The full-length Auxin Response Factor 8 isoform ARF8.1 controls pollen cell wall formation and directly regulates TDF1, AMS and MS188 expression.

Auxin Response Factor 8 plays a key role in late stamen development: its splice variants ARF8.4 and ARF8.2 control stamen elongation and anther dehiscence. Here, we characterized the role of ARF8 isoforms in pollen fertility. By phenotypic and ultrastructural analysis of arf8-7 mutant stamens, we found defects in pollen germination and viability caused by alterations in exine structure and pollen coat deposition. Furthermore, tapetum degeneration, a prerequisite for proper pollen wall formation, is delayed in arf8-7 anthers. In agreement, the genes encoding the transcription factors TDF1, AMS, MS188 and MS1, required for exine and pollen coat formation, and tapetum development, are downregulated in arf8-7 stamens. Consistently, the sporopollenin content is decreased, and the expression of sporopollenin synthesis/transport and pollen coat protein biosynthetic genes, regulated by AMS and MS188, is reduced. Inducible expression of the full-length isoform ARF8.1 in arf8-7 inflorescences complements the pollen (and tapetum) phenotype and restores the expression of the above transcription factors. Chromatin immunoprecipitation-quantitative polymerase chain reaction assay revealed that ARF8.1 directly targets the promoters of TDF1, AMS and MS188. In conclusion, the ARF8.1 isoform controls pollen and tapetum development acting directly on the expression of TDF1, AMS and MS188, which belong to the pollen/tapetum genetic pathway.

Optimizing foliar N-fertilization in sugarcane depends on plant genotype and nitrogen concentration.

Foliar N-fertilization (FNf) has emerged as a promising approach to synchronize plant nitrogen (N) demands and application timing, reducing the N losses to the environment associated with traditional soil-based fertilization methods. However, limited information exists regarding the effectiveness of FNf in sugarcane. This study aimed to optimize FNf in sugarcane by evaluating N-fertilizer recovery by the plant (NRP) and assessing potential toxicity effects. Four sugarcane genotypes were subjected to FNf using 15 N-urea at five nitrogen concentrations. NRP was assessed at five time points for roots, stalk, old leaves, 15 N-urea-fertilized leaves (15 NL), and unexpanded leaves (UEL). Leaf scorching, indicating FNf toxicity, was analyzed using morpho-anatomical and histochemical techniques. The results showed that FNf promoted high NRP, with an average recovery of 62.3%. Surprisingly, the redistribution of 15 N-urea did not follow the nitrogen uptake rate by sugarcane leaves, with an average of 41.3% of the total-NRP. The stalk emerged as the primary sink for 15 N-urea, followed by the UEL. Genotypes differed in the leaf scorching intensity, which increased with higher concentration of 15 N-urea. Genotypes also differed in the 15 N-urea uptake rate, down-regulated by the N content in the 15 NL. These findings emphasize that by carefully choosing the appropriate genotype and nitrogen concentration, FNf can significantly enhance N-fertilizer uptake, resulting in potential environmental and economic benefits.

Exosomal miR-17-5p, miR-146a-3p, and miR-223-3p Correlate with Radiologic Sequelae in Survivors of COVID-19-Related Acute Respiratory Distress Syndrome.

We investigated the association between circulating microRNAs (miRNAs) potentially involved in the lung inflammatory process and fibrosis development among COVID-19-related acute respiratory distress syndrome (ARDS) survivors. At 4 ± 2 months from clinical recovery, COVID-19-related ARDS survivors matched for age, sex, and clinical characteristics underwent chest high-resolution computerized tomography (HRCT) and were selected based on imaging pattern evolution into fully recovered (N = normal), pulmonary opacities (PO) and fibrosis-like lesions (FL). Based on the previous literature, we performed plasma miRNA profiling of exosomal miRNAs belonging to the NLRP3-inflammasome platform with validated (miR-17-5p, miR-223-3p) and putative targets (miR-146a-5p), miRNAs involved in the post-transcriptional regulation of acute phase cytokines (miR128-3p, miR3168, miR125b-2-3p, miR106a-5p), miRNAs belonging to the NLRP4-inflammasome platform (miR-141-3p) and miRNAs related to post-transcriptional regulation of the fibrosis process (miR-21-5p). miR-17-5p, miR-223-3p, and miR-146a-5p were significantly down-regulated in patients with FL when compared to patients with PO. miR-146a-5p was also down-regulated in patients with FL than in N. The expression of the remaining miRNAs did not differ by group. In patients with long-term pulmonary radiological sequelae following COVID-19-related ARDS, a down-regulation of miR-17-5p, miR-146a-3p, and miR-223-3p correlated to fibrosis development in patients showing persistent hyper-reactivity to inflammatory stimulation. Our results support the hypothesis that NLRP3-Inflammasome could be implicated in the process of fibrotic evolution of COVID-19-associated ARDS.

Infection by Moniliophthora perniciosa reprograms tomato Micro-Tom physiology, establishes a sink, and increases secondary cell wall synthesis.

Witches' broom disease of cacao is caused by the pathogenic fungus Moniliophthora perniciosa. By using tomato (Solanum lycopersicum) cultivar Micro-Tom (MT) as a model system, we investigated the physiological and metabolic consequences of M. perniciosa infection to determine whether symptoms result from sink establishment during infection. Infection of MT by M. perniciosa caused reductions in root biomass and fruit yield, a decrease in leaf gas exchange, and down-regulation of photosynthesis-related genes. The total leaf area and water potential decreased, while ABA levels, water conductance/conductivity, and ABA-related gene expression increased. Genes related to sugar metabolism and those involved in secondary cell wall deposition were up-regulated upon infection, and the concentrations of sugars, fumarate, and amino acids increased. 14C-glucose was mobilized towards infected MT stems, but not in inoculated stems of the MT line overexpressing CYTOKININ OXIDASE-2 (35S::AtCKX2), suggesting a role for cytokinin in establishing a sugar sink. The up-regulation of genes involved in cell wall deposition and phenylpropanoid metabolism in infected MT, but not in 35S::AtCKX2 plants, suggests establishment of a cytokinin-mediated sink that promotes tissue overgrowth with an increase in lignin. Possibly, M. perniciosa could benefit from the accumulation of secondary cell walls during its saprotrophic phase of infection.

Water retention and metabolic changes improve desiccation tolerance in Barbacenia graminifolia (Velloziaceae).

Barbacenia graminifolia is a Velloziaceae species endemic to the campos rupestres in Serra do Cipó, Minas Gerais state (Brazil). This biome is characterised by high irradiance and limited water conditions. Unlike other resurrection plants, B. graminifolia can maintain a high hydric status (>80%) after 28 days of water suppression before desiccation. We investigated the physiological and metabolic mechanisms associated with structural changes that allow B. graminifolia to maintain hydration under a prolonged water deficit and to recover after desiccation. After 30 days of water deficit, desiccated plants exhibited chlorophyll degradation, a 178.4% and 193.7% increase in total carotenoids and MDA, respectively, and twice the CAT and APX activity compared to hydrated plants. The metabolite profile showed increased amino acids, carbohydrates, saturated fatty acids and benzoic acids during dehydration, while trichloroacetic acid cycle acids were higher in hydrated and rehydrated plants. Anatomical and ultrastructural data corroborated the physiological and metabolic changes and revealed the presence of mucilaginous cells with high water retention capacity. Our data indicated that combined strategies of assimilatory metabolism shutdown, accumulation of compatible solutes and antioxidant compounds, increase in hydrophilic molecules, changes in the composition of membrane lipids and remodelling of cell organelles conditioned the efficiency of B. graminifolia in delaying water loss, tolerating further desiccation and quickly recovering after rehydration. These attributes evidence that this species is well adapted to cope with adverse environmental conditions, mainly directing the metabolism to an efficient antioxidant response and improving its capacity to retain water during the dry season.

Moniliophthora perniciosa, the causal agent of witches' broom disease of cacao, interferes with cytokinin metabolism during infection of Micro-Tom tomato and promotes symptom development.

Moniliophthora perniciosa causes witches' broom disease of cacao and inflicts symptoms suggestive of hormonal imbalance. We investigated whether infection of the tomato (Solanum lycopersicum) model system Micro-Tom (MT) by the Solanaceae (S)-biotype of Moniliophthora perniciosa, which causes stem swelling and hypertrophic growth of axillary shoots, results from changes in host cytokinin metabolism. Inoculation of an MT-transgenic line that overexpresses the Arabidopsis CYTOKININ OXIDASE-2 gene (35S::AtCKX2) resulted in a reduction in disease incidence and stem diameter. RNA-sequencing analysis of infected MT and 35S::AtCKX2 revealed the activation of cytokinin-responsive marker genes when symptoms were conspicuous. The expression of an Moniliophthora perniciosa tRNA-ISOPENTENYL-TRANSFERASE suggests the production of isopentenyladenine (iP), detected in mycelia grown in vitro. Inoculated MT stems showed higher levels of dihydrozeatin and trans-zeatin but not iP. The application of benzyladenine induced symptoms similar to infection, whereas applying the cytokinin receptor inhibitors LGR-991 and PI55 decreased symptoms. Moniliophthora perniciosa produces iP that might contribute to cytokinin synthesis by the host, which results in vascular and cortex enlargement, axillary shoot outgrowth, reduction in root biomass and an increase in fruit locule number. This strategy may be associated with the manipulation of sink establishment to favour infection by the fungus.

Full donor chimerism after allogeneic hematopoietic stem cells transplant for myelofibrosis: The role of the conditioning regimen.

The aim of this retrospective study was to assess the rate of full donor chimerism (F-DC) in patients with myelofibrosis, prepared for an allogeneic stem cell transplant, with one or two alkylating agents. We analyzed 120 patients with myelofibrosis, for whom chimerism data were available on day +30. There were two groups: 42 patients were conditioned with one alkylating agent (ONE-ALK), either thiotepa or busulfan or melphalan, in combination with fludarabine, whereas 78 patients were prepared with two alkylating agents, thiotepa busulfan and fludarabine (TBF). Patients receiving TBF were older (57 vs 52 years), were less frequently splenectomized pre-HSCT (31% vs 59%), had more frequently intermediate-2/high DIPSS scores (90% vs 74%), were grafted more frequently from alternative donors (83% vs 33%) and received more frequently ruxolitinib pre-HSCT (26% vs 7%). The proportion of patients with F-DC on day +30, in the TBF vs the ONE-ALK group, was respectively 87% vs 45% (P < .001). The 5-year cumulative incidence of relapse was 9% in the TBF group, vs 43% for the ONE-ALK group (P < .001). The 5-year actuarial disease-free survival was 63% for TBF and 38% for the ONE-ALK group (P = .004). In conclusion, early full donor chimerism is a prerequisite for long term control of disease in patients with myelofibrosis, undergoing an allogeneic HSCT. The combination of two alkylating agents in the conditioning regimen, provides a higher chance of achieving full donor chimerism on day+30, and thus a higher chance of long term disease free survival.

Unraveling the mechanisms controlling Cd accumulation and Cd-tolerance in Brachiaria decumbens and Panicum maximum under summer and winter weather conditions.

We evaluated the mechanisms that control Cd accumulation and distribution, and the mechanisms that protect the photosynthetic apparatus of Brachiaria decumbens Stapf. cv. Basilisk and Panicum maximum Jacq. cv. Massai from Cd-induced oxidative stress, as well as the effects of simulated summer or winter conditions on these mechanisms. Both grasses were grown in unpolluted and Cd-polluted Oxisol (0.63 and 3.6 mg Cd kg-1 soil, respectively) at summer and winter conditions. Grasses grown in the Cd-polluted Oxisol presented higher Cd concentration in their tissues in the winter conditions, but the shoot biomass production of both grasses was not affected by the experimental conditions. Cadmium was more accumulated in the root apoplast than the root symplast, contributing to increase the diameter and cell layers of the cambial region of both grasses. Roots of B. decumbens were more susceptible to disturbed nutrients uptake and nitrogen metabolism than roots of P. maximum. Both grasses translocated high amounts of Cd to their shoots resulting in oxidative stress. Oxidative stress in the leaves of both grasses was higher in summer than winter, but only in P. maximum superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities were increased. However, CO2 assimilation was not affected due to the protection provided by reduced glutathione (GSH) and phytochelatins (PCs) that were more synthesized in shoots than roots. In summary, the root apoplast was not sufficiently effective to prevent Cd translocation from roots to shoot, but GSH and PCs provided good protection for the photosynthetic apparatus of both grasses.

Stigma structure and receptivity in papaya (Carica papaya L.).

The objective of this study was to evaluate the stigma morphoanatomy and receptivity in ten promising papaya accessions, to expand knowledge useful for genetic improvement of the culture. The morphoanatomy was analyzed by light and scanning electron microscopy, and the stigma receptivity was investigated by application of hydrogen peroxide and α-naphthyl-acetate with fast blue B salt, in pre-anthesis, anthesis and post-anthesis. The papaya accessions presented dry stigma surface, presence of one to six erect stigmatic lobes, with structures joined to the upper base of the style and covered with numerous elongated unicellular tubular papillae, distributed on both faces of the epidermis. The morphoanatomy had a similar pattern in all the accessions, differing only in the timing of floral development. The stigma receptivity in some accessions occurred even before floral opening, continuing with greater intensity in anthesis and post-anthesis. Pre-anthesis is the stage least propitious for controlled hybridizations due to the weak or absent stigmatic receptivity. The results obtained provide information on the floral stage that is most propitious for fertilization, as well as supporting future investigations of the botanical morphology of the species.

Post-seminal development and cryopreservation of endemic or endangered bromeliads.

Vriesea bahiana, Hohenbergia castellanosii and Encholirium spectabile are endemic Brazilian species that are considered endemic or endangered. Development of strategies to conserve these species is important to prevent irreversible genetic erosion. The objective of this study was to evaluate the post-seminal development and seed cryopreservation of three endemic or in danger of extinction bromeliad species in Brazil, to obtain a protocol that can safeguard the genetic variability of these species. In the seed cryopreservation assay, we evaluated five desiccation periods. The seeds in the cryotubes were taken from the desiccator and immediately plunged into liquid nitrogen. For the analysis of post-seminal development, seeds in different germination stages were collected and evaluated by light and scanning electron microscopy. Vriesea bahiana seeds frozen in liquid nitrogen presented almost 100% germination, indicating dormancy break of this species. Vriesea bahiana can be cryopreserved with 5.9% water content after being dried for 24 hours. Hohenbergia castellanosii and E. spectabile seeds did not need to be desiccated before being cryopreserved. The most relevant morphological traits for differentiation of genera and subfamilies of Bromeliaceae are the shape and type of seed appendages. In this study, all three species presented well-differentiated size and shape of their structures.

Morphoanatomical aspects of the starting material for the improvement of pineapple cryopreservation by the droplet-vitrification technique.

Cryopreservation of pineapple shoot tips has been established from various protocols, including droplet vitrification. Thus, this work aimed to evaluate the morphoanatomical conditions of the starting material over different times (30, 45 and 60 days) of culture before freezing and its correlation with the survival percentage of the cryopreserved shoot tips. Four accessions, Ananas comosus var. comosus (BGA-009); var. bracteatus (BGA-119); var. parguazensis (BGA-376), var. erectifolius (BGA-750) from the Pineapple Active Germplasm Bank (BGA Pineapple) and two hybrids from the Embrapa Genetic Breeding Program, FIB-ROX1 (var. bracteatus X var. erectifolius) and FIB-ROX2 ( var. erectifolius X var. bracteatus), recently introduced in the field from in vitro storage, were used. Histological sections before freezing and the percentages of survival after freezing were obtained taking into account the different times of cultivation of the donor plants. The results showed a significative interaction between genotypes (accessions and hybrids) and the culture period. The accessions BGA-009 and BGA-119 showed the highest survival rates, with 95% and 90% respectively for the 30-day culture time. Different results were obtained for each genotype, showing the need for improvements in the standardization of starting material, which would allow better repeatability of the protocol.

Characterization of floral morphoanatomy and identification of marker genes preferentially expressed during specific stages of cotton flower development.

MAIN CONCLUSION: Characterization of anther and ovule developmental programs and expression analyses of stage-specific floral marker genes in Gossypium hirsutum allowed to build a comprehensive portrait of cotton flower development before fiber initiation. Gossypium hirsutum is the most important cotton species that is cultivated worldwide. Although cotton reproductive development is important for fiber production, since fiber is formed on the epidermis of mature ovules, cotton floral development remains poorly understood. Therefore, this work aims to characterize the cotton floral morphoanatomy by performing a detailed description of anther and ovule developmental programs and identifying stage-specific floral marker genes in G. hirsutum. Using light microscopy and scanning electron microscopy, we analyzed anther and ovule development during 11 stages of flower development. To better characterize the ovule development in cotton, we performed histochemical analyses to evaluate the accumulation of phenolic compounds, pectin, and sugar in ovule tissues. After identification of major hallmarks of floral development, three key stages were established in G. hirsutum floral development: in stage 1 (early-EF), sepal, petal, and stamen primordia were observed; in stage 2 (intermediate-IF), primordial ovules and anthers are present, and the differentiating archesporial cells were observed, marking the beginning of microsporogenesis; and in stage 6 (late-LF), flower buds presented initial anther tapetum degeneration and microspore were released from the tetrad, and nucellus and both inner and outer integuments are developing. We used transcriptome data of cotton EF, IF and LF stages to identify floral marker genes and evaluated their expression by real-time quantitative PCR (qPCR). Twelve marker genes were preferentially expressed in a stage-specific manner, including the putative homologs for AtLEAFY, AtAPETALA 3, AtAGAMOUS-LIKE 19 and AtMALE STERILITY 1, which are crucial for several aspects of reproductive development, such as flower organogenesis and anther and petal development. We also evaluated the expression profile of B-class MADS-box genes in G. hirsutum floral transcriptome (EF, IF, and LF). In addition, we performed a comparative analysis of developmental programs between Arabidopsis thaliana and G. hirsutum that considered major morphoanatomical and molecular processes of flower, anther, and ovule development. Our findings provide the first detailed analysis of cotton flower development.

Seed and soil? - Pharyngeal Merkel cell carcinoma after radiotherapy for laryngeal squamous cell carcinoma.

Merkel cell carcinoma (MCC) is a neuroendocrine cutaneous malignancy that may present as metastatic disease without a known primary site but, most commonly originates in the sun-exposed skin of the head, neck, and extremities. We present a 66-year-old male treated with chemo-radiation for T3N2cM0 laryngeal squamous cell carcinoma (SCCa) six years before he was diagnosed with MCC isolated to the radiated laryngopharynx. Mucosal MCC is rare and radiation-induced MCC has been hypothesized to occur in previously radiated tissue but, never before to the laryngopharynx. Implications regarding cancer biology and management is focused with discussion on relevant advances in pathologic assessment and immunotherapy.

Relationship between Mg, B and Mn status and tomato tolerance against Cd toxicity.

Distinct tomato genotypes possess different tolerance degree to cadmium (Cd), but the mechanisms behind this phenomenon are scarcely understood. To this end, the physiological, biochemical, anatomical, nutritional and molecular mechanisms associated to the plant tolerance against Cd toxicity were investigated in five tomato accessions with contrasting sensitivity to Cd exposure. Firstly, the data revealed that larger biomass loss was not always coupled to higher Cd concentration, indicating that other events, in addition to the internal Cd accumulation, impact tomato performance at early stages of Cd exposure. Secondly, the results indicated that the fine regulation of nutrient status, particularly magnesium (Mg), boron (B) and manganese (Mn), is associated to the mitigation of Cd toxicity. Magnesium status was coupled to the modulation of root development, resulting in changes in root hair formation and biomass allocation. Boron accumulation in leaves was linked to Cd toxicity, suggesting that tolerance mechanisms involved strategies to decrease or even avoid B excess in photosynthetic tissues. Disturbances in Mn status, i.e. Mn excess in leaves and Mn deficiency in roots, were also related to tomato sensitivity to Cd exposure. Thirdly, plant capacity to maintain leaf blade expansion is a relevant strategy for a better tomato development after short-term Cd exposure. Fourthly, tomato tolerance to Cd-induced stress does not depend on CAT activity enhancements in such conditions. In conclusion, tomato ability to quickly manage its nutritional status is necessary for alleviation of the Cd effects at early stages of exposure to this metal. The better understanding about tolerance mechanisms and mode of action of Cd toxicity in plants can help in the establishment of strategies to mitigate its impacts on crops.

Post-seminal development and morphoanatomy of vegetative and reproductive organs in Stevia rebaudiana (Bert.) Bertoni (Asteraceae).

Stevia rebaudiana belongs to the Asteraceae family with high economic and medicinal potential. This article describes and illustrates morphological and histological aspects of leaves and reproductive organs, and the germination process, to provide detailed information on this species and to contribute to taxonomic, phylogenetic and pharmacobotanical projects. The fruit is a cypsela, small, simple, dry, indehiscent, monospermic, light or dark colored, with aristate pappus, and the seed presents a spatulate axile embryo. Germination is phaneroepigeal with a pivotal root system and many absorbing root hairs. The leaves are simple, elliptical to obovate, with two types of trichomes (glandular and tector), with a short petiole, exhibiting an opposite decussate phyllotaxy. Our results showed 37.5% germination after 12 days, only in the dark cypsela, the light colored being considered unviable. The inflorescence is paniculate and the florets are grouped in capitula with isomorphic ends, monoclinous (bisexual), dichlamydeous, heterochlamydeous, pentamerous calyx and corolla, gamossepalous and gamopetalous. The androecium is gamostemone comprised of five stamens with free filaments, isodynamous and epipetalous stamens, synandrous and rimose anthers. The flower presents an inferior ovary, bicarpelar, unilocular and ovules with a basal placentation. The pollen grains are small, isopolar, radial symmetry, tricolporate, with echinate ornamentation.

Comparative pollen morphological analysis in the subgenera Passiflora and Decaloba.

The genus Passiflora is the most diversified of the Passifloraceae, and its palynology presents wide morphological variability. The objective of the study was to evaluate the pollen morphology of 18 Passiflora species in order to identify informative pollinic characteristics to contribute to the taxonomic classification of the genus. The morphology of the pollen grains and the exine structure were investigated using light microscopy and scanning electron microscopy. Differences in the pollen morphology were found in the studied species, mainly in terms of shape, pollen aperture and ornamentation pattern of the exine. Most of the species belonging to the subgenus Passiflora presented ornamented 6-syncolpate pollen grains with an oblate-spheroidal shape and an exine with large lumens. In the subgenus Decaloba the pollen grains were 6-colporate, 12-colpate and 12-colporate, with subprolate to prolate-spheroidal shape, as well as an exine with smaller lumen size and few ornamented. The pollen morphology of the species of the subgenera Passiflora and Decaloba has shown palynological characteristics that have specific diagnostic value, thus allowing a better understanding of the taxonomy of the genus Passiflora.

Changes in protein serum levels during stem cell transplantation.

BACKGROUND: GvHD is one of the major complication after stem cell transplantation affecting transplant-related mortality. Throughout the last years, many serum proteins were been proposed as possible biomarkers for GvHD. AIMS: We studied the trend of five of the most studied serum proteins to evaluate whether a correlation exists between proteins concentration and post-HSCT outcomes. MATERIALS AND METHODS: We measured serum concentration of REG3α, ST2, B-cell activating factor (BAFF), CXCL9 and elafin in a cohort of 77 patients submitted to Hematopoietic allogeneic stem cell transplantation (HSCT) in our department. Blood samples were been collected at baseline, day +30, GvHD onset and GvHD resolution. RESULTS: REG3α levels showed an association only with acute GvHD. Elafin and ST2 levels varied according to both acute and chronic GvHD occurrence. BAFF concentration showed an inverse association with acute GvHD development. Interestingly, baseline BAFF and ST2 levels predicted post-HSCT survival. No associations were found for CXCL9. CONCLUSIONS: Except for CXCL9, the protein levels seem to change according to GvHD development, independently from organ involvement and grading. Pretransplant ST2 and BAFF appeared to be predictors for survival after HSCT.

Fecal but not serum calprotectin is a potential marker of GVHD after stem cell transplantation.

Gastrointestinal graft-versus-host disease (GvHD) represents a life-threatening complication after stem cell transplantation. Differential diagnosis between gut GvHD and other causes of diarrhea after HSCT is still subjected to endoscopy and histological findings. The research for a reliable biomarker for gut GvHD might allow an early diagnosis of this condition and a consequent prompt treatment that could reduce unfavorable outcomes. Recently, fecal calprotectin was reported as reliable marker of gut involvement. We would evaluate if serum instead of fecal calprotectin could be considered a possible biomarker of gut GvHD. Serum calprotectin was measured in a cohort of 54 patients submitted to allogeneic stem cell transplantation using ELISA assay. For a subset of 21 patients, calprotectin serum levels were compared with fecal calprotectin detection. Contrary to fecal calprotectin, we found only a trend to high level of serum calprotectin for GvHD development and gut involvement, but statistical difference was not reached. Fecal but not serum calprotectin could be considered as possible biomarker for gut GvHD.