Multimodality local ablative therapy of 23 lung metastases with surgical resection and percutaneous cryoablation in a patient with Li-Fraumeni Syndrome: A case report

Patients with Li-Fraumeni syndrome (LFS) are prone to develop a variety of malignancies due to insufficient activity of the encoded tumor suppressor protein P53, including adrenocortical carcinoma, breast cancer, lung cancer, pancreatic cancer, and sarcoma. In the setting of LFS, local treatment options for lung metastases are limited to surgery and thermal ablation since radiotherapy and some systemic therapies predispose patients to additional future malignancies. We present the case of a 45-year-old woman with LFS with leiomyosarcoma metastases to both lungs who underwent bilateral wedge resections to treat a total of eight lung metastases followed by six percutaneous cryoablation sessions to treat 15 additional lung metastases over a period of 24 months. Our case demonstrates the option of multimodal local ablative therapies for lung metastases in patients with LFS, including percutaneous cryoablation.

Evaluation of Five Commercial SARS-CoV-2 Antigen Tests in a Clinical Setting

BACKGROUND

Point-of-care antigen tests (AgTs) for the detection of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) enable the rapid testing of infected individuals and are easy-to-use. However, there are few studies evaluating their clinical use.

OBJECTIVE

The present study aimed to evaluate and compare the clinical performance characteristics of various commercial SARS-CoV-2 AgTs.

DESIGN

The sensitivity of five AgTs, comprising four rapid antigen tests (RAT; AMP Rapid Test SARS-CoV-2 Ag, NADAL COVID-19 Antigen Rapid Test, CLINITEST Rapid COVID-19 Antigen Test, and Roche SARS-CoV-2 Rapid Antigen Test) and one sandwich chemiluminescence immunoassay (CLIA; LIAISON SARS-CoV-2 Assay), were evaluated in 300 nasopharyngeal (NP) swabs. Reverse transcriptase (RT) polymerase chain reaction (PCR) was used as a reference method.

PARTICIPANTS

NP swabs were collected from patients admitted to hospital due to COVID-19.

KEY RESULTS

Sensitivities of the AgTs ranged from 64.9 to 91.7% for samples with RT-PCR cycle threshold (Ct) values lower than 30 and were 100% for cycle threshold (Ct) values lower than 20. The highest sensitivity was observed for CLINITEST Rapid COVID-19 Antigen Test, and Roche SARS-CoV-2 rapid antigen test. Multivariate analysis using time from symptom onset and the Ct value for AgT sensitivity showed an inverse correlation. Further, the female sex was an independent factor of lower RAT sensitivity.

CONCLUSIONS

Antigen tests from NP swab samples show high sensitivity in patients with a Ct value < 20. The best clinical sensitivity can be obtained using AgTs within the first 6 days after symptom onset.

A Rapid, Highly Sensitive and Open-Access SARS-CoV-2 Detection Assay for Laboratory and Home Testing

RT-qPCR-based diagnostic tests play important roles in combating virus-caused pandemics such as Covid-19. However, their dependence on sophisticated equipment and the associated costs often limits their widespread use. Loop-mediated isothermal amplification after reverse transcription (RT-LAMP) is an alternative nucleic acid detection method that overcomes these limitations. Here, we present a rapid, robust, and sensitive RT-LAMP-based SARS-CoV-2 detection assay. Our 40-min procedure bypasses the RNA isolation step, is insensitive to carryover contamination, and uses a colorimetric readout that enables robust SARS-CoV-2 detection from various sample types. Based on this assay, we have increased sensitivity and scalability by adding a nucleic acid enrichment step (Bead-LAMP), developed a version for home testing (HomeDip-LAMP), and identified open-source RT-LAMP enzymes that can be produced in any molecular biology laboratory. On a dedicated website, rtlamp.org (DOI: 10.5281/zenodo.6033689), we provide detailed protocols and videos. Our optimized, general-purpose RT-LAMP assay is an important step toward population-scale SARS-CoV-2 testing.

Immunological Aspects of AXL/GAS-6 in the Context of Human Liver Regeneration

AXL and its corresponding ligand growth arrest-specific 6 (GAS-6) are critically involved in hepatic immunomodulation and regenerative processes. Pleiotropic inhibitory effects on innate inflammatory responses might essentially involve the shift of macrophage phenotype from a pro-inflammatory M1 to an anti-inflammatory M2. We aimed to assess the relevance of the AXL/GAS-6-pathway in human liver regeneration and, consequently, its association with clinical outcome after hepatic resection. Soluble AXL (sAXL) and GAS-6 levels were analyzed at preoperative and postoperative stages in 154 patients undergoing partial hepatectomy and correlated with clinical outcome. Perioperative dynamics of interleukin (IL)-6, soluble tyrosine-protein kinase MER (sMerTK), soluble CD163 (sCD163), and cytokeratin (CK) 18 were assessed to reflect pathophysiological processes. Preoperatively elevated sAXL and GAS-6 levels predicted postoperative liver dysfunction (area under the curve = 0.721 and 0.722; P < 0.005) and worse clinical outcome. These patients failed to respond with an immediate increase of sAXL and GAS-6 upon induction of liver regeneration. Abolished AXL pathway response resulted in a restricted increase of sCD163, suggesting a disrupted phenotypical switch to regeneratory M2 macrophages. No association with sMerTK was observed. Concomitantly, a distinct association of IL-6 levels with an absent increase of AXL/GAS-6 signaling indicated pronounced postoperative inflammation. This was further supported by increased intrahepatic secondary necrosis as reflected by CK18M65. sAXL and GAS-6 represent not only potent and easily accessible preoperative biomarkers for the postoperative outcome but also AXL/GAS-6 signaling might be of critical relevance in human liver regeneration. Refractory AXL/GAS-6 signaling, due to chronic overactivation/stimulation in the context of underlying liver disease, appears to abolish their immediate release following induction of liver regeneration, causing overwhelming immune activation, presumably via intrahepatic immune regulation.

Multiplexed detection of SARS-CoV-2 and other respiratory infections in high throughput by SARSeq

The COVID-19 pandemic has demonstrated the need for massively-parallel, cost-effective tests monitoring viral spread. Here we present SARSeq, saliva analysis by RNA sequencing, a method to detect SARS-CoV-2 and other respiratory viruses on tens of thousands of samples in parallel. SARSeq relies on next generation sequencing of multiple amplicons generated in a multiplexed RT-PCR reaction. Two-dimensional, unique dual indexing, using four indices per sample, enables unambiguous and scalable assignment of reads to individual samples. We calibrate SARSeq on SARS-CoV-2 synthetic RNA, virions, and hundreds of human samples of various types. Robustness and sensitivity were virtually identical to quantitative RT-PCR. Double-blinded benchmarking to gold standard quantitative-RT-PCR performed by human diagnostics laboratories confirms this high sensitivity. SARSeq can be used to detect Influenza A and B viruses and human rhinovirus in parallel, and can be expanded for detection of other pathogens. Thus, SARSeq is ideally suited for differential diagnostic of infections during a pandemic.

Massively parallel but cost-effective testing is essential to monitor the spread of pathogenic agents. Here the authors present SARSseq, which uses a dual indexing strategy in a multiplexed RT-PCR reaction to diagnose SARS-CoV-2 at scale.

Low SARS-CoV-2 seroprevalence in the Austrian capital after an early governmental lockdown

We analyzed SARS-CoV-2 seroprevalence in a large, well-described representative Viennese cohort after an early governmental lockdown with respect to the occurrence of symptoms and household transmission. Participants of the LEAD Study, a population-based cohort study from Vienna, Austria, were invited along with their household members (April 20th to May20th 2020). Sera were analyzed using anti-SARS-CoV-2 immunoassay including a neutralization test as a confirmatory assay. A total of 12,419 individuals participated (5984 LEAD participants; 6435 household members), 163 (1.31%; 59 LEAD cohort members) of whom were SARS-CoV-2 antibody positive. The estimated number of COVID-19 cases projected from our findings by age and sex for Vienna was 21,504 (1.13%). Cumulative number of positively tested cases in Vienna until May 20th 2020 was 3020, hence 7.1 times (95% confidence interval 5.5-9.1) lower than projected. Relative risk (RR) of seropositivity by age was highest for children aged 6-9 years [RR compared to age group 20-49: 1.21 (CI 0.37-4.01)], lowest for ≥ 65 years [RR 0.47 (CI 0.21-1.03)]. Half of the positive individuals developed no or mild symptoms. In a multivariate analysis, taste and smell disturbances were most strongly related to SARS-CoV-2 positivity. Infection probability within households with one confirmed SARS-CoV-2-specific antibody-positive person was 31%. Although seroprevalence was very low (1.13%) for a central European capital city, due to an early governmental lockdown, SARS-CoV-2 infections were more prevalent than officially reported polymerase chain reaction-positive cases. Of note, seroprevalence was highest in young children. Half of SARS-CoV-2 antibody-positive subjects had no or only mild symptoms. Taste and smell disturbances were most prominent, possibly guiding clinicians in diagnosing SARS-CoV-2 infection.

Impact of HFE gene variants on iron overload, overall survival and leukemia-free survival in myelodysplastic syndromes

Although iron overload is a clinical challenge, little is known about the clinical impact of HFE-variants in myelodysplastic syndromes (MDS) to date. We analyzed the HFE status in 167 MDS patients and 494 healthy controls. One or more of the 3 HFE-variants (H63D, C282Y, S65C) were found in 65/167 (38.9%) MDS patients and in 164/494 (33.2%) controls. At diagnosis, the median serum ferritin levels were higher in MDS patients with HFE-variants (409 µg/L; range: 23-7415) compared to those without HFE-variants (346.5 µg/L; range: 10-5450) (P=0.62). Moreover, 'HFE-mutated' patients had a slightly faster increase in serum ferritin in follow up examinations. The percentage of patients with HFE-variants was higher in refractory anemia (RA) (22/53=41.5%) or RA with ring sideroblasts (RARS) (17/39=43.6%) compared to RA with excess of blasts (RAEB) (16/46=34.8%) or RAEB in transformation (RAEB-T) (5/17=29.4%). Differences were also detectable when comparing low- and high-risk MDS variants defined by the World Health Organization classification. There was no significant correlation between HFE-variants and MDS-related somatic mutations. Progression-free survival was substantially longer in patients with HFE-variants compared to those without HFE-variants H63D and C282Y (P=0.089). Together, the HFE-variants H63D and C282Y are frequently detected in Austrian MDS patients. These patients have substantially higher ferritin levels at diagnosis, accumulate iron slightly faster and have a better progression-free survival than non-mutated patients.

Dynamics of CD4 T Cell and Antibody Responses in COVID-19 Patients With Different Disease Severity

Disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ranges from mild illness to severe respiratory disease and death. In this study, we determined the kinetics of viral loads, antibody responses (IgM, IgG, neutralization) and SARS-CoV-2-specific CD4 T cells by quantifying these parameters in 435 serial respiratory and blood samples collected from a cohort of 29 COVID-19 patients with either moderate or severe disease during the whole period of hospitalization or until death. Remarkably, there was no significant difference in the kinetics and plateau levels of neutralizing antibodies among the groups with different disease severity. In contrast, the dynamics of specific CD4 T cell responses differed considerably, but all patients with moderate or severe disease developed robust SARS-CoV-2-specific responses. Of note, none of the patients had detectable cross-reactive CD4 T cells in the first week after symptom onset, which have been described in 20–50% of unexposed individuals. Our data thus provide novel insights into the kinetics of antibody and CD4 T cell responses as well as viral loads that are key to understanding the role of adaptive immunity in combating the virus during acute infection and provide leads for the timing of immune therapies for COVID-19.

The Effect of ABCB1 Polymorphisms on Serial Tacrolimus Concentrations in Stable Austrian Long-Term Kidney Transplant Recipients

BACKGROUND

The multidrug resistance 1 gene (ABCB1) encodes P-glycoprotein (PGP), mainly expressed in the liver and engaged in metabolism of drugs including the immunosuppressant tacrolimus (TAC). ABCB1 single nucleotide polymorphisms (SNP) may significantly alter pharmacokinetics and influence TAC concentrations of kidney transplant recipients (KTR).

METHODS

The genotype distribution of ABCB1 1236C>T, 2677G>T/A and 3435C>T was investigated among 96 Austrian KTR who were converted from cyclosporin to TAC. Dose adjusted TAC trough levels and L/D ratios were assessed at week 1, 2, 4, and 8, and month 3, 12, and 24, and the influence of ABCB1 genotypes on dose adjusted TAC trough levels and level to dose (L/D) ratios were analyzed.

RESULTS

The genotype distributions for ABCB1 1236C>T were CC 36.4%, CT 5.2%, TT 58.3%, for ABCB1 2677G>T/A GA 2%, GG 63.5%, GT 20.8%, TA 1%, TT 12.5%, and for ABCB1 3435C>T CC 20.8%, CT 7.2%, TT 71.8%. Dose adjusted TAC trough levels and L/D ratios were independent of ABCB1 genotypes except for ABCB1 1236C>T at a single time point (week 2: 0.02599 [CC] vs. 0.05704 [CT] vs. 0.03218 [TT]; p = 0.024).

CONCLUSIONS

Serial analyses of TAC trough levels revealed no significant association with important ABCB1 genotypes among stable long-term Austrian KTR.

Subclinical hypothyroidism and mortality in a large Austrian cohort: a possible impact on treatment?

BACKGROUND

Clinical implications of subclinical hypothyroidism (SCH) are still matter of intense debate, resulting in the controversial discussion whether subclinical hypothyroidism should be treated. We performed a cohort study to evaluate the impact of subclinical hypothyroidism on vascular and overall mortality.

METHODS

Between 02/1993 and 03/2004, a total of 103,135 persons attending the General Hospital Vienna with baseline serum thyrotropin (TSH, thyroid-stimulating hormone) and free thyroxin (fT4) measurements could be enrolled in a retrospective cohort study. Subclinical hypothyroidism was defined by elevated TSH ranging from 4.5 to 20.0 mIU/L and normal fT4 concentration (0.7-1.7 ng/dL). Overall and vascular mortality as primary endpoints were assessed via record linkage with the Austrian Death Registry.

RESULTS

A total of 80,490 subjects fulfilled inclusion criteria of whom 3934 participants (3.7%) were classified as SCH (868 males and 3066 females, median age 48 years). The mean follow-up among the 80,490 subjects was 4.1 years yielding an observation period of 373,301 person-years at risk. In a multivariate Cox regression model adjusted for age and gender TSH levels showed a dose-dependent association with all-cause mortality. The association between SCH and overall or vascular mortality was stronger in men below 60 years compared to older males or females.

CONCLUSION

Our data support the hypothesis that SCH might represent an independent risk factor for overall and vascular mortality, especially in men below 60 years. Whether this group would benefit from replacement therapy should be evaluated in interventional studies.

Benefits and limitations of laboratory diagnostic pathways

Diagnostic pathways are an essential subset of clinical pathways and a logical consequence of DRG-based reimbursement. They combine the principle of stepwise reflex and reflective testing with a management concept that helps to fulfill medical needs with organizational and economic efficacy. The two most common formats describing diagnostic pathways are graphical decision trees on paper and "if…then…else" rules on computers. From a laboratory point of view, diagnostic pathways represent "smart" test profiles, which - in contrast to conventional (inflexible) profiles - are not necessarily worked off completely, but just to a point, where a diagnostic decision can be made. This improves the cost-effectiveness of laboratory testing, while making sure that no essential tests are missed. The paper describes benefits and limitations of diagnostic pathways from a medical, organizational, and economic point of view. Their major advantage is also their major drawback, since they make the diagnostic process on the one hand extremely straight-forward and transparent, while on the other hand oversimplifying the underlying medical decision principles. This may provoke the abuse of their primarily medical intentions for mere economic purposes.

High frequency of concomitant mastocytosis in patients with acute myeloid leukemia exhibiting the transforming KIT mutation D816V

The KIT mutation D816V is associated with autonomous growth of mast cells (MC) and is detectable in most patients with systemic mastocytosis (SM), including cases with associated hematologic non-MC-lineage disease (AHNMD). Recently, KIT D816V was reported to be expressed in patients with acute myeloid leukemia (AML). However, it was not clarified whether these patients have co-existing occult SM. We investigated neoplastic cells in 101 patients with AML for expression of KIT D816V. In 7/101 patients (6.9%), KIT D816V was detectable. After a thorough histologic, molecular, and biochemical analysis, all 7 cases were found to have an associated SM, leading to the final diagnosis SM-AML. Microdissected tryptase+ MC displayed KIT D816V in all patients tested, whereas CD34+ blasts exhibited KIT D816V in only 2/4 patients. In one AML patient, SM without KIT D816V was detected. In all other patients, no associated SM was found, and leukemic blasts were negative for KIT D816V. In summary, our data show that KIT D816V in AML is highly associated with co-existing SM (SM-AML). Moreover, our data show that AML blasts may lack this transforming target-mutant, which may be important when considering the use of KIT D816V-targeting drugs for treatment of patients with KIT D816V-positive AML.

[Stroke in cancer patients. A paraneoplastic neurological syndrome?]

The coincidence of stroke and cancer is frequently encountered. From recent epidemiological data, the stroke risk in cancer patients seems to be equally distributed as compared to the non-cancer population. However, there are several clinical conditions in cancer patients which increase the risk for stroke: Trousseau's syndrome, non-bacterial thrombotic endocarditis and disseminated intravascular coagulation. Also some tumour-specific conditions such as coagulopathies, changes of viscosity and cellular mechanisms such as leukocytosis or thrombocytopathies must be considered. In several types of tumour treatment, such as various anticancer drugs, an increased occurrence of stroke has been reported. Presently there is no indication that stroke and cancer are related to the immune-mediated "classic" paraneoplastic syndromes. However, there are several cancer-specific types and causes of stroke which need to be considered in each patient, as they can be of significance in the treatment.

Duplications of the functional CYP21A2 gene are primarily restricted to Q318X alleles: evidence for a founder effect

CONTEXT

Rare haplotypes with Q318X mutations and duplicated CYP21A2 genes have been reported to occur in different populations to a varying extent. Discrimination between a normal (Q318X mutation on one of the duplicated CYP21A2 genes) and a congenital adrenal hyperplasia (CAH, Q318X mutation without duplicated functional gene) allele is of importance, particularly for prenatal diagnosis and the respective genetic counseling. Although methods to differentiate between such alleles have been published only recently, it remains unclear with which frequency Q318X mutations are associated with duplicated CYP21A2 genes and whether these haplotypes have a common ancestry.

SUBJECTS AND METHODS

Human leukocyte antigen (HLA) typing has been performed in 38 unrelated individuals and in 11 family members detected to carry a Q318X mutation in the course of CYP21 genotyping using sequence, multiplex ligation-dependent probe amplification, and Southern blot analyses.

RESULTS

The majority (n = 32, 84.2%) of the 38 unrelated individuals carrying the Q318X mutation had the trimodular RCCX haplotype, carrying the Q318X mutation on a duplicated CYP21A2 gene. Twenty-two individuals of these 32 (68.8%) were of the rare HLA-B*50-Cw*06 haplotype, suggesting a common ancestry of this haplotype. In five (13.2%) of the 38 subjects, the Q318X mutation was not associated with a duplicated CYP21A2 gene and thus represents a CAH allele. None of these five patients had the above mentioned HLA haplotype.

CONCLUSION

The majority of individuals in whom Q318X mutations are detected carry a duplicated functional CYP21A2 gene and the rare HLA-B*50-Cw*06 haplotype.

Splenic Mastocytosis: Report of Two Cases and Detection of the Transforming SomaticC-KITMutation D816V

In the vast majority of patients with systemic mastocytosis (SM), the bone marrow is the primary extracutaneous site of disease. In addition to bone marrow involvement, other visceral organs such as the spleen, liver or the gastrointestinal tract, may also be affected. However, isolated involvement of a single extramedullary organ is rarely seen in SM. We report on two patients with SM with splenic involvement, lack of 'diagnostic' mast cell (MC) infiltrates in the bone marrow, and absence of skin lesions. In one patient, a myelodysplastic syndrome was diagnosed prior to the detection of SM. Both patients presented with massive splenomegaly and multifocal MC infiltrates in splenic tissues. These MCs also expressed CD25 as well as the C-KIT mutation D816V. In consecutive examinations, the mutation was also detected in the bone marrow in both patients suggesting diffuse infiltration with neoplastic cells. In summary, our data show that the spleen can be a primary site of disease in rare cases of SM. Mastocytosis should therefore be considered as a (rare) differential diagnosis in patients with splenomegaly of unknown etiology.

Anderson-Fabry disease: a case-finding study among male kidney transplant recipients in Austria

The diagnosis of Anderson-Fabry disease is often delayed or even missed. As severe renal manifestations are a hallmark of alfa-galactosidase A (AGAL) deficiency, we tested the hypothesis that Anderson-Fabry disease is under-recognized among male kidney transplant recipients. This nation-wide study in Austria enrolled 1306 patients (ca 65% of all kidney transplanted males) from 30 kidney centers. AGAL activity was determined from filter paper dried blood spots by a fluorescence assay. A positive screening test was defined by an AGAL activity below 1.5 nmol/h/ml. In patients with a positive blood spot-screening test, AGAL activity was re-examined in peripheral blood leukocytes. Genetic testing for mutations in the GLA gene was performed by sequencing to confirm the diagnosis of Anderson-Fabry disease. Two previously not recognized cases with Anderson-Fabry disease were identified. Our study is the first showing that a diagnosis of Anderson-Fabry disease can be missed even in patients who undergo kidney transplantation. Case-finding strategies may be considered a useful tool for diagnosis of this rare disease that may be somewhat more prevalent among kidney transplant recipients compared with dialysis populations.

Mixed-lineage eosinophil/basophil crisis in MDS: a rare form of progression

BACKGROUND

Basophilic crisis and eosinophilia are well recognized features of advanced chronic myeloid leukaemia. In other myeloid neoplasms, however, transformation with marked basophilia and eosinophilia is considered unusual.

DESIGN

We examined the long-term follow-up of 322 patients with de novo myelodysplastic syndromes (MDS) to define the frequency of basophilic, eosinophilic and mixed lineage (basophilic and eosinophilic) transformation.

RESULTS

Of all patients, only one developed mixed lineage crisis (>or= 20% basophils and >or= 20% eosinophils). In this patient, who initially suffered from chronic myelomonocytic leukaemia, basophils increased to 48% and eosinophils up to 31% at the time of progression. Mixed lineage crisis was not accompanied by an increase in blast cells or organomegaly. The presence of BCR/ABL and other relevant fusion gene products (FIP1L1/PDGFRA, AML1/ETO, PML/RAR alpha, CBF beta/MYH11) were excluded by PCR. Myelomastocytic transformation/myelomastocytic leukaemia and primary mast cell disease were excluded by histology, KIT mutation analysis, electron microscopy and immunophenotyping. Basophils were thus found to be CD123+, CD203c+, BB1+, KIT- cells, and to express a functional IgE-receptor. Among the other patients with MDS examined, 4(1.2%) were found to have marked basophilia (>or= 20%) and 7(2.1%) were found to have massive eosinophilia ( >or= 20%), whereas mixed-lineage crisis was detected in none of them.

CONCLUSIONS

Mixed basophil/eosinophil crisis may develop in patients with MDS but is an extremely rare event.

Immunohistochemical assessment of CD25 is equally sensitive and diagnostic in mastocytosis compared to flow cytometry

BACKGROUND

Systemic mastocytosis (SM) is a clonal myeloid disorder characterized by abnormal accumulation and growth of mast cells (MC) in internal organs. In most cases, the bone marrow is involved. Expression of CD25 in bone marrow MC, with or without coexpression of CD2, is an important minor SM criterion. So far, most studies have examined CD25-expression on MC by flow cytometry.

MATERIALS AND METHODS

We examined the expression of CD25 in MC in patients with SM (n = 25) by immunohistochemistry (IHC) and compared these data with results obtained by flow cytometric assessment of CD25-expression. In addition, we compared CD25-staining results with that obtained with an antibody against CD2.

RESULTS

In a majority of all patients (> 80%), CD25 was detectable by both staining techniques. However, in one patient, CD25 was only detectable on MC by IHC, but not by flow cytometry, and in two patients in whom IHC could not be applied because of lack of compact MC infiltrates, flow cytometry revealed aberrant expression of CD25. The antibody against CD2 produced diagnostic staining results in a smaller group of patients (flow cytometry: 65%; IHC: 28% of SM cases) compared to CD25 (> 80%).

CONCLUSIONS

CD25-IHC is equally diagnostic and sensitive in SM compared to flow cytometry and thus can be recommended as a diagnostic test. Our data also suggest that the diagnostic value of CD25 exceeds that of CD2, and that optimal assessment of CD25-expression in neoplastic MC in all patients requires the application of both techniques, flow cytometry and IHC.

Total homocysteine, B-vitamins and genetic polymorphisms in patients with classical phenylketonuria

Hyperhomocysteinemia has occasionally been reported in patients with phenylketonuria (PKU) and B-vitamin deficiency. In our study total homocysteine (tHcy) and B-vitamins were measured in treated PKU patients and healthy controls. In the patients, dietary parameters and genetic polymorphisms affecting the Hcy pathway were investigated to identify parameters modulating tHcy. A case control study including 37 PKU patients and 63 healthy controls was conducted. t-Tests for independent samples were used to test between groups. Multiple regressions with tHcy as dependent variable were calculated. Hardy-Weinberg expectations were tested against the observed distribution of genotypes applying the Chi-square goodness-of-fit method. THcy concentrations were not significantly different (p=0.059) while folate and cobalamin (Cbl) concentrations were significantly higher in PKU patients compared to controls. However, 29.7% of patients had tHcy concentrations >97th centile. THcy did not vary with age nor correlate with folate and Cbl concentrations probably due to high saturatory levels. The presence of genetic polymorphisms had no impact on tHcy. In conclusion, in PKU patients treated with amino acid mixtures enriched with B-vitamins, tHcy is not significantly higher than in healthy controls, but tHcy concentrations exceed the 97th centile in about one third of patients. Even higher B-vitamin saturation may be required to further decrease tHcy concentrations and factors generally influencing tHcy such as betaine are to be investigated in PKU patients in the future.

Low-turnover bone disease in hypercalcemic hyperparathyroidism after kidney transplantation

Hypercalcemia in persistent secondary hyperparathyroidism after kidney transplantation is considered to result from increased bone resorption. Bone biopsies' studies, however, have never been performed in these patients. Bone biopsies after double tetracycline labeling were obtained from 17 patients with hypercalcemic hyperparathyroidism and an estimated glomerular filtration rate > 30 mL/min/1.73 m2. Serologic bone markers, calcitriol, intact fibroblast growth factor-23 (iFGF-23), and serum and 24h urine concentration of calcium and phosphate were measured in all patients. Tubular maximum for phosphate corrected for GFR (TmP/GFR), and the fractional excretion of calcium (FeCa) were calculated. High-turnover renal osteodystrophy (ROD) was present in nine and low-turnover ROD in eight patients. The bone formation rate was significantly associated with bone alkaline phosphatase, c-telopeptide and osteocalcin. In patients with high turnover ROD, osteocalcin was also significantly higher than in patients with decreased bone formation. The FeCa was normal or below normal in 14/17 patients. TmP/GFR was below normal in all patients. Neither intact PTH nor iFGF-23 was associated with TmP/GFR, FeCa or any histomorphometric bone parameter. We conclude that hypercalcemia of posttransplant hyperparathyroidism can be associated with high or low turnover bone disease. Decreased calcium excretion suggests an additive tubular effect on hypercalcemia.

No associations between prolactin concentrations and response to erythropoiesis-stimulating agents in hemodialysis patients

BACKGROUND

The effect of serum prolactin levels on the response to erythropoiesis-stimulating agents (ESA) in patients on chronic hemodialysis is unknown.

METHODS

We included 111 stable hemodialysis patients in this study and examined the association of serum prolactin concentrations with the response to ESA. Accordingly we implemented an ESA index as a measure of therapeutic efficacy. The two outcomes of this cohort study were the association of prolactin concentrations with response to ESA, both at baseline (cross-sectional component) and after 1-year of follow-up (prospective component), and the presence of macroprolactin.

RESULTS

Two male patients, but none of the female patients, had serum prolactin concentrations within the reference range. Following precipitation with polyethylene glycol (PEG), 17 males (25.4%) and 9 females (20.6%) had serum prolactin concentrations within the reference range. Females had somewhat higher levels than males: 39.8 (IQR 32.3-64.5) versus 27.8 (IQR 23.4-47.8) ng/ml (p = 0.003). The ratio of prolactin(PEG)/prolactin(Native) was greater than 0.60 in 103 patients (92.8%), thus excluding significant amounts of macroprolactin. From uni- and multivariate analyses we did not find associations of serum prolactin concentrations with a response to ESA either at baseline or at follow-up.

CONCLUSIONS

From this prospective study we provide evidence that elevated serum prolactin levels are not related to the presence of macroprolactin in chronic hemodialysis patients. Furthermore, serum prolactin concentrations are not associated with the response to erythropoietic therapy in these individuals.

Standards and standardization in mastocytosis: consensus statements on diagnostics, treatment recommendations and response criteria

Although a classification for mastocytosis and diagnostic criteria are available, there remains a need to define standards for the application of diagnostic tests, clinical evaluations, and treatment responses. To address these demands, leading experts discussed current issues and standards in mastocytosis in a Working Conference. The present article provides the resulting outcome with consensus statements, which focus on the appropriate application of clinical and laboratory tests, patient selection for interventional therapy, and the selection of appropriate drugs. In addition, treatment response criteria for the various clinical conditions, disease-specific symptoms, and specific pathologies are provided. Resulting recommendations and algorithms should greatly facilitate the management of patients with mastocytosis in clinical practice, selection of patients for therapies, and the conduct of clinical trials.

Eosinophilia in systemic mastocytosis: clinical and molecular correlates and prognostic significance

BACKGROUND

In a group of patients with systemic mastocytosis (SM), marked and sustained eosinophilia is detectable (SM-eo).

OBJECTIVE

Although the molecular defect has been defined in some cases, little is known about the impact and clinical correlates of eosinophilia.

METHODS

In a cohort of 63 patients with SM, we identified 9 with permanent eosinophilia (>1500/microL). According to the World Health Organization classification, 2 had indolent SM, 1 had smoldering SM, 2 had SM with associated chronic eosinophilic leukemia (SM-CEL), and 4 had aggressive SM.

RESULTS

SM-eo was found to be associated with a significantly reduced probability of overall and event-free survival compared with SM without eosinophilia (P < .05). In the 2 patients with SM-CEL, a CHIC2 deletion was found. By contrast, no KIT mutation at codon 816 was detectable in these patients. In the other patients with SM-eo, KIT D816V was demonstrable. The 2 patients with SM-CEL had cardiomyopathy, whereas other organ systems remained largely unaffected. By contrast, in all other patients with SM-eo, organopathy, if recorded, affected the bone marrow, liver, or/and skeletal system, but not the heart, even when eosinophilia persisted for many years.

CONCLUSIONS

The biochemical basis of eosinophilia in SM is variable and predictive for the type of organopathy.

CLINICAL IMPLICATIONS

In SM eosinophilia is of prognostic significance but is not a final diagnosis and is not invariably associated with cardiomyopathy. The latter might be restricted to cases with an associated primary eosinophilic disorder (SM-CEL).

Prognostic associations of serum calcium, phosphate and calcium phosphate concentration product with outcomes in kidney transplant recipients

Disturbances in calcium and phosphate metabolism have been linked to increased mortality in hemodialysis patients, but not in kidney transplant recipients (KTR). We enrolled 733 KTR from the Vienna General Hospital into this study. Detailed demographic, clinical, laboratory, and transplant-related information was collected at baseline. We used the Austrian Dialysis and Transplantation Registry for follow-up. Using multivariate proportional hazard regression, we examined the independent associations between serum calcium, serum phosphate, and calcium phosphate (CaPO(4)) product with the outcomes of death from any cause and kidney allograft loss. Over a median follow-up of >6 years, 154 patients died and 259 kidney allografts were lost. Associations with serum calcium, phosphate concentrations, and CaPO(4) product concentrations were found for allograft loss, but not for patient mortality. Patients in the highest quintile of phosphate concentration and CaPO(4) product had an increased risk for allograft loss compared with patients in the lowest quintile of these parameters (hazards ratio, HR = 2.15; 95% confidence interval, CI: 1.36-3.40 and HR = 1.72; 95% CI: 1.10-2.71, respectively). High calcium levels were associated with a reduced risk for allograft loss. Results were even more pronounced for death-censored allograft loss. High concentrations of serum phosphate and CaPO(4) product were associated with an increased risk for allograft loss in these KTR, whereas high serum calcium concentrations seemed to lower the risk.

A J-shaped association between high-sensitivity C-reactive protein and mortality in kidney transplant recipients

In kidney transplant recipients (KTR), C-reactive protein (CRP) has been shown to be associated with increased mortality, but data on this association within the high-sensitivity (hs) range of CRP (<5 mg/l) are lacking. We prospectively studied 710 prevalent and stable KTR over >6 years. We thawed frozen plasma and measured baseline hs-CRP using an ultrasensitive assay. Detailed clinical and demographic baseline characteristics were available for study. We stratified patients by quartile of hs-CRP within the hs range (<5 mg/l), and also included KTRs whose hs-CRP was above the hs range (>5-10 and >10 mg/l). We used multivariate proportional hazards models to test for independent associations. After careful multivariate adjustment, we found a J-shaped association between hs-CRP and mortality. Compared with KTR whose hs-CRP was in the second lowest quartile of hs-CRP (0.06-1.26 mg/l), patients in the lowest quartile (<0.06 mg/l) had more than twice their mortality risk (HR = 2.07; 95% CI: 1.05-4.07), as did patients whose hs-CRP was > or =2.44 mg/l (all HRs >2.27). No association was found between hs-CRP and death-censored allograft loss. In contrast to the general population, the association between hs-CRP and mortality in KTRs is not linear, but J-shaped, suggesting that KTRs with very low hs-CRP may also be at increased risk of death.

A J-shaped association between high-sensitivity C-reactive protein and mortality in kidney transplant recipients

In kidney transplant recipients (KTR), C-reactive protein (CRP) has been shown to be associated with increased mortality, but data on this association within the high-sensitivity (hs) range of CRP (<5 mg/l) are lacking. We prospectively studied 710 prevalent and stable KTR over >6 years. We thawed frozen plasma and measured baseline hs-CRP using an ultrasensitive assay. Detailed clinical and demographic baseline characteristics were available for study. We stratified patients by quartile of hs-CRP within the hs range (<5 mg/l), and also included KTRs whose hs-CRP was above the hs range (>5-10 and >10 mg/l). We used multivariate proportional hazards models to test for independent associations. After careful multivariate adjustment, we found a J-shaped association between hs-CRP and mortality. Compared with KTR whose hs-CRP was in the second lowest quartile of hs-CRP (0.06-1.26 mg/l), patients in the lowest quartile (<0.06 mg/l) had more than twice their mortality risk (HR = 2.07; 95% CI: 1.05-4.07), as did patients whose hs-CRP was > or =2.44 mg/l (all HRs >2.27). No association was found between hs-CRP and death-censored allograft loss. In contrast to the general population, the association between hs-CRP and mortality in KTRs is not linear, but J-shaped, suggesting that KTRs with very low hs-CRP may also be at increased risk of death.

Photodegradation of folic acid during extracorporeal photopheresis

BACKGROUND

Photodegradation of folic acid (FA) by ultraviolet (UV) radiation is a well-documented photochemical reaction, and decreased serum levels of FA have been found in patients receiving photochemotherapy (psoralen plus UVA). During extracorporeal photopheresis (ECP) leucocytes and plasma are subjected to 8-methoxypsoralen (8-MOP) plus UVA.

OBJECTIVES

To investigate whether ECP leads to the photodegradation of FA in the extracorporeal system.

METHODS

In 30 patients undergoing ECP on two consecutive days the FA levels were measured in the extracorporeal collected plasma prior to and after UVA exposure. Healthy donor plasma was exposed to 8-MOP and increasing doses of UVA in vitro. In five patients serum folate levels were determined before and after ECP.

RESULTS

We found a mean reduction of 44% and 46% on the first and second day of treatment, respectively. This effect could be reproduced in vitro: the irradiation of healthy donor plasma with UVA led to a dose-dependent reduction of FA of up to 54.75% at 16 J cm(-2). This was independent of the presence of 8-MOP and the base concentration of 5-methyltetrahydrofolate; minimal changes were observed for vitamin B(12) and homocysteine, not undergoing photodegradation. Serum folate levels did not change significantly before and after ECP.

CONCLUSIONS

We conclude that extracorporeal exposure of plasma to UVA during ECP leads to photodegradation of FA. Further investigations are required to determine the biological effects of folate photoproducts and whether clinically relevant loss of FA might be a consequence of ECP.

Total homocysteine, folate, and cobalamin, and their relation to genetic polymorphisms, lifestyle and body mass index in healthy children and adolescents

We investigated total homocysteine (tHcy) concentrations and relations between tHcy and folate, cobalamin (Cbl), genetic polymorphisms (MTHFR 677C > T, MTHFR 1298A > C, MTHFR 1793G > A), blood pressure (BP), body mass index (BMI), cholesterol, triglycerides, sports activities, family and individual history of cardiovascular disease (CVD) and lifestyle issues in 264 healthy children and adolescents (2-17 y). THcy concentrations significantly increased while folate and Cbl decreased with age without gender differences. Age, folate and Cbl were significant predictors for tHcy concentrations. THcy was higher but within normal ranges in MTHFR 677TT homozygotes (10.6%) and carriers of the MTHFR 1793A allele (8%). Only two individuals (0.8%), both with low tHcy concentrations, were homozygous for MTHFR 1793AA. THcy concentration correlated positively with creatinine, triglycerides, BMI and systolic BP and was not related to cholesterol, sports activities and family history of CVD. In conclusion, tHcy concentrations in this pediatric population were significantly influenced by age, folate and Cbl concentrations. No gender differences for tHcy, folate or Cbl concentrations were observed. Both the MTHFR 677TT genotype and the MTHFR 1793A allele were not associated with hyperhomocysteinemia. The prevalence of the MTHFR 1793AA genotype was too low for meaningful interpretation.

Diagnostic and subdiagnostic accumulation of mast cells in the bone marrow of patients with anaphylaxis: Monoclonal mast cell activation syndrome

BACKGROUND

Patients with mastocytosis may suffer from severe hypotension after wasp or bee stings. In these patients, no specific IgE is detectable, but they usually have skin lesions and an elevated serum tryptase level.

METHODS

We report on 6 patients who were referred to our department because of severe hypotension following bee or wasp stings without cutaneous lesions.

RESULTS

In 3 patients, the baseline serum tryptase level was elevated (26, 36, and 67 ng/ml, respectively), and investigation of their bone marrow revealed systemic mastocytosis (SM). In the remaining 3 patients, serum tryptase levels were <20 ng/ml, and bone marrow histology and tryptase immunohistochemistry did not reveal diagnostic mast cell infiltrates. However, in 1 patient, three minor SM criteria were demonstrable leading to the diagnosis SM, and in the 2nd patient, two minor SM criteria, including an aberrant mast cell phenotype, were found. In the 3rd patient, no minor SM criteria were detected.

CONCLUSIONS

All patients with unexplained hypotension after hymenoptera stings should undergo a thorough investigation for major and minor SM criteria regardless of the tryptase level or presence of skin lesions, in order to diagnose or exclude SM or a related subdiagnostic condition (1 or 2 minor SM criteria) tentatively termed monoclonal mast cell activation syndrome.

Genetic aspects of hyperhomocysteinemia in chronic kidney disease

Patients with chronic kidney disease who are on dialysis or with a kidney transplant have higher total plasma homocysteine concentrations than individuals who are free from kidney disease. Several single-nucleotide polymorphisms of genes encoding enzymes that are involved in homocysteine metabolism have been studied in these patients. These polymorphisms are located in genes encoding of 5,10-methylenetetrahydrofolate reductase (MTHFR), methionine synthase reductase, methionine synthase, cystathionine beta-synthase, glutamate carboxy peptidase II, reduced folate carrier 1, and transcobalamin II. Among the single-nucleotide polymorphisms studied, only MTHFR 677C>T was associated consistently with total plasma homocysteine levels, but there currently is no evidence of any association between MTHFR 677C>T genotype and long-term outcomes.

Prognostic Associations Between Lipid Markers and Outcomes in Kidney Transplant Recipients

BACKGROUND

Hyperlipidemia is highly prevalent in kidney transplant recipients, but the prognostic significance for mortality and allograft survival in these patients has not been established sufficiently.

METHODS

We prospectively enrolled 733 kidney transplant recipients between 1996 and 1998. Clinical information was collected and blood was drawn for laboratory evaluation. Information on the previous transplantation procedures and organ donor were obtained from the Eurotransplant Foundation database. We used the Austrian Dialysis and Transplantation Registry for follow-up. Using multivariate proportional hazard regression, independent relations of fasting plasma triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol levels to risk for death from any cause and risk for kidney allograft loss were examined.

RESULTS

During a median follow-up of 6.1 years, 154 patients died and 260 kidney allografts were lost. After careful multivariate adjustment, there were no significant associations between TG and TC levels and patient mortality. Patients in the highest quartile of TG and TC levels had no difference in risks for mortality compared with patients in the lowest quartile of these parameters (hazards ratio, 0.81; 95% confidence interval, 0.51 to 1.28; hazards ratio, 0.68; 95% confidence interval, 0.42 to 1.10, respectively). Similarly, no associations were found with allograft loss. Further analysis of associations between high-density lipoprotein cholesterol or low-density lipoprotein cholesterol categories and patient mortality or kidney allograft loss did not show associations.

CONCLUSION

Elevated levels of TC or its subfractions and elevated TG levels are not associated with increased risk for patient mortality or allograft loss in these kidney transplant recipients.

Intravenous iron increases labile serum iron but does not impair forearm blood flow reactivity in dialysis patients

BACKGROUND

There are concerns about adverse vascular effects of intravenous iron by inducing oxidative stress. We therefore examined the effect of a single high dose of intravenous iron on endothelial function and biochemical markers of iron homeostasis.

METHODS

In a randomized, placebo-controlled, double-blind, parallel-group study, forearm blood flow (FBF) was assessed by strain-gauge plethysmography in 38 peritoneal dialysis patients before and after a single intravenous infusion of 300 mg iron sucrose.

RESULTS

Iron infusion increased total (Delta 601 microg/100 mL, CI 507, 696) and non-transferrin-bound iron (Delta 237.2 micromol/L, CI 173.6, 300.8) approximately 10-fold, as well as redox-active iron nearly five-fold (Delta 0.76 micromol/L, CI 0.54, 0.98). After iron infusion basal FBF was 59% higher than after placebo. FBF response to acetylcholine before and after iron infusion was 263 +/- 32% and 310 +/- 33%, corresponding to 304 +/- 43% and 373 +/- 29% in the placebo group, respectively. Before and after iron or placebo infusion, glyceryl-trinitrate increased resting FBF to 232 +/- 22% and 258 +/- 21% in the iron group, and to 234 +/- 18% and 270 +/- 30% in the placebo group. L-N-monomethyl-arginine decreased FBF to 70 +/- 4% and 72 +/- 3% before and after iron, and to 74 +/- 4% and 73 +/- 4% before and after placebo infusions, respectively. Despite higher basal FBF after iron infusion, absolute and relative FBF changes in response to vasoactive substances were not significantly different between iron and placebo groups.

CONCLUSION

Our data suggest that 300 mg intravenous iron sucrose has a vasodilatory effect, but does not impair vascular reactivity in dialysis patients, despite a significant increase in non-transferrin-bound and redox-active iron.

Endothelial Progenitor Cells in Kidney Transplant Recipients

BACKGROUND

Lower concentrations of endothelial progenitor cells (EPCs) may be associated with increased cardiovascular risk. EPC counts and their correlates have not yet been studied in kidney transplant recipients (KTR).

METHODS

We cross-sectionally studied EPC counts in 105 middle-aged KTR (mean estimated glomerular filtration rate 45.2 ml/min/1.73 m; range: 5.4 to 117.5). Using univariate and multivariate linear regression assuming a gamma distribution of the outcome, we examined the associations between counts of cultured EPCs and traditional cardiovascular disease risk factors (hypertension, diabetes, hyperlipidemia, smoking), kidney function, and immunosuppressive agents, amongst others.

RESULTS

The median count of cultured EPCs was 34 cells per high-power field (interquartile range: 19 to 64), comparable to healthy individuals. From multivariate analyses, we found independent inverse associations between counts of cultured EPCs and body mass index, mean arterial pressure, and history of cardiovascular disease. Statin use was associated with greater EPC counts, whereas patients receiving azathioprine or angiotensin II receptor treatment had lower EPC counts (all P<0.01).

CONCLUSIONS

This study suggests negative associations in KTR between EPC counts and body mass index, and blood pressure, whereas statin use was associated with greater EPC counts. These findings raise the hypothesis whether EPCs are responsible, at least in part, for the well established associations between these factors and cardiovascular outcomes in KTR.

Effects of single-nucleotide polymorphisms in MTHFR and MTRR on mortality and allograft loss in kidney transplant recipients

BACKGROUND

Plasma total homocysteine (tHcy) is associated with cardiovascular outcomes in kidney transplant recipients (KTR). The methylenetetrahydrofolate-reductase (MTHFR) 677C>T polymorphism, an important determinant of plasma tHcy concentrations, could therefore constitute an important prognostic marker.

METHODS

We prospectively followed 710 KTR over >6 years. The MTHFR677C>T, MTHFR1298A>C, MTHFR1793G>A, and MTRR66A>G polymorphisms were analyzed. Demographic, clinical, and transplant-related information was obtained, and patients were followed-up using the Austrian Dialysis and Transplant Registry. Using Cox regression, we established the independent relations of each genotype to the risk of death from any cause, and/or kidney allograft loss.

RESULTS

During a median follow-up of 6.1 years, 154 participants died and 260 kidney allografts were lost. Compared to patients with the MTHFR677CC genotype, patients with MTHFR677CT had an adjusted relative mortality risk of 1.02 (95%CI 0.70-1.47), and those with MTHFR677TT of 0.98 (95%CI 0.52-1.85). Compared to MTHFR677CC, the relative risks of kidney allograft loss were 0.93 (95%CI 0.70-1.23; MTHFR677CT) and 0.78 (95%CI 0.47-1.30; MTHFR677TT), respectively. None of the other genotypes were associated with the risks studied, either. These findings did not depend on whether we controlled for tHcy levels.

CONCLUSION

This study does not support the routine use of MTHFR or MTRR genotyping for prognostic evaluation or risk-stratification in kidney transplant recipients.

The European Competence Network on Mastocytosis (ECNM)

The European Competence Network on Mastocytosis (ECNM) is a Europe-wide, multinational cooperative approach attempting to improve recognition, diagnosis, and therapy of mastocytosis. The network is composed of local centers, physicians, and scientists who have dedicated their work to patients with mastocytosis. However, because of the rarity and complexity of the disease, each single component in the network alone would fail to meet important demands and to reach solid conclusions in this field of applied medicine. The ECNM represents an attempt to overcome this restriction as a cooperative multicenter platform that should serve as an important basis for the development of new therapeutic strategies and diagnostic concepts, and for the standardization of techniques used to determine diagnostic and prognostic parameters. Moreover, using future central databases and registries, a suitable infrastructure for the development of co-operative multicenter clinical trials will be established. In addition, the ECNM is dedicated to provide the best available information about the disease to patients and physicians.

Methylenetetrahydrofolate reductase gene polymorphisms in essential hypertension relation: with the development of hypertensive end-stage renal disease

BACKGROUND

The pathogenesis of hypertensive nephropathy is multifactoral and in addition to BP, other factors contribute to the development of this renal pathology and its progression to end-stage renal disease. These include genetic predisposition and increased pleasure level of homocysteine-intermediate protein catabolism product known to induce kidney injury. The 677C --> T polymorphism in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene is associated with elevated homocysteine level in the general population, and therefore it has been hypothesized to be a risk factor for the development of renal failure in the course of essential hypertension.

METHODS

In this case-control, cross-sectional study the frequency of the MTHFR 677C --> T and the 1298A --> C polymorphism was compared between patients with hypertension-related chronic renal failure (n = 90), patients with essential hypertension without kidney injury (n = 90), and healthy individuals (n = 90) who were matched for age and gender. In addition, the influence of these polymorphisms on homocysteine concentration in individuals with essential hypertension was examined.

RESULTS

The frequency of the MTHFR 677 TT genotype did not differ between groups (4.5%, 12.3%, and 11.1%, respectively). Patients with hypertension and the 677TT genotype showed significantly higher homocysteine levels as compared to individuals having CC and CT. In the multivariate correlation analysis the MTHFR 677TT genotype (P < .01; beta = 0.27), age (P < .001; beta = 0.33), and body mass index (P < .01; beta = 0.3) were independent predictors for total homocysteine level.

CONCLUSIONS

Plasma homocysteine levels in individuals with essential hypertension is affected by the MTHFR 677C --> T polymorphism. However, we did not prove the hypothesis that MTHFR 677C --> T influences the risk of development of renal failure in the course of hypertension.

Delineation of patterns of bone marrow mast cell infiltration in systemic mastocytosis: value of CD25, correlation with subvariants of the disease, and separation from mast cell hyperplasia

In most cases, the diagnosis of systemic mastocytosis (SM) is based on histomorphologic evaluation of the bone marrow. We analyzed mast cell (MC) infiltration patterns in 57 cases of SM and 31 cases of mast cell hyperplasia (MCH). Tryptase immunohistochemical analysis was used for MC detection and CD25 to distinguish neoplastic from normal MCs. The following infiltration patterns were found: I, diffuse interstitial; II, focal, dense; III, focal, dense with an additional diffuse component, located preferentially around focal infiltrates; IV, focal, dense with an additional diffuse component evenly distributed throughout; and V, diffuse, dense. In 29 cases of MCH, MCs formed the type I pattern. The majority of SM cases exhibited patterns II to V; type IV was the most frequent (n = 36). Type V was seen in 3 cases of MC leukemia and 1 case of smoldering SM. In 1 case of SM, type I infiltration was found; the SM diagnosis was based on 3 minor SM criteria. Our data show that the infiltration pattern in SM correlates with the disease subtype and should be recognized as an important aspect in the histomorphologic evaluation of the bone marrow.

Vitamin B12 deficiency: New data on an old disease

Cobalamin deficiency is a common finding. In the elderly the prevalence is 10-20%, but only 5-10% of these are clinically symptomatic. Typical clinical symptoms include macrocytic anemia, neuropsychiatric symptoms and glossitis. In many cases this triad is lacking, however. The serum cobalamin assay is the best first line test, but the results must be carefully interpreted, since a normal level does not exclude deficiency. Markers of cobalamin activity, such as serum homocysteine or methylmalonic acid may be helpful in this situation. The main cause of cobalamin deficiency is atrophic gastritis. It is either caused by an autoimmune process which leads to achlorhydria and severe intrinsic factor deficiency ("classical pernicious anemia") or by atrophic gastritis from other causes, in particular helicobacter pylori infection. In the latter cases the lack of gastric acid does not allow separation of cobalamin from proteins, but intrinsic factor, although low, is sufficient for cobalamin protection (food cobalamin malabsorption). Helicobacter pylori eradication may cure some of these patients. While in food cobalamin malabsorption syndrome small doses of oral cobalamin are effective, parenteral therapy or high oral doses are required for treatment of pernicious anemia. While almost all patients respond hematologically, only half of the patients with neurological signs, and a small minority of psychiatric patients respond to treatment. Patients with pernicious anemia and atrophic gastritis have a greatly increased long-term risk for gastric carcinoids.

History of Cardiovascular Disease Is Associated With Endothelial Progenitor Cells in Peritoneal Dialysis Patients

BACKGROUND

It is unknown whether traditional cardiovascular disease risk factors influence the number of endothelial progenitor cells (EPCs) and whether numbers of EPCs correlate with endothelial function in patients with end-stage renal disease.

METHODS

In a cross-sectional study of 38 peritoneal dialysis patients, we examined numbers of circulating CD34+/KDR+/CD133+ cells, CD34+ hematopoietic stem cells, and EPCs cultured from peripheral blood. We also assessed conventional cardiovascular disease risk factors, such as history of vascular disease, diabetes, hypercholesterolemia, hypertension, and smoking. We determined endothelial function by measurement of endothelium-dependent and endothelium-independent reactivity of forearm resistance arteries by using strain-gauge plethysmography.

RESULTS

Numbers of EPCs cultured from peripheral blood and forearm blood flow reactivity did not differ between erythropoietin-treated peritoneal dialysis patients and healthy individuals. A history of vascular disease was associated with number of cultured EPCs, but other cardiovascular disease risk factors showed no association. Furthermore, there was no association of endothelial-dependent and endothelial-independent forearm blood flow reactivity with EPCs in peritoneal dialysis patients.

CONCLUSION

In this first study of EPCs in peritoneal dialysis patients, we found an association between history of vascular disease and EPCs, but no association of EPCs with endothelial function or other cardiovascular disease risk factors.

Mastocytosis: pathology, genetics, and current options for therapy

Mast cell disorders are defined by an abnormal accumulation of tissue mast cells (MCs) in one or more organ systems. Symptoms in mastocytosis result from MC-derived mediators and, less frequently, from destructive infiltration of MCs. Cutaneous mastocytosis (CM) is a benign disease of the skin and may regress spontaneously. Systemic mastocytosis (SM) is a persistent disease in which a somatic c-kit mutation at codon 816 is usually detectable in MCs and their progenitors. The clinical course in these patients is variable ranging from asymptomatic for years to highly aggressive and rapidly devastating. The WHO discriminates five categories of SM: indolent SM (ISM), aggressive SM (ASM), SM with associated clonal hematological non-MC-lineage disease (AHNMD), and mast cell leukemia (MCL). The c-kit mutation D816V is quite common and may be found in all SM-categories. In SM-AHNMD, additional genetic abnormalities have been reported, whereas no additional defects are yet known for ASM or MCL. Patients with ISM and CM are treated with "mediator-targeting" drugs, whereas patients with ASM or MCL are candidates for cytoreductive therapy. The use of "Kit-targeting" tyrosine kinase inhibitors such as STI571 (Imatinib, Gleevec), has also been suggested. However, the D816V mutation of c-kit is associated with relative resistance against STI571. Therefore, these patients require alternative targeted drugs or new drug-combinations. In patients with SM-AHNMD, separate treatment plans for the SM-component and the AHNMD should be established. Examples include the use of STI571 in patients with SM plus hypereosinophilic syndrome (SM-HES) and the FIPL1/PDGFRA fusion gene target, or chemotherapy for eradication of AML in patients with SM-AML.

Associations between MTHFR 1793G>A and plasma total homocysteine, folate, and vitamin B12 in kidney transplant recipients

BACKGROUND

Currently, no evidence is available on the putative associations between a novel single nucleotide polymorphism of the 5,10-methylenetetrahydrofolate reductase gene MTHFR 1793G>A and plasma levels of vitamin B(12), folate, or total homocysteine (tHcy).

METHODS

In a cross-sectional study of 730 kidney allograft recipients, patients were categorized by MTHFR 1793G>A genotype. In univariate and multivariate linear regression models that allowed the outcome variables vitamin B(12), folate, and tHcy plasma levels to follow a gamma distribution, we tested for possible associations of allelic variants of MTHFR 1793G>A and these three dependent variables. As hypothesized in previous work, we specifically evaluated possible effect modification between the MTHFR 1793G>A and 1298A>C mutations on these outcomes.

RESULTS

The allele frequency for MTHFR 1793G>A was 0.052. Heterozygosity (N= 72) or homozygosity (N= 2) for MTHFR 1793G>A was not independently associated with plasma levels of vitamin B(12) (P= 0.33) or tHcy (P= 0.70), but a borderline association with higher folate concentrations was detected (Deltafolate = 1.91 nmol/L) (95% CI -0.03 to 3.86 nmol/L) (P= 0.05). Further, we found strong and significant positive interactions between the MTHFR 1793G>A and 1298A>C mutations on vitamin B(12) concentrations.

CONCLUSION

Higher folate concentrations in kidney transplant recipients with MTHFR 1793GA or 1793AA and markedly higher concentrations of vitamin B(12) in patients with combined MTHFR 1793G>A and 1298A>C mutations may contribute to the survival advantage that has been postulated for such patients showing these genotypes.

Measurement of renal function in patients with Fabry disease

Appropriate measurement of the glomerular filtration rate (GFR) is important for the assessment of renal function. This paper reviews the methods used to assess GFR in clinical trials of enzyme replacement therapy (ERT) in patients with Fabry disease, which include inulin clearance, 24-hour creatinine clearance, chromium ethylene diamine tetraacetate (51Cr-EDTA) clearance and cystatin C concentrations. GFR has also been estimated using calculations based on creatinine clearance (the Cockcroft-Gault formula) and the Modification of Diet in Renal Disease (MDRD) equation. Analysis of the results of these studies shows that there are striking discrepancies between estimated and measured GFR. For example, the MDRD equation overestimates GFR in patients with Fabry disease who have normal renal function. In addition, cystatin C has been shown to be of limited use for measuring renal function during ERT, because it is influenced by other factors such as age, gender and weight.

CONCLUSION

The use of exact methods, such as inulin clearance, 124I-iothalamate, 99mTc-DTPA, 51Cr-EDTA and iohexol, appears to be mandatory for a robust evaluation of the effects of ERT on GFR in patients with Fabry disease.