Consensus on performing skin biopsies, laboratory workup, evaluation of tissue samples and reporting of the results in patients with suspected cutaneous graft-versus-host disease

BACKGROUND

Histopathological diagnosis including selection of lesions, the determination of the best point of time for biopsy and workup is not trivial in cutaneous graft-versus-host disease (GvHD).

OBJECTIVES

To develop interdisciplinary recommendations on performing, the laboratory work up and reporting of the results of skin biopsies in patients with suspected cutaneous GvHD.

METHODS

A working group consisting of dermatopathologists, dermatologists, transplant-physicians and transplant-pathologists prepared recommendations for performing skin biopsies, laboratory workup and evaluation of tissue samples, and reporting of the results in patients with cutaneous GvHD. After achieving a consensus within the working group, a survey that comprised the core issues of the recommendations was electronically sent out to 72 alloHSCT centres within Germany, Austria, and Switzerland and their Departments of Pathology. The answers were discussed in a Consensus Conference and final recommendations were established.

RESULTS

Twenty-five centres responded to the clinical and 17 centres to the histopathological survey. Questions addressed to the clinicians comprised the indication for skin biopsy in chronic GvHD (cGvHD) and acute GvHD (aGvHD) and the appropriate point of time for skin biopsy. Eighty-eight per cent agreed that the skin biopsy is generally indicated in patients with suspected cGvHD lacking diagnostic features. In contrast, with suspected aGvHD, only 62% of respondents felt that skin biopsy was necessary even if GvHD had not been confirmed in another organ. Although restricted due to the fact that immunosuppression is often applied in an emergency setting most centres supported skin biopsies before initiation of topical or systemic immunosuppression. The majority of pathologists agreed that in non-sclerotic GvHD a punch biopsy is adequate, whereas in sclerotic GvHD a scalpel biopsy is preferred.

CONCLUSION

While a consensus on the need for biopsies in cGvHD was reached the value of skin biopsies in aGvHD and subsequent biopsies during therapy requires further evaluation.

Histopathological diagnosis of graft-versus-host disease of the skin: an interobserver comparison

BACKGROUND

Histopathology is an important tool in diagnosing cutaneous graft-versus-host disease (GvHD). Minimum diagnostic criteria for active chronic GvHD have recently been defined. However, they are not specific and their interpretation is dependent on observer judgement.

OBJECTIVE

AIMS OF THE STUDY

i) to explore interobserver variability in the interpretation of histopathological changes in GvHD, and ii) to analyse the impact of detailed clinical data on histopathological diagnosis of GvHD.

METHODS

Histopathological slides from 15 skin biopsies of GvHD and from dermatoses with histopathologically similar appearance were sent in two phases to four dermatopathologists experienced in cutaneous GvHD in France, Germany, Italy and Switzerland (first round of 'blind' review followed by a second round with complete clinical information provided).

RESULTS

Interface dermatitis, especially vacuolar alteration, was the most inconsistently evaluated, particularly in cases with minor alterations. Interestingly, for vacuolar alteration and apoptotic keratinocytes, interobserver variability was lower in the adnexal epithelia than in the interfollicular epidermis. Complete clinical information resulted in increased diagnostic confidence and greater concordance on the final diagnosis, rising from 53% (first round, k = 0.345, fair agreement) to 80% (second round, k = 0.529, moderate agreement). The percentage of correct diagnoses increased from 33.3% to 80%.

CONCLUSION

For the diagnosis of GvHD, histopathological analysis is of importance, but, for correct diagnosis, the correlation of pathological findings with clinical results is crucial. In cases of minor alteration, histopathologists should focus on the interpretation of vacuolar changes and apoptotic keratinocytes, possibly on the adnexal epithelia.

Human de novo papillary renal-cell carcinomas in a kidney graft: evidence of recipient origin with adenoma-carcinoma sequence

Papillary renal-cell carcinoma (pRCC) is unusual for its occurrence in kidneys with chronic dysfunction, for its frequent multifocality and for its common association with papillary adenoma, a benign renal lesion morphologically indistinguishable from pRCC. Concomitant development of papillary adenoma and pRCC in five transplanted kidneys, where donor and recipient characteristics are well established, provided a unique opportunity for molecular studies of de novo pRCC carcinogenesis. We aimed to study this tumor type to determine whether or not the different papillary tumors have the same origin, and whether or not papillary adenomas are precursor lesions of pRCC. We performed XY-FISH in sex-mismatched kidney transplants, and polymorphic microsatellite DNA and high-resolution melting of mitochondrial DNA analyzes in all five patients on laser-microdissected tumor cells, then compared these molecular profiles to donor and recipient profiles. This study (i) identified the recipient origin of de novo papillary adenomas and pRCCs in a kidney transplant, (ii) demonstrated an identical origin for precursor cells of papillary adenomas and pRCCs and (iii) showed additional genetic alterations in pRCCs compared to papillary adenomas. This molecular approach of papillary tumors developed in transplanted kidney identified successive steps in carcinogenesis of human de novo papillary renal-cell carcinoma.

Increased apoptosis is linked to severe acute GVHD in patients with Fanconi anemia

Fanconi anemia (FA) patients have an increased risk of acute GVHD (aGVHD) after hematopoietic SCT, with hypersensitivity to DNA-cross-linking agents and defective DNA repair. MicroRNA-34 and p53 can induce apoptosis after DNA damage.Here we assessed epithelial cell apoptosis, and studied TP53 and miR-34a expression in the skin and gut biopsies in five non-transplanted FA patients, in 20 FA patients with aGVHD and in 25 acquired aplastic anemia patients (AA). Epithelial apoptosis was higher in FA than in acquired AA patients in both the skin and gut biopsies, though they had a similar preparative regimen. Further study on gut biopsies in FA patients showed that this deleterious effect was not linked to TP53 gene overexpression. As, among p53-independent signaling pathways of apoptosis, the microRNA-34 family mimics p53 apoptotic effects in response to DNA damage, we studied miR-34a expression in the same series of FA patients' gut biopsies. MiR-34a expression level was higher in severe aGVHD compared with non-aGVHD subjects or non-transplanted patients, and significantly related to apoptotic cell numbers across the three groups of FA patients. Thus, in FA patients, increased apoptosis occurs in target epithelial cells of severe aGVHD, and this deleterious effect is linked to overexpression of miR-34a but not TP53.

The proteasome inhibitor bortezomib interacts synergistically with the histone deacetylase inhibitor suberoylanilide hydroxamic acid to induce T-leukemia/lymphoma cells apoptosis

Interactions between inhibitors of the proteasome and histone deacetylases have been examined in human T-leukemia/lymphoma cells both in vitro and in vivo. Co-exposure of cells to bortezomib and suberoylanilide hydroxamic acid (SAHA) synergistically induces T-leukemia/lymphoma cells to undergo apoptosis, consistent with a significant increase in mitochondrial injury and caspase activation. These events are accompanied by inhibition of cyto-protective signaling pathways, including the nuclear factor (NF)-kappaB, Raf-1/mitogen-induced extracellular kinase (MEK)/extracellular signal-related kinase (ERK) and AKT pathways, and activation of stress-related cascades, including the stress-activated kinases c-jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38MAPK). Moreover, bortezomib in conjunction with SAHA efficiently induces apoptosis of primary T-leukemia/lymphoma cells and inhibits tumor growth in a murine xenograft model established with subcutaneous injection of Jurkat cells. Taken together, these findings confirm the synergistic anti-tumor effect of the proteasome and histone deacetylase inhibitors, and provide an insight into the future clinical applications of bortezomib-SAHA combining regimen in treating T-cell malignancies.

Oral mucosa lesions in hypereosinophilic syndrome--an update

Hypereosinophilic syndrome (HES) is a rare disorder characterized by persistent and marked eosinophilia. Some HES forms have a poor prognosis, either because of end-organ damage (particularly endomyocardial fibrosis), or because of associated myeloid leukemia or malignant T-cell lymphoma. Oral mucosa ulcerations can be early clinical signs in severe forms. They are discrete, round or oval, sometimes confluent ulcers or erosions, located on non-keratinized, unattached oral mucosa. In the last 15 years a better understanding of eosinophil biology has led to a new clinical classification of HES. The lymphocytic form is characterized by T-lymphocyte clonality, IL-5 production, and a possible progression to T-cell lymphoma. Oral lesions are more frequently associated with the myeloproliferative form, characterized by an increased risk of developing myeloid malignancies and a good response to a recent anti-tyrosine kinase therapy (imatinib mesylate). The target of imatinib is a novel kinase resulting from an 800-kb deletion on chromosome 4. Recently, the resulting FIP1L1-PDGFRalpha fusion gene was characterized as a marker of response to imatinib. Exclusion of other erosive ulcerative oral disease and early recognition of HES in patients with oral ulcerations, and precise characterization of the lymphocytic or myeloproliferative form are therefore important to rapidly initiate an effective therapy.

Changes in allelic imbalances in locally advanced breast cancers after chemotherapy

In advanced breast cancers, TP53 mutation is highly predictive of complete response to high-dose epirubicin/cyclophosphamide chemotherapy. In these tumours with an altered control of genomic stability, accumulation of chemotherapy-induced genetic alterations may contribute to cell death and account for complete response. To explore the effects of chemotherapy on stability of the tumour genome, allelic profiles were obtained from microdissected tumour samples before and after chemotherapy in 29 unresponsive breast cancers (9 with TP53 mutation). Ninety-four per cent allelic profiles remained unchanged after treatment. Interestingly, 11 profiles (6%) showed important changes after treatment; allelic imbalances significantly increased (four cases) or decreased (seven cases) after chemotherapy in three distinct experiments, two of which using laser microdissected tumour cells. These genetic changes were not linked to the TP53 status, but one tumour showed complete disappearance of TP53-mutated cells in the residual tumour after treatment. Altogether, these observations carry important implications for the clonal evolution of breast cancers treated with DNA-damaging agents, as they point both to the importance of tumour heterogeneity and chemotherapy-driven selection of subclones.

Keratinocyte growth factor improves alterations of lung permeability and bronchial epithelium in allergic rats

Chronic allergic asthma is associated with marked inflammatory reaction, microvascular leakage and epithelium injury. As previously shown in a rat model of chronic asthma, these alterations increase lung permeability and distal airway fluid clearance. Keratinocyte growth factor (KGF) has been shown to induce epithelial cell proliferation and to protect from acute lung injuries. Therefore, the current authors evaluated the potential role of KGF treatment on lung permeability and airway inflammation in rats with chronic asthma. KGF (1 mg x kg(-1)) was administered intravenously before the last ovalbumin (OVA) challenge in sensitised rats. Permeability was assessed by the leak of radiolabelled albumin from the alveolar and systemic compartments. Histopathological analysis was also performed. Treatment with KGF decreased the leak of both markers and decreased the level of extravascular lung water in sensitised rats challenged with OVA. KGF treatment also reduced the inflammatory cell number in bronchoalveolar lavage fluid but not in bronchial mucosa. KGF markedly limited the allergen-induced alterations in epithelium integrity and the expression of the intercellular junction proteins beta-catenin and zonula occludens protein-1. In conclusion, keratinocyte growth factor administration markedly limits lung permeability and airway inflammation, an effect associated with a decrease in epithelium alterations during chronic allergic asthma. These data open new prospects in the therapeutic strategy of asthma.

Inactivation of the CDKN2A and the p53 tumour suppressor genes in external genital carcinomas and their precursors

BACKGROUND

p53 has been extensively studied in external genital carcinoma (EGC), and is frequently inactivated, but little is known about the role of the CDKN2A tumour suppressor gene in the oncogenesis of EGC.

OBJECTIVES

To investigate the role of CDKN2A and p53 in the pathogenesis of EGCs and their precursor lesions vulval intraepithelial neoplasia (VIN3), penile intraepithelial neoplasia and lichen sclerosus (LS).

METHODS

By means of CDKN2A and p53 mutation screening (single-strand conformational polymorphism analysis and sequencing), methylation analysis of alternative CDKN2A promoters (methylation-specific polymerase chain reaction) and p53 immununochemistry, we analysed eight invasive EGCs (five from vulva and three from penis) and 25 precancerous lesions (two undifferentiated VIN3 and 23 vulval/penile lesions of LS) from 33 patients.

RESULTS

p53 mutations (mainly transversions) and CDKN2A mutations (including one hot spot) were present in 75% and 50% of invasive tumours, respectively, but were absent in all precancerous lesions. Remarkably, all CDKN2A-mutated tumours also harboured a p53 mutation. CDKN2A or p53 mutations were observed more frequently in LS-derived EGCs than in human papillomavirus-derived EGCs (P = 0.053). A positive anti-p53 staining, but without p53 mutations, was also detected in 30% of LS lesions, suggesting a p53 stabilization in response to inflammation and carcinogenic insult. Methylation of p16(INK4a) and p14(ARF) promoters was not a frequent mechanism of CDKN2A inactivation.

CONCLUSIONS

Our study shows a high prevalence of co-inactivating mutations of p53 and/or CDKN2A genes in EGC, that seem to occur preferentially in LS-derived tumours and late in oncogenesis.

Localisation cutanée et épidurale d’une histiocytose de Rosai-Dorfman

BACKGROUND

Rosai-Dorfman disease, or sinus histiocytosis with massive lymphadenopathy, is a rare benign histiocytic proliferative lymph node disorder. Whereas the association of nodal and extranodal involvement is common, purely extranodal diseases are rare.

CASE-REPORT

We report the case of a thirty-year-old man with papulonodular skin lesions of the face and the legs initially followed by onset of hyposensitivity of the lower extremities. Histologic examination of a facial lesion showed a dermal polymorphous infiltrate, chiefly composed of large histiocytes, some of which contained intracytoplasmic lymphocytes and neutrophils, a process referred to as emperipolesis. Immunohistochemistry revealed positive staining of the histiocytes with anti-S100 protein and anti-CD68 antibodies and negative staining with anti-CD1a antibody. Magnetic resonance showed spinal cord compression linked to epidural involvement. We concluded on cutaneous and epidural Rosai-Dorfman disease. Neurological symptoms rapidly and partially resolved after intravenous corticosteroid therapy, which was followed by oral corticosteroid therapy and etoposide chemotherapy leading to the regression of the cutaneous lesions.

DISCUSSION

This case report of cutaneous and epidural Rosai-Dorfman disease is interesting because of the lack of lymph node involvement associated with the cutaneous lesions and because of the presence of an epidural site, rarely described in this disease.

Disruption of T cell regulatory pathways is necessary for immunotherapeutic cure of T cell acute lymphoblastic leukemia in mice

Acute lymphoblastic leukemia (ALL) is the most common cancer in children. In recent years, the outcome has been globally improved by current therapies, but it remains poor in patients with high, persistent residual disease following the first course of chemotherapy, prompting evaluation of the possible beneficial effects of immunotherapy protocols. In this study, we hypothesized that the disruption of two immunoregulatory pathways controlling the auto-reactive T cell response might synergize with dendritic cell-based immunotherapy of the disease, which is considered to be poorly immunogenic. In this study, we used TAL1xLMO1 leukemia cells adoptively transferred in mice, to generate murine leukemia with poorly immunogenic cells as a model for human T-ALL. Subsequently, these animals were treated with several different immunotherapeutic protocols. We compared the efficiency of a classical, dendritic cell-based immunotherapy (injection of dendritic cells loaded with tumor-derived antigenic products), to a combined treatment associating injection of antigen-loaded dendritic cells and disruption of the two immunoregulatory pathways: CD25+ suppressive T cells and cytotoxic T lymphocyte-associated antigens (CTLA-4). We show that this combined treatment resulted in cure, concomitantly with in vivo generation of immune memory, and TNF-alpha secretion. This study demonstrates that the disruption of these two immunoregulatory pathways synergized with immunostimulation by dendritic cells loaded with tumor-derived antigens, and paves the way for the testing of this combination in clinical trials.

Microsatellite instability and mutation analysis of candidate genes in urothelial cell carcinomas of upper urinary tract

A subset of upper urinary tract urothelial cell carcinomas (UUC), arising sporadically or as a manifestation of hereditary non-polyposis colorectal cancer, displays microsatellite instability (MSI). MSI tumours are characterized by defective mismatch repair and accumulation of frameshift mutations in numerous genes harbouring repeats in their coding sequences. We have evaluated the incidence of MSI in UUC and the intratumoral distribution of mutations in 13 candidate target genes. A total of 58 unselected UUC were screened for MSI using the panel of five mononucleotide markers recently recommended by the National Cancer Institute for a precise MSI assessment. Four tumours displayed MSI (7%), among which at least three had alterations in the genes MSH3, BAX, MRE11, RAD50. Mutations in genes involved in key cellular pathways (ATR, DNA-PKcs, MBD4, TCF-4, MSH6, and BLM) were further detected. BAX and MRE11 mutations tend to present homogeneously within the three MSI UUC. Immunohistochemistry (MLH1, MSH2, MSH6) showed that loss of mismatch repair protein expression occurred in all MSI UUC defining the gene defect and that MRE11 and RAD50 mutations were associated with their concomitant loss expression. In conclusion, MSI UUC represent a small proportion of UUC in which BAX and MRE11 mutations are frequent and may play a role early in UUC tumorigenesis.

Does one size fit all? Drug resistance and standard treatments: results of six tuberculosis programmes in former Soviet countries

SETTING

After the collapse of the Soviet Union, countries in the region faced a dramatic increase in tuberculosis cases and the emergence of drug resistance.

OBJECTIVE

To discuss the relevance of the DOTS strategy in settings with a high prevalence of drug resistance.

DESIGN

Retrospective analysis of one-year treatment outcomes of short-course chemotherapy (SCC) and results of drug susceptibility testing (DST) surveys of six programmes located in the former Soviet Union: Kemerovo prison, Russia; Abkhasia, Georgia; Nagorno-Karabagh, Azerbaijan; Karakalpakstan, Uzbekistan; Dashoguz Velayat, Turkmenistan; and South Kazakhstan Oblast, Kazakhstan. Results are reported for new and previously treated smear-positive patients.

RESULTS

Treatment outcomes of 3090 patients and DST results of 1383 patients were collected. Treatment success rates ranged between 87% and 61%, in Nagorno-Karabagh and Kemerovo, respectively, and failure rates between 7% and 23%. Any drug resistance ranged between 66% and 31% in the same programmes. MDR rates ranged between 28% in Karakalpakstan and Kemerovo prison and 4% in Nagorno-Karabagh.

CONCLUSION

These results show the limits of SCC in settings with a high prevalence of drug resistance. They demonstrate that adapting treatment according to resistance patterns, access to reliable culture, DST and good quality second-line drugs are necessary.

[Multinucleate cells angiohistiocytoma]

INTRODUCTION

Multinucleate cell angiohistiocytoma is a rare entity. We report two unusual cases of this lesion.

CASE REPORT

A 39 year-old man had presented since two years an arciform papular eruption of the forehead. A 40 year-old woman had a disseminated maculo-papular eruption since three years. Histological examination of skin samples of the two patients showed a dermal small vessel proliferation, associated with multinucleate cells, and confirmed the diagnosis of multinucleate cell angiohistiocytoma.

DISCUSSION

Our cases, typical histologically, have unusual clinical presentation (first case observed in a man, and the second in a disseminated form). Multinucleate cell angiohistiocytoma is a rare benign vascular proliferation individualized in 1985. Clinically, the lesion consists in small circumscribed papules. Acral sites and notably of the dorsum of the hands are the more frequent topography. It generally occurs in women aged over 50 years. Histologically, there is a dermal proliferation of capillaries and venules, and a fibrosis associated with the interstitial mononucleate cells and multinucleate cells.

Intra-individual comparison of the cutaneous safety and efficacy of calcitriol 3 microg g(-1) ointment and calcipotriol 50 microg g(-1) ointment on chronic plaque psoriasis localized in facial, hairline, retroauricular or flexural areas

BACKGROUND

Psoriasis involving sensitive skin areas remains difficult to treat because of the side-effects of topical corticosteroids and the irritancy potential of vitamin D3 derivatives. Several clinical trials have demonstrated that calcitriol, the naturally occurring and hormonally active form of vitamin D3, is effective and safe at the dose of 3 microg g(-1) for the treatment of psoriasis affecting the trunk and limbs.

METHODS

We compared the safety and efficacy of calcitriol 3 microg g(-1) ointment and calcipotriol 50 microg g(-1) ointment in a multicentre, randomized, investigator-blinded, left-right comparison in mild to moderate chronic plaque psoriasis affecting sensitive areas, defined as being the face, hairline, retroauricular and flexural areas. One pair of symmetrical and bilateral target lesions was selected from each area and assessed for perilesional erythema, oedema, and stinging/burning. Global assessment of local tolerability and global improvement were rated by the investigator, and the subjects were asked to evaluate the tolerability and efficacy of each product and to express their global preference.

RESULTS

In the 75 subjects, calcitriol and calcipotriol both led to clearing of at least one target lesion in 21 (28%) of the subjects each. Perilesional erythema (P < 0.001), perilesional oedema (P < 0.02) and stinging/burning (P < 0.001) were all significantly less severe with calcitriol than with calcipotriol. The subjects' evaluation of local tolerability was significantly (P < 0.0001) in favour of calcitriol. Ten treatment-related dermatological events occurred in eight subjects, including one subject who experienced skin discomfort on both sides. All other events occurred only on the calcipotriol-treated side (irritant dermatitis, six subjects; contact dermatitis, one subject). Global assessment of improvement from baseline by the investigators was significantly greater for the calcitriol-treated lesions (P < 0.02). The subjects' global preference was significantly in favour of calcitriol (P < 0.02).

CONCLUSIONS

In the present study, calcitriol ointment was found to be better tolerated and would appear to be more effective than calcipotriol ointment in the treatment of psoriasis in sensitive areas.

Histochemical and immunohistochemical protocols for routine biopsies embedded in Lowicryl resin

Tissue processing and analysis require good preservation of both the shape and content of cells. Lowicryl resin is one of the few embedding media that allow good preservation of both tissue architecture and cellular contents. Therefore, different histochemical and immunohistochemical reactions can be applied to semithin sister sections from one biopsy. Further examination of a zone of interest can be carried out under the electron microscope. The hydrophilic property of Lowicryl resins makes possible different histochemical reactions; however, the technique used for paraffin sections must be adapted for each reaction. Antigenic preservation of cells by low temperature embedding allows immunolabeling on either semithin sections or in the zone of interest on ultrathin sections. We have shown the application and adaptation of different histochemical and immunohistochemical reactions on semithin and ultrathin sections from hepatic biopsies that were large, but thin. The variety of techniques that can be used on sister Lowicryl sections of a single biopsy makes this medium useful for extensive pathological studies of precious needle biopsies.

Effect of mutated TP53 on response of advanced breast cancers to high-dose chemotherapy

TP53 activation by genotoxic drugs can induce apoptosis or cell-cycle arrest. Thus, whether the gene is mutated or wild type could affect the response of a tumour to chemotherapy. Clinical data are unclear, possibly as a result of heterogeneity of tumours, drugs, methods of assessing response, or TP53 status. We studied 50 non-inflammatory, locally advanced breast cancers that had been treated with high doses of a combination of epirubicin and cyclophosphamide. We noted eight complete responses, which all occurred in the 14 patients with tumours containing mutated TP53 (p<0.0001). In high-grade, advanced breast cancers, inactivation of the TP53 pathway could greatly improve the response to this chemotherapy regimen.

Acute flare-up of conjunctival graft-versus-host disease with eosinophil infiltration in a patient with chronic graft-versus-host disease

Chronic graft-versus-host disease (cGvHD) is a disabling alloimmune disease. Acute flare-ups of alloimmune reactions can occur even at the chronic clinical stage necessitating modulation of immunosuppression therapy. We studied conjunctival lesions of a patient with an acute flare-up in cGvHD. Along with severe GvHD lesions, biopsies showed eosinophils with pathological signs of activation. Since eosinophil recruitment and activation is observed in flare-ups of patients with autoimmune or inflammatory bowel diseases, we suggest that activated eosinophils in target organs may be a marker of evolutive lesions in alloimmune reactions as in other kinds of inflammatory diseases.

A new defensive mechanism to prevent apoptosis in salivary ductal cells from patients with Sjögren's syndrome: over-expression of p53 and p21

OBJECTIVE

In Sjögren's syndrome (SS), salivary acinar cells are destroyed even though ductal cells are frequently spared from destruction and can sometimes proliferate. We made the hypothesis that abnormalities of the tumour suppressor protein p53, either by mutations leading to proliferation or by activation of the functional wild-type p53, explain this phenomenon.

METHODS

Immunohistochemistry to detect p53 and its transcription target p21, which is expressed only if p53 is functional and not mutated, was performed on labial salivary glands (LSG) from 10 patients with primary SS, all of whom had a Chisholm grade 4 LSG biopsy, and from 10 control patients with sicca symptoms or systemic diseases and a normal LSG biopsy (grade 0 or 1).

RESULTS

The p53 antigen could be detected in ductal cells of nine of 10 LSG from SS patients and only one of 10 LSG from controls. The p21 antigen was detected in ductal cells of eight of 10 LSG from SS patients and two of 10 LSG from controls. The p53 and p21 antigens were localized in the same ductal cells in SS patients, and the positive ducts were those located around lymphoid foci.

CONCLUSION

The colocalization of p53 and its transcription factor p21 in salivary ductal cells surrounding lymphoid foci demonstrated that p53 was functional and not mutated. Its expression may be a defensive mechanism that provides ductal cells with time to repair DNA damage and prevents apoptosis. The lack of over-expression of p53 and p21 in acinar cells could be one of the key mechanisms of acinus destruction by apoptosis in SS and could be a target for new therapeutic strategies.

Endocan is a novel chondroitin sulfate/dermatan sulfate proteoglycan that promotes hepatocyte growth factor/scatter factor mitogenic activity

Proteoglycans that modulate the activities of growth factors, chemokines, and coagulation factors regulate in turn the vascular endothelium with respect to processes such as inflammation, hemostasis, and angiogenesis. Endothelial cell-specific molecule-1 is mainly expressed by endothelial cells and regulated by pro-inflammatory cytokines (Lassalle, P., Molet, S., Janin, A., Heyden, J. V., Tavernier, J., Fiers, W., Devos, R., and Tonnel, A. B. (1996) J. Biol. Chem. 271, 20458-20464). We demonstrate that this molecule is secreted as a soluble dermatan sulfate (DS) proteoglycan. This proteoglycan represents the major form either secreted by cell lines or circulating in the human bloodstream. Because this proteoglycan is specifically secreted by endothelial cells, we propose to name it endocan. The glycosaminoglycan component of endocan consists of a single DS chain covalently attached to serine 137. Endocan dose-dependently increased the hepatocyte growth factor/scatter factor (HGF/SF)-mediated proliferation of human embryonic kidney cells, whereas the nonglycanated form of endocan did not. Moreover, DS chains purified from endocan mimicked the endocan-mediated increase of cell proliferation in the presence of HGF/SF. Overall, our results demonstrate that endocan is a novel soluble dermatan sulfate proteoglycan produced by endothelial cells. Endocan regulates HGF/SF-mediated mitogenic activity and may support the function of HGF/SF not only in embryogenesis and tissue repair after injury but also in tumor progression.

Toxoplasmic pneumonitis leading to fatal acute respiratory distress syndrome after engraftment in three bone marrow transplant recipients

Toxoplasmosis is a rare but severe complication of bone marrow transplantation. Here, we report three patients in whom toxoplasmic pneumonitis developed, leading to fatal acute respiratory distress syndrome (ARDS). All patients had positive pretransplantation tests for Toxoplasma gondii and were therefore at risk to develop toxoplasmosis reactivation. They all recovered from aplasia, but soon after they died from brutal and severe ARDS. The possible role of an immunopathologic response to T gondii in the lungs in triggering ARDS is discussed.Early screening of parasitemia using highly sensitive polymerase chain reaction methods in seropositive patients with unexplained fever may be needed.