Major determinants of hyperhomocysteinemia in peritoneal dialysis patients

The mechanisms leading to elevated total homocysteine concentrations in peritoneal dialysis patients are only partially understood. We show that a common polymorphism in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene (C677T transition) results in increased total homocysteine levels in peritoneal dialysis patients compared to age- and sex-matched healthy individuals. The allelic frequency of the C677T transition in the MTHFR gene in peritoneal dialysis patients (0.29) was comparable to the frequency in healthy individuals (0.34). Separate comparison of the total homocysteine plasma levels between non-carriers of the MTHFR polymorphism (C/C), heterozygous (C/T) and homozygous (T/T) subjects was performed by analysis of covariance in the patient and the control group. In the patient group the mean total homocysteine level was 61.7 +/- 40.1 mumol/liter in individuals with the (T/T) genotype, which was significantly higher than the total homocysteine concentration of 23.1 +/- 15.8 mumol/liter in (C/T) patients and 22.2 +/- 11.1 mumol/liter for non-carriers (P = 0.0001). Vitamin B12 (P = 0.0001), folate (P = 0.0005), serum creatinine (P = 0.016), albumin (P = 0.0157) and dialysis center (P = 0.0173) significantly influenced total homocysteine plasma levels in peritoneal dialysis patients, whereas this was not the case for age, gender, weekly Kt/V, weekly creatinine clearance, residual renal function, duration of dialysis, mode of peritoneal dialysis and vitamin intake. Folate levels in peritoneal dialysis patients were significantly affected by the MTHFR genotype (P = 0.016). Elevated total homocysteine levels in diabetic patients with cardiovascular disease were associated with increased cardiovascular morbidity. In summary, the present study provides evidence that homozygosity for the C677T transition in the MTHFR gene, low vitamin B12 and low folate levels result in elevated total homocysteine levels in peritoneal dialysis patients.

A lethal course of chronic hepatitis C, glomerulonephritis, and pulmonary vasculitis unresponsive to interferon treatment

Several extrahepatic syndromes have been associated with chronic hepatitis C virus infection. In our patient (a 57-yr-old woman without risk factors for hepatitis), chronic active hepatitis C was diagnosed serologically and histologically. Three months later, membranoproliferative glomerulonephritis with compromised renal function and peripheral edema, cryoglobulinemia, and a vasculitis of the finger tips developed. During interferon treatment for 3 months, neither the clinical condition nor serological parameters improved significantly. Progressive dyspnea was due to bilobar pulmonary infiltration. Despite antibiotic, virostatic, and corticosteroid therapy, the patient died from respiratory failure. Autopsy revealed diffuse pulmonary vasculitis. Thus, this is the first description of chronic hepatitis C virus infection, glomerulonephritis, and cryoglobulinemia complicated by immunologically mediated pulmonary vasculitis. Because interferon therapy may be ineffective, immunosuppressive therapy should be considered.

Non-radioactive detection of the rearranged BCR/ABL sequences amplified by polymerase chain reaction

The polymerase chain reaction (PCR) is a powerful technique for the detection of the bcr/abl rearrangement in chronic myelogenous leukemia (CML). It allows the exponential amplification of the rearranged region, thus facilitating its detection. The specificity of the bcr/abl cDNA sequence amplified by PCR is most commonly verified by hybridization to a 32P-labeled probe. In this paper, an assay for the colorimetric detection of the amplified bcr/abl fragment is described, which offers several advantages over the use of radioactive probes. We adapted the PCR for synthesis and simultaneous labeling of DNA fragments with a non-radioactive steroid compound called digoxigenin. This labeling procedure was used to generate a digoxigenin-labeled internal probe for the chimeric bcr/abl mRNA. The assay described is based on the hybridization of the amplified bcr/abl sequence to the non-radioactively labeled probe and on the subsequent detection by an enzyme-linked immunoassay and enzyme-catalyzed color reaction. Using this protocol, we investigated 20 patients with CML along with six healthy individuals and two cell lines derived from patients with CML for the presence of the bcr/abl rearrangement. It is shown that the assay is both highly sensitive and specific and that it is readily applicable to the routine diagnosis of CML. In addition, the assay could be adapted to a number of clinical diagnostic uses.

Electrophysiologic testing after aortic valve replacement in two patients with aortic stenosis and preoperative ventricular fibrillation

In two patients with severe aortic stenosis successful resuscitation from ventricular fibrillation was documented by Holter recording/ECG monitoring. After aortic valve replacement programmed ventricular stimulation was performed in both patients, but ventricular tachycardia/ventricular fibrillation was not inducible. The patients were left without antiarrhythmic therapy and have been free from cardiac events for 18 and 20 months, respectively. The prognostic value of postoperative electrophysiologic testing after aortic valve replacement in patients with severe aortic stenosis and preoperative resuscitation is discussed.

Beta-2-microglobulin for differentiation between ciclosporin A nephrotoxicity and graft rejection in renal transplant recipients

The clinical relevance of daily measurement of beta 2-microglobulin in serum and urine was evaluated in 49 patients undergoing renal transplantation. The changes in beta 2-microglobulin levels were compared to standard parameters for assessment of renal function. One hundred episodes of acute deterioration of renal function, clinically diagnosed as rejection, were analyzed retrospectively: (1) In 18 episodes renal malfunction did not respond to methylprednisone but improved immediately upon dose reduction of ciclosporin A, thus indicating a nephrotoxic effect of the drug. In these cases a mean increase of beta 2-microglobulin in urine as high as 7.9 mg/l was observed while serum values decreased. (2) Fifty episodes of apparent rejection (responsive to steroids) were preceded by a 3-day lasting continuous rise of beta 2-microglobulin in serum of up to 3.6 mg/l as a mean with only a moderate elevation in urine. (3) In 13 episodes antirejection treatment could have been avoided as continuously declining laboratory parameters indicated spontaneous improvement of renal function. We conclude that parallel determination of beta 2-microglobulin in serum and urine allows to differentiate between ciclosporin A nephrotoxicity and rejection in 91% of the cases.

[Mechanism of action of interferon-alpha 2 in hairy cells and lymphoblastoid cell lines: the significance of type I interferon receptors and RNA synthesis]

Lymphoblastoid cells were subjected to Western Blot analysis for detection of Interferon-alpha-binding proteins. JOK-1 cells--a human hairy cell leukemia line--revealed three proteins with apparent molecular weights of 120, 100 and 32 kD, respectively. Down-regulation of the receptor was observed. A differential binding pattern of two proteins (100 and 85 kD) was observed in T-CLL, whereas no signal detection was achieved in B-CLL. Mononuclear cells from 6 patients with hairy cell leukemia and 6 patients with CLL were found to differ significantly in terms of nucleic acid precursor incorporation.

Value of flumazenil in benzodiazepine self-poisoning

The efficacy of the benzodiazepine-antagonist flumazenil (Ro 15-1788) was evaluated in 26 patients with coma due to benzodiazepine self poisoning, alone or in combination with alcohol or other psychoactive drugs. 77% of the patients responded to the administration of a mean dose of 1.73 mg (range 0.2 to 8 mg) with immediate awakening or an improvement of at least 2 coma grades. In the patients without response (n = 3) or with minor improvement (n = 3) other psychoactive drugs turned out to be predominantly responsible for their comatose state. Adverse effects of flumazenil treatment such as altered blood pressure or increased heart rate were observed, but were generally mild. An acute benzodiazepine withdrawal syndrome was seen in 2 cases. In conclusion, flumazenil proved to be effective in the treatment of severe benzodiazepine intoxication. Beyond that, in cases of mixed overdosage or initially unknown diagnosis the antidote assisted in the clarification of the clinical condition.

A special technique of compound osteosynthesis of the distal humerus. A case report about extramedullary blast crisis in chronic myelogenous leukemia

In a rare case of chronic myelogenous leukemia, extramedullary myeloblast crisis occurred in the distal humerus after 27 years. The pathological fracture was stabilized with double-plate compound osteosynthesis. The small distal fragment was stabilized without restriction of the range of movement of the elbow joint. The osteosynthesis remained stable until the patient died.

Interferon alpha-2 for hairy cell leukemia: evidence for induction of RNA synthesis in hairy cells and failure to correlate enhancement of natural killer cells with elimination of hairy cells

The effect of human recombinant interferon alpha 2 (IFN alpha 2) on hairy cells obtained from 16 patients was evaluated. All patients promptly responded to induction of remission with 2 X 10(6) U/m2 interferon alpha 2 b, three times a week, sc. In order to achieve a more detailed insight into the mode of action of interferon in this disease, we determined the influence of IFN alpha 2 on the incorporation of radiolabeled thymidine and uridine into hairy cells. While both 3H-thymidine and 3H-uridine incorporation were unaffected by IFN alpha 2 in a 3-hour incubation period, a significant increase in uridine incorporation into hairy cells, but not CLL cells, was observed after 24 h. Cell surface marker analysis performed with monoclonal antibodies did not reveal a quantitative alteration of the immunophenotype of hairy cells in vitro. In addition, natural killer cells, assessed by monoclonal antibodies and a cytotoxicity assay against K 562 cells, were found to be decreased in 9 out of 10 patients prior to therapy. Although IFN alpha 2 could stimulate natural killer cells in vivo, we did not find a consistent correlation between the activation of these cells and the response to therapy. We conclude, therefore, that NK cells play no major role in the regression of hairy cells. Furthermore, IFN alpha 2 does not alter antigenic determinants in vitro, but leads to an enhanced incorporation of 3H-uridine into hairy cells in vitro, thus indicating a possible role for the induction of RNA synthesis in vivo.

[Recombinant (IFN-alpha 2b) therapy in hairy cell leukemia]

Eighty-five patients with hairy-cell leukemia were treated in a multicentric "open label" study with IFN-alpha 2b and evaluated. Induction therapy was 2 X 10(6) U IFN-alpha 2b/m2, 3 times a week, s.c. The results show this regimen to be highly effective with only a few tolerable and transient side effects consisting mainly of flu-like symptoms. After 6 months of therapy 4% CR, 69% PR, and 16% MR, were noted. In a small group of four patients who had achieved CR or PR, we tested the effect of varying doses for maintenance therapy. Our preliminary results indicate that a relapse caused by interruption of IFN therapy or dose reduction to 3 X 10(6) U given once a week, o.c. could be successfully treated by readministration, or escalating the dosage of IFN. It seems that remission maintenance requires long-term treatment with IFN. In a short-term in vitro test we studied the effect of IFN-alpha 2 on the incorporation of 3H-thymidine and 3H-uridine into hairy cells of five patients. Fort both precursors no appreciable effect was detected. However, after prolonged incubation for 48 h, a significant enhancement of 3H-uridine incorporation was observed, while 3H-thymidine incorporation remained unaffected. Cell marker analysis performed with monoclonal antibodies before and after incubation of hairy cells with IFN-alpha 2 for up to 7 days did not reveal any change of the phenotype of hairy cells.

[Specific therapy of acute benzodiazepine poisoning using flumazenil (Ro 15-1788)]

In 20 patients with coma (grade 4: n = 7, grade 3: n = 8, grade 2: n = 2, grade 1: n = 3) due to benzodiazepine intoxication, solely or combined with alcohol or other psychoactive drugs, the effect of a specific benzodiazepine antagonist, Flumazenil (Ro 15-1788), was evaluated. In terms of coma depth, 80% of the patients responded to application of 1.96 mg Flumazenil as a mean with immediate awakening or improvement of at least two steps in coma grading. In those 3 patients, who failed to respond to Flumazenil, the history revealed amitriptyline or barbiturates to be responsible for the comatose state. The observed side-effects of Flumazenil included increase (n = 4) or decrease (n = 3) of blood pressure, increase of heart rate (n = 7), cutaneous flush (n = 1) and ventricular extrasystoles (n = 1). Agitation and generalized convulsions, each observed in 1 patient, presumably were due to an acute benzodiazepine-withdrawal rather than an intrinsic side effect of the antagonist. In conclusion, Flumazenil proved to be a potent antagonist of benzodiazepines in patients with severe coma and even may serve as a valuable diagnostic in cases of suspected benzodiazepine intoxication.

Effect of alpha 2-interferon on hairy cells and cell lines: a role for type I interferon receptors and RNA synthesis

The binding of alpha 2-interferon to highly purified plasma membrane proteins of malignant human lymphoid cells was assessed by Western Blotting. The human hairy cell leukemia cell line JOK-1 revealed three major alpha-interferon binding proteins with molecular weights of 120, 100, and 32 kD. Pretreatment of JOK-1 cells with alpha-interferon in vitro results in a disappearance of these proteins, which is in concordance with receptor down-regulation on JOK-1 cells. In a case of T chronic lymphocytic leukemic (CLL), a differential binding pattern of two proteins with 100 and 85 kD was observed, whereas a case of B-CLL did not yield any signal detection. In addition, mononuclear cells from patients with hairy cell leukemia and CLL were found to differ with respect to the in vitro incorporation of nucleic acid precursors. alpha 2-Interferon enhances [3H] uridine incorporation into hairy cells, whereas this phenomenon can be detected in CLL cells only to a much lesser extent.

Acute leukemia with mediastinal mass, lymphadenopathy, and monocytic precursor cells

Cell marker analysis with monoclonal antibodies (MoAb) as well as differentiation studies with the chemical inducer TPA were used to identify a population of apparently lymphoid cells as monocytic precursor cells in a patient with acute leukemia. The initial manifestation of the disease with mediastinal mass and lymphadenopathy was followed by the appearance of small lymphocyte-like blast cells in bone marrow (BM) and peripheral blood (PB). Although a lymph node biopsy revealed an infiltration with monoblasts, the leukemic cells in BM and PB were not classifiable. However, when the patient relapsed after chemotherapy with large monoblasts and again with morphologically lymphoid blast cells, the latter could be classified by treatment with TPA. After incubation with the inducer (12-48 hr) the cells became positive with the MoAB VIM-D5, showed a strong reaction with alpha-naphthyl-acetate-esterase and developed macrophage like morphology, as well as phagocytic properties. During the terminal phase of the disease, small, lymphocyte-like blast cells predominated. These cells could be classified by a panel of MoABs. They expressed myeloid determinants (VIM-D5, VIM-2, MY 9, VIM-12, VIM-13) but showed no reactivity with MoABs specific for lymphocytic cells.

B-immunoblastic lymphoma arising in angioimmunoblastic lymphadenopathy

We present a female patient with a B-immunoblastic lymphoma of the IgM-lambda type arising in angioimmunoblastic lymphadenopathy. An increased ratio of helper/inducer to suppressor/cytotoxic lymphocytes in the lymph node could have triggered the proliferation of B cells. Evolution of IgM cryoglobulinemia was paralleled by malignant transformation in the lymph node. A short-term in vitro chemosensitivity test could predict response to COP combination chemotherapy suggesting that in vitro chemosensitivity testing can be useful for the therapeutic management of angioimmunoblastic lymphadenopathy.