Sensitivity and specificity of clinical, histologic, and immunologic features in the diagnosis of paraneoplastic pemphigus

BACKGROUND

Paraneoplastic pemphigus (PNP) is an autoimmune blistering disease characterized by the production of autoantibodies mainly directed against proteins of the plakin family. An overlapping distribution of autoantibody specificities has been recently reported between PNP, pemphigus vulgaris (PV), and pemphigus foliaceus (PF), which suggests a relationship between the different types of pemphigus.

OBJECTIVE

Our purpose was to evaluate the sensitivity and the specificity of clinical, histologic, and immunologic features in the diagnosis of PNP.

METHODS

The clinical, histologic, and immunologic features of 22 PNP patients were retrospectively reviewed and compared with those of 81 PV and PF patients without neoplasia and of 8 PV and 4 PF patients with various neoplasms.

RESULTS

One clinical and 2 biologic features had both high sensitivity (82%-86%) and high specificity (83%-100%) whatever the control group considered: (1) association with a lymphoproliferative disorder, (2) indirect immunofluorescence (IIF) labeling of rat bladder, and (3) recognition of the envoplakin and/or periplakin bands in immunoblotting. Two clinicopathologic and two biologic features had high specificity (87%-100%) but poor sensitivity (27%-59%): (1) clinical presentation associating erosive oral lesions with erythema multiforme-like, bullous pemphigoid-like, or lichen planus-like cutaneous lesions; (2) histologic picture of suprabasal acantholysis with keratinocyte necrosis, interface changes, or lichenoid infiltrate; (3) presence of both anti-epithelial cell surface and anti-basement membrane zone antibodies by IIF; and (4) recognition of the desmoplakin I and/or BPAG1 bands in immunoblotting. Interestingly, 45% of patients with PNP presented initially with isolated oral erosions that were undistinguishable from those seen in PV patients, and 27% had histologic findings of only suprabasal acantholysis, which was in accordance with the frequent detection of anti-desmoglein 3 antibodies in PNP sera.

CONCLUSION

The association with a lymphoproliferative disorder, the IIF labeling of rat bladder, and the immunoblotting recognition of envoplakin and/or periplakin are both sensitive and specific features in the diagnosis of PNP.

De novo synthesis of proteinase 3 by cytokine primed circulating human polymorphonuclear neutrophils and mononuclear cells

OBJECTIVE

When polymorphonuclear neutrophils (PMN) and peripheral blood monocytes (PBMC) are stimulated with tumor necrosis factor alpha (TNF-alpha), preexisting granule stored proteinase 3 (PR3) is translocated to the surface of their plasma membrane. We investigated whether PR3 gene reactivation and new PR3 protein production were also features of priming by cytokine.

METHODS

Normal human PMN and PBMC were isolated and stimulated in vitro with TNF-alpha. They were harvested at different intervals and subjected to total RNA and protein analysis. PR3 mRNA was identified by reverse transcription polymerase chain reaction, Northern blot, and sequencing. De novo PR3 synthesis was evaluated by metabolic labeling with [35S] methionine followed by immunoprecipitation using anti-neutrophil cytoplasmic antibodies from serum of patients with active Wegener's granulomatosis and mouse monoclonal anti-native PR3 antibodies.

RESULTS

Resting PMN and PBMC do not express PR3 mRNA. During priming, PR3 mRNA appears in PMN at 2 h, peaks at 6 h, and has disappeared at 12 h. By comparison, in primed PBMC, PR3 mRNA appears at 6 h, peaks at 12 h, and disappears at 24 h. Immunoprecipitation of metabolically labeled PR3 revealed new synthesis of PR3 by both cell types, a process that was inhibited by cycloheximide.

CONCLUSION

Primed PMN and PBMC can express PR3 mRNA and synthesize new PR3 protein, providing an alternative source to membrane PR3. Whether that small amount of inducible PR3 has a primary structure, a localization, or a role different from those of preformed PR3 stored in granules remains to be clarified.

Fibroblast growth factor (FGF)-2 mediates cell attachment through interactions with two FGF receptor-1 isoforms and extracellular matrix or cell-associated heparan sulfate proteoglycans

In the presence of FGF-2, cells in suspension expressing FGF receptor-1 will attach to monolayers of cells expressing heparan sulfates. This attachment provides physical evidence for the formation of a trimolecular complex between FGF-2, heparan sulfate, and FGF receptors. We have used this system to determine if receptor isoforms containing or lacking the first of three immunoglobulin-like domains are equally able to form complexes with FGF-2 and heparan sulfates. In the presence of FGF-2, cells expressing either isoform of the receptor were able to attach to monolayers of CHO cells expressing heparan sulfates. No attachment was observed in the absence of FGF-2 or if heparin was included in the incubation medium. Attachment of cells expressing the two receptor isoforms occurred at similar concentrations of FGF-2, and similar concentrations of heparin were required to disrupt the interactions. Thus, there appeared to be little difference between these receptor isoforms in their ability to form trimolecular complexes with FGF-2 and cell-associated heparan sulfates. We also found that, in the presence of FGF-2, cells expressing FGF receptor-1 are able to form complexes with both extracellular matrix and cell-surface heparan sulfates.

Is there a distortion of body projection in extracorporeal space in neglect patients?

Neglect patients often present with a rightward shift of the direction straight-ahead of body midline. We investigated whether directions ahead of other body parts were similarly shifted or were differentially affected. Right brain-damaged patients, with and without neglect, and normal subjects had to indicate by manual pointings, the directions straight-ahead of the navel, the nose, the left and right shoulders. In neglect patients, constant errors varied across directions with a decrease in magnitude from left to right, suggesting a compression of body projection in extracorporeal space. Moreover, the projection of the left hemibody was smaller than the right in all subjects, with and without neglect. This unexpected finding is discussed with regard to other spatial asymmetries observed in normal subjects.

Relation between respiratory changes in arterial pulse pressure and fluid responsiveness in septic patients with acute circulatory failure

In mechanically ventilated patients with acute circulatory failure related to sepsis, we investigated whether the respiratory changes in arterial pressure could be related to the effects of volume expansion (VE) on cardiac index (CI). Forty patients instrumented with indwelling systemic and pulmonary artery catheters were studied before and after VE. Maximal and minimal values of pulse pressure (Pp(max) and Pp(min)) and systolic pressure (Ps(max) and Ps(min)) were determined over one respiratory cycle. The respiratory changes in pulse pressure (DeltaPp) were calculated as the difference between Pp(max) and Pp(min) divided by the mean of the two values and were expressed as a percentage. The respiratory changes in systolic pressure (DeltaPs) were calculated using a similar formula. The VE-induced increase in CI was >/= 15% in 16 patients (responders) and < 15% in 24 patients (nonresponders). Before VE, DeltaPp (24 +/- 9 versus 7 +/- 3%, p < 0.001) and DeltaPs (15 +/- 5 versus 6 +/- 3%, p < 0.001) were higher in responders than in nonresponders. Receiver operating characteristic (ROC) curves analysis showed that DeltaPp was a more accurate indicator of fluid responsiveness than DeltaPs. Before VE, a DeltaPp value of 13% allowed discrimination between responders and nonresponders with a sensitivity of 94% and a specificity of 96%. VE-induced changes in CI closely correlated with DeltaPp before volume expansion (r(2) = 0. 85, p < 0.001). VE decreased DeltaPp from 14 +/- 10 to 7 +/- 5% (p < 0.001) and VE-induced changes in DeltaPp correlated with VE-induced changes in CI (r(2) = 0.72, p < 0.001). It was concluded that in mechanically ventilated patients with acute circulatory failure related to sepsis, analysis of DeltaPp is a simple method for predicting and assessing the hemodynamic effects of VE, and that DeltaPp is a more reliable indicator of fluid responsiveness than DeltaPs.

Molecular pathology of galactosialidosis in a patient affected with two new frameshift mutations in the cathepsin A/protective protein gene

Galactosialidosis is a recessively inherited lysosomal storage disease characterized by the combined deficiency of neuraminidase and beta-galactosidase secondary to the genetic deficiency of cathepsin A/protective protein. In lysosomes, cathepsin A forms a high-molecular-weight complex with beta-galactosidase and neuraminidase that protects these enzymes against intralysosomal proteolysis. In a patient affected with late infantile form of galactosialidosis, we found two new cathepsin A mutations, a two-nucleotide deletion, c517delTT and an intronic mutation, IVS8+9C-->G resulting in abnormal splicing and a five-nucleotide insertion in the cathepsin A cDNA. Both mutations cause frameshifts and result in the synthesis of truncated cathepsin A proteins, which, as suggested by structural modeling, are incapable of dimerization, complex formation, and catalysis. However, enzymatic assays, gel-filtration, and Western blot analysis of the patient's cultured skin fibroblast extracts showed the presence of a small amount of normal-size, catalytically active cathepsin A and cathepsin A-beta-galactosidase 680 kDa complex, suggesting that a low amount of cathepsin A mRNA is spliced normally and produces the wild-type protein. This may contribute to the relatively mild phenotype of the patient and illustrates the importance of critically comparing molecular results with clinical and biochemical phenotypes.

c-Myc antagonizes the effect of p53 on apoptosis and p21WAF1 transactivation in K562 leukemia cells

c-myc protooncogene positively regulates cell proliferation and overexpression of c-myc is found in many solid tumors and leukemias. In the present study we used the K562 human myeloid leukemia cell line as a model to study the functional interaction between c-Myc and p53. Using two different methods, we generated K562 transfectant cell lines with conditional expression of either c-Myc or p53. The cells expressed the p53Vall35 mutant, which adopts a wild-type conformation at 32 degrees C, while c-Myc induction was achieved with a zinc-inducible expression vector. We found that p53 in wild-type conformation induces growth arrest and apoptosis of K562. Expression of c-Myc significantly attenuated apoptosis and impaired the transcriptional activity of p53 on p21WAF1, Bax and cytomegalovirus promoters. The impairment of p21WAF1 transactivation by c-Myc was confirmed by transfection of a c-Myc-estrogen receptor fusion protein and by induction of c-myc by zinc in transfected cells. Also, p53-mediated up-regulation of p21WAF1 mRNA protein were significantly reduced by c-Myc, while Bax levels were unaffected. Consistently, c-Myc increased cyclin-dependent kinase 2 activity in K562 cells expressing p53 in wild-type conformation. These results suggest that c-Myc overexpression may antagonize the pro-apoptotic function of p53, thus providing a molecular mechanism for the frequently observed deregulation of c-myc in human cancer.

Characterization of the sialidase molecular defects in sialidosis patients suggests the structural organization of the lysosomal multienzyme complex

Sialidosis is an autosomal recessive disease caused by the genetic deficiency of lysosomal sialidase, which catalyzes the hydrolysis of sialoglycoconjugates. The disease is associated with progressive impaired vision, macular cherry-red spots and myoclonus (sialidosis type I) or with skeletal dysplasia, Hurler-like phenotype, dysostosis multiplex, mental retardation and hepatosplenomegaly (sialidosis type II). We have analyzed the genomic DNA from nine sialidosis patients of multiple ethnic origin in order to find mutations responsible for the enzyme deficiency. The activity of the identified variants was studied by transgenic expression. One patient had a frameshift mutation (G623delG deletion), which introduced a stop codon, truncating 113 amino acids. All others had missense mutations: G679G-->A (Gly227Arg), C893C-->T (Ala298Val), G203G-->T (Gly68Val), A544A-->G (Ser182Gly) C808C-->T (Leu270Phe) and G982G-->A (Gly328Ser). We have modeled the three-dimensional structure of sialidase based on the atomic coordinates of the homologous bacterial sialidases, located the positions of mutations and estimated their potential effect. This analysis showed that five mutations are clustered in one region on the surface of the sialidase molecule. These mutations dramatically reduce the enzyme activity and cause a rapid intralysosomal degradation of the expressed protein. We hypothesize that this region may be involved in the interface of sialidase binding with lysosomal cathepsin A and/or beta-galactosidase in their high-molecular-weight complex required for the expression of sialidase activity in the lysosome.

Myeloid leukemia cell growth and differentiation are independent of mitogen-activated protein kinase ERK1/2 activation

The mitogen-activated protein kinase ERK1/2 pathway is essential in the control of cell proliferation and differentiation in most cellular systems. As such, it has been considered a potential target for antineoplastic therapy. For this purpose, we have examined the role of ERK activation in myeloid leukemia cell growth and differentiation. Using a representative set of myeloid leukemia cell lines, we show that cell proliferation was not accompanied by increases on ERK1/2 activation, and mitogenic stimulation did not enhance ERK activity. Moreover, abolition of ERK function by the inhibitor PD98059 or by a dominant inhibitory mutant ERK2 had no significant effects on proliferation. With the aid of various differentiation inducers, we found that within the same cell line, differentiation to a given lineage could occur with and without ERK1/2 activation, depending on the stimulus. Also, a differentiator could have the same effect in the presence or absence of ERK stimulation, depending on the cell line. ERK inhibition did not affect the differentiation elicited by stimuli whose effects were accompanied by ERK activation. Finally, constitutive ERK activity was also ineffective on proliferation and differentiation. Thus, our results indicate that ERK1/2 activation is not an essential requirement for leukemic cell growth and differentiation.

Activation of a pro-apoptotic amplification loop through inhibition of NF-kappaB-dependent survival signals by caspase-mediated inactivation of RIP

Death domain containing members of the tumor necrosis factor receptor (TNFR) superfamily can induce apoptosis or cell activation. However, the mechanisms by which these opposing programs are selected remain unclear. Frequently, NF-kappaB activation conveys protection against cell death. We show that the serine/threonine kinase RIP that is required for TNF-induced NF-kappaB activation is processed by caspase-8 into a dominant-negative (DN) fragment during death receptor-induced apoptosis, thereby leading to a blockade of NF-kappaB-mediated anti-apoptotic signals. Our results suggest that cleavage of RIP is part of an amplification loop which is triggered by Fas and most likely by other death receptors.

Characterization of the LI818 polypeptide from the green unicellular alga Chlamydomonas reinhardtii

The LI818 gene from Chlamydomonas encodes a polypeptide that is related to the chlorophyll a/b-binding proteins (CAB) of higher plants and green algae. However, despite this relatedness, LI818 gene expression is not coordinated with that of cab genes and is regulated differently by light, suggesting a different role for LI818 polypeptide. We show here that, in contrast to CAB polypeptides, LI818 polypeptide is not tightly embedded into the thylakoid membranes and is localized in stroma-exposed regions. Moreover, during chloroplast development, LI818 polypeptide accumulates before CAB polypeptides. We also show that the LI818 polypeptide forms with certain chlorophyll a/c-binding proteins (CAC) from the haptophyte Isochrysis galbana and the diatom Cyclotella cryptica a natural group that is distinct from those constituted by CAB, CAC and the chlorophyll a/a-binding proteins (CAA). Such an association suggests a very ancient origin for this group of polypeptides, which predates the division of the early photosynthetic eukaryotes into green (chlorophyte), red (rhodophyte) and brown (chromophyte) algae. Possible roles for the LI818 polypeptide are discussed.

Chlorhexidine compared with povidone-iodine as skin preparation before blood culture. A randomized, controlled trial

BACKGROUND

Chlorhexidine is better than povidone-iodine for care of catheter sites, but it is not known whether chlorhexidine is superior in reducing blood culture contamination.

OBJECTIVE

To determine whether alcoholic chlorhexidine is a more effective skin antiseptic for collection of blood cultures than aqueous povidone-iodine.

DESIGN

Randomized, controlled trial.

SETTING

Three adult intensive care units in a French university hospital.

PATIENTS

403 adults who had at least one blood culture drawn through a peripheral vein.

INTERVENTIONS

Patients were randomly assigned to receive skin preparation with an aqueous solution of 10% povidone-iodine or an alcoholic solution of 0.5% chlorhexidine before phlebotomy.

MEASUREMENTS

Contamination rates of blood cultures.

RESULTS

Of 2041 blood cultures collected in 403 patients, 124 yielded pathogens. Chlorhexidine reduced the incidence of blood culture contamination more than povidone-iodine (14 of 1019 cultures [1.4%] compared with 34 of 1022 cultures [3.3%]; odds ratio, 0.40 [95% CI, 0.21 to 0.75]; P = 0.004).

CONCLUSION

Skin preparation with alcoholic chlorhexidine is more efficacious than skin preparation with aqueous povidone-iodine in reducing contamination of blood cultures.

Primary lymphoplasmacytoid lymphoma of the trachea with immunoglobulin G paraprotein

A primary tracheal lymphoma with immunoglobulin G (IgG)-associated monoclonal serum paraprotein treated with surgery and chemotherapy is reported. As far as we know this is the first lymphoplasmacytoid lymphoma reported in the tracheobronchial tree and the first with a serum and tissue IgG monoclonal paraprotein. Differential diagnosis must be made essentially with extramedullary plasmacytoma and mucosa-associated lymphoid tissue lymphoma. CD-45RB strong positivity and the absence of lymphoepithelial lesions may help to differentiate lymphoplasmacytoid lymphoma from them. We expand the spectrum of lymphoid lesions with plasmacytoid features that can occur in the tracheobronchial tract.

Translocation (10;11)(p13;p15) in an infant acute myeloid leukemia with MLL gene rearrangement

Molecular rearrangements of the MLL gene at the 11q23 region have been identified in most cases of infant leukemia, regardless of the phenotype. We present a case of acute myeloid leukemia which coexpressed myeloid and lymphoid markers in a 12-month-old girl. Karyotype analysis revealed the presence of a thus far unreported translocation t(10;11)(p13;p15). Although no 11q23 abnormalities were cytogenetically detectable, an MLL gene molecular rearrangement was found.

[Fenfluramines and cardiac valvular lesions]

We report cardiac valvulopathy occurring after prolonged intake of anorectic drugs containing fenfluramine (Fen) and/or dexfenfluramine (D-Fen) in 14 patients whose evolution was followed by Doppler echocardiography. A relation between these drugs and valvular regurgitation was first suspected after 4 cases reported in 1991-1992 and confirmed after 3 more patients in 1993-94-95, who were taken D-Fen or Fen alone. All were women, aged 42 to 73 years. Patient 1 to 7 had been taking Fen and/or D-Fen for 14 to 52 months. Patients 8 to 14 had been taking a mixture of Fen and/or D-Fen, diethylpropion and chinese-herbs for 3 to 69 months. These last 7 patients developed renal failure requiring hemodialysis or peritoneal dialysis in 5 and subsequent renal transplantation in 4. All presented with cardiac murmur(s) and some with dyspnea or palpitations. An initial echocardiography was performed at the time of diagnosis, and was repeated annually for a follow-up period extending to 8 years. We conclude that a relation between Fen and/or D-Fen and the outbreak of valvular heart disease is identified in our patients, confirming previous findings. The nephrotoxicity observed in 7 patients is due to the "chinese-herbs". When Fen and/or D-Fen are stopped and proper therapy initiated, the cardiac symptoms may stabilize or even subside, though slowly. Hemodynamic unstability and/or infection appear to be an aggravating factor. These patient's follow up must be prolonged for several years and is readily achieved with echocardiography. Systematic screening of all patients having taken Fen and/or D-Fen must be performed, as renal and urinary screening for all patients having taken chinese-herbs. Endocardial prophylaxis must always be prescribed.

Forssman penta- and tetraglycosylceramide are xenoantigens of ostrich kidney and liver

The heterophile antigens Galalpha1-->3Gal and N-glycolylneuraminic acid are the major obstacle to grafting mammal organs, especially from pig, to man. Lack of expression of these common xenoantigens by birds has raised interest in ostrich as a potential organ donor for xenotransplantation. Glycosphingolipids of ostrich liver and kidney were investigated for their carbohydrate determinants. Both organs were found similar in their glycolipid composition with three major species, mono-, di-, and pentaglycosylceramide. The pentaglycosylceramide was characterized as the Forssman antigen. In both organs, the ceramide portion was highly hydroxylated with prevalence of alpha-hydroxylated fatty acids, C18 phytosphingosine in kidney and C18 sphingosine in liver Forssman glycolipid. These data indicate that hydroxylation of kidney glycosphingolipids, which is found in mammals, has been maintained since the divergence of birds from other vertebrates. Characterization of a minor glycolipid as a Forssman tetraglycosylceramide built on the galabiosylceramide core indicates that the Forssman tetraglycosylceramide also exists in vivo. Its precursors, galactosyl- and galabiosylceramide, were characterized in kidney and liver. The Forssman antigen is the third heterophile antigen against which man raises natural antibodies. Its localization in the vascular endothelium and connective tissue makes ostrich an unpromising organ or cell donor for xenotransplantation to man.

Regulation of c-Myc and Max in megakaryocytic and monocytic-macrophagic differentiation of K562 cells induced by protein kinase C modifiers: c-Myc is down-regulated but does not inhibit differentiation

We have studied the regulation and role of c-Myc and Max in the differentiation pathways induced in K562 cells by 12-O-tetradecanoyl phorbol-13 acetate (TPA) and staurosporine, an activator and inhibitor, respectively, of protein kinase C (PKC). We found that staurosporine induced megakaryocytic differentiation, as revealed by the cellular ultrastructure, platelet formation, and DNA endoreduplication. In contrast, TPA induced a differentiated phenotype that more closely resembled that of the monocyte-macrophage lineage. c-myc expression was down-regulated in K562 differentiated by both TPA and staurosporine, whereas max expression did not change in either case. Although PKC enzymatic activity was low in cells terminally differentiated with TPA and staurosporine, inhibition of PKC activity by itself did not induce c-myc down-regulation. We conclude that the c-myc gene is switched off as a consequence of the differentiation process triggered by these drugs in a manner independent from PKC. Ectopic overexpression of c-Myc in K562 cells did not affect the monocytic-macrophagic and megakaryocytic differentiation, indicating that c-Myc suppression is not required for these processes in K562. Similarly, both differentiation pathways were not affected by Max overexpression or by concomitant overexpression of c-Myc and Max. This result is in contrast with the inhibition of erythroid differentiation of K562 exerted by c-Myc, suggesting divergent roles for c-Myc/Max, depending on the differentiation pathway.

Apoptosis and mitotic arrest are two independent effects of the protein phosphatases inhibitor okadaic acid in K562 leukemia cells

Treatment of human myeloid leukemia K562 cells with the serine/threonine protein phosphatases inhibitor okadaic acid induced mitotic arrest followed by apoptosis in a synchronized manner. The effect was observed at drug concentrations that inhibited the protein phosphatase type 2A but not type 1. We investigated whether apoptosis was a consequence of the preceding mitosis arrest or was induced independently by okadaic acid. We found that (1) apoptosis, but not mitotic arrest, was inhibited in cells with constitutive expression of Bcl-2; (2) pretreatment of cells with the DNA synthesis inhibitor hydroxyurea blocked the mitotic arrest but not the apoptosis mediated by okadaic acid; (3) down-regulation of c-myc gene was associated with apoptosis, but not with mitotic arrest; and (4) inhibition of protein synthesis abrogated mitotic arrest, but not apoptosis. The results suggest that inhibition of protein phosphatase 2A by okadaic acid provokes mitotic arrest and apoptosis of leukemia cells by independent mechanisms.

Lymphoid hypoplasia and somatic cloning

BACKGROUND

Adult somatic cloning by nuclear transfer is associated with high rate of perinatal mortality but there is still no evidence that nuclear transfer itself is responsible for these failures. We report on a longlasting defect linked to somatic cloning.

METHODS

Skin cells grown from an ear biopsy specimen from a 15-day-old calf were used as a source of nuclei. The donor animal was a clone of three females obtained from embryonic cells. Clinical examination, haematological, and biochemical profiles, and echocardiography of the somatic clone were done from birth to death.

FINDINGS

After 6 weeks of normal development, the somatic cloned calf had a sudden and rapid fall in lymphocyte count and a decrease in haemoglobin. The calf died on day 51 from severe anaemia. Necropsy revealed no abnormality except thymic atrophy and lymphoid hypoplasia.

INTERPRETATION

Somatic cloning may be the cause of long-lasting deleterious effects. Our observation should be taken into account in debates on reproductive cloning in human beings.