values were correlated, provided that nucleic acid (NA) in plasma was isolated by COBAS AmpliPrep and not by the manual protocol. Six (18%) of 34 episodes with active CMV infection were not detected using CMV PCR in plasma; whereas in times of white blood cell aplasia or blast crisis of leukemia, samples with active CMV infection in plasma could not be detected using blood cells. We conclude that CMV monitoring in whole blood could be favorable compared with assays using plasma or blood cells alone. Automated NA isolation could become an attractive tool for a more sensitive and better standardized molecular diagnostics.

Moxifloxacin prophylaxis in neutropenic patients

OBJECTIVES

Recent studies have shown a beneficial impact of fluoroquinolones on infection-related morbidity and mortality for patients with haematological malignancies during neutropenia. Among the fluoroquinolones moxifloxacin currently provides one of the broadest spectra of antibacterial activity and may be suitable for prophylaxis during neutropenia.

PATIENTS AND METHODS

In this controlled before and after observational study, moxifloxacin chemoprophylaxis was used during prolonged neutropenia in haemato-oncological patients (period 2; 282 episodes). Data were compared with two periods with levofloxacin prophylaxis, one preceding period (period 1; 399 episodes) and a post-observational period (period 3; 53 episodes). Endpoints for evaluation were the rates of Gram-negative and Gram-positive bacteraemia and infection-related mortality.

RESULTS

We found similar survival rates as compared with levofloxacin. The rate of Gram-negative bacteraemia was higher during prophylaxis with moxifloxacin (11%) when compared with levofloxacin (6% for period 1 and 6% for period 3). In addition we observed a marked increase in diarrhoea associated with Clostridium difficile toxin A (CDAD) after a formula change from levofloxacin to moxifloxacin (attack rate 6% versus 33%). A decrease was attained after changing back to levofloxacin and reinforcing hygienic measures (13%).

CONCLUSIONS

During moxifloxacin prophylaxis, we observed a significantly increased incidence of Gram-negative bacteraemia and CDAD. Careful attention must be paid not to trade the particularly beneficial effects of fluoroquinolones in the neutropenic setting for such disadvantageous effects. Until further data are obtained, caution is warranted when applying fluoroquinolones with high anaerobic activity in the neutropenic setting.

One-pot synthesis of amino-alcohols using a de-novo transketolase and β-alanine: Pyruvate transaminase pathway inEscherichia coli

Biocatalysis continues to emerge as a powerful technique for the efficient synthesis of optically pure pharmaceuticals that are difficult to access via conventional chemistry. The power of biocatalysis can be enhanced if two or more reactions can be achieved by a single whole cell biocatalyst containing a pathway designed de-novo to facilitate a required synthetic sequence. The enzymes transketolase (TK) and transaminase (TAm) respectively catalyze asymmetric carbon--carbon bond formation and amine group addition to suitable substrate molecules. The ability of a transaminase to accept the product of the transketolase reaction can allow the two catalysts to be employed in series to create chiral amino-alcohols from achiral substrates. As proof of principle, the beta-alanine: pyruvate aminotransferase (beta-A:P TAm) from Pseudomonas aeruginosa has been cloned, to create plasmid pQR428, for overexpression in E.coli strain BL21gold(DE3). Production of the beta-A:P TAm alongside the native transketolase (overexpressed from plasmid pQR411), in a single E.coli host, has created a novel biocatalyst capable of the synthesis of chiral amino alcohols via a synthetic two-step pathway. The feasibility of using the biocatalyst has been demonstrated by the formation of a single diastereoisomer of 2-amino-1,3,4-butanetriol (ABT) product, in up to 21% mol/mol yield, by the beta-A:P TAm, via transamination of L-erythrulose synthesized by TK, from achiral substrates glycolaldehyde (GA) and beta-hydroxypyruvate (beta-HPA). ABT synthesis was achieved in a one-pot process, using either whole cells of the dual plasmid strain or cell lysate, while the dual alcohol-amine functionality of ABT makes it an excellent synthon for many pharmaceutical syntheses.

KOC is a novel molecular indicator of malignancy

The detection of malignant cells in fine-needle aspirates (FNA's) using marker genes is hampered by the fact that these markers are only expressed by certain malignancies or lack sensitivity and/or specificity. Here we report the results of a prospective pilot study examining the expression of KOC (KH-domain containing protein over expressed in cancer), a novel onco-foetal gene, in 76 patients who underwent fine-needle aspiration for further diagnosis of abdominal lesions, aszites, cysts or cerebrospinal fluid. Aspirates were examined by cytology and by a KOC RT-PCR assay. KOC expression was a highly sensitive and specific indicator of malignancy. The KOC assay could be useful to facilitate screening for malignant disease and to improve the diagnostic accuracy of FNAs.

Initial results in the assessment of multiple myeloma using 18F-FDG PET

This prospective study was undertaken to investigate the appearance of multiple myeloma on fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET). Furthermore, the accuracy of FDG-PET in detecting myeloma lesions and its influence on patient management were evaluated. Forty-three patients with known multiple myeloma (n=28) or solitary plasmacytoma (n=15) underwent FDG-PET. The results of routinely performed radiographs and of scans obtained using all available imaging modalities (MRI, CT), as well as the clinical course, were used for verification of detected lesions. Focally increased tracer uptake was observed in 38 of 41 known osteolytic bone lesions (sensitivity 92.7%) in 23 patients. In addition, 71 further bone lesions which were negative on radiographs were detected in 14 patients. Twenty-six (36.6%) of these lesions could be confirmed in ten patients. As a result of FDG-PET imaging, clinical management was influenced in five (14.0%) patients. The positive predictive value for active disease was 100% in patients with focal or mixed focal/diffuse skeletal FDG uptake and 75% in patients with diffuse bone marrow uptake. Depending on the interpretation of the PET scans in patients with diffuse bone marrow uptake, the sensitivity ranged from 83.8% to 91.9% and the specificity from 83.3% to 100%. FDG-PET thus proved highly accurate in detecting multiple myeloma, and revealed a greater extent of disease than routine radiographs in 14 of 23 (60.9%) patients who had osteolytic bone lesions. FDG-PET might contribute to the initial staging of solitary plasmacytoma.

Effects of elevated triiodothyronine on cognitive performance and mood in healthy subjects

The acute effects of experimentally elevated triiodothyronine (T3) serum levels were investigated in 14 healthy male subjects. After oral application of 100 micrograms triiodothyronine on 3 consecutive days a battery of neuropsychological tests and rating scales for mood and bodily complaints were administered. Results show slight mood disturbances but no cognitive impairment caused by T3 level changes. Time intervals were estimated as being longer than in euthyroid state, and word production showed a trend to accelerate. It is concluded that the immediate effects of elevated circulating T3 on cognition and mood are merely discrete. More severe cognitive impairments reported in hyperthyroid patients are probably due to long-term effects on the brain.

[Misdiagnosis of psychic symptoms of hyperthyroidism in affective psychosis]

A 71-year-old woman known to have suffered from a depressive illness for fifty years developed further psychological and somatic symptoms 18 months ago (agitation, increased impulsiveness, depressive mood, decreased appetite, diarrhoea and weight loss). Within five days there occurred nocturnal confusion with disordered word finding and counting. Biochemical tests indicated hyperthyroidism and scintigraphy showed multifocal activity increase. The psychological and somatic symptoms responded to thyrostatic treatment with carbimazole, 30 mg daily. This case demonstrates that added somatic causes of psychological symptoms should be thought of in previously known psychiatric illness.

Psychopathological and neuropsychological symptoms in patients with subclinical and remitted hyperthyroidism

To investigate relationships between hyperthyroidism and behavior, 45 formerly hyperthyroid patients (now euthyroid) and 51 control subjects were investigated by (a) a semi-structured psychiatric examination, (b) self-rating scales to assess mood states and personality, and (c) neuropsychological tests. Patients with "subclinical" or "remitted" hyperthyroidism showed more abnormalities than the controls in all dimensions investigated. Forty-three percent of patients (10% of controls) complained of "seriously reduced" well-being with feelings of fear, hostility, and inability to concentrate. While a fearful-agitated syndrome dominated in the initial phase of the illness, a mainly depressive syndrome was characteristic after a longer period of remission. More than 25% of the patients (2% of controls) showed "markedly impaired" neuropsychological functioning. Patients with a relapse within 2.5 years exhibited the most abnormal results. Even after a longer period of hormonal remission, there was no complete psychopathological and neuropsychological normalization. A thorough follow-up of hyperthyroid patients is recommended.

In vivo modulation of rat hypothalamic opioid peptide content by intracerebroventricular injection of guanidinoethylmercaptosuccinic acid (GEMSA): possible physiological role of enkephalin convertase

Twice-daily intracerebroventricular (i.c.v.) injections for three days of increasing doses of guanidino-ethyl-mercapto-succinic acid (GEMSA) produced a dose-dependent decrease in methionine-enkephalin- and leucine-enkephalin levels in rat hypothalami. GEMSA is a specific and potent inhibitor of a carboxypeptidase B-like processing enzyme, referred to as enkephalin convertase (EC). The administration of GEMSA (0.1 microgram) resulted in more than 50% reduction in the levels of these two opioid peptides. However, no changes occurred in the hypothalamic content of beta-endorphin or dynorphin1-17. Moreover, in GEMSA-treated animals, hypothalamic luteinizing hormone-releasing hormone and serum luteinizing hormone levels were increased by 75%. Serum prolactin concentrations were decreased by 60% at the same time. Subcutaneous naloxone administration resulted in a 75% elevation of serum LH concentrations in control animals whereas GEMSA-treated animals showed a blunted response, most likely due to a decreased amount of opioid-active peptides. The present study is in agreement with the putative role of EC in the processing of the multivalent opioid precursor (proenkephalin A) in the rat hypothalamus. The enzyme inhibition by GEMSA may result in a reduced enkephalinergic tone, which is then accompanied by an altered endocrine status.

Neuropeptides and other secretagogues in bovine chromaffin cells: their effect on opioid peptide metabolism

Bovine adrenal medullary cells released significant amounts of opioid pentapeptides (Methionine- and Leucine-enkephalin), when stimulated with neuropeptides like angiotensin II (AT), bradykinin (BK) or neurotensin (NT). Dose-response curves for angiotensin II and bradykinin were shown to be double-sigmoidal, with the first EC50 in the nM range; much lower than that for acetylcholine, nicotine or histamine. Secretory effects were dependent on extracellular CA++ and impaired by the Ca++ channel blockers D600. Moreover, these peptides produced an increase in opioid peptide cell content after 48 h of incubation, as did nicotine-, histamine- and K+ treated cells. The compound's capacity to induce long-term Met-enk secretion was similar to their efficacy in raising intracellular opioid peptide levels, suggesting compensatory increases. Besides affecting opioid peptide metabolism, AT, BK and NT produced a significant accumulation of inositol-1-phosphates (IP1), the role of which remains to be clarified. The physiological significance of vasoactive compounds in the adrenal medulla will be discussed.

Neurotensin affects metabolism of opioid peptides, catecholamines and inositol phospholipids in bovine chromaffin cells

Bovine adrenal medullary cells released significant amounts of opioid pentapeptides Met- and Leu-enkephalin and catecholamines, when stimulated by neurotensin (NT). Maximal release induced by this peptide was about 40-50% of that seen after nicotinic activation of cholinergic receptors. Dose-response curves for neurotensin-induced secretion revealed an EC50 of 1x10(-6)M, thereby being in the range of that for acetylcholine or nicotine. Secretory effects were dependent on extracellular Ca++ and impaired by the Ca++ channel blocker D 600. Moreover NT produced an increase in opioid peptide cell content after 48 and 72 hrs of incubation. Besides affecting opioid peptide metabolism, NT significantly produced accumulation of inositol- 1-phosphates (IP1), the significance of which remains to be clarified in the observed metabolic effects.

H1-histaminergic activation of catecholamine release by chromaffin cells

Bovine adrenal medullary chromaffin cells, prelabeled with [3H]norepinephrine, released a large proportion of cellular 3H-labeled catecholamines (CAs) when stimulated with nicotine, K+, histamine, gamma-aminobutyric acid (GABA) and several peptidic hormones [bradykinin, angiotensin II, thyrotropin releasing hormone (TRH) and neurotensin]. The histamine-induced response was dose dependent and occurred through H1 histaminergic receptors. Quantitatively and temporally the histamine- and nicotine-induced responses differed. Nicotine, during the first minutes, induced a large increase of [3H]CAs, but this response was desensitized rapidly. In contrast, histamine initially provoked a smaller release of [3H]CAs than nicotine but, with prolonged exposure (hours), a much greater response was found with histamine. Moreover, little desensitization was observed with histamine even during extended stimulation. External Ca2+ was obligatory for the histamine response, and both inorganic (Co2+ and Ni2+) and organic (verapamil, nifedipine and D-600) Ca2+ channel blockers significantly reduced release of [3H]CAs. These studies suggest that histamine as well as certain other neuroactive substances could play an important role in the physiology and biochemistry of adrenal medullary chromaffin cells.

Histamine affects release and biosynthesis of opioid peptides primarily via H1-receptors in bovine chromaffin cells

Histamine is a potent secretagogue for opioid pentapeptides (Met- and Leu-enkephalin) in adrenal chromaffin cells in vitro. This effect is dependent on extracellular Ca2+ and is reduced by Ca2+ channel blockers such as Co2+, D 600, and nifedipine. Moreover, histamine also produced a profound compensatory increase in cellular peptide content after 48 h of exposure, most likely caused by a four- to fivefold increase in the mRNA levels coding for the proenkephalin A precursor. All the histamine-induced effects (acute release, changes in peptide cell content, proenkephalin A mRNA levels) are antagonized by the H1-receptor antagonist, clemastine, whereas the H2-receptor antagonists, ranitidine and cimetidine, were less effective (approximately 20% inhibition).

Inhibition of nicotine-induced secretion from bovine chromaffin cells by the amidated C-terminal sequence of the opioid peptide amidorphin

The nicotine-induced release of catecholamines and opioid peptides from bovine chromaffin cells is inhibited by the amidated opioid peptide amidorphin. The active site of this inhibitory activity is located at the peptide's C-Terminus, which is, in contrast to the N-terminal sequence TYR-GLY-GLY-PHE, not responsible for the opioidergic activity of opioid peptides. The noradrenaline-secretion induced by histamine, a non-cholinergic secretagogue, has not been inhibited by amidorphin.

H1-histaminergic activation stimulates inositol-1-phosphate accumulation in chromaffin cells

Adrenal medullary chromaffin cells maintained in vitro were prelabeled with [3H]inositol and the accumulation of [3H]inositol-1-phosphate, was determined following stimulation with a variety of pharmacological agents. Carbachol, bradykinin, and histamine produced significantly greater accumulation of [3H] inositol-1-phosphate over basal levels, with histamine producing the greatest effect. H1-histamine receptor antagonists, mepyramine, pyrilamine, tripelennamine and clemastine were all able to reduce or completely block the histamine response. The two specific H2-histamine receptor antagonists, cimetidine and ranitidine, had no effect on this response. Histamine dose-response characteristics in the presence of mepyramine and clemastine suggest the H1 antagonism to be competitive in nature.