Engineered mucoperiosteal scaffold for cleft palate regeneration towards the non-immunogenic transplantation.

Cleft lip and palate (CL/P) is the most prevalent craniofacial birth defect in humans. None of the surgical procedures currently used for CL/P repair lead to definitive correction of hard palate bone interruption. Advances in tissue engineering and regenerative medicine aim to develop new strategies to restore palatal bone interruption by using tissue or organ-decellularized bioscaffolds seeded with host cells. Aim of this study was to set up a new natural scaffold deriving from a decellularized porcine mucoperiosteum, engineered by an innovative micro-perforation procedure based on Quantum Molecular Resonance (QMR) and then subjected to in vitro recellularization with human bone marrow-derived mesenchymal stem cells (hBM-MSCs). Our results demonstrated the efficiency of decellularization treatment gaining a natural, non-immunogenic scaffold with preserved collagen microenvironment that displays a favorable support to hMSC engraftment, spreading and differentiation. Ultrastructural analysis showed that the micro-perforation procedure preserved the collagen mesh, increasing the osteoinductive potential for mesenchymal precursor cells. In conclusion, we developed a novel tissue engineering protocol to obtain a non-immunogenic mucoperiosteal scaffold suitable for allogenic transplantation and CL/P repair. The innovative micro-perforation procedure improving hMSC osteogenic differentiation potentially impacts for enhanced palatal bone regeneration leading to future clinical applications in humans.

NOTCH1 mutations are associated with high CD49d expression in chronic lymphocytic leukemia: link between the NOTCH1 and the NF-κB pathways.

In chronic lymphocytic leukemia (CLL), stabilizing mutations of NOTCH1, affecting up to 10-15% of cases, have been associated to poor prognosis, disease progression and refractoriness to chemotherapy. NOTCH1 mutations are significantly overrepresented in trisomy 12 CLL, a disease subset frequently expressing CD49d, the α4 chain of the very-late-activation-4 integrin, a well-known key regulator of microenviromental interactions, and negative prognosticator in CLL. In the present study, by analysing a wide cohort of 1180 CLL, we observed a very strong association between the presence of NOTCH1 mutations and the expression of CD49d (P<0.0001), occurring also outside the trisomy 12 CLL subset. Using both the MEC-1 CLL-like cells stably transfected with the NOTCH1 intracellular domain and primary CLL cells bearing a mutated or wild-type NOTCH1 gene configuration, we provide evidence that triggering of the NOTCH1 pathway resulted in a positive CD49d expression regulation, which was driven by a NOTCH1-dependent activation of nuclear factot-κB (NF-κB). Consistently, pharmacological inhibition of the NOTCH1 and/or of the NF-κB pathways resulted in impaired NF-κB nuclear translocation with consequent down-modulation of CD49d expression. Altogether, our data link for the first time NOTCH1 mutations to CD49d expression regulation through the involvement of the NF-κB pathway in CLL.

NOTCH1-mutated chronic lymphocytic leukemia cells are characterized by a MYC-related overexpression of nucleophosmin 1 and ribosome-associated components.

In chronic lymphocytic leukemia (CLL), the mechanisms controlling cell growth and proliferation in the presence of NOTCH1 mutations remain largely unexplored. By performing a gene expression profile of NOTCH1-mutated (NOTCH1-mut) versus NOTCH1 wild-type CLL, we identified a gene signature of NOTCH1-mut CLL characterized by the upregulation of genes related to ribosome biogenesis, such as nucleophosmin 1 (NPM1) and ribosomal proteins (RNPs). Activation of NOTCH1 signaling by ethylenediaminetetraacetic acid or by coculture with JAGGED1-expressing stromal cells increased NPM1 expression, and inhibition of NOTCH1 signaling by either NOTCH1-specific small interfering RNA (siRNA) or γ-secretase inhibitor reduced NPM1 expression. Bioinformatic analyses and in vitro activation/inhibition of NOTCH1 signaling suggested a role of MYC as a mediator of NOTCH1 effects over NPM1 and RNP expression in NOTCH1-mut CLL. Chromatin immunoprecipitation experiments performed on NOTCH1 intracellular domain (NICD)-transfected CLL-like cells showed the direct binding of NOTCH1 to the MYC promoter, and transfection with MYC-specific siRNA reduced NPM1 expression. In turn, NPM1 determined a proliferation advantage of CLL-like cells, as demonstrated by NPM1-specific siRNA transfection. In conclusion, NOTCH1 mutations in CLL are associated with the overexpression of MYC and MYC-related genes involved in protein biosynthesis including NPM1, which are allegedly responsible for cell growth and/or proliferation advantages of NOTCH1-mut CLL.

HLA-G regulatory polymorphisms are associated with susceptibility to HCV infection.

BACKGROUND: Hepatitis C virus (HCV) is able to bypass the immune system modulating innate and adaptive immune response and blocking T helper 1 (Th1) cell production. Because the human leukocyte antigen (HLA)-G molecule has immunomodulatory properties inhibiting the function and production of natural killer and cytotoxic lymphocyte T cells, as well as promoting shift from Th1 toward Th2 response, we hypothesized its involvement in susceptibility to HCV infection. MATERIALS AND METHODS: Considering that HLA-G mRNA expression has been reported to be under genetic control, an association study was conducted analyzing 800 base pairs upstream the ATG at the 5'upstream regulator region (URR) and 850 base pairs from ATG to exon 3 and the 3'untranslated region (UTR) of HLA-G gene in Italian HCV-positive patients and uninfected controls. RESULTS: Four 5'URR polymorphisms (-725C>G>T, -509C>G, -400G>A and -398G>A), 7 polymorphisms at coding region (+15G>A, +36G>A, +243G>A, insC506, 531G>C, delA615 and 685G>A), the +644G>T polymorphism, and 1 haplotype (TTGTTCCIGAC) showed different frequency distributions between HCV patients and uninfected controls. CONCLUSION: The results from our study suggest a possible involvement of HLA-G in the risk modulation toward HCV infection.

MBL2 Genetic Variants in HCV Infection Susceptibility, Spontaneous Viral Clearance and Pegylated Interferon Plus Ribavirin Treatment Response.

Hepatitis C is disease that damages the liver, and it is caused by the hepatitis C virus (HCV). The pathology became chronic in about 80% of the cases due to virus persistence in the host organism. The standard of care consists of pegylated interferon plus ribavirin; however, the treatment response is very variable and different host/viral factors may concur in the disease outcome. The mannose-binding protein C (MBL) is a component of the innate immune system, able to recognize HCV and consecutively activating the immune response. MBL is encoded by MBL2 gene, and polymorphisms, two in the promoter region (H/L and X/Y) and three in exon 1 (at codon 52, 54 and 57), have been described as functionally influencing protein expression. In this work, 203 Italian HCV patients and 61 healthy controls were enrolled and genotyped for the five MBL2 polymorphisms mentioned above to investigate their role in HCV infection susceptibility, spontaneous viral clearance and treatment response. MBL2 polymorphisms were not associated with HCV infection susceptibility and with spontaneous viral clearance, while MBL2 O allele, O/O genotype, HYO haplotype and DP combined genotype (all correlated with low or deficient MBL expression) were associated with sustained virological response. Moreover, a meta-analysis to assess the role of MBL2 polymorphisms in HCV infection susceptibility was also performed: YA haplotype could be associated with protection towards HCV infection.

CD49d prevails over the novel recurrent mutations as independent prognosticator of overall survival in chronic lymphocytic leukemia.

CD49d, the alpha-chain of the integrin heterodimer α4ß1, was identified among the strongest predictors of overall survival (OS) in chronic lymphocytic leukemia (CLL), along with IGHV mutational status and deletion of the 17p chromosome involving TP53. In addition to TP53, the clinical relevance of NOTCH1, SF3B1 and BIRC3 gene mutations has been recently emphasized. By analyzing a cohort of 778 unselected CLL patients, we assessed the clinical relevance of CD49d as an OS predictor in subgroups defined by mutation/deletion of the TP53, NOTCH1, SF3B1 and BIRC3 genes. In this context, CD49d emerged as an independent predictor of OS in multivariate Cox analysis (Hazard ratio =1.88, P<0.0001). Consistently, high CD49d expression identified CLL subsets with inferior OS in the context of each category of a previously reported hierarchical risk stratification model. Moreover, by evaluating the relative importance of biological prognosticators by random survival forests, CD49d was selected among the top-ranked OS predictor (variable importance =0.0410), along with IGHV mutational status and TP53 abnormalities. These results confirmed CD49d as an independent negative OS prognosticator in CLL also in comprehensive models comprising the novel recurrent mutations. In this context, TP53 disruption and NOTCH1 mutations retained prognostic relevance, in keeping with their roles in CLL cell immuno-chemoresistance.

NOTCH1 mutations associate with low CD20 level in chronic lymphocytic leukemia: evidence for a NOTCH1 mutation-driven epigenetic dysregulation.

In chronic lymphocytic leukemia (CLL), NOTCH1 mutations have been associated with clinical resistance to the anti-CD20 rituximab, although the mechanisms behind this peculiar behavior remain to be clarified. In a wide CLL series (n=692), we demonstrated that CLL cells from NOTCH1-mutated cases (87/692) were characterized by lower CD20 expression and lower relative lysis induced by anti-CD20 exposure in vitro. Consistently, CD20 expression by CLL cells was upregulated in vitro by γ-secretase inhibitors or NOTCH1-specific small interfering RNA and the stable transfection of a mutated (c.7541-7542delCT) NOTCH1 intracellular domain (NICD-mut) into CLL-like cells resulted in a strong downregulation of both CD20 protein and transcript. By using these NICD-mut transfectants, we investigated protein interactions of RBPJ, a transcription factor acting either as activator or repressor of NOTCH1 pathway when respectively bound to NICD or histone deacetylases (HDACs). Compared with controls, NICD-mut transfectants had RBPJ preferentially complexed to NICD and showed higher levels of HDACs interacting with the promoter of the CD20 gene. Finally, treatment with the HDAC inhibitor valproic acid upregulated CD20 in both NICD-mut transfectants and primary CLL cells. In conclusion, NOTCH1 mutations are associated with low CD20 levels in CLL and are responsible for a dysregulation of HDAC-mediated epigenetic repression of CD20 expression.

The CD49d/CD29 complex is physically and functionally associated with CD38 in B-cell chronic lymphocytic leukemia cells.

CD49d and CD38 are independent negative prognostic markers in chronic lymphocytic leukemia (CLL). Their associated expression marks a disease subset with a highly aggressive clinical course. Here, we demonstrate a constitutive physical association between the CD49d/CD29 integrin complex and CD38 in primary CLL cells and B-cell lines by (i) cocapping, (ii) coimmunoprecipitation and (iii) cell adhesion experiments using CD49d-specific substrates (vascular-cell adhesion molecule-1 or CS-1/H89 fibronectin fragments). The role of CD38 in CD49d-mediated cell adhesion was studied in CD49d(+)CD38(+) and CD49d(+)CD38(-) primary CLL cells, and confirmed using CD38 transfectants of the originally CD49d(+)CD38(-) CLL-derived cell line Mec-1. Results indicate that CD49d(+)CD38(+) cells adhered more efficiently onto CD49d-specific substrates than CD49d(+)CD38(-) cells (P < 0.001). Upon adhesion, CD49d(+)CD38(+) cells underwent distinctive changes in cell shape and morphology, with higher levels of phosphorylated Vav-1 than CD49d(+)CD38(-) cells (P = 0.0006) and a more complex distribution of F-actin to the adhesion sites. Lastly, adherent CD49d(+)CD38(+) cells were more resistant to serum-deprivation-induced (P < 0.001) and spontaneous (P = 0.03) apoptosis than the CD49d(+)CD38(-) counterpart. Altogether, our results point to a direct role for CD38 in enhancing CD49d-mediated adhesion processes in CLL, thus providing an explanation for the negative clinical impact exerted by these molecules when coexpressed in neoplastic cells.

Oral lesions and lymphoproliferative disorders.

Lymphoproliferative disorders are heterogeneous malignancy characterized by the expansion of a lymphoid clone more or less differentiated. At the level of the oral cavity, the lymphoproliferative disorder can occur in various ways, most commonly as lymphoid lesions with extranodal externalization, but sometimes, oral lesions may represent a localization of a disease spread. With regard to the primary localizations of lymphoproliferative disorders, a careful examination of the head and neck, oral, and oropharyngeal area is necessary in order to identify suspicious lesions, and their early detection results in a better prognosis for the patient. Numerous complications have been described and frequently found at oral level, due to pathology or different therapeutic strategies. These complications require precise diagnosis and measures to oral health care. In all this, oral pathologists, as well as dental practitioners, have a central role in the treatment and long-term monitoring of these patients.

[Fibronectin gene polymorphisms and clinical manifestations of mixed cryoglobulinemic syndrome: increased risk of lymphoma associated to MspI DD and HaeIII AA genotypes]. / Polimorfismi del gene della fibronectina e manifestazioni cliniche della sindrome crioglobulinemica: aumentato rischio di linfoma legato ai genotipi MspI DD e HaeIII AA.

OBJECTIVE: To analyse FN gene polymorphisms in type II mixed cryoglobulinemic syndrome (MCsn), an immune-complex mediated systemic vasculitis linked to hepatitis C virus (HCV) infection and characterized by rheumatoid factor (RF) positive B-cell proliferation at high risk for the progression into non Hogkin's lymphoma (NHL). METHODS: Samples from eighty-one patients, with MCsn (type II serum cryoglobulins and clinical signs of vasculitis were studied. Sixty-five (65/81, 80.3%) patients were HCV-positive. Twenty-one (25.9%) patients had developed a B-cell NHL during the course of MCsn. Seventy-two patients with HCV-negative and MC-unrelated NHL and 110 healthy blood donors (HBDs) were taken as controls. HaeIIIb and MspI FN gene polymorphisms were analysed by ELISA, whenever possible. RESULTS: HaeIIIb and MspI allele and genotypic frequencies did not differ between MCsn patients and HBDs. Of note, the DD-MspI allele and genotype frequencies did not differ between MCsn patients and HBDs. Of note, the DD-MspI (OR = 5.56; DI = 1.67-18.51, p = 0.0046) and the AA-HaeIIIb (OR = 5.54, CI = 1.64- 18.76, p = 0.0066) homozygosis appeared significantly and independently associated with the development of B-cell NHL in MCsn patients, with the HaeIIIbA allele possibly conferring an increased risk of NHL in the general population (OR = 1.72, CI = 1.128-2.635, p = 0.0133). In contrast, the major vasculitic manifestations, such as peripheral neuropathy, skin ulcers and glomerulonephritis tended to be associated with the counterpart MspI C allele. No association between FN plasma levels and FN genotypes was found. CONCLUSION: Genotyping for MspI and HaeIIIb FN gene polymorphisms may be clinically relevant to define the predisposition to the major clinical manifestations in MCsn.

Fibronectin gene polymorphisms are associated with the development of B-cell lymphoma in type II mixed cryoglobulinemia.

OBJECTIVE: To analyse fibronectin (FN) gene polymorphisms in type II mixed cryoglobulinemic syndrome (MCsn), an immune-complex mediated systemic vasculitis linked to hepatitis C virus (HCV) infection and characterised by rheumatoid factor (RF) positive B-cell proliferation at high risk for the progression into non-Hodgkin's lymphoma (NHL). METHODS: Samples from 74 patients with MCsn (type II serum cryoglobulins and clinical signs of vasculitis) were studied. In all, 58 (78.4%) patients were HCV-positive. In total, 21 (28.4%) patients developed a B-cell NHL during the course of MCsn. A total of 72 patients with HCV-negative and MC-unrelated NHL and 110 healthy blood donors (HBDs) were taken as controls. HaeIIIb and MspI FN gene polymorphisms were analysed by PCR and specific restriction enzyme digestions, following reported procedures. Plasma FN levels were analysed by ELISA, whenever possible. RESULTS: HaeIIIb and MspI allele and genotype frequencies did not differ between MCsn patients and HBDs. Of note, the DD-MspI (OR = 5.99; CI 1.77-20.261, p = 0.0039) and the AA-HaeIIIb (OR = 4.82, CI 1.42-16.39, p = 0.0176) homozygosis appeared significantly associated with the development of B-cell NHL in MCsn patients, with the HaeIIIb A allele possibly conferring an increased risk of NHL in the general population (OR = 1.72, CI 1.128-2.635, p = 0.0133). None of the other MCsn-related clinical manifestations were significantly associated with a particular genetic pattern. No association between FN plasma levels and FN genotypes was found. CONCLUSION: Genotyping for MspI and HaeIIIb FN gene polymorphisms may be clinically relevant to define the risk of lymphoma development in MCsn.

Favorable tissue effects of quantum molecular resonance device (Vesalius) compared with standard electrocautery. A novel paradigm in lung surgery.

BACKGROUND: Electrosurgical devices are largely employed in thoracic surgery but their use is burdened by extensive necrosis and second intention healing. METHODS: A rat model of thoracotomy was performed on 46 adult male rats using a standard electrocautery or a new quantum molecular resonance (QMR) instrument called Vesalius. Skin, muscle and lung specimens were obtained immediately and 2 weeks after surgery to evaluate acute and late effects. RESULTS: Both in the short- and long-term study, Vesalius produced less severe tissue damage than that of standard electrocautery. CONCLUSIONS: The use of the QMR device may provide an alternative to gold-standard electrosurgical devices in thoracic surgery.

B-Lymphocyte stimulator (BLyS) up-regulation in mixed cryoglobulinaemia syndrome and hepatitis-C virus infection.

OBJECTIVES: To investigate the role of B-Lymphocyte stimulator (BLyS) in mixed cryoglobulinaemia syndrome (MCsn), a systemic vasculitis associated with a high risk to develop lymphoma, since BLyS up-regulation may favour both autoimmunity and lymphoproliferation. METHODS: BLyS serum levels were analysed by enzyme-linked immunosorbent assay (positive when >0.85 ng/ml) in 66 patients with MCsn, 54 (81.8%) of whom were positive for hepatitis-C virus (HCV) infection. Thirty-three HCV-positive patients without MCsn were also studied. Patients were compared with 48 healthy blood donors (HBDs). BLyS modifications after antiviral therapy were also studied. RESULTS: A significantly higher frequency of BLyS serum positivity was detected both in MCsn patients and in HCV-positive patients without MCsn (37.9 and 30.3%, respectively) when compared with HBDs (4.2%) (P < 0.0001 vs MCsn and P = 0.0026 vs HCV-positive patients without MCsn, respectively). BLyS appeared significantly higher in MCsn (3.70 +/- 2.97 ng/ml) than in HCV-positive patients without MCsn (1.56 +/- 0.63 ng/ml; P = 0.0044). BLyS expression did not correlate with rheumatoid factor levels, cryoglobulin levels or definite MCsn-related systemic features. High BLyS levels were significantly associated only with MCsn-related overt lymphoproliferative disorder. Finally, antiviral treatment significantly increased BLyS levels, independently from HCV-RNA negativization. However, BLyS normalization was noticed after both HCV-RNA negativization and suspension of antiviral therapy by preliminary data. CONCLUSIONS: BLyS is up-regulated and may play a pathogenetic role in a fraction of patients with MCsn, similarly to other autoimmune diseases. HCV infection likely represents the early event leading to BLyS up-regulation in this setting. BLyS is up-regulated during antiviral treatment. Overall, these data provide new insights for BLyS and virus-related autoimmunity, lymphoproliferation and possible treatment strategies.

Hepatitis C virus and non-Hodgkin's lymphoma 10 years later.

Hepatitis C virus is associated with chronic liver disease as well as with lymphoproliferative disorders such as mixed cryoglobulinemia and, likely, non-Hodgkin's lymphomas. The association between hepatitis C virus infection and B-cell lymphoma is controversial since it shows a strong regional variation. In fact, the prevalence of hepatitis C virus infection in non-Hodgkin's lymphoma shows a prevalence ranging between 7.4 and 37.0%. However, the intimate pathogenetic mechanism involved in hepatitis C virus-associated lymphomas remains considerably unknown. Hepatitis C virus may exert its oncogenic potential via an indirect mechanism or utilise other pathways directly. It is reasonable to assume that several different pathogenetic mechanisms operate in the wide spectrum of hepatitis C virus-related lymphoproliferative disorders, which include the intermediate to high-grade lymphoma, and the more common indolent, low-grade lymphoma, preceded by long standing symptomatic mixed cryoglobulinemia Type II. In this review, the etiopathogenetic role of hepatitis C virus in non-Hodgkin's lymphoma is discussed on the basis of molecular, clinical and epidemiological considerations. The management of hepatitis C virus-associated non-Hodgkin's lymphoma is similar to that of conventional lymphoma, although viral reactivation or the underlying chronic liver disease can complicate chemotherapy. Whether to treat low-grade hepatitis C virus-related lymphomas with anti-viral therapy is still debatable, but encouraging data emerge from some recent studies.

Molecular analysis of V(H)I+ B lymphocytes in hepatitis C patients.

BACKGROUND AND AIMS: Hepatitis C virus infection is often associated with lymphoproliferative disorders such as essential mixed cryoglobulinemia and B-cell non-Hodgkin lymphoma, which show preferential expression of VHI family products. By analyzing immunoglobulin heavy chain usage, we addressed the question of whether or not clonal B-cell expansion occurrs in patients free of essential mixed cryoglobulinemia or non-Hodgkin lymphoma. PATIENTS AND METHODS: Four hepatitis C virus-positive patients, all undergoing liver transplantation, were studied. Peripheral blood, intra-hepatic, and lymph node lymphocytes were used as a source of B cells. A patient with hepatocellular carcinoma and fresh blood from four healthy donors were used as negative controls. VHI family sequences were cloned and analyzed by reverse transcription-polymerase chain reaction. RESULTS: Immunoglobulin heavy chain sequences from clonally expanded B lymphocytes were identified in three out of four hepatitis C virus-infected patients. The clonally expanded B lymphocyte populations showed a broad spectra of immunoglobulin heavy chain gene usage. CONCLUSIONS: HCV infection can induce B-cell expansion with larger clonal variation. The restricted V gene usage in hepatitis C virus-associated non-Hodgkin lymphoma suggests that there may be selection mechanisms to develop non-Hodgkin lymphoma from non-malignant, clonally expanded B-cell populations in hepatitis C virus-infected patients.

Effectiveness of leukocyte interferon in patients affected by HCV-positive mixed cryoglobulinemia resistant to recombinant alpha-interferon.

OBJECTIVE: Interferon is the first-choice therapy for HCV-positive mixed cryoglobulinemia, but only a small fraction of the patients show long-term recovery from the disease. In non-responders or relapsers, the second-line therapy (high dose interferon) generally is not effective. The aim of this study was to evaluate the effectiveness of leukocyte interferon as a second-line therapy in patients who are non-responders or relapsers to a first course of recombinant interferon. METHODS: Twenty-eight patients with HCV-positive mixed cryoglobulinemia were enrolled. In each case the HCV-RNA and HCV genotype, as well as the usual laboratory parameters, were determined before, at the end of therapy and 1 year after the end of therapy. All patients were treated following the same schedule: leukocyte interferon 3,000,000 three times a week for one year. RESULTS: Only 5 patients obtained complete recovery from viral infection as well as from all signs and symptoms of the disease. Most patients (80%) experienced relief from clinical symptoms without recovery from HCV replication. Responders to the second interferon course were "relapsers" to the first treatment. No patient considered as a "non-responder" showed complete remission from the disease after the second treatment. CONCLUSIONS: A second leukocyte interferon course could be useful for patients affected by mixed crvoglobulinemia who relapsed after a first course of recombinant interferon therapy.

Thalidomide in myelodysplastic syndromes.

The myelodysplastic syndromes are a heterogeneous group of clonal diseases of haemopoiesis, which are a challenge for both biologists and clinicians. In this paper the current classification and the recent advances in the understanding the disease mechanisms are reviewed. The recent therapeutic advances are also indicated, such as intensive and low-dose chemotherapy, new drugs, erythropoietin and colony-stimulating factors. However, the work has been focused on thalidomide, its therapeutic potential, its modes of actions, side effects, indications and future applications.

Human leucocyte interferon-alpha in the treatment of chronic hepatitis C.

AIM: To assess the efficacy of different schedules of human leucocyte interferon alpha in chronic hepatitis C. PATIENTS AND METHODS: A total of 213 naive patients with chronic hepatitis C were treated with 4 different schedules of human leucocyte interferon alpha. Sustained response was defined as persistently normal alanine amino transferase values with negative serum hepatitis C virus-RNA up to 12 months after therapy withdrawal. RESULTS: Rates of sustained response were 16% with 3 MU tiw for 6 months, 33% with 6 MU tiw for 5 months after a priming dose of 9 MU tiw for a month, 32% with 3 MU tiw for 12 months and 20% with 3 MU daily for 6 months. The major factors affecting the response rate were age and the hepatitis C virus genotype, as a sustained response was significantly higher in patients under 45 years and infected by hepatitis C virus types other than hepatitis C virus-1. Treatment was well tolerated and side-effects and drop-out events were similar to those described with other types of alpha-interferons. CONCLUSIONS: Human leucocyte interferon alpha appears to be equivalent to recombinant interferon-alpha in the treatment of chronic hepatitis C.