Alfa-1-antitrypsin deficiency: a predisposing factor leading to invasive infections?

This case report highlights for the first time a possible link between the presence of alfa-1-antitrypsin deficiency (AATD) and the susceptibility to invasive infections. The current patient, with known AATD, initially presented with nausea, vomiting and headache secondary to Listeria monocytogenes rhombencephalitis. Further on, he developed respiratory insufficiency due to probable invasive pulmonary aspergillosis. Diagnostic work-up could not show any arguments for an underlying immunodeficiency or malignancy. The consecutive course of two rare invasive infections in a healthy individual posed the hypothesis if the underlying AATD could be considered a possible trigger for infections. Indirect clinical observations in literature indeed support this link and in addition, two possible pathophysiological pathways might explain the higher susceptibility for infections in AATD patients. First, alveolar macrophages are dysfunctional in AATD patients leading to a lower apoptotic clearance of bacteria and other (mostly intracellular) pathogens. Secondly, a lower release and lower function of tumour necrosis factor α (TNFα) is seen in alfa-1-antitrypsin depletion, priming the path to more frequent infections, a mechanism that is similar in anti-TNFα treated patients. This case is the first to report on severe or invasive infections related to AATD in humans.

An abnormally glycosylated isoform of erythropoietin in hemangioblastoma is associated with polycythemia.

BACKGROUND: Hemangioblastomas express erythropoietin and the patients often present with polycythemia. METHODS: Serum erythropoietin was measured using a commercial immunoassay, a functional erythropoietin assay and iso-electric focusing. RESULTS: Despite the polycythemia, serum erythropoietin remained low, while a functional erythropoietin-assay showed a 4-5 higher activity in serum compared to the immunoassay. Iso-electric focusing of serum erythropoietin indicated overrepresentation of highly sialylated erythropoietin isoforms produced by the tumor. As a result, altered affinity of the monoclonal antibody used in the immunoassay for the hypersialylated isoforms was suggested. CONCLUSION: Analysis of erythropoietin isoforms may be helpful in distinguishing the ectopic erythropoietin isoforms from normally glycosylated erythropoietin.

A rare cause of cardiac tamponade.

Cardiac tamponade is a life-threatening condition which must be quickly diagnosed and treated. This medical urgency can have several possible causes. We report the case of a 59-year-old patient presenting with a cardiac tamponade caused by extramedullary haematopoiesis due to myelofibrosis.

Erythrocyte indices in the assessment of iron status in dialysis-dependent patients with end-stage renal disease on continuous erythropoietin receptor activator versus epoetin beta therapy.

BACKGROUND: European guidelines stress that iron status should be regularly assessed for the optimal management of renal anemia. These guidelines include the hemoglobin content of reticulocytes and the percentage of hypochromic RBC as markers for functional iron deficiency. Recently, equivalents of these indices have become available on the automated hematology analyzer Sysmex XE-2100, these being reticulocyte hemoglobin equivalent (Ret-He) and DF-HYPO XE, respectively. METHODS: In a prospective study, we closely monitored these parameters in dialysis-dependent patients with end-stage renal disease during the switch from a first-generation epoetin (EPO) once weekly to a third-generation EPO [continuous erythropoietin receptor activator (CERA)] once monthly. As a control, patients staying on EPO beta were monitored. RESULTS: During follow-up, no changes in erythrocyte indices were noticed in the EPO beta group. By contrast, in the CERA group, a decrease in Ret-He and an increase in DF-HYPO XE were transiently found 7-10 days after administration. The transient state of functional iron deficiency could not be prevented by extra intravenous iron. CONCLUSION: Fluctuations in Ret-He and DF-HYPO XE have to be taken into account when these parameters are used for the assessment of iron-deficient states. We suggest that a fixed time point in the CERA schedule should be chosen for iron monitoring.

EVI1 activation in blast crisis CML due to juxtaposition to the rare 17q22 partner region as part of a 4-way variant translocation t(9;22).

BACKGROUND: Variant translocations t(9;22) occur in 5 to 10% of newly diagnosed CMLs and additional genetic changes are present in 60-80% of patients in blast crisis (BC). Here, we report on a CML patient in blast crisis presenting with a four-way variant t(9;22) rearrangement involving the EVI1 locus. METHODS: Dual-colour Fluorescence In Situ Hybridisation was performed to unravel the different cytogenetic aberrations. Expression levels of EVI1 and BCR/ABL1 were investigated using real-time quantitative RT-PCR. RESULTS: In this paper we identified a patient with a complex 4-way t(3;9;17;22) which, in addition to BCR/ABL1 gene fusion, also resulted in EVI1 rearrangement and overexpression. CONCLUSION: This report illustrates how a variant t(9;22) translocation can specifically target a second oncogene most likely contributing to the more aggressive phenotype of the disease. Molecular analysis of such variants is thus warranted to understand the phenotypic consequences and to open the way for combined molecular therapies in order to tackle the secondary oncogenic effect which is unresponsive to imatinib treatment.

Rheumatoid factor interference in the determination of carbohydrate antigen 19-9 (CA 19-9).

BACKGROUND: Investigation of a 61-year-old Caucasian male suffering from fatigue and weight loss led to the finding of a carbohydrate antigen 19-9 (CA 19-9) concentration of 80 kU/L using an ADVIA Centaur analyser. Determination of CA 19-9 on Vidas, AxSYM and Architect i2000 systems gave normal results. His rheumatoid factor concentration was very high (900 kIU/L) and assay interference was suspected. METHODS: Besides using several laboratory procedures to show the cause of the interference, we tried to estimate the frequency of the suspected interference. Therefore, two studies were performed. The first was carried out in a multicentre setting using four different CA 19-9 methods on 51 randomly selected samples with high rheumatoid factor concentrations and ten samples containing no or very low rheumatoid factor. In the second study we used heterophilic blocking tubes for 68 routinely analysed samples with CA 19-9 concentrations ranging between 37 and 250 kU/L using an ADVIA Centaur analyser. RESULTS: In the multicentre study we found eight discrepant CA 19-9 results, but only one was clearly due to interference. We showed that the interference detected, just as in the index case, was caused by rheumatoid factor. The other discrepancies could not be explained, but are probably related to method-dependent differences. In the 68 routinely analysed samples, no interference could be shown using the heterophilic blocking tubes. CONCLUSIONS: Although interferences in the CA 19-9 assay are not frequent, the ADVIA Centaur system appears to be more sensitive to rheumatoid factor interference. The lack of standardisation remains an important issue for this assay. The determination of CA 19-9 during the follow-up of patients should be performed using a single method. If, however, there is any clinical doubt about a result, CA 19-9 should be determined using another method to exclude possible interferences.