Lipid transfer protein sensitization: reactivity profiles and clinical risk assessment in an Italian cohort.

BACKGROUND: Nonspecific lipid transfer proteins (nsLTPs) represent a major cause of systemic food allergic reactions in the Mediterranean area. This study investigate hierarchical patterns and cluster relationships of IgE sensitization to different nsLTPs, and the relationship to clinical allergy in a large Italian cohort. METHODS: A total of 568 nsLTP-positive subjects after IgE ImmunoCAP-ISAC microarray analysis with Ara h 9, Art v 3, Cor a 8, Jug r 3, Pla a 3, Pru p 3 and Tri a 14 allergens were studied. IgE inhibition experiments were carried out with mugwort and plane tree pollen extracts. RESULTS: Eighty-two per cent of nsLTP-positive participants (94% if <6 years old) were Pru p 3(pos) , and 71% were Jug r 3(pos) . Participants who reacted to >5 nsLTPs reported a higher incidence of food-induced systemic reactions. Only Art v 3 and Pla a 3 (mugwort and plane tree nsLTPs, respectively) were associated with respiratory symptoms, and a correlation was observed between sensitization to pollen and plant food nsLTPs, particularly between Pla a 3 and tree nut/peanut nsLTPs. Co-sensitization to Par j 2 and PR-10 or profilin pan-allergens was associated with a lower prior prevalence of severe food-induced reactions. In inhibition assays, plane and mugwort pollen extracts inhibited 50-100% of IgE binding to food nsLTPs in microarrays. CONCLUSIONS: Testing IgE reactivity to a panel of nsLTP allergens unveils important associations between nsLTP sensitization profiles and clinical presentation and allows the identification of novel cluster patterns indicating likely cross-reactivities and highlighting potential allergens for nsLTP immunotherapy.

Peamaclein--a new peach allergenic protein: similarities, differences and misleading features compared to Pru p 3.

BACKGROUND: Among the peach-derived allergens which are already known, the lipid transfer protein (Pru p 3) seems to be the one to exert severe allergic reactions. OBJECTIVE: To identify and characterize a new peach allergen causing a clinical picture similar to that of Pru p 3. METHODS: Patients were selected on the basis of their severe clinical reactivity and negative results to a panel of peach allergens available on the ISAC103 microarray. Several in-house and commercial preparations were compared. Several methods were used to characterize the newly identified molecule. Specific IgE and inhibition assays were performed using the Allergen micro-Beads Array (ABA) assay. RESULTS: Negative ISAC results to Pru p 3 were confirmed by additional testing in contrast with the positive results obtained by commercial Pru p 3-enriched peach peel extracts. The analyses of one of these preparations led to the identification of Peamaclein, a new allergenic protein. It is a small, basic, cysteine-rich, heat-stable, digestion-resistant protein, homologous to a potato antimicrobial peptide. Peamaclein was able to trigger positive skin test reactions and to bind IgE in the ABA assay. It displays an electrophoretic mobility and chromatographic behaviour similar to that of Pru p 3; therefore, it can be hidden in Pru p 3 preparations. In fact, Pru p 3-enriched peach peel extracts were found to contain both Pru p 3 and Peamaclein by means of comparative in vivo testing, and by biochemical and immunochemical assays. Commercially available anti-Pru p 3 polyclonal antibodies were found to have a double specificity for the two molecules. CONCLUSIONS AND CLINICAL RELEVANCE: A new allergen from peach belonging to a new family of allergenic proteins has been identified and characterized. This knowledge on Peamaclein will improve our understanding on the clinical aspects of the peach allergy and the quality of diagnostic reagents.

Detection of IgG and IgE reactivity to BP180 using the ISAC® microarray system.

BACKGROUND: Bullous pemphigoid (BP) is an autoimmune skin disease in which patient autoantibodies react with BP180 and BP230 proteins. In addition to IgG, IgE has been shown to play a role in the disease. OBJECTIVES: To evaluate the feasibility of detecting IgE and IgG against the immunodominant BP180 NC16A domain (BP180) using a microarray system. METHODS: BP180 was immobilized on an experimental version of the ISAC(®) microarray (Exp96). The BP study group and the controls were all tested on the commercial ISAC 103 version and on the Exp96. IgG and IgE were measured in a single run. BP180 IgG and IgE results were compared with those using an enzyme-linked immunosorbent assay (ELISA). RESULTS: All results obtained using the IgG ELISA on the 31 patients with BP were replicated with the ISAC IgG. Five of eight BP sera tested by ELISA showed similar results with ISAC IgE. Twenty-nine (94%) and 19 (61%) of the 31 patients with BP were IgG and IgE positive to BP180, respectively, whereas four (3%) and six (4%) of 138 normal donors were IgG and IgE positive, respectively. Interestingly, the levels of IgG against BP180 detected using the ISAC system were related to the disease severity. Patients with BP showed a peculiar profile of IgE recognition toward some groups of allergens, which was absent in a group of allergic individuals. A significant, higher prevalence of hen's egg recognition was observed in patients with BP who had specific IgE to BP180. CONCLUSIONS: The present preliminary study indicates that the ISAC microarray system is suitable for detecting IgG and IgE autoantibodies in patients with BP. Notably, this system allows the assessment of IgE and IgG autoantibodies at the same time, could be employed for the detection of autoantibodies to other autoantigens, and allows profiling for specific IgE to allergens.

Proteomics plus genomics approaches in primary immunodeficiency: the case of immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) is a rare syndrome due to a mutation in the forkhead box protein 3 gene (FOXP3) leading to an impaired regulatory T cell (T(reg) ) activity associated both with skewed T helper type 2 (Th2) response and autoreactive phenomena. The purpose of this study was to describe a combined proteomics and genomics approach to comprehensively evaluate clinical and immunological phenotypes of patients affected by IPEX. T cell receptor (TCR)-Vß repertoire and peripheral blood lymphocytes phenotype from three brothers affected by IPEX were studied by flow cytometry. Specific immunoglobulin (Ig)E were evaluated by means of an allergenic molecules microarray [immuno solid-phase allergen chip (ISAC)]. Total RNA was extracted and hybridized to Affymetrix oligonucleotide arrays to obtain quantitative gene-expression levels. No FOXP3 protein was detectable within CD127(-) CD25(high) CD4(+) T cells from peripheral blood. A T cell-naive phenotype (CD62L(+) CD45R0(-)) associated with a reduction of both CD26 and CD7 expression and a TCR-Vß 8 and 22 family expansions were found. B lymphocytes were mainly CD5(+) (B1) cells expressing a naive phenotype (tcl1(+) CD27(-)). The three IPEX patients had severe food allergy and specific IgE reactivity to cow's milk allergens, a hen's egg allergen and a wheat allergen. Gene expression profile analysis revealed a dysregulation associated mainly with Th1/Th2 pathways. The multiplexing evaluation reported in this study represents a comprehensive approach in the assessment of genetic conditions affecting the immune system such as the IPEX syndrome, paving the way for the development of diagnostic tools to improve the standard clinical and immunological profiling of the disease.

Cross-sectional survey on immunoglobulin E reactivity in 23,077 subjects using an allergenic molecule-based microarray detection system.

BACKGROUND: The availability of allergenic molecules and high-throughput microtechnologies allow the collection of a large number of IgE results at the same time in a single test. This can be carried out applying the test in the routine diagnostic work-up. OBJECTIVE: The aim of this study was to make a cross-sectional evaluation of the raw prevalence of IgE reactivity to allergenic molecules in serum samples from a cohort of Italian patients using an innovative tool. METHODS: The ISAC, a microarray system, has been used for specific IgE detection using 75 different allergenic molecules. Sera were collected from 23,077 unselected consecutive individuals complaining about any allergic disease. RESULTS: Sixteen thousand four hundred and eight of 23,077 patients had IgE to at least one of 75 allergenic molecules. The top-ranked molecules in this cohort were Cup a 1 (42.7%), Der f 2 (38.7%), and Phl p 1 (37.9%), whereas all the other allergens tested scored in a range between 36.8% and 0.04%, including the first food allergen, Pru p 3, ranked 15th (9.79%). Prevalence varied quite markedly depending on the age range considered, and showing a different behaviour in the lifetime sensitization process. Unsupervised two-way hierarchical clustering analysis generated distinctive patterns of reactivity as the result of IgE recognition of either homologous allergens belonging to different biological sources or non-homologous belonging to the same biological source. CONCLUSIONS: Allergen-based microarray is a tool for the detection of IgE-related sensitization to panels of allergens and gives a more precise and comprehensive evaluation for an IgE-based epidemiology. This insight brings data for better understanding of the sensitization process.

Cryptic epitopes on alpha-fetoprotein induce spontaneous immune responses in hepatocellular carcinoma, liver cirrhosis, and chronic hepatitis patients.

To determine alpha-fetoprotein (AFP) immunogenicity in vivo, the presence of antibodies in sera of 60 hepatocellular carcinoma, 15 liver cirrhosis, and 15 chronic hepatitis patients was evaluated by Western blotting and immunoprecipitation analyses using purified human AFP. High titers of anti-AFP immunoglobulins were detected in 14 hepatocellular carcinomas (P = 0.0006), 3 liver cirrhosis (P = 0.0173), and 1 chronic hepatitis patient, but they were not detected in 40 healthy individuals. Therefore, spontaneous immune responses to AFP are significantly associated to liver diseases (P = 0.0015). Patient immunoglobulins recognized proteic linear epitopes that were cryptic in the native protein, as demonstrated by their restricted reactivity with denatured deglycosylated AFP. Thus, in pathological liver conditions, tolerance to this self-molecule is circumvented. The identification of AFP immunogenic epitopes may contribute to defining novel immunotherapeutic strategies targeting this antigen.

Chromosome 9 aberrations by fluorescence in situ hybridisation in bladder transitional cell carcinoma.

To investigate the role of the monosomy 9 in bladder carcinogenesis, 96 cases of superficial bladder transitional cell carcinoma (TCC) were studied and followed periodically for around 3 years (mean+/-standard error of the mean (SEM); 3.46+/-0.34 years). Samples from bladder washings were analysed by fluorescent in situ hybridisation (FISH) to detect numerical anomalies of chromosome 9. Moreover, to evaluate the relative under representation of this chromosome, we detected numerical changes of chromosome 8 and DNA ploidy by flow cytometric analysis (FCM). Chromosome 8 copy number were related to FCM DNA ploidy and both were related with tumour grade. Monosomy 9 did not correlate with tumour grade, stage, chromosome 8 aneuploidies and abnormal DNA content, but correlated with tumour progression. Comparing the results in the primary and subsequent tumours, we observed an increase in the frequency of aneuploidies by FCM, associated with an increase of chromosome 8 polysomies. The mean chromosome 9 copy number/nucleus remained nearly the same in most of the primary and invasive tumours. Our results confirm that monosomy 9 is an early event and that it is retained during tumour progression and invasion and that the loss occurs before the tetraploidisation process. The relationship between the presence of a sub-population with monosomy 9 and tumour progression suggests the presence of a region that could have a role in the progression of superficial bladder TCC.

Unusual chromosome patterns of renal cell carcinomas common to two brothers.

In this study, we describe two renal cell carcinomas (RCC) that occurred at the same time in two brothers, yielding information on the carcinogenic process. We used flow cytometry (FCM) to evaluate nuclear DNA content, and performed cytogenetic analysis. We also carried out fluorescence in situ hybridization (FISH) with a panel of centromeric probes for chromosomes 3, 7, 8, 9, 12, 17, 20, and Y in interphase cells. Flow cytometry analysis revealed diploid histograms in the tumor and "nonmalignant" samples of patient 1, while an aneuploid cell subpopulation was found in the tumor and "nonmalignant" samples of patient 2. Tumor samples from the two brothers were studied by FISH, and had common numerical chromosome aberrations: trisomy of chromosomes 3 and 7, and monosomy and trisomy of chromosomes 9 and 17. Moreover, in normal samples from both brothers, we found monosomy 9, and in a normal sample from patient 1, monosomy 17. Cytogenetic analysis revealed trisomy 3 in some cells grown from normal kidney tissue of each brother. The identification of the same chromosome alterations in both brothers appears to provide evidence of an unusual process of carcinogenesis, probably due to a common genetic basis.

An unusual case of ascites.

A 76-year-old woman with abdominal pain and diarrhoea developed ascites that did not respond to treatment. There were no signs of liver damage. Abdominal ultrasonography with colour Doppler revealed an arterial-like flow in the enlarged splenic vein. Using selective mesenteric arteriography, we were able to diagnose a shunt between the inferior mesenteric artery and the inferior mesenteric vein. This is an unusual case of ascites due to prehepatic portal hypertension secondary to an extrahepatic arterioportal fistula.

Serum-induced basophil CD63 expression by means of a tricolour flow cytometric method for the in vitro diagnosis of chronic urticaria.

BACKGROUND: Functional autoantibodies against the alpha-chain of the high-affinity IgE receptor (FcepsilonRIalpha) identify a subset of patients with chronic urticaria (CU) due to autoreactivity, as assessed by an in vivo positive response to autologous serum skin test (ASST). We performed a study to standardize the serum-induced basophil activation assay by flow cytometry (FCM) using a new tricolour method, assessing the diagnostic performance of this test in discriminating between ASST+ and ASST- CU patients. METHODS: Sera of 64 CU patients (22 ASST+ CU and 42 ASST- CU) and 10 healthy subjects were tested for their ability to induce basophil CD63 expression when incubated with whole blood of both atopic (DA) and non-atopic donors (DNA). Using a triple-labelled strategy with anti-CD123, anti-HLA-DR and anti-CD63 antibodies, CD63+ basophils were identified on a selected population of CD123+ HLA-DR- cells. In 3 ASST+ CU patients who underwent cyclosporine therapy, the assay was performed before and after treatment. RESULTS: The ASST+ CU sera resulted in a significant higher induction of basophil CD63 expression compared with ASST- CU and healthy donors sera; when whole blood from DA was used, sensitivity and specificity of the assay were 95.5% and 90.5% respectively. ASST+ CU serum activity was significantly decreased during cyclosporine A treatment, in parallel with clinical remission. CONCLUSIONS: Chronic urticaria serum-induced CD63 expression assay performed on DA whole blood by means of our tricolour FCM method could be the most useful tool for identification of a subset of patients with autoimmune CU and may become a promising tool also for monitoring treatment efficacy.

Bladder transitional cell carcinomas: a comparative study of washing and tumor bioptic samples by DNA flow cytometry and FISH analyses.

OBJECTIVE AND METHODS: We compared information obtained from samples of tumor biopsy and bladder washing to evaluate the representatives of the latter type of sampling. Both types of samples from 44 cases of superficial bladder TCCs and one papilloma were analyzed by FCM, to evaluate cellular DNA content, and FISH, to detect numerical aberration of chromosome 9. RESULTS: The use of both tumor and washing samples by FCM and FISH analyses evidenced alterations in 95% of cases. FCM evidenced higher aneuploid frequency in bladder washing than in bioptic specimens. In bladder washing, FISH analysis showed higher frequency of monosomy and lower frequency of trisomy than in biopsy. No correlation was found between histological grade and centromeric chromosome 9 loss while correlation was evidenced with centromeric 9 gain. CONCLUSION: Irrigation specimens, analyzed by FCM and FISH, can complement information obtained by biopsy in cytodiagnosis and follow-up of patients with bladder TCC.

Expression and cell distribution of the intercellular adhesion molecule, vascular cell adhesion molecule, endothelial leukocyte adhesion molecule, and endothelial cell adhesion molecule (CD31) in reactive human lymph nodes and in Hodgkin's disease.

The immunocytochemical expression of intercellular adhesion molecule (ICAM-1), vascular cell adhesion molecule (VCAM-1), endothelial leukocyte adhesion molecule (ELAM-1), endothelial cell adhesion molecule (EndoCAM CD31), and HLA-DR antigens was investigated in sections of 24 reactive lymph nodes and in 15 cases of Hodgkin's disease. ICAM-1 was detected in sinus macrophages, follicular dendritic reticulum cells (FDRCs), interdigitating reticulum cells (IDRCs), epithelioid macrophages, Hodgkin's cells (HCs), and vascular endothelium. ICAM-1 expression was often associated with that of HLA-DR antigens. VCAM-1 was detected in FDRCs, in fibroblast reticulum cells (FRCs), in macrophages, and in rare blood vessels. EndoCAM (CD31) was constitutively expressed in all types of endothelial cells, sinus macrophages, and in epithelioid granulomas. ELAM-1 was selectively expressed by activated endothelial cells of high endothelium venules (HEVs). When expression of the inducible adhesion molecules ICAM-1, VCAM-1 and ELAM-1 was comparatively evaluated in HEVs, it was found that ICAM-1 + HEVs were present in all reactive and HD nodes, whereas ELAM-1 and/or VCAM-1 were expressed only in those pathologic conditions characterized by high levels of interleukin-1/tumor necrosis factor (IL-1/TNF) production, such as granulomatosis and Hodgkin's disease. In Hodgkin's disease, the expression of ELAM-1/VCAM-1 was more pronounced in cases of nodular sclerosis and was associated with a significantly higher content of perivascular neutrophils.

Immunoreactivity for IL-1 beta and TNF alpha in human lymphoid and nonlymphoid tissues.

Monoclonal antibodies (MAbs) against two non-cross-reacting antigens of human IL-1 beta (Vhp20 and BRhC3) and human TNF alpha (B154.2 and B154.7) were applied to identify cytokine-containing cells in tissue sections and in cell suspensions. IL-1 beta- or TNF alpha-positive cells were not present in immunostained cytocentrifuge smears prepared from freshly isolated peripheral blood leukocytes, spleen, and lymph node cells. After 18 hours of culture with bacterial endotoxin (LPS), 80% to 90% of blood monocytes, 30% of spleen macrophages, and 2% to 28% of lymph node macrophages were strongly positive for IL-1 beta with either of the MAbs. Furthermore, 25% to 35% of blood monocytes and 6% to 60% of lymph node macrophages were stained for TNF alpha. Cells positive for IL-1 beta or TNF alpha were extremely rare in sections of normal thymus, spleen, and lymph nodes. Immunoreactivity for IL-1 beta or TNF alpha was frequently observed in sections of granulomatous lymphadenitis (N = 11). IL-1 beta or TNF alpha staining was confined to the epithelioid macrophages forming the granuloma, and the intensity of TNF alpha reactivity was generally stronger. The high frequency of cytokine-containing cells in this pathologic condition was confirmed in a cell suspension study showing that 20% of epithelioid macrophages were weakly positive for IL-1 beta and 80% were strongly positive for TNF alpha. The presence of cytokine-containing cells was investigated in cryostat sections of several nonlymphoid organs with normal histologic appearance. IL-1 beta reactivity was not observed in any of the tissues. TNF alpha reactivity was frequently demonstrated in isolated macrophages embedded in the interstitial connective tissue.

Expression of ICAM-1, VCAM-1 and ELAM-1 in angiofollicular lymph node hyperplasia (Castleman's disease): evidence for dysplasia of follicular dendritic reticulum cells.

The inducible adhesion molecules mediate important functions in the lymphoid tissues. We have investigated the expression of intercellular adhesion molecule 1 (ICAM-1), endothelial leucocyte adhesion molecule 1 (ELAM-1), vascular cell adhesion molecule 1 (VCAM-1), and platelet endothelial cell adhesion molecule (PECAM/CD31), using immunocytochemistry on cryostat sections of five lymph nodes from patients with Castleman's disease of the hyaline-vascular type. All five cases were characterized by marked hyperplasia of follicular dendritic reticulum cells, which were extensively present even in the mantle zone. Hyperplastic follicular dendritic reticulum cells showed marked expression of VCAM-1, and weak expression of ICAM-1. In two cases, several dysplastic giant cells with aberrant, polyploid nuclei showed aberrant expression of ELAM-1, an endothelium-restricted molecule. Dysplastic giant cells were positive with DRC-1 (an antibody to dendritic reticulum cells), VCAM-1 and occasionally ICAM-1, were negative for the endothelial cell markers factor VIII-related antigen and CD31 and were non-proliferating (Kl-67-). Cells positive for ICAM-1 or VCAM-1 were rare in the interfollicular areas. In all cases vascular hyperplasia was prominent, but endothelial cells were poorly activated in terms of expression of inducible adhesion molecules and of HLA-DR antigens. The possibility that dysplastic follicular dendritic reticulum cells have a pathogenetic role in Castleman's disease is discussed.

Macrophages and interdigitating reticulum cells in normal human thymus and thymomas: immunoreactivity for interleukin-1 alpha, interleukin-1 beta and tumour necrosis factor alpha.

Pairs of monoclonal/polyclonal antibodies directed against interleukin-1 (IL-1) alpha, IL-1 beta and tumour necrosis factor (TNF) alpha were used for immunocytochemical identification of cytokine-containing cells in cryostat sections of human fetal thymuses and thymomas. In the fetal thymus immunoreactivity for IL-1 alpha was mainly confined to the medulla and was detected in S-100 positive interdigitating reticulum cells. The pattern of immunoreactivity for IL-1 beta was similar to that for IL-1 alpha, but the number of positive cells was much lower. Cells positive for TNF alpha were extremely rare in the fetal thymus. In 11 thymomas macrophages were constantly present and were regularly distributed throughout the tumour, whereas S-100 positive interdigitating reticulum cells were fewer and were characterized by a zonal distribution. Thymoma-associated macrophages were negative for IL-1 beta and were poorly reactive for IL-1 alpha, only a few positive cells being detected in five of the cases. Some macrophages with immunoreactivity for TNF alpha were detected in seven cases; they formed rosettes with surrounding lymphocytes or were located in a perivascular position. A marked immunoreactivity for TNF alpha was constantly detected in mast cell granules, which were observed in nine thymomas but not in fetal thymus. Positive immunoreactivity of interdigitating reticulum cells for IL-1 alpha was confirmed in five reactive lymph nodes and was also observed in Langerhans' cells in dermatopathic lymphadenitis. Our findings suggest that IL-1 alpha is a crucial molecule for interdigitating reticulum cell and Langerhans' cell function.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytokine production (IL-1 alpha, IL-1 beta, and TNF alpha) and endothelial cell activation (ELAM-1 and HLA-DR) in reactive lymphadenitis, Hodgkin's disease, and in non-Hodgkin's lymphomas. An immunocytochemical study.

Cryostat sections of 58 lymph nodes were immunostained with a polyclonal rabbit serum against IL-1 alpha, and with monoclonal antibodies directed to IL-1 alpha (Vmp18), IL-1 beta (Vhp20 and BRhC3), and tumor necrosis factor alpha (TNF alpha) (B154.7). Furthermore the presence of cytokine-containing cells was correlated with the expression of endothelial leukocyte adhesion molecule (ELAM-1; 29F2) and of human leukocyte antigen (HLA-DR) (OKIa-1) by endothelial cells. Cells containing IL-1 and/or TNF alpha were detected mainly in pathologic conditions characterized by reactive or neoplastic expansion of the lymph node paracortex. Cells positive for IL-1 were detected in 16 of 21 cases of Hodgkin's disease, in 4 of 4 cases of T-NHL, and in 5 cases of diffuse or mixed lymphadenitis. Interleukin-1 alpha was detected in macrophages, interdigitating reticulum cells (IDRCs), endothelial cells, and neoplastic Hodgkin's and Reed-Sternberg (H-RS) cells. Cells positive for IL-1 beta were much fewer and consisted mainly of macrophages. Hodgkin's Reed-Sternberg cells were negative for IL-1 beta even after in vitro stimulation with bacterial endotoxin. Tumor necrosis factor alpha (TNF alpha) was present in macrophages and H-RS cells. Endothelial leukocyte adhesion molecule-1 expression by endothelial venules was detected in 17 of 20 cases of Hodgkin's disease, in 2 of 4 cases of T-NHL, and in 5 of 5 cases of diffuse lymphadenitis. In these pathologic conditions, HLA-DR antigens also were expressed frequently by endothelial cells. Cytokine-containing cells and ELAM-1-positive high endothelial venules (HEV) were extremely rare in lymph nodes involved by follicular lymphadenitis (12 cases) or B-NHL (16 cases). In cases of reactive or neoplastic B-cell proliferations, HLA-DR-positive HEVs still were present often. Our results indicate that IL-1/TNF alpha production at tissue level is often associated with ELAM-1 expression by HEVs, but is less well correlated with expression of HLA-DR antigens by endothelial cells.

HIV infection increases the risk of squamous intra-epithelial lesions in women with HPV infection: an analysis of HPV genotypes. DIANAIDS Collaborative Study Group.

We assessed the association between different HPV genotypes, HIV infection, and cervical squamous intra-epithelial lesions (SIL) in 236 women with known HIV serostatus enrolled in a longitudinal multicentric study in Italy. Of these women, 135 were HIV-infected, and were not markedly different from HIV-negative women with regard to demographic characteristics, sexual practices, smoking, or intravenous drug use. We obtained 232 cervical smears suitable for cytological examination and HPV-genotype analysis (134 from HIV-positive women and 98 from HIV-negative women). For 86 HIV-positive and 89 HIV-negative women, the smears appeared normal at cytomorphological analysis. Cytological dysplasia of varying degrees was detected in 48 smears from HIV-positive women and in 9 from HIV-negative women. HPV prevalence, assessed using polymerase-chain-reaction analysis, did not significantly differ between HIV-positive and HIV-negative women. The prevalence of HPV-associated SIL was much greater among HIV-infected women. The most frequently detected genotypes in both groups were HPV 16 and HPV 18. The prevalence of HPV 16 among HIV-positive women was similar to that for HIV-negative women; this was also true for HPV 18. However, in the HIV-positive group, most of these genotypes were associated with SIL. HIV-positive women showed a wider spectrum of genotypes, including non-oncogenic and rare types. An association between SIL and HIV infection was confirmed for all HPV genotype classes.