Platelet mass index in very preterm infants: can it be used as a parameter for neonatal morbidities?

Platelet Indices: Universally Available Clinical Adjunct for Diagnosing Necrotizing Enterocolitis

OBJECTIVE

Platelet function parameters can be predictive of several adult diseases and their severity. However, few studies report on the association between platelet indices and neonatal diseases, specifically necrotizing enterocolitis (NEC). The objective of this study is to investigate whether platelet indices are associated with NEC diagnosis and NEC-related mortality.

STUDY DESIGN

We retrospectively examined records from infants admitted to the neonatal intensive care unit with a diagnosis of NEC, verified by the presence of pneumatosis on X-ray or pathology at surgery. We compared them with an age-matched group of prematures without NEC. We investigated platelet count, mean platelet volume (MPV), platelet distribution width and red cell distribution width to platelet ratio (RPR) and delta platelets from birth to the time of NEC diagnosis or day of life 14 in the control group.

RESULTS

Sixty-nine infants with NEC and 78 control infants were studied. Basic sociodemographic data were similar in both groups. All platelet parameters measured-except for MPV-were significantly associated with NEC diagnosis. Although MPV was not associated with the diagnosis of NEC (p = 0.800), it was significantly associated with NEC-related mortality (p < 0.001). Only total platelet count and RPR were significantly associated with both NEC diagnosis (p < 0.0001) and mortality (p = 0.04 and 0.01, respectively). On multivariable analysis only the change in platelet count from birth to time of diagnosis remained significant.

CONCLUSION

While not definitive, this study demonstrates that these routinely available, inexpensive, and easily calculated platelet indices can provide a clinical adjunct in the often-elusive attempts to definitively diagnose NEC in preterm neonates.

KEY POINTS

· Platelet indices were associated with NEC diagnosis.. · MPV was predictive of NEC-related mortality.. · Delta platelet count from birth was significantly related to NEC diagnosis..

Platelet Counts and Risk of Severe Retinopathy of Prematurity: A Bayesian Model-Averaged Meta-Analysis

BACKGROUND

We aimed to conduct a systematic review and Bayesian model-averaged meta-analysis (BMA) on the association between platelet counts and severe retinopathy of prematurity (ROP).

METHODS

We searched for studies reporting on platelet counts (continuous variable) or thrombocytopenia (categorical variable) and severe ROP or aggressive posterior ROP (APROP). The timing of platelet counts was divided into Phase 1 (<2 weeks) and Phase 2 (around ROP treatment). BMA was used to calculate Bayes factors (BFs). The BF10 is the ratio of the probability of the data under the alternative hypothesis (H1) over the probability of the data under the null hypothesis (H0).

RESULTS

We included 21 studies. BMA showed an association between low platelet counts and severe ROP. The evidence was strong (BF10 = 13.5, 7 studies) for phase 1 and very strong (BF10 = 51.0, 9 studies) for phase 2. Thrombocytopenia (<100 × 109/L) in phase 2 was associated with severe ROP (BF10 = 28.2, 4 studies). Following adjustment for publication bias, only the association of severe ROP with thrombocytopenia remained with moderate evidence in favor of H1 (BF10 = 4.30).

CONCLUSIONS

Thrombocytopenia is associated with severe ROP. However, the evidence for this association was tempered when results were adjusted for publication bias.

Association of Positive Bacterial Cultures Obtained from the Throat, Anus, Ear, Bronchi and Blood in Very-Low-Birth-Weight Premature Infants with Severe Retinopathy of Prematurity-Own Observations

BACKGROUND

The causative factors responsible for the development of Retinopathy of Prematurity (ROP) are still unexplored. Therefore, one of the most important factors can be perinatal inflammation.

METHODS

This retrospective study included 114 premature infants (228 eyes) meeting a birth criteria of ≤ 32 weeks gestational age (GA) and a birth weight (BW) ≤ 1710. Examined Group (EG) n = 51 of BW 852.7 ± 255.7; GA 26.3 ± 2.0 with severe ROP treated by diode laser or anti-VEGF intravitreal injection. Control Group (CG) n = 63 of BW 1313.9 ± 284.5; GA 28.8 ± 1.6 without ROP. Microbiological bacterial and fungal cultures of the ear, anus, bronchial throat and blood were taken. Medical data and laboratory tests in correlation to 3 ROP and A-ROP were analysed.

RESULTS

Positive bacterial tests dominated in EG, 47% vs. CG, 23%. Significant correlations between positive cultures obtained from natural cavities: anus (p < 0.001), throat (p = 0.002), as well as from blood (p = 0.001) and severe ROP which requires diode laser and anti-VEGF treatment were noted. Significant inflammation markers which correlate with the development of severe ROP are Klebsiella pneumoniae (KP) (p = 0.002) and Coagulase-negative Staphylococci (CoNS) (p < 0.001). CoNS, p < 0.001; KP, p = 0.002; the remaining Maltophilia stenotrophomonas (MS); Staphylococcus aureus (SA), p = 0.005; and Enterobacter cloacae (EC), p = 0.02 were the most frequent bacteria in severe ROP. High levels of white blood cells (WBC), C-reactive protein (CRP), lymphocytes (LYM) and low thrombocytes (PLT) correlated sequentially with (Odds Ratio, OR) CoNS (2.3); MS (5.9); KP (3.1); and all positive cultures (APC) (9.5). An important correlation between the BPD-EC (4.3); intrauterine inflammation-KP (3.4); PDA-EC (3.9); and asphyxia-CoNS (3.0) was identified.

CONCLUSIONS

It cannot be ruled out that positive microbiological results of blood, anal and pharyngeal cultures may become prognostic markers for the early development of ROP, which would enable early initiation of ophthalmological treatment in premature infants from the VLBW group.

Performance of Platelet Mass Index as a Marker of Severity for Sepsis and Septic Shock in Children

Platelet mass index (PMI) as a prognostic indicator in pediatric sepsis has not been previously reported. In this retrospective observational study, we evaluated PMI's performance as a prognostic indicator in children aged younger than 18 years with sepsis and septic shock in relationship with survival. Over 5 years, we collected data from 122 children admitted to our pediatric intensive care unit (PICU). PMI accuracy was assessed with sensitivity and specificity and its discrimination was assessed using the area under the receiver operating characteristic curve (AUC). Median PMI values on days 1 and 3 of PICU admission were lower among nonsurvivors. On day 1 of PICU admission, a cutoff PMI value of 1,450 fL/nL resulted in a sensitivity of 72% and a specificity of 69%, and the AUC was 0.70 (95% confidence interval [CI]: 0.55-0.86). Similarly, on day 3, a cutoff of 900 fL/nL resulted in a sensitivity of 71% and a specificity of 70%, and the AUC was 0.76 (95% CI: 0.59-0.92). Our exploratory study suggests that low PMI in children with septic shock is associated with increased mortality. Considering the PMI's fair performance, further studies should be performed to assess its clinical value.

Relationship between platelet mass index and postoperative atrial fibrillation after elective coronary artery bypass surgery: a retrospective study

BACKGROUND

Atrial fibrillation (AF) is the most common complication after cardiac surgery. The pathogenesis of postoperative atrial fibrillation (POAF) is multifactorial and one of the known factors is inflammation. Platelet mass index (PMI) is an indicator of platelet activation and a better inflammatory marker than mean platelet volume (MPV). In this retrospective study, we investigated the relationship between POAF and PMI.

METHODS

The study included 848 consecutive patients (655 male and 193 female) who had elective isolated coronary artery by-pass grafting (CABG) or combined CABG and valvular surgery. Platelet count and MPV were measured from preoperative blood samples to calculate PMI. Post-operative atrial fibrillation was defined as irregular and fibrillatory P waves occurring 48-96 h after cardiac surgery and lasting at least 30 s. The PMI values in patients who developed POAF were compared with those in patients who did not develop POAF.

RESULTS

Patients who developed POAF had higher PMI values (2549.3 ± 1077.1) when compared with patients in sinus rhythm (2248.1 ± 683.4; p < 0.01). In multivariate regression analysis, age (OR: 1.05; 95% CI: 1.02-1.09; p = 0.01), left atrial diameter (OR: 1.05; 95% CI: 1.03-1.09; p = 0.02), hs-CRP (OR: 1.09; 95%CI: 1.05-1.13; p < 0.01), EuroSCORE II (OR: 1.27; 95% CI: 1.14-1.41; p < 0.01), and PMI (OR: 1.01; 95% CI: 1.001-1.02; p < 0.01) were independent predictors of POAF. In ROC analysis, PMI ≥ 2286 predicted POAF development with a sensitivity of 69% and a specificity of 58% (AUC: 0.66; p < 0.01) CONCLUSION: A significant relationship was found between preoperatively calculated PMI and POAF. We showed that PMI may be used to predict patients who are at high risk of developing POAF.

Platelet parameters and the association with morbidity and mortality in Preterm Infants

BACKGROUND

There is growing recognition of the role of platelets in inflammation and immune responses, and platelets have been associated with various cardiovascular diseases. It is also known that neonatal morbidities are related to overall platelet activity, and platelet parameters may have the potential to predict morbidities and mortality in preterm infants. This study aimed to assess the initial platelet parameters and the association with major morbidities and mortality in preterm neonates.

METHODS

We retrospectively reviewed data from very preterm neonates with a gestational age (GA) <32 weeks who were admitted between June 2020 and May 2021 for platelet parameters (counts, mean platelet volume (MPV), platelet distribution width (PDW) and plateletcrit (platelet counts x MPV/10000(%)) at birth. Major morbidities included early- onset sepsis (EOS) ≤3 days after birth, severe intraventricular hemorrhage (IVH) grade ≥3, and early or overall mortality.

RESULTS

A total of 197 very preterm neonates were studied. Their mean (±SD) GA was 28.0 ± 2.4 weeks, birth weight was 990 ± 293 g, platelet counts were 245 ± 81 x1000/μL, MPV was 10.0 ± 0.7 fl, PDW was 11.0 ± 1.6 fl, and plateletcrit was 0.24 ± 0.08%. MPV had a weak negative correlation with both GA (r = -0.234, p = 0.001) and BW (r = -0.343, p <0.001). A lower plateletcrit was associated with EOS (0.14 (0.04-0.22) % vs. 0.23 (0.19-0.30) %, p = 0.027), severe IVH ≤7 days after birth (0.18 (0.14-0.27) % vs. 0.23 (0.20-0.30) %, p = 0.022), and early and overall mortality (0.15 (0.20-0.30) % vs. 0.23 (0.20-0.30) %, p = 0.049; 0.20 ± 0.09 % vs. 0.25 ± 0.07 %, p = 0.008).

CONCLUSION

A lower plateletcrit within 24 hours of birth was associated with EOS, severe IVH ≤7 days after birth, and first-week and overall mortality in very preterm neonates.

The relationship between mean platelet volume (MPV) and intraventricular hemorrhage in very low birth weight infants

BACKGROUND

Intra ventricular hemorrhage (IVH) is a major cause of mortality among very low birth weight infants. This study aimed to investigate the relationship between mean platelet volume (MPV) and IVH in very low birth weight infants.

METHOD

In this cohort study, all premature infants weighing less than 1500 grams who were admitted to the NICU were enrolled from August 2018 to July 2019. Brain ultrasonography was performed on the first and seventh days and one month of age and were compared with Platelet count and MPV.

RESULTS

From 183 neonates, 23 cases (12.6%) had IVH. The mean MPV on the first day in the group with IVH was 10.48±0.85 and in the non-IVH group was 9.9±0.74 (P = 0.005). The mean MPV on the seventh day in the IVH and non-IVH group were 10.4±0.92 and 10.03±0.74 (P = 0.04) respectively. On the first and seventh day, for one unit of MPV increase, the chance of IVH increased by 2.68 and 2.1 respectively. (p = 0.001; OR3.643; 95% CI [1.703-7.753]).

CONCLUSION

The mean MPV index is significantly higher in the infants with IVH and therefore it can be used in early detection of IVH in neonates weighing less than 1500 grams.

Is thrombocytopenia and postnatal weight gain associated with treatment‐requiring retinopathy of prematurity? A matched case–control study

PURPOSE

The purpose of the study was to investigate the association of platelet parameters and postnatal weight gain with treatment-requiring ROP (TR-ROP).

METHODS

In this retrospective matched case-control study, infants with TR-ROP were individually matched, according to gestational age and birth weight, with one or two untreated infants who developed no or spontaneously regressed ROP. Longitudinal data on platelet count (PLT), mean platelet volume (MPV), daily weight and platelet transfusions were collected. Platelet mass index (PMI) and weight standard deviation score (WSDS) were also calculated. Conditional logistic regression analysis was performed to adjust for matching.

RESULTS

Fourteen cases, presenting type I ROP, and 25 matched controls were included. The odds of developing TR-ROP decreased as PLT increased during 31^st week of postmenstrual age (PMA) or during 1^st and 2^nd week of postnatal age (PNA). The odds of developing TR-ROP were 16.7 times higher in infants receiving at least one platelet transfusion compared with those who were not transfused. The odds of developing TR-ROP increased by 31.2% as the mean volume of platelet transfusion per infant increased by 1 ml. The odds of developing TR-ROP decreased as PMI increased during 1^st week PNA, and as weight and WSDS increased during 4^th -6^th week PNA. Analysis of MPV, number of thrombopenic episodes per infant, number of platelet transfusions per infant and days with WSDS < -2 showed no association with TR-ROP.

CONCLUSION

To our knowledge, this is the first study ascertaining an association of platelet transfusions with type I ROP. Prospective cohort studies are required to confirm our findings.

Features of platelet and plasma hemostasis in premature infants with hemorrhagic disorders

The research revealed features of platelet and plasma hemostasis indicators in children born before 32 weeks with hemorrhagic disorders in the early neonatal period, a method for predicting the development of intraventricular hemorrhage was developed.

Material and methods. 132 premature newborns were examined, a detailed clinical blood test, a coagulogram with the determination of: activated partial thromboplastin time, prothrombin time, thrombin time, prothrombin index, fibrinogen content, D-dimer were performed on 1–3 days of life. The main group consisted of 58 children with hemorrhagic disorders, the comparison group included 74 children without hemorrhagic disorders.

Results. Risk factors for the formation of hemorrhagic disorders in the early neonatal period were established: a lower gestational age of the child, lower Apgar scores at the end of the first and fifth minutes of life, the need for the introduction of an exogenous surfactant, and the use of higher concentrations of oxygen-air mixture during respiratory therapy. The features of hemostasis indicators in deep-premature newborns with hemorrhagic disorders in the early neonatal period were revealed: a lower number of platelets in the blood and higher platelet granularity, higher activated partial thromboplastin time, and a decrease in the prothrombin index. Based on the data obtained, a new method for predicting the formation of intraventricular hemorrhage in deeply premature newborns is proposed based on determining the concentration of total Ca2+ in the blood and the average concentration of platelet components. The results of this study can be used in intensive care units for newborns. Conclusion. The implementation of the obtained results in practice will help timely assess the state of hemostasis in deeply premature newborns to predict the development of intraventricular hemorrhages in the early neonatal period. 

Association of platelet deficiency with severe retinopathy of prematurity: a review

AIM

The aim of this review was to compile existing evidence on the role of platelets in the development of severe retinopathy of prematurity (ROP), highlight the strengths and weaknesses of the available studies and critically discuss the reported data.

METHODS

A comprehensive literature search was conducted on PubMed from January 2000 to January 2022, and the reference lists of the included studies were screened manually.

RESULTS

There were 19 primary studies that fulfilled the eligibility criteria. Experimental research indicated lower platelet count in mice oxygen-induced retinopathy model compared with normoxia controls, while platelet transfusions suppressed neovascularisation. The latter finding was not consistently confirmed in clinical research, where a low platelet count, an increased number of thrombopenic episodes and of platelet transfusions have all been implicated in the development of ROP requiring treatment, either type I or aggressive posterior or both. However, existing studies exhibit significant clinical heterogeneity and present methodological limitations that imperil their reliability and validity.

CONCLUSION

Platelet deficiency has been associated with severe ROP. However, critical thresholds of platelet parameters are still unrecognised. Future research is required to determine whether platelet parameters can be predictive biomarkers for ROP requiring treatment and at what thresholds.

Carbapenem-Resistant Klebsiella pneumoniae Outbreak in a Neonatal Intensive Care Unit: Risk Factors for Mortality

AIM

The aim of our study was to determine the factors associated with mortality in neonates with carbapenem-resistant Klebsiella pneumoniae (CRKP).

MATERIAL AND METHODS

This retrospective, single-center study was conducted in the Neonatal Intensive Care Unit of Harran University Faculty of Medicine between January 2017 and July 2018 who had CRKP growth in their blood, urine or cerebrospinal fluid cultures. The discharged group was designated as the control group (Group 1), whereas the group that faced mortality was classified as the case group (Group 2). The demographic data, clinical findings and laboratory and microbiological results of the two groups were compared to identify risk factors.

RESULTS

A total of 58 patients (36 in Group 1 and 22 in Group 2) exhibited CRKP growth during the study period. Low birth weight (p = 0.039), previous antifungal (p = 0.002) or amikacin use (p = 0.040), congenital anomalies (p = 0.002), total parenteral nutrition (TPN) administration (p = 0.002), surgery (p = 0.035), thrombocytopenia (p = 0.007), low platelet mass index (p = 0.011), elevated C-reactive protein (p = 0.004), high carbapenem minimum inhibitory concentration (MIC) (p = 0.029) and high amikacin MIC (p = 0.019) were associated with mortality. In a multivariate regression analysis, previous antifungal use (p = 0.028), congenital anomalies (p = 0.032) and TPN use (p = 0.013) were independent factors in predicting mortality.

CONCLUSION

Previous antifungal use, congenital anomalies and TPN use were found to be independent risk factors for mortality in neonates with CRKP infection.

Role of platelets in neonatal necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is an inflammatory bowel necrosis of premature infants and is a leading cause of morbidity and mortality in infants born between 23 and 28 weeks of gestation. Fifty to 95% of all infants with NEC develop thrombocytopenia (platelet counts <150 × 109/L) within 24-72 h of receiving this diagnosis. In many patients, thrombocytopenia is severe and is treated with one or more platelet transfusions. However, the underlying mechanism(s) and biological implications of NEC-related thrombocytopenia remain unclear. This review presents current evidence from human and animal studies on the clinical features and mechanisms of platelet depletion in NEC. Anecdotal clinical experience is combined with evidence from laboratory studies and from an extensive literature search in databases PubMed, EMBASE, and Scopus and the electronic archives of abstracts presented at the annual meetings of the Pediatric Academic Societies. To avoid bias in identification of existing studies, key words were short-listed prior to the actual search both from anecdotal experience and from PubMed's Medical Subject Heading (MeSH) thesaurus. IMPACT: Fifty to 95% of infants with necrotizing enterocolitis (NEC) develop idiopathic thrombocytopenia (platelet counts <150 × 109/L) within 24-72 h of disease onset. Early clinical trials suggest that moderate thrombocytopenia may be protective in human NEC, although further work is needed to fully understand this relationship. We have developed a neonatal murine model of NEC-related thrombocytopenia, where enteral administration of an immunological stimulant, trinitrobenzene sulfonate, on postnatal day 10 induces an acute necrotizing ileocolitis resembling human NEC. In this murine model, thrombocytopenia is seen at 15-18 h due to platelet consumption and mild-moderate thrombocytopenia is protective.

Close Association Between Platelet Biogenesis and Alveolarization of the Developing Lung

Bronchopulmonary dysplasia (BPD) is a neonatal chronic lung disease characterized by an arrest in alveolar and vascular development. BPD is secondary to lung immaturity, ventilator-induced lung injury, and exposure to hyperoxia in extremely premature infants, leading to a lifelong impairment of lung function. Recent studies indicate that the lung plays an important role in platelet biogenesis. However, the dynamic change of platelet production during lung development and BPD pathogenesis remains to be elucidated. We investigated the dynamic change of platelet parameters in extremely premature infants during BPD development, and in newborn rats during their normal development from birth to adulthood. We further studied the effect of hyperoxia exposure on platelet production and concomitant pulmonary maldevelopment in an experimental BPD rat model induced by prolonged exposure to hyperoxia. We detected a physiological increase in platelet count from birth to 36 weeks postmenstrual age in extremely premature infants, but platelet counts in extremely premature infants who developed BPD were persistently lower than gestational age-matched controls. In line with clinical findings, exposure to hyperoxia significantly decreased the platelet count in neonatal rats. Lung morphometry analysis demonstrated that platelet counts stabilized with the completion of lung alveolarization in rats. Our findings indicate a close association between platelet biogenesis and alveolarization in the developing lung. This phenomenon might explain the reduced platelet count in extremely premature infants with BPD.

Using Platelet Parameters to Anticipate Morbidity and Mortality Among Preterm Neonates: A Retrospective Study

Background: Platelets participate in many physiological and pathological functions and some platelet parameters predict adult diseases. However, few studies report whether platelet parameters may reflect neonatal disease and mortality in a large cohort. Objective: We aimed to investigate whether platelet parameters could predict bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), intraventricular hemorrhage (IVH), and NICU mortality. Study Design and Methods: This retrospective cohort study examined records from 2006 to 2017 at the neonatal intensive care unit (NICU) of Fukushima Medical University Hospital. We retrospectively investigated platelet count, plateletcrit (PCT), mean platelet volume (MPV), and platelet distribution width (PDW) on the first day of life in preterm newborns born <32 weeks' gestation admitted to our NICU from 2006 to 2017. Receiver operating characteristic (ROC) and multiple regression analyses, along with Cox proportional hazard modeling, identified independent predictors of morbidities and mortality in preterm newborns. Results: Of 1,501 neonates admitted to our NICU, a total of 305 preterm newborns were included in this study. Gestational age, birth weight, and Apgar score were significantly lower in non-survivors than in survivors. Platelet count, PCT, PDW and PMI did not differ significantly between the two groups, whereas mean MPV in non-survivors was significantly higher than in survivors (10.5 fl vs. 10.0 fl, p = 0.001). Multivariate Cox hazard modeling showed that shorter GA [HR: 0.628, 95% CI: 0.464-0.840, p = 0.003], male sex [HR: 0.269, 95% CI: 0.113-0.640, p = 0.001], and MPV [HR: 1.469, 95% CI: 1.046-2.063, p = 0.026] independently predicted overall survival. Per receiver operating curve, an MPV threshold of 10.2 fl. MPV predicts prognosis in neonates with a sensitivity of 72.4% and a specificity of 58.6% (AUC = 0.685, 95% CI: 0.600-0.789, p = 0.001). Furthermore, multivariate analysis revealed that platelet parameters were not associated with BPD and NEC, whereas small for gestational age (SGA), Apgar score at 5 min, and low PCT were associated with intraventricular hemorrhage (IVH). Conclusion: This study demonstrates that low PCT predicts IVH, and MPV ≥ 10.2 fL correlates with mortality among infants born after <32 weeks' gestation.

Platelet mass index and prediction of severity of transient tachypnea of the newborn

BACKGROUND

Platelet mass index (PMI) is associated with platelet functionality. The aim of this study was to evaluate the role of PMI in predicting the severity of transient tachypnea of the newborn (TTN).

METHODS

Infants with gestational age ≥37 weeks and birthweight ≥2,000 g who were given nasal intermittent mandatory ventilation for TTN ≤6 h after birth were retrospectively enrolled in this study. PMI was calculated using the following formula: PMI = platelet count × mean platelet volume/10³ (fL/nL). The study infants (n = 101) were divided into two groups according to the duration of tachypnea: ≤48 h (n = 45) and >48 h (n = 56).

RESULTS

The PMI and platelet count were significantly lower in the group with tachypnea duration >48 h than in the tachypnea duration ≤48 h group (P < 0.001 and P = 0.04, respectively). A negative significant correlation was noted between PMI and the duration of tachypnea (r = -0.43, P < 0.001). A PMI cut-off of 1,562 fL/nL can predict prolonged tachypnea (>48 h) with a sensitivity of 62.5%, specificity of 68.9%, positive predictive value of 71.4%, and negative predictive value of 59.6% (area under the curve, 0.682 ± 0.053; P = 0.002).

CONCLUSIONS

Lower PMI and lower platelet count are associated with longer duration of tachypnea in patients with TTN.

Recent advances in our understanding of the mechanisms of late lung development and bronchopulmonary dysplasia

The objective of lung development is to generate an organ of gas exchange that provides both a thin gas diffusion barrier and a large gas diffusion surface area, which concomitantly generates a steep gas diffusion concentration gradient. As such, the lung is perfectly structured to undertake the function of gas exchange: a large number of small alveoli provide extensive surface area within the limited volume of the lung, and a delicate alveolo-capillary barrier brings circulating blood into close proximity to the inspired air. Efficient movement of inspired air and circulating blood through the conducting airways and conducting vessels, respectively, generates steep oxygen and carbon dioxide concentration gradients across the alveolo-capillary barrier, providing ideal conditions for effective diffusion of both gases during breathing. The development of the gas exchange apparatus of the lung occurs during the second phase of lung development-namely, late lung development-which includes the canalicular, saccular, and alveolar stages of lung development. It is during these stages of lung development that preterm-born infants are delivered, when the lung is not yet competent for effective gas exchange. These infants may develop bronchopulmonary dysplasia (BPD), a syndrome complicated by disturbances to the development of the alveoli and the pulmonary vasculature. It is the objective of this review to update the reader about recent developments that further our understanding of the mechanisms of lung alveolarization and vascularization and the pathogenesis of BPD and other neonatal lung diseases that feature lung hypoplasia.

Platelet mass index is increased in psoriasis. A possible link between psoriasis and atherosclerosis

INTRODUCTION

Psoriasis, whose relation with atherosclerosis etc. has long been known, is a chronic inflammatory disease. Besides providing hemostasis, platelets play important roles in inflammatory reactions and immune responses and contribute to endothelial damage, thus leading to atherosclerotic plaque formation. Mean platelet volume (MPV) has been previously reported as a platelet activation marker. Platelet mass index (PMI) is also related to platelet functionality and is thought to be a useful parameter for plaque formation capacity of platelets.

MATERIAL AND METHODS

Sex, age, age of onset, disease duration, family history, psoriasis area severity index, nail and joint involvement, platelet count, mean platelet volume, platelet mass index, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) of 320 patients with psoriasis and 200 healthy persons were evaluated.

RESULTS

Mean platelet counts were 277.7 ±73.374 and 265.06 ±59.682 (p = 0.032); MPV values were 8.248 ±1.150 and 7.442 ±1.626 (p < 0.001); and PMI values were 2259 ±545.617 and 1964 ±622.762 (p < 0.001) respectively in the psoriasis and control group. The MPV showed a significant but inverse correlation with hs-CRP (p = 0.047, r = -0.149), and no correlation with ESR (p > 0.05). Platelet count and PMI had a significant and positive correlation with ESR (p < 0.001, r = 0.404 and p < 0.001, r = 0.371), but had no correlation with hs-CRP (p > 0.05).

CONCLUSIONS

Higher PMI and MPV values, which mean higher plaque formation capacity and more active platelets, in psoriasis may make psoriasis patients more sensitive to atherosclerotic plaque formation and complications. On the other hand, because of the positive PMI correlation with ESR (MPV had no correlation with ESR and had a negative correlation with CRP), PMI may be a better predictor of inflammation than MPV in psoriasis.