Calreticulin Mutations Variants of ET and PMF Patients Studied in Almazov Medical Research Center Russian Federation

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5499-5499 ◽  
Author(s):  
Pavel Butylin ◽  
Natalia Matyuhina ◽  
Ekaterina Lisina ◽  
Nadia Siordia ◽  
Olga Senderova ◽  
...  

Abstract We analyzed CALR mutations in cohort of patients with ET and PMF. Diagnoses were determined according to the WHO criteria. 33 PMF and 45 ET patients that were negative for JAK2V617F and MPL515L/K mutations have been studied for CALR mutations presence as described in original paper (Т.Klampfi , 2013). 29 ET and 25 PMF patients found mutated. In PMF group sex ratio was equal - 12 males/13 females, in ET group females prevailed - 21 males/69 females. Median age in PMF group was 64 (41-78) and in ET group 58 (22-80). Exon 9 was Sanger sequenced and mutation type identified. All the mutated CALR sequences were translated with verified +1 frameshift with alternative C-end. In PMF group we found type 1 52bp deletion p.L367fs*46 (n=11), type 2 TTGCT insertion p.K385fs*47 (n=5), type 3 p.L367fs*48 (n=3), type 7 p.K368fs*45 (n=2), type 19 p.E372fs*48 (n=2) and single cases of p.K368fs*51, p.K385fs*47 , p.Q365fs*50. In ET group we found type1 52bp deletion p.L367fs*46 (n=10), type 2 TTGCT insertion p.K385fs*47 (n=6), and single cases of p.L367fs*52, p.K368fs*51, p.E378fs*45, p.K374fs*49), p.E364fs*49. Also in ET group we identified two cases with alternative insertion c.1154_1155insGTGTC p.E386fs*46. In one ET case we found complex CALR mutation variant c. с.1126_1142delInsACCTTTGCATTTT (p.R376fs*53). In this case alternative C-end, different from what was described before will be formed. CALR mutations were grouped in Type1 like and Type2 like according to protein sequence similarity (A. Tefferi, 2014). In PMF group type1/2 like mutation ratio was 18/7 and in ET group it was 16/13, confirming higher CALR type2 like mutations rate in ET. We analyzed CALR mutations in cohort of patients with ET and PMF. Diagnoses were determined according to the WHO criteria. 33 PMF and 45 ET patients that were negative for JAK2V617F and MPL515L/K mutations have been studied for CALR mutations presence as described in original paper (Т.Klampfi, 2013). 29 ET and 25 PMF patients found mutated. In PMF group sex ratio was equal - 12 males/13 females, in ET group females prevailed - 21 males/69 females. Median age in PMF group was 64 (41-78) and in ET group 58 (22-80). Exon 9 was Sanger sequenced and mutation type identified. All the mutated CALR sequences were translated with verified +1 frameshift with alternative C-end. In PMF group we found type 1 52bp deletion p.L367fs*46 (n=11), type 2 TTGCT insertion p.K385fs*47 (n=5), type 3 p.L367fs*48 (n=3), type 7 p.K368fs*45 (n=2), type 19 p.E372fs*48 (n=2) and single cases of p.K368fs*51, p.K385fs*47 , p.Q365fs*50. In ET group we found type1 52bp deletion p.L367fs*46 (n=10), type 2 TTGCT insertion p.K385fs*47 (n=6), and single cases of p.L367fs*52, p.K368fs*51, p.E378fs*45, p.K374fs*49), p.E364fs*49. Also in ET group we identified two cases with alternative insertion c.1154_1155insGTGTC p.E386fs*46. In one ET case we found complex CALR mutation variant c. с.1126_1142delInsACCTTTGCATTTT (p.R376fs*53). In this case alternative C-end, different from what was described before will be formed. CALR mutations were grouped in Type1 like and Type2 like according to protein sequence similarity (A. Tefferi, 2014). In PMF group type1/2 like mutation ratio was 18/7 and in ET group it was 16/13, confirming higher CALR type2 like mutations rate in ET. Klampfl T. et al. Somatic mutations of calreticulin in myeloproliferative neoplasms. N Engl J Med. 2013 Dec 19;369(25):2379-90. Tefferi A. et al. The prognostic advantage of calreticulin mutations in myelofibrosis might be confined to type 1 or type 1-like CALR variants. Blood. 2014 Oct 9;124(15):2465-6. Disclosures Zaritskey: Janssen: Consultancy; Novartis: Consultancy.

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3215-3215 ◽  
Author(s):  
Daniela Pietra ◽  
Elisa Rumi ◽  
Chiara Milanesi ◽  
Christian A Di Buduo ◽  
Marta Bellini ◽  
...  

Abstract About 25% of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF) carry a somatic mutation of CALR, the calreticulin gene [N Engl J Med. 2013;369:2379-90]. So far, more than 50 different indels in CALR exon 9 have been found, but a 52-bp deletion (type 1 mutation) and a 5-bp insertion (type 2) are the most common lesions. All indels generate a novel C-terminus of the mutant protein, in which the endoplasmic reticulum retention signal KDEL is lost and the negatively charged amino acids are replaced by neutral and positively charged amino acids, disrupting the Ca-binding site. This suggests that both cellular dislocation and impaired Ca-binding activity may be involved in the abnormal proliferation of cells expressing a mutant calreticulin. It is still unclear, however, why the same mutant gene is associated with 2 different disease phenotypes (ET and PMF). In particular, little in known about the effect of the mutant protein on megakaryocyte biology and bone marrow collagen deposition. We studied the relationships between CALR mutation type, megakaryocyte biology, and clinical phenotype in patients with myeloproliferative neoplasms. According to the 2008 WHO criteria, 716 out of 892 patients had ET and 176 had PMF. Overall, 578 (65%) patients carried JAK2 (V617F), 230 (26%) had a CALR indel, and 84 (9%) had nonmutated JAK2 and CALR. Patients with MPL mutations were excluded. Twenty-six different types of CALR lesions were identified: 120 (52%) patients had type 1 mutation, 75 (33%) had type 2, and 35 (15%) carried other indels. The frequency of type 1 mutation was significantly higher in PMF than in ET (71% vs 46%, P=.004). All these variants involved 3 different stretches of negatively charged amino acids, with an increase in the isoelectric points (pI) of the mutant protein. As type 1 and type 2 mutations affected stretch I and III, respectively, the 26 indels were categorized into 3 groups on the basis of the stretch they affected: i) type 1-like (61%), affecting stretch I; ii) type 2-like (36%), stretch III; iii) and other types (3%), stretch II. The pI values were significantly different in the 3 groups (P<.001). The frequency of type-1 like mutations was significantly higher in PMF than in ET (82% vs 55%, P=.001). In vitro differentiated megakaryocytes from CALR-mutant patients displayed a significant increase in the extent of both intracellular Ca2+ release from the endoplasmic reticulum and extracellular Ca2+ entry inside the cytoplasm, as compared with healthy controls. Megakaryocytes carrying type 1-like CALR mutations exhibited the highest amplitude of Ca2+ flows regardless of the type of disease. In ET, impaired Ca2+ homeostasis was accompanied by atypical proplatelet architecture (ie, more branches and bifurcations). With respect to clinical phenotype at diagnosis, ET patients with type 2-like CALR mutation showed a trend towards higher PLT count (P=.063) and lower age (P=.053), and significantly lower LDH values (P=.021) than those with type 1-like mutation. In a hierarchical cluster analysis including demographic, clinical and molecular data, CALR mutation type (1 vs 2) identified the 2 clusters with the highest dissimilarity. Considering all patients, those with type 2-like CALR lesions had a better survival than those with JAK2 (V617F) (96.1% vs 84.4% at 10 years, P=.039), while no difference was found between the 2 CALR mutation types. ET patients with type 2-like CALR mutations showed a lower risk of thrombosis than those with JAK2 (V617F) (P=.010). By contrast, ET patients with type 1-like CALR mutations had a higher risk of myelofibrotic transformation that those with type 2-like CALR mutations (P=.029) and especially those with JAK2 (V617F) (P=.011). Finally, PMF patients with type 1-like CALR variants had a better survival than those with JAK2 (V617F) (80.1% vs 48% at 10 years, P=.008). In summary, abnormalities in megakaryocyte calcium metabolism and proplatelet architecture are found in patients with CALR-mutant myeloproliferative neoplasms, and their extent is related to mutation type. Type 2-like CALR mutations are more likely to be associated with isolated thrombocytosis without bone marrow fibrosis, ie, with an ET phenotype. By contrast, type 1-like CALR mutations are generally associated with bone marrow fibrosis, ie, with a PMF phenotype. Thus, in CALR-mutant myeloproliferative neoplasms, the mutation type is a major determinant of the clinical phenotype. Disclosures No relevant conflicts of interest to declare.


2019 ◽  
Vol 51 (3) ◽  
pp. 306-309
Author(s):  
Jee-Soo Lee ◽  
Ho Young Kim ◽  
Miyoung Kim ◽  
Young Kyung Lee

Abstract The clinical phenotypes and prognoses of CALR-mutant myeloproliferative neoplasms depend on the mutation type. The 2 most common mutations, type 1 (52-bp deletion) and type 2 (5-bp insertion), account for 85% of CALR-mutated neoplasms. The former confers a myelofibrotic phenotype, and the latter is associated with a low risk of thrombosis and an indolent clinical course. Individual case reports for patients with novel pathogenic CALR mutations are rare. Herein, we present the first case in the literature, to our knowledge, of a 63-year old ethnic Korean man with essential thrombocythemia who was diagnosed with a novel +1-bp frameshift mutation in CALR, which was predicted to exhibit a type 2–like phenotype.


Author(s):  
Razan Hayati Zulkeflee ◽  
Zefarina Zulkafli ◽  
Muhammad Farid Johan ◽  
Azlan Husin ◽  
Md Asiful Islam ◽  
...  

Mutations of JAK2V617F, CALR, and MPL genes confirm the diagnosis of myeloproliferative neoplasm (MPN). This study aims to determine the genetic profile of JAK2V617F, CALR exon 9 Type 1 (52 bp deletion) and Type 2 (5 bp insertion), and MPL W515 L/K genes among Malaysian patients and correlate these mutations with clinical and hematologic parameters in MPN. Mutations of JAK2V617F, CALR, and MPL were analyzed in 159 Malaysian patients using allele-specific polymerase chain reaction, including 76 polycythemia vera (PV), 41 essential thrombocythemia (ET), and 42 primary myelofibrosis (PMF) mutations, and the demographics of the patients were retrieved. The result showed that 73.6% JAK2V617F, 5.66% CALR, and 27.7% were triple-negative mutations. No MPL W515L/K mutation was detected. In ET and PMF, the predominance type was the CALR Type 1 mutation. In JAK2V617F mutant patients, serum LDH was significantly higher in PMF compared to PV and ET. PV has a higher risk of evolving to post PV myelofibrosis compared to ET. A thrombotic event at initial diagnosis of 40.9% was high compared to global incidence. Only one PMF patient had a CALR mutation that transformed to acute myeloid leukemia. JAK2V617F and CALR mutations play an important role in diagnostics. Hence, every patient suspected of having a myeloproliferative neoplasm should be screened for these mutations.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5494-5494
Author(s):  
Minuncio Juliana ◽  
Alexandre Nonino ◽  
Juliana Forte Mazzeu ◽  
Cintia do Couto Mascarenhas

Abstract Myelofibrosis is the rarest and most severe Ph- myeloproliferative neoplasm and can present de novo or post Polycythemia Vera or Essential Thrombocythemia. It is characterized by bone marrow fibrosis, extramedullary hematopoiesis and abnormal expression of inflammatory cytokines resulting in several atypical events and may progress to Acute Leukemia. The disease arises from clonal expansion of a single hematopoietic stem cell (HSC), driven by a somatic mutation of JAK2, CALR or MPL genes combined with dysregulation of hematopoietic microenvironment, additional mutations and cytogenetic abnormalities.The aims of this study are to assess driver mutations status in primary or secondary myelofibrosis patients and to correlate their mutational profile with clinical outcomes. The search for JAK2V617F, exon 12 JAK2, calreticulin exon 9 c.1092_1143del52 and c.1154_1155insTTGT, MPLW515K and MPLW515L mutations was performed in 31 subjects using MLPA technique, a method of DNA analysis that allows simultaneous appraisal of different mutations in multiple samples. 48.4% of patients present the JAK2V617F mutation,indel CALR mutations in 38.7% of patients (of these, 66.7% with del52 bp, 33.3% harbored insTTGTC),MPL W515L in 3.2% of patients and 9.7% of patients were triple-negative. From the mutational profile information obtained by MLPA,the clinical-molecular risk score was calculated for each of the individuals in the sample, according Rumi et al.. Being at 12,9% (4) as very low risk, 9.7% (3) as low risk,35.4% (11) as intermediary risk, 29.1% (9) and of high risk, and 12.9%(4) as very high risk. Patients with mutated JAK2 were older, with minor degree of anemia and more leukocytosis, whereas those with CALR mutations had less frequency of leukocytosis and thrombocytopenia. Triple-negative subjects displayed the lowest median age at diagnosis (49.3 years), and bone marrow failure phenotype, similar to Myelodysplastic Syndrome. Risk stratification provided by DIPSS was similar to other centers.Individuals with PMF present constitutional symptoms significantly more often than those with post-ET MF(p = 0.0365).Mortality rate was 29%, and mean survival after diagnosis was 68.3 months. CALR mutated individuals presented higher average survival and median survival according to DIPSS was higher than predicted by the prognostic model, possibly due to the higher frequency of CALR mutations reported.Median follow-up time was 32 months (ranging from 10 months to 13 years).Thromboembolic phenomena were recorded in 19.3% of patients, and evolution to AML in 6.4% of patients and it was verified that 75% of the individuals with Myelofibrosis Post-ET presented thrombotic events at some point in the disease. The association between the DIPSS clinical-laboratory parameters and the demand of transfusion at diagnosis, with the occurrence of Acute Leukemia was assessed using Fisher's exact test but have no significant difference in these parameters between patients who evolved or not for Acute Leukemia. The JAK2 V617F mutation is expected to be present in 60 to 65% of individuals with Myelofibrosis, but this mutation has been identified in only 48% of patients. In contrast, the observed frequency of indel of the CALR, of 38%, was higher than the classically described, from 25 to 30%. The rate of mutation type 2 (ins 5-bp) was also higher than expected, 33.6%.Regarding the mutation subtypes of CALR, mutation type 1 (52-bp deletion) is observed in up to 80% of MFP cases, but has a similar frequency as type 2 (5-bp insertion) in patients with ET. The grouping of patients with primary MF and post-ET may have contributed to the higher incidence of type 2 CALR mutation observed in this sample, although much higher than the 13% frequency described in the literature in a mixed population. The type 1 mutation was observed in 66% of our patients with post-ET and mutated CALR, but the small number of individuals in the study does not allow to estimate the impact of this mutation in the evolution of the disease. Our fraction of CALR-mutated patients is much higher than those described in Asian, European, North American and Argentinean populations. The complex genetic landscape involved in initiation and progression of Myelofibrosis, instigates the adoption of integrative prognostic stratification models. In this scenario, MLPA is a powerful tool for molecular study, and a promising ally for MPN molecular characterization. Disclosures No relevant conflicts of interest to declare.


Author(s):  
A.M. Satarkulova

The assessment and dynamic control over students’ status is a very important task. It allows timely detection of prenosological status prior to pathology and health maintenance in students. The objective of the paper is to assess the adaptive abilities of the body, to analyze changes in heart rate variability indicators in students with various types of autonomic regulation, to identify prenosological status and precursory pathological symptoms. Materials and Methods. The study enrolled 302 students from India, aged 21.54±1.43. Programming complex «Psychophysiologist» was used to register the main HRV parameters within 5 minutes. Health status was evaluated according to the index of functional changes and the scale of functional states. Results. N.I. Shlyk (2009) distinguished two groups of students with different types of autonomic regulation: type 1 (53 %) with moderate and type 2 (5 %) with marked characteristics of central regulation profile, type 3 (35 %) with moderate and type 4 (7 %) with marked characteristics of autonomous regulation profile. Main parameters of HRV and adaptation potential were defined for each student.All the parameters characterized functional and health status. Conclusions. It was shown that 82 % of trial subjects (type 1), 53 % (type 2), 94 % (type 3) and 95 % (type 4) demonstrated satisfactory adaptation and their physiological processes were at an optimal level. 18 % of students (type 1) demonstrated reduced adaptive abilities of the body. Moreover, they were under moderate stress. 47 % of subjects (type 2) were also under a significant stress, which was proven by excessively high SI, low SDNN and TP, and an increased index of functional changes. 5 % of students (type 4) revealed dysfunctional characteristics in the heart rhythm, peculiar to pathology. Keywords: foreign students, heart rate variability, types of autonomic regulation, adaptation potential, functional status. Оценка состояния студентов и динамический контроль за ним является важной задачей, поскольку позволяет своевременно выявлять у студентов донозологические состояния, предшествующие патологии, и способствовать сохранению здоровья. Цель. Оценка адаптивных возможностей организма, анализ изменений показателей вариабельности сердечного ритма у студентов с различными типами вегетативной регуляции, выявление донозологических состояний и ранних признаков патологии. Материалы и методы. В исследовании участвовало 302 студента в возрасте 21,54+1,43 года из Индии. Регистрировались основные параметры ВСР в течение 5 мин с использованием программно-аппаратного комплекса «Психофизиолог». Состояние и уровень здоровья оценивались по индексу функциональных изменений и шкале функциональных состояний. Результаты. По способу, предложенному Н.И. Шлык, выделены группы студентов с различными типами вегетативной регуляции: I (53 %) и II типы (5 %) – с умеренным и выраженным преобладанием центрального контура регуляции соответственно, III (35 %) и IV типы (7 %) – с умеренным и выраженным преобладанием автономного контура регуляции соответственно. У каждого из студентов определены основные параметры ВСР и адаптационного потенциала, характеризующие функциональное состояние и уровень здоровья. Выводы. Показано, что для 82 % обследуемых с I типом, 53 % со II типом, 94 % c III типом и 95 % с IV типом регуляции характерно состояние удовлетворительной адаптации, физиологические процессы сохраняются на оптимальном уровне. В группе студентов I типа у 18 % студентов адаптивные возможности организма снижены, выявлено состояние умеренного напряжения. У 47 % обследуемых II типа также зафиксировано состояние резко выраженного напряжения, индикатором которого является чрезмерно высокое значение SI, низкие величины SDNN и ТP, повышенное значение индекса функциональных изменений. В группе студентов с IV типом у 5 % учащихсяв регуляции ритма сердца выявлены дисфункциональные признаки, характерные для патологии. Ключевые слова: иностранные студенты, вариабельность сердечного ритма, типы вегетативной регуляции, адаптационный потенциал, функциональное состояние.


1954 ◽  
Vol 32 (1) ◽  
pp. 119-125
Author(s):  
W. Wood ◽  
Eina M. Clark ◽  
F. T. Shimada ◽  
A. J. Rhodes

Studies on the basic immunology of poliomyelitis in Canadian Eskimos have been continued. Some 87 sera collected from Eskimos at Pangnirtung, Baffin Island, have been examined for the presence of Type 1 and Type 3 poliomyelitis antibody by quantitative tests in tissue cultures. The same sera were previously examined for Type 2 antibody by quantitative tests in mice. The results of the three determinations are now presented together for comparison. These sera came from Eskimos aged 2 to 72 years of age. None of the Eskimos showed any evidence of paralysis. Examination of the medical records did not suggest that any paralytic disease had been present in this part of Baffin Island. Very few of the sera showed the presence of poliomyelitis antibody; thus, Type 1 antibody was demonstrated in the sera of 8%, Type 2 antibody in the sera of 9%, and Type 3 antibody in the sera of 14%. No significant number of Eskimos below the age of 45 years had acquired poliomyelitis antibody. The antibody titers mostly ranged between 10−1.0 and 10−2.0, and were significantly lower than the titers customarily found in recently paralyzed cases. These findings suggest that poliomyelitis infection occurred in Pangnirtung Eskimos many years before the date on which the samples were taken (1951). These results point to the worldwide prevalence of the three types of poliomyelitis virus.


2021 ◽  
Vol 47 (02) ◽  
pp. 192-200
Author(s):  
James S. O'Donnell

AbstractThe biological mechanisms involved in the pathogenesis of type 2 and type 3 von Willebrand disease (VWD) have been studied extensively. In contrast, although accounting for the majority of VWD cases, the pathobiology underlying partial quantitative VWD has remained somewhat elusive. However, important insights have been attained following several recent cohort studies that have investigated mechanisms in patients with type 1 VWD and low von Willebrand factor (VWF), respectively. These studies have demonstrated that reduced plasma VWF levels may result from either (1) decreased VWF biosynthesis and/or secretion in endothelial cells and (2) pathological increased VWF clearance. In addition, it has become clear that some patients with only mild to moderate reductions in plasma VWF levels in the 30 to 50 IU/dL range may have significant bleeding phenotypes. Importantly in these low VWF patients, bleeding risk fails to correlate with plasma VWF levels and inheritance is typically independent of the VWF gene. Although plasma VWF levels may increase to > 50 IU/dL with progressive aging or pregnancy in these subjects, emerging data suggest that this apparent normalization in VWF levels does not necessarily equate to a complete correction in bleeding phenotype in patients with partial quantitative VWD. In this review, these recent advances in our understanding of quantitative VWD pathogenesis are discussed. Furthermore, the translational implications of these emerging findings are considered, particularly with respect to designing personalized treatment plans for VWD patients undergoing elective procedures.


2021 ◽  
Author(s):  
Hui Xu ◽  
Lei Chen ◽  
Wansuo Duan

AbstractThe optimally growing initial errors (OGEs) of El Niño events are found in the Community Earth System Model (CESM) by the conditional nonlinear optimal perturbation (CNOP) method. Based on the characteristics of low-dimensional attractors for ENSO (El Niño Southern Oscillation) systems, we apply singular vector decomposition (SVD) to reduce the dimensions of optimization problems and calculate the CNOP in a truncated phase space by the differential evolution (DE) algorithm. In the CESM, we obtain three types of OGEs of El Niño events with different intensities and diversities and call them type-1, type-2 and type-3 initial errors. Among them, the type-1 initial error is characterized by negative SSTA errors in the equatorial Pacific accompanied by a negative west–east slope of subsurface temperature from the subsurface to the surface in the equatorial central-eastern Pacific. The type-2 initial error is similar to the type-1 initial error but with the opposite sign. The type-3 initial error behaves as a basin-wide dipolar pattern of tropical sea temperature errors from the sea surface to the subsurface, with positive errors in the upper layers of the equatorial eastern Pacific and negative errors in the lower layers of the equatorial western Pacific. For the type-1 (type-2) initial error, the negative (positive) temperature errors in the eastern equatorial Pacific develop locally into a mature La Niña (El Niño)-like mode. For the type-3 initial error, the negative errors in the lower layers of the western equatorial Pacific propagate eastward with Kelvin waves and are intensified in the eastern equatorial Pacific. Although the type-1 and type-3 initial errors have different spatial patterns and dynamic growing mechanisms, both cause El Niño events to be underpredicted as neutral states or La Niña events. However, the type-2 initial error makes a moderate El Niño event to be predicted as an extremely strong event.


Author(s):  
Mi Hyeon Seong ◽  
Eunyoung Shin ◽  
Sohyune Sok

The purpose of this study is to identify the types of perception of successful aging in middle-aged men and to analyze and describe the characteristics of each type of successful aging perception of middle-aged men in South Korea. This study uses an exploratory study design, applying the Q methodology, which is a subjective research method. The participants were 25 middle-aged men (40 to 60 years old) living in C, Y, and B cities, which were P-samples that were judged to best reveal the successful aging of middle-aged men. In this study, principal component analysis of the PQ method program was used. The five perception types of successful aging among middle-aged men are Type 1 for the “leisure type”, Type 2 for the “mature type”, Type 3 for the “health-oriented type”, Type 4 for the “patriarchal type”, and Type 5 for the “family-centered type”. The mature type had the highest variance among the five types, and the leisure type was the type that showed the second-highest variance. In nursing practice, nurses need to pay attention to the successful aging perceptions of middle-aged Korean men for their successful aging in the future.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2645
Author(s):  
Omer Cohen ◽  
Dieter D. Bosshardt ◽  
Evegeny Weinberg ◽  
Gil Slutzkey ◽  
Ofer Moses

Stress concentrated at an implant’s neck may affect bone-to-implant contact (BIC). The objective of this study was to evaluate four different implant neck designs using two different drilling protocols on the BIC. Methods: Ninety-six implants were inserted in 12 minipigs calvarium. Implants neck designs evaluated were: type 1–6 coronal flutes (CFs), 8 shallow microthreads (SMs); type 2–6 CFs,4 deep microthreads (DMs); type 3–4 DMs; type 4–2 CFs, 8 SMs. Two groups of forty-eight implants were inserted with a final drill diameter of 2.8 mm (DP1) or 3.2 mm (DP2). Animals were sacrificed after 1 and 3 months, total-BIC (t-BIC) and coronal-BIC (c-BIC) were evaluated by nondecalcified histomorphometry analysis. Results: At 1 month, t-BIC ranged from 85–91% without significant differences between implant types or drilling protocol. Flutes on the coronal aspect impaired the BIC at 3 m. c-BIC of implant types with 6 CFs was similar and significantly lower than that of implant types 3 and 4. c-BIC of implant type 4 with SMs was highest of all implant types after both healing periods. Conclusions: BIC was not affected by the drilling protocol. CFs significantly impaired the -BIC. Multiple SMs were associated with greater c-BIC.


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