Acute Erythroid Leukemia Post-Chemo-Radiotherapy and Autologous Stem Cell Transplantation Due to Multiple Myeloma: Tracing the Paths to Leukemic Transformation.

The clinical impact of therapy-related acute leukemias is increasing with the extension of cancer-related survival; however, the origins remain largely unknown. Acute erythroleukemia (AEL), a rare unfavorable type of myeloid neoplasia, may also develop secondary to cytotoxic therapy. The disorder is featured by specific genetic alterations, most importantly multi-allelic mutations of the TP53 gene. While AEL might appear as a part of the therapy-related MDS/AML, spectrum information regarding the genetic complexity and progression is largely missing. We present two AEL cases arising after cytotoxic therapy and melphalan-based myeloablation/autologous peripheral stem cell transplantation due to multiple myeloma (MM). As stated, multiple pathogenic TP53 variants were present unrelated to preexisting MM, in parallel with uninvolved/wild-type hemopoiesis. Potential mechanisms of leukemic transformation are discussed, which include (1) preexisting preneoplastic hemopoietic stem cells (HSC) serving as the common origin for both MM and AEL, (2) the generation and intramedullary survival of p53-deficient post-chemotherapy HSCs, (3) reinoculation of mobilized autologous TP53 mutated HSCs, and (4) melphalan treatment-related late-onset myelodysplasia/leukemia with newly acquired TP53 mutations.

Landscape of BCL2 Resistance Mutations in a Real-World Cohort of Patients with Relapsed/Refractory Chronic Lymphocytic Leukemia Treated with Venetoclax.

The oral, highly selective Bcl2 inhibitor venetoclax has substantially improved the therapeutic landscape of chronic lymphocytic leukemia (CLL). Despite the remarkable response rates in patients with relapsed/refractory (R/R) disease, acquired resistance is the leading cause of treatment failure, with somatic BCL2 mutations being the predominant genetic drivers underpinning venetoclax resistance. To assess the correlation between disease progression and the most common BCL2 mutations G101V and D103Y, sensitive (10-4) screening for the most common BCL2 mutations G101V and D103Y was performed in 67 R/R CLL patients during venetoclax single-agent or venetoclax-rituximab combination therapy. With a median follow-up time of 23 months, BCL2 G101V and D103Y were detected in 10.4% (7/67) and 11.9% (8/67) of the cases, respectively, with four patients harboring both resistance mutations. Ten out of eleven patients carrying BCL2 G101V and/or D103Y experienced relapse during the follow-up period, representing 43.5% of the cases (10/23) showing clinical signs of disease progression. All BCL2 G101V or D103Y variants were detected in patients receiving venetoclax as a continuous single-agent treatment while these mutations were not observed during or after fixed-duration venetoclax therapy. Targeted ultra-deep sequencing of BCL2 uncovered three additional variants in four patient samples obtained at relapse, suggesting convergent evolution and implying a cooperating role of BCL2 mutations in driving venetoclax resistance. This cohort is the largest R/R CLL patient population reported to date in which BCL2 resistance mutations were investigated. Our study demonstrates the feasibility and clinical value of sensitive screening for BCL2 resistance mutations in R/R CLL.

DNA analysis of partial hydatidiform mole revealing triandric monogynic tetraploidy.

The authors present a case of a partial hydatidiform mole where DNA analysis (STR - short tandem repeat genotyping) showed a triandric monogynic tetraploid genome composition with a XXXY gonosomal complement. This genetic finding clinicopathologically correlates with a partial hydatidiform mole, although it is rare in comparison with the typical, diandric monogynic triploid partial moles. The genetic analysis definitively confirmed the suspected diagnosis of a partial mole. To exclude the possibility that molar pregnancy represented retained products of conception after elective pregnancy termination, STR profiles from molar pregnancy and previous products of conception were compared. Short tandem repeats genotyping is a useful molecular genetic method in the differential diagnosis of partial hydatidiform moles, where clinical-pathological findings are frequently ambiguous.

Screening and monitoring of the BTKC481S mutation in a real-world cohort of patients with relapsed/refractory chronic lymphocytic leukaemia during ibrutinib therapy.

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib has revolutionised the therapeutic landscape of chronic lymphocytic leukaemia (CLL). Acquired mutations emerging at position C481 in the BTK tyrosine kinase domain are the predominant genetic alterations associated with secondary ibrutinib resistance. To assess the correlation between disease progression, and the emergence and temporal dynamics of the most common resistance mutation BTKC481S , sensitive (10-4 ) time-resolved screening was performed in 83 relapsed/refractory CLL patients during single-agent ibrutinib treatment. With a median follow-up time of 40 months, BTKC481S was detected in 48·2% (40/83) of the patients, with 80·0% (32/40) of them showing disease progression during the examined period. In these 32 cases, representing 72·7% (32/44) of all patients experiencing relapse, emergence of the BTKC481S mutation preceded the symptoms of clinical relapse with a median of nine months. Subsequent Bcl-2 inhibition therapy applied in 28/32 patients harbouring BTKC481S and progressing on ibrutinib conferred clinical and molecular remission across the patients. Our study demonstrates the clinical value of sensitive BTKC481S monitoring with the largest longitudinally analysed real-world patient cohort reported to date and validates the feasibility of an early prediction of relapse in the majority of ibrutinib-treated relapsed/refractory CLL patients experiencing disease progression.

Partial hydatidiform moles with unclear histopathological profile - importance of genetic diagnostics.

OBJECTIVE: The aim of the study was the genetic characterization of a set of cases with an unclear morphological profile of the placental tissue suspected of a partial hydatidiform mole. PATIENTS AND METHODS: This work presents the results of a genetic analysis of a group of 10 patients with various clinical manifestations of reproductive loss, where a partial hydatidiform mole was suspected on the basis of a histopathological examination. The composition of the genome of the products of conception was determined by short tandem repeats (STR) genotyping using a commercial kit;Devyser Compact v3 (Devyser). RESULTS AND CONCLUSIONS: Out of 10 analyzed cases, five had diandric monogynic triploid genome, characteristic for a partial mole. Aneuploidies of chromosomes 13, 18, 21, X and Y were excluded in four cases and Pataus syndrome was dia-gnosed in one case. In the case of an unclear histopathological profile, consultative DNA analysis (ideally STR genotyping) can significantly help the pathologist in the differential dia-gnosis of a partial mole. The histopathological profile of a partial hydatidiform mole may be in some cases incomplete and unclear, especially in the early weeks of gestation, which can lead to false negativity of the examination. On the other hand, other pathologies, for example aneuploides or digynic triploidy, may produce a histopathological profile similar to a partial mole, which leads to false positivity. Accurate dia-gnosis of a partial hydatidiform mole using molecular genetic methods contributes to the determination of adequate dispensary care for patients.

Survey of KI, WU, MW, and STL Polyomavirus in Cancerous and Non-Cancerous Lung Tissues.

BACKGROUND/AIMS: The pathogenesis of the human polyomavirus (PyV) KI, WU, MW, and STL has not been elucidated yet. Respiratory transmission is suggested, but the site of the replication, tissue, and cell tropism is not clarified. KIPyV and WUPyV DNA and/or antigen were detected in normal lung tissues previously by others. In fact, a KIPyV DNA sequence was found in lung cancer samples. Up to date, there is no publication about the DNA prevalence of MWPyV and STLPyV neither in normal nor in cancerous lung tissues. The aim of the present study was to examine the DNA prevalence of these polyomaviruses in cancerous and non-cancerous lung tissue samples, in order to study the possible site for viral replication and/or persistence, and the potential association of these viruses with lung carcinogenesis as well. METHODS: 100 cancerous and 47 non-cancerous, formalin-fixed paraffin-embedded lung tissue samples were studied for KIPyV, WUPyV, MWPyV, and STLPyV by real-time PCR. RESULTS AND CONCLUSION: Neither of the viruses was found in samples from small-cell, non-small-cell (adenocarcinoma, squamous-cell carcinoma and large-cell neuroendocrine lung cancer), mixed-type and non-differentiated lung carcinoma, and non-cancerous lung tissues (from patients with pneumonia, emphysema and fibrosis).

The Impact of Drug Metabolism Gene Polymorphisms on Therapeutic Response and Survival in Diffuse Large B-Cell Lymphoma Patients.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) accounts for 30% of all non-Hodgkin lymphomas (NHL) and 80% of agressive lymphomas. Besides the traditional International Prognostic Index (IPI), some other factors may also influence the prognosis of DLBCL patients. OBJECTIVES: To study how the genetic polymorphisms in the metabolic pathway influence the event-free and overall survivals and therapeutic responses in DLBCL. METHODS: The study was comprised of 51 patients (32 men, 19 women). The average age was 53.1 years. DLBCL was diagnosed between 2011 and 2016 and the average follow-up time was 3.78 years. These patients received 1-8 cycles (an average of 6.2 cycles) of rituximab, cyclophosphamide, doxorubicin, vincristin, prednisolon (R-CHOP) immunochemotherapy. Real-time polymerase chain reaction was used to determine the genetic polymorphisms of CYP2E1, GSTP1, NAT1, and NAT2 genes. RESULTS: Our results showed that the polymorphisms of CYP2E1, GSTP1, and NAT1 genes did not influence the prognosis of DLBCL patients significantly. In terms of the NAT2 gene, GG homozygous patients showed slightly better therapeutic response and survival results compared to those bearing an A allele; however, the differences were not statistically significant. CONCLUSIONS: Our results could not confirm that genetic polymorphism in metabolic pathways has any predictive role in DLBCL.

[Drug therapy of lymphomas]. / A limfómák gyógyszeres terápiája.

The therapy of lymphomas has undergone a major expansion during the last decade. Novel therapeutic targets have appeared beyond classical chemotherapeutic combinations. These novel drugs have very pronounced action across lymphoma types, and their toxicity profile is usually better tolerable compared to standard chemotherapies. These new therapies are enabling us to offer treatment to those patients who have refractory disease, and we had no option to treat them before these drugs. The author describes several new therapeutic options. New chemotherapeutic drugs are pixantrone and bendamustin. Monoclonal antibodies, like rituximab, ofatumumab, obinotuzumab are described, and conjugated antibodies like brentuximab vedotin and inotuzumab ozogamicin are also discussed. The bispecific antibody blinatumomab can modulate the immune response, and the new class of immune checkpoint inhibitors (pembrolizumab, nivolumab) is also discussed. Therapies targeting the epigenetic regulatory network are also important. Several studies reported promising results of abexinostat, vorinostat, belinostat and panobinostat. The new class of immunomodulatory drugs (imids) is also growing, results with thalidomid and lenalidomid are discussed. The proteasome inhibitors are offering new combinations, with the use of bortezomid, carfilzomib, ixazomib. All these new drugs described above offer to the physician several therapeutic options to better treat patients with lymphoma.

No Evidence of Human Polyomavirus 9, WU and KI DNA in Kidney and Urinary Bladder Tumour Tissue Samples.

BACKGROUND/AIMS: The oncogenic potential of human polyomaviruses (HPyVs) has been proposed, but so far only Merkel cell carcinoma polyomavirus seems to be associated with a human tumour. The role of BK polyomavirus (BKPyV) in human tumourigenesis remains controversial. BKPyV establishes persistent infection in the urinary tract, and renal and bladder neoplasms have been studied extensively, but conflicting prevalence data are reported. KI, WU and HPyV9 were detected in urine samples suggesting that these viruses may also infect the urinary tract, but their presence in urinary tract tumours has not been studied. The aim of this work was to examine the prevalence of KIPyV, WUPyV, HPyV9 and BKPyV by PCR in renal and bladder neoplasms. METHODS: A total of 190 formalin-fixed paraffin-embedded renal neoplasms, bladder cancer and kidney biopsy samples were analysed for the presence of BKPyV, KIPyV, WUPyV and HPyV9 DNA by real-time and nested PCR. RESULTS: Amplifiable DNA was extracted from all the samples, but none of the studied viruses were detected in benign renal neoplasia (0/23), malignant renal tumours (0/89) or bladder cancer (0/76). CONCLUSION: Our study did not find any evidence that BKPyV, KIPyV, WUPyV or HPyV9 are associated with bladder and renal tumours.

[Recent advances in the understanding and treatment of diffuse large B-cell lymphoma]. / A diffúz nagy B-sejtes lymphoma modern szemlélete és kezelése.

Diffuse large B-cell lymphoma is the most common type of non-Hodgkin's lymphoma. Using the conventional cyclophosphamide adriablastin vincristin prednisolon polychemotherapy about 50% of the patients were cured. The addition of rituximab to the regimen increased the cure rate to 60%. This is a major improvement, however, further advance is still needed to increase the cure rate. The extensive genetic testing performed recently revealed several important pathognomic mutations as potential targets in this disease. Routine diagnosis of patients now includes the use of (18)Fluor-deoxy-glucose positron emission computer tomography, according to the recent Lugano classification system. With all these data we can better predict the prognosis of patients, and we can select candidates for novel targeted therapies as well. Answering these questions, and utilizing novel therapies possibly will further increase the cure rate in the near future. This paper summarizes current diagnostic and therapeutic approaches and describes recent understanding in the mutations and pathognomic changes resulting in the disease. The authors also summarize the data available on experimental therapies possibly entering clinical pratice in the forthcoming years. Orv. Hetil., 2016, 157(31), 1232-1241.

[Autoimmune haemolytic anaemia: a review and report of four cases]. / Az autoimmun haemolyticus anaemiáról négy eset kapcsán.

Treatment of autoimmune haemolytic anaemia is still a challenge to clinicians. Even today it may be lethal. Half of the cases are secondary due to an underlying disease, and the others are primary or idiopathic cases. According to the specificity and type of autoantibodies there are warm and cold type forms of autoimmune haemolytic anaemia. The hallmark of the diagnosis is to detect the presence of haemolysis by clinical and laboratory signs and detect the underlying autoantibodies. Treatment of autoimmune haemolytic anaemia is still a challenge to clinicians. We still loose patients due to excessive haemolysis or severe infections caused by immunosuppression. First line treatment is corticosteroids. Other immunosuppressive agents like: cyclophosphamide, azathioprine, cyclosporine or the off label rituximab can be used in case of corticosteroid refractoriness. Splenectomy is a considerable option in selective cases. The authors discuss treatment options and highlight difficulties by presenting 4 cases.

The Possible Role of Pathogens and Chronic Immune Stimulation in the Development of Diffuse Large B-Cell Lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma. The disease is very heterogeneous, with distinct genetic alterations in subtypes. The WHO 2022 5th edition classification identifies several minor groups of large B-cell lymphoma where the pathogenetic role of viruses (like EBV and HHV-8) is identified. Still, most cases fall into the group of DLBCL not otherwise specified (NOS). No review focuses only on this specific lymphoma type in the literature. The pathogenesis of this entity is still not fully understood, but several viruses and bacteria may have a role in the development of the disease. The authors review critical pathogenetic events in the development of DLBCL (NOS) and summarize the data available on several pathogenetic viruses and bacteria that have a proven or may have a potential role in the development of this lymphoma type. The possible role of B-cell receptor signaling in the microenvironment is also discussed. The causative role of the Epstein-Barr virus (EBV), human herpesvirus-8 (HHV-8), Hepatitis C virus (HCV), human immunodeficiency virus (HIV), Hepatitis B virus (HBV), and other viruses are explored. Bacterial infections, such as Helicobacter pylori, Campylobacter jejuni, Chlamydia psittaci, Borrelia burgdorferi, and other bacteria, are also reviewed.

The efficacy and safety of second salvage autologous transplantation in myeloma patients.

Despite the availability of many novel therapies for multiple myeloma, it remains an incurable disease with relapse fated in almost all patients. In the era of modern agents, second autologous stem cell transplantation still holds its role in patients relapsing after first-line autologous transplant. The authors reviewed a single-center experience with a second auto-SCT for relapsed multiple myeloma. Thirty patients had received a salvage auto-SCT at the institution. The median follow-up after diagnosis was 86 months, and the median time between transplants was 59.1 months. Response before second ASCT was the following: CR - 11 cases, VGPR - 9 cases, PR - 10 cases. Most patients received reduced dose (140 mg/m2) of melphalan as a conditioning regimen for the second auto-SCT. Treatment-related mortality was 3%. With a median follow-up time of 34 months after the second transplant, median progression-free survival was 24 months. The median PFS in the patients achieving CR or VGPR at day 100 after the second transplantation was 32 months. By 15 months, all patients achieved only partial remission progressed, with a median PFS of 8.5 months. During the follow-up period, no MDS or AML developed, and the frequency of second malignancy was also low, 3%. In conclusion, second autologous stem cell transplantation is a well-tolerated and effective treatment option for relapsed multiple myeloma in selected patients, though with a shorter PFS than in first remission.

Post-mortem rapid aneuploidy testing for holoprosencephaly.

BACKGROUND: Abortion and fetal death are common in fetuses with holoprosencephaly, so genetic examinations often have to be made in a post-mortem setting. The efficiency of the conventional karyotyping using cultured fibroblasts in these situations is limited due to frequent culture failure. In the current study, archived cases of holoprosencephaly, where post-mortem genetic evaluation was requested and sufficient frozen material was available, were reevaluated using the quantitative fluorescence polymerase chain reaction (QF-PCR) technique. METHODS: Testing for aneuploidies of chromosomes 13, 15, 16, 18, 21, 22, X, and Y with the QF-PCR technique was carried out on DNA isolated from archived frozen chorionic villi in seven cases of holoprosencephaly. RESULTS: QF-PCR was successful in all seven cases. Two cases of trisomy 13, two cases of triploidy, and one case of trisomy 18 was found meaning a 71% diagnostic yield. The success rate of QF-PCR (100%, 7/7) was superior compared to conventional karyotyping (43%, 3/7). CONCLUSIONS: Rapid aneuploidy testing using the QF-PCR technique is a simple, reliable, time- and cost-effective method sufficient to conclude the etiologic investigation in the majority of holoprosencephaly cases post-mortem.

Eculizumab Treatment of Massive Hemolysis Occurring in a Rare Co-Existence of Paroxysmal Nocturnal Hemoglobinuria and Myasthenia Gravis.

The co-occurrence of myasthenia gravis (MG) and paroxysmal nocturnal hemoglobinuria (PNH) is rare; only one case has been published so far. We report a 63-year-old Caucasian female patient who was diagnosed with MG at the age of 43. Thymoma was also detected, and so it was surgically resected, which resulted in reasonable disease control for nearly 20 years. Slight hemolysis began to emerge, and then myasthenia symptoms progressed, so immunosuppressive therapy was started. Due to progressive disease and respiratory failure, the patient underwent plasmapheresis, and ventilatory support was stopped. Marked hemolysis was present, and diagnostic tests confirmed PNH with type III PNH cells. Her myasthenia symptoms aggravated, mechanical ventilation had to be started again, and due to the respiratory acidosis, massive hemolysis occurred. After two plasmapheresis sessions, the patient received eculizumab at 600 mg, resulting in prompt hemolysis control. After the second dose of the treatment, the patient was extubated. Still, due to their inability to cough, she developed another respiratory failure and pneumonia-sepsis, resulting in the patient's death. This case highlights the rare association between these two serious diseases and similar immune-mediated pathophysiology mechanisms involving the complement system.

Multiple bronchial carcinoids associated with Cowden syndrome.

Cowden syndrome (CS) is a rare genetic condition due to the various germline mutations in the phosphatase and tensin homologue on chromosome ten (PTEN) tumour suppressor gene. As a result, CS is characterised by an increased risk of developing various benign and malignant tumours, such as thyroid, breast, endometrial and urogenital neoplasms, as well as gastrointestinal tract tumours. However, the neuroendocrine tumour association with CS is not elucidated yet. We present a case of a 46-year-old male patient diagnosed with testicular seminoma and follicular thyroid cancer in his medical history. Our patient met the clinical diagnostic criteria of Cowden syndrome. Genetic analysis established the clinical diagnosis; a known heterozygous PTEN mutation was detected [PTEN (LRG_311t1)c.388 C > T (p.Arg130Ter)]. Incidentally, he was also seen with multiple pulmonary lesions during his oncological follow-up. A video-assisted thoracoscopic left lingula wedge resection and later resections from the right lung were performed. Histological findings revealed typical pulmonary carcinoid tumours and smaller tumorlets. Somatostatin receptor SPECT-CT, 18F-FDG-PET-CT and 18F-FDOPA-PET-CT scans and endoscopy procedures could not identify any primary tumours in other locations. Our patient is the first published case of Cowden syndrome, associated with multifocal pulmonary carcinoids. Besides multiple endocrine neoplasia type 1, we propose Cowden syndrome as another hereditary condition predisposing to multiple pulmonary tumorlets and carcinoid tumours.

Short tandem repeats genotyping of gestational choriocarcinoma - our experiences.

OBJECTIVE: This short communication demonstrates how short tandem repeat genotyping can identify the origin of gestational choriocarcinoma. MATERIALS AND METHODS: The origin of gestational choriocarcinoma in our three cases was determined using the short tandem repeats genotyping technique, which involved quantitative fluorescent PCR and fragmentation analysis. RESULTS: In Case 1 despite no medical history of molar pregnancy, DNA analysis indicated that the choriocarcinoma originated from a homozygous complete hydatidiform mole. We conclude, that the patient's complete abortion 10 years prior to the choriocarcinoma diagnosis was an undiagnosed complete hydatidiform mole. In Case 2 and Case 3 the clinically presumed origin of choriocarcinoma was confirmed. CONCLUSION: Determining the origin of choriocarcinoma is essential for clinical application, as it affects the FIGO scoring system for gestational trophoblastic neoplasia, which determines the patient's prognosis and treatment approach.

Low-burden TP53 mutations represent frequent genetic events in CLL with an increased risk for treatment initiation.

TP53 aberrations predict chemoresistance and represent a contraindication for the use of standard chemoimmunotherapy in chronic lymphocytic leukaemia (CLL). Recent next-generation sequencing (NGS)-based studies have identified frequent low-burden TP53 mutations with variant allele frequencies below 10%, but the clinical impact of these low-burden TP53 mutations is still a matter of debate. In this study, we aimed to scrutinise the subclonal architecture and clinical impact of TP53 mutations using a sensitive, NGS-based mutation analysis in a 'real-world' cohort of 901 patients with CLL. In total, 225 TP53 mutations were identified in 17.5% (158/901) of the patients; 48% of these alterations represented high-burden mutations, while 52% were low-burden TP53 mutations. Low-burden mutations as sole alterations were identified in 39% (62/158) of all mutated cases with 82% (51/62) of these being represented by a single low-burden TP53 mutation. Patients harbouring low-burden TP53 mutations had significantly lower time to first treatment compared to patients with wild-type TP53. Our study has expanded the knowledge on the frequency, clonal architecture, and clinical impact of low-burden TP53 mutations. By demonstrating that patients with sole low-burden TP53 variants represent more than one-third of patients with TP53 mutations and have an increased risk for treatment initiation, our findings strengthen the need to redefine the threshold of TP53 variant reporting to below 10% in the routine diagnostic setting.

Activation of Src, Fyn and Yes non-receptor tyrosine kinases in keratinocytes expressing human papillomavirus (HPV) type 16 E7 oncoprotein.

BACKGROUND: The Src family tyrosine kinases (SFK) are cellular regulatory proteins that influence cell adhesion, proliferation, invasion and survival during tumor development. Elevated activity of Src was associated with increased cell proliferation and invasivity in human papillomavirus (HPV)-associated malignancies; therefore, transduced human foreskin keratinocytes (HFK) were used to investigate whether SFK activation is a downstream effect of papillomaviral oncoproteins. Activation of ubiquitously expressed SFKs, namely Src, Yes and Fyn, was investigated in both proliferating and differentiating keratinocytes. RESULTS: In proliferating keratinocytes, Src, Yes and Fyn mRNA levels were not affected by HPV 16 E6 or E7 oncoproteins, while at the protein level as detected by western blot, the presence of both E6 and E7 resulted in substantial increase in Src and Yes expression, but did not alter the high constitutive level of Fyn. Phospo-kinase array revealed that all ubiquitously expressed SFKs are activated by phosphorylation in the presence of HPV 16 E7 oncoprotein. Keratinocyte differentiation led to increased Yes mRNA and protein levels in all transduced cell lines, while it did not influence the Src transcription but resulted in elevated Src protein level in HPV16 E7 expressing lines. CONCLUSIONS: This study revealed that HPV 16 oncoproteins upregulate Src family kinases Src and Yes via posttranscriptional mechanisms. A further effect of HPV 16 E7 oncoprotein is to enhance the activating phosphorylation of SFKs expressed in keratinocytes.

Genomic differences in the background of different severity in juvenile-onset respiratory papillomatoses associated with human papillomavirus type 11.

This study aimed to compare complete genome sequences of human papillomavirus (HPV) type 11 from two solitary papillomas (considered minimally aggressive), two moderately (six and nine episodes) and two highly aggressive (30 and 33 episodes) juvenile-onset respiratory papillomatoses. Genomic regions were sequenced using the Sanger method; sequences were compared to available GenBank genomes. Activity of the long control region (LCR) was assessed in HEp-2 cell line using luciferase assays and compared to that of the reference (GenBank Accession Number M14119). Site-directed mutagenesis was performed to confirm the association of polymorphisms with differences in LCR activity. Eleven alterations resulted in amino acid changes in different open reading frames. A72E in E1 and Q86K in E2 proteins were exclusively present in a moderately aggressive disease, L1 alterations A476V and S486F were unique to a severe papillomatosis. HPV11s in both solitary papillomas had identical LCRs containing a T7546C polymorphism, which strongly attenuated LCR activity, as confirmed by site-directed mutagenesis. This strong attenuator polymorphism was also present in the other four genomes showing significantly higher activities, but in these other alterations with demonstrable but statistically not significant attenuating (A7413C, 7509 T deletion) or enhancing (C7479T, T7904A) effect on transactivating potential (as demonstrated by site-directed mutagenesis) were also detected. LCR activities corresponded well to severity, excepting the highly aggressive papillomatosis with the L1 alterations. Presence of intratypic variants cannot explain differences in severity of respiratory papillomatoses associated with HPV11; virulence seems to be determined by the interaction of multiple genetic differences.