Comparison of effects of different anticoagulants on the release of growth factor and injection pain of platelet-rich plasma in SD rats / 中国输血杂志

【Objective】 To investigate the effects of different anticoagulants on platelet-rich plasma(PRP) release content of growth factor and injection pain. 【Methods】 A total of 15 voluntary blood donors were selected, with each blood donor using four kinds of anticoagulant tubes with EDTA-K2 anticoagulation, EDTA-NA2 anticoagulation, citrate anticoagulation, ACD-A anticoagulation respectively as group A, B, C and D. PRP was isolated and prepared by the rich plasma method, and the contents of PDGF-AA, TGF-β, IGF-1, VEGF, and PF-4 were detected by enzyme-linked immunosorbent assay. Meanwhile, SD rats (20, 4 / group) were injected subcutaneously or intradermally with the supernatant of PRP and PG gel prepared in the 4 groups and normal saline in the control group. The pain status of SD rats during the injection was observed and recorded. The pain status of the 5 groups of experimental animals was evaluated according to the American Laboratory Animal Pain Guide. 【Results】 The platelet counts in PRP in group D was the highest [(1 294.53±277.37) × 109/L], which was significantly higher than that in group A [ (789.13±377.13) ×109/L] and group C [ (990.94±493.12) ×109/L] (P<0.05). The OD value of PDGF-AA in group A, B, C, and D were 1.51± 0.18, 1.69±0.21, 0.66±0.19and 1.72±0.13, respectively, with statistically significant difference between groups (P<0.05 ) and group D better than the other three groups. The OD value of PF-4 was 1.18±0.24, 1.61±0.14, 0.65±0.26 and 1.72±0.10 respectively, with statistically significant difference between groups (P<0.05) and group D better than other three groups. The OD value of IGF-1 was 1.02±0.08, 0.98±0.11, 1.06±0.11 and 1.32±0.65 respectively, with no significant difference between groups (P>0.05). The OD value of VEGF was 0.13±0.04, 0.21±0.14, 0.08±0.02 and 0.13±0.04 respectively, with statistically significant difference between group B and C (P<0.05). The OD value of TGF-β was 0.14±0.01, 0.15±0.01, 0.28±0.17 and 1.10±0.37 respectively, with statistically significant difference between groups (P<0.05) and group D better than other three groups. Comparison of injection pain: when the supernatant of PRP and PG gel was injected, there were significant differences between group A, B, C and D, and the control group (P<0.05) . The median pain scores of PRP injection of group A, B, C, and D were 6 (1.5), 5 (0.75), 4.5 (2.5), and 3(3) respectively, with group D lower than other three groups, and no statistically significant difference was noticed (P>0.05) . The median pain scores of the PG supernatant injection of group A, B, C, and D were 4 (2.25), 3 (2.75), 4 (3), 1 (1.5), and the difference was not statistically significant (P>0.05). There was no significant difference between the PRP injection group and the PG supernatant group (P> 0.05). 【Conclusion】 PRP prepared by two-step centrifugation with ACD-A anticoagulant can obtain the higher platelet counts and the maximum release of PDGF-AA, PF-4, IGF-1, and TGF-β. In terms of pain, ACD-A anticoagulant injection has the lowest pain with the animals.

Platelet Rich Plasma - Platelet Counts and Application - A Literature Review

Platelet rich plasma (PRP) is a novel method of using plasma concentrated with platelets for wound healing and tissue regeneration. Platelet rich plasma is prepared from the venous blood using a differential centrifugation technique. It involves a separation spin and a concentration spin, yielding platelet rich plasma. PRP products have been classified into 4 types depending upon major cell constituent and fibrin density upon activation. These are as follows: Pure PRP, Leukocyte and PRP, Pure PRF, Leukocyte and PRF. PRF differs from PRP in that it is rich in a high density fibrin network after activation. PRP is abundant in a variety of growth factors such as VEGF, PDGF, TGF, EGF, and Interleukin-1. Literature consists of reports by different authors about the platelet yield of PRP centrifuged by different systems. A number of factors have also been quoted to influence the platelet concentration in platelet rich plasma. Hence, the aim of this review is to discuss the platelet concentration in PRP centrifuged by different systems and to observe for variations if any

A study to evaluate the prognostic significance of thrombocytopenia among critically ill children

Background: Pediatric critical care differs from Adult critical care not only in age but also in the outcomes. There are no studies regarding thrombocytopenia in the pediatric population. Therefore, in the current study, our objective was to study the prevalence and, the severity of thrombocytopenia, clinical features, and prognostic significance of low platelet count as an independent predictor of mortality and prolonged hospital and ICU stay.Methods: This was a prospective observational study conducted at tertiary care paediatric intensive care unit in India. Children between 1 month to 18 years admitted to the Pediatrics intensive care unit with thrombocytopenia due to any cause at admission were involved in the study. Detailed history was documented. Haemoglobin levels, total leucocyte counts, platelet counts, and platelet indices were recorded on the first and fourth day of admission. Outcomes were analysed in term of survivors and non-survivors and duration of ICU and hospital stay.Results: The study group consisted of 150 children with mean age of 8.458(' 5.604) years. Majority of children in the study group had severe thrombocytopenia 77 (51.3%). Moderate and mild thrombocytopenia was seen in 35(23.3%) and 38(25.4%) children respectively. Infection (50.66%) was the most common cause of thrombocytopenia, followed by sepsis (10.66%). Sepsis (27.5%) was observed to be the most common cause of mortality. Rise in platelet count on the fourth day among survivors, and no survivors were observed in 79.1% and 15.9% respectively.' Failure of the rise in platelet count on the fourth day of admission was significantly associated with mortality (p value=0.001). The severity of thrombocytopenia does not correlate with duration of hospital and ICU stay.Conclusions: Platelet counts and indices at the time of admission to a critical care unit have limited use as a prognostic marker for predicting mortality in children.

The relationship between the continuous opening of arterial catheters and platelet parameters in preterm infants / 中华实用儿科临床杂志

Objective To analyze the correlation between the continuous opening of patent ductus arteriosus (PDA) in preterm infants and platelet parameters in the first 24 hours of life.Methods The preterm infants (gestational age ＜ 34 weeks) admitted to Neonatal Intensive Care Unit(NICU) of the Affiliated Xuzhou Hospital of Southeast University from November 2012 to July 2018 were enrolled.The following data were collected retrospectively:the platelet parameters in the first 24 hours of life,clinical factors possibly related to continuous opening of PDA,and echocardiography examination fin-dings on the 4th-7th day after birth.According to the diagnostic criteria of PDA,all preterm infants were divided into symptomatic PDA (sPDA) group,non-sPDA (nsPDA) group,and non-PDA (nPDA) group.SPSS 20.0 software was used for data analysis.Data were analyzed by Chi-square test,LSD or Tambane's T2 of One-Way analysis of variance,and binary Logistic regression analysis of the receiver operating characteristic (ROC) curve.Results Totally 760 preterm infants were chosen,and among them there were 67 cases (8.8％) in sPDA group,106 cases (14.0％) in nsPDA group,and 587 cases (77.2％) in nPDA group.There were significant differences in the terms of gestation age,birth weight,platelet counts (PLT),and plateletcrit (PCT) in the first 24 hours of life among 3 groups (all P ＜ 0.05).The smaller gestation age,the lower birth weight,the lower PLT and PCT in the first 24 hours of life,and the higher incidence of PDA in preterm infants.There were no significant differences in the platelet distribution width,mean platelet volume,and platelet large cell ratio in the first 24 hours of life among 3 groups (all P ＞ 0.05).The low lower birth weight and PCT in the first 24 hours of life were independent risk factors for the occurrence of sPDA in preterm infants (P =0.013,0.000).The risk of occurrence of sPDA in preterm infants will be increased by 3.279-fold (95 ％ CI:2.369-4.479) if PCT in the first 24 hours of life is decreased by 0.10％.The area under the ROC curves of PCT and PLT in the first 24 hours of life for prediction of sPDA in preterm infants was 0.757 (95 ％ CI:0.712-0.814) and 0.718 (95 ％ CI:0.671-0.768),respectively.The best cutoff values of PCT and PLT were 0.178％ (sensitivity was 75.7％,specificity was 71.9％) and 207.5 × 109/L (sensitivity was 71.4％,specificity was 63.2％).Conclusions The continuous opening of PDA in preterm infants may have correlation with the platelet.The low PCT,rather than PLT,in the first 24 hours of life was an independent risk factor and has medium predictive value for the occurrence of sPDA in preterm infants on the 4th-7th day after birth.

The effect of hypertension on the prognosis of acute aortic dissection / 中华急诊医学杂志

Objective To investigate the clinical characteristics and prognosis of patients with acute aortic dissection (AAD) and hypertension,and explore other related prognostic factors in AAD.Methods The present study enrolled consecutive patients diagnosed with AAD who were admitted to Peking University People's Hospital between January 2000 to December 2015.Patients diagnosed with AAD by CT angiography,aortography or magnetic resonance imaging within 14 days of onset were included.Patients with infectious diseases,haematological diseases,malignancies,autoimmune diseases and patients without clearly clinical diagnosis or incomplete data were excluded.The patients were initially divided into two groups based on their history of hypertension,and their clinical characteristics were compared and analyzed.We further divided AAD patients into survival group and death group according to their in-patient outcomes,and factors related to their prognoses were analyzed.Logistic regression analysis was applied to analyze the independent risk factors related to hospital death in AAD patients with P＜0.05 as the significant value.Results The hypertensive group contained 237/346 cases included (68.45％),patients in this group were generally older than their non-hypertensive counterparts,accompanied by increased prevalence of comorbidities (coronary heart diseases or diabetes) and a statistical significant elevated admission blood pressures (systolic and diastolic,P＜0.05).No significant difference were found between the groups in terms of white blood cell and platelet count,D-dimer,neutrophil to lymphocyte ratio(NLR),fibrinogen,serum creatinine and serum lipid profiles (P＞0.05).Hypertensive patients were less likely to receive surgical treatment compared with those without hypertension(P＜0.05),with increased risk of in-hospital mortality (P＞0.05).Further logistic regression analysis revealed the presence of hypertension did not independently predict in-hospital mortality of AAD patients.Factors such as age,Stanford classification of the AAD,NLR and platelet counts were found to have independent predictive values for in-hospital mortality (P＜0.05).Conclusion AAD patients with hypertension are generally older,have more comorbidities such as coronary heart diseases and diabetes.The presence of hypertension itself is not directly associated with in-hospital mortality in AAD patients,while the Stanford classification,age,NLR and platelet counts are independent risk predictors.

The relationship between the continuous opening of arterial catheters and platelet parameters in preterm infants / 中华实用儿科临床杂志

Objective@#To analyze the correlation between the continuous opening of patent ductus arteriosus(PDA) in preterm infants and platelet parameters in the first 24 hours of life.@*Methods@#The preterm infants (gestational age <34 weeks) admitted to Neonatal Intensive Care Unit(NICU)of the Affiliated Xuzhou Hospital of Southeast University from November 2012 to July 2018 were enrolled.The following data were collected retrospectively: the platelet parameters in the first 24 hours of life, clinical factors possibly related to continuous opening of PDA, and echocardiography examination fin-dings on the 4th-7th day after birth.According to the diagnostic criteria of PDA, all preterm infants were divided into symptomatic PDA(sPDA) group, non-sPDA (nsPDA) group, and non-PDA (nPDA) group.SPSS 20.0 software was used for data analysis.Data were analyzed by Chi-square test, LSD or Tambane′s T2 of One-Way analysis of variance, and binary Logistic regression analysis of the receiver operating characteristic (ROC) curve.@*Results@#Totally 760 preterm infants were chosen, and among them there were 67 cases (8.8%) in sPDA group, 106 cases (14.0%) in nsPDA group, and 587 cases (77.2%) in nPDA group.There were significant diffe-rences in the terms of gestation age, birth weight, platelet counts (PLT), and plateletcrit (PCT) in the first 24 hours of life among 3 groups (all P<0.05). The smaller gestation age, the lower birth weight, the lower PLT and PCT in the first 24 hours of life, and the higher incidence of PDA in preterm infants.There were no significant differences in the platelet distribution width, mean platelet volume, and platelet large cell ratio in the first 24 hours of life among 3 groups (all P>0.05). The low lower birth weight and PCT in the first 24 hours of life were independent risk factors for the occurrence of sPDA in preterm infants (P=0.013, 0.000). The risk of occurrence of sPDA in preterm infants will be increased by 3.279-fold (95%CI: 2.369-4.479) if PCT in the first 24 hours of life is decreased by 0.10%.The area under the ROC curves of PCT and PLT in the first 24 hours of life for prediction of sPDA in preterm infants was 0.757 (95%CI: 0.712-0.814) and 0.718 (95%CI: 0.671-0.768), respectively.The best cutoff values of PCT and PLT were 0.178% (sensitivity was 75.7%, specificity was 71.9%) and 207.5×109/L (sensitivity was 71.4%, specificity was 63.2%).@*Conclusions@#The continuous opening of PDA in preterm infants may have correlation with the platelet.The low PCT, rather than PLT, in the first 24 hours of life was an independent risk factor and has medium predictive value for the occurrence of sPDA in preterm infants on the 4th-7th day after birth.

Effects Of First-Line Anti-Retroviral Therapy On Blood Coagulation Parameters Of HIV-Infected Patients Attending A Tertiary Hospital At Abuja, Nigeria

Background: Blood coagulation abnormalities are common in persons infected with the human immunodeficiency virus (HIV). However, few studies showed the association of these abnormalities with anti-retroviral therapy (ART). Objective: This cross-sectional study investigated the effects of ART on blood coagulation parameters of patients infected with HIV attending HIV special clinics of the University of Abuja Teaching Hospital (UATH), Gwagwalada, Abuja, Nigeria. Material and Methods: A total of 191 patients comprising 128 HIV subjects on ART (test subjects) and 63 other HIV patients not on ART (control subjects) were included in the study. CD4+ lymphocyte counts, platelet counts, prothrombin time (PT) and partial thromboplastin time with kaolin (PTTK) of subjects were determined using flow cytometry, automated hematology analyser and Quick one-stage methods respectively. Results: Of the total test subjects, 21 (16.4%) were CD4 lymphopaenic, and the mean CD4+ cell count for the test subjects was statistically higher than that of the control subjects (578 versus 322 cells/ mm3 ) (p = 0.014). Eight (6.3%) of test subjects had prolong PTTK, and the mean values of PT and PTTK were statistically not significant between test subjects and control subjects (p = 0.358 and p= 0.141 respectively). Eight (6.3%) of test subjects had thrombocytopaenia, the mean platelet count was significantly lower than that of the control subjects (238 versus 278.6 x 109 /L, p = 0.001), and also varied significantly with the duration of ART (p = 0.0086). Conclusion: Findings from this study revealed ART decreased platelet counts of HIV-infected individuals, but did not affect the PT and PTTK results.

Efficacy of helicobacter pylori eradication as an upfront treatment of secondary immune thrombocytopenia: an experience from Pakistan

Background: The effect of Helicobacter-pylori eradication therapy on the platelet counts in patients with immune thrombocytopenia is still debatable. The aim of this study was to assess the response rates of standard triple eradication therapy in secondary immune thrombocytopenia with Helicobacter pylori infection. Methods: From January 2012 to December 2013, 197 patients were diagnosed to have immune thrombocytopenia, out of which 22(11.1%) patients infected with HelicobacterPylorus were enrolled in this study. Helicobacter-Pylori infection was documented by Helicobacter-pylori stool antigen enzyme immunoassay method. All positive patients were put on triple eradication therapy. The responses rates to treatment were defined as per International Working Group on ITP. Results: Mean age of patients was 43.18±12.5 years. There were 10(45.5%) males and 12 (54.5%) females. Of the 22 patients, 7(31.8%) exhibited a complete response (CR) to Hpylori eradication therapy; 10(45.4%) attained a response; and 5(22.7%) had no response. Mean base line platelet counts were 53.36±24.5x109 /l, while platelet counts at 4 week following eradication was 80.86±51.0x109 /l (P=0.003). The predictive factor of response following eradication therapy was baseline platelet counts. Virtually all responders had baseline platelet counts >30x109 /l and all non-responders had <30x109 /l of platelet counts. Conclusions: Though the prevalence of H-pylori is low, this study confirmed the efficacy of eradication in increasing the platelet counts in H-pylori positive patients with ITP. It is an important measure in short time, safe and very cost effective to achieve platelets increment. We endorse the routine detection and eradication treatment of H-pylori infective ITP patients.

Relationship Between Platelet Counts at Admission and In-hospital Mortality in Patients With Type A Acute Aortic Dissection / 中国循环杂志

Objective: To explore the relationship between platelet counts at admission and in-hospital mortality in patients with type A acute aortic dissection (AAD). Methods: We investigated 183 consecutive patients with CT conifrmed diagnosis of type A AAD treated in our hospital from 2012-02 to 2013-05. There were 126 (68.9%) male and the patients were divided into 3 sets of groups.①In-hospital surviving group,n=157 and In-hospital death group,n=26.②According to platelet counts, the patients were divided into 5 groups: Q1 group, platelet counts ≤ 119×109/L,n=36, Q2 group, platelet (120-149) ×109/L,n=37, Q3 group, platelet (150-173)×109/L, n=36, Q4 group, platelet (174-228)×109/L,n=37, Q5 group, platelet >228×109/L,n=37.③At admission, platelet ≤ 119×109/L,n=36 and platelet >119×109/L,n=147. In addition, the patients were further divided into another 4 groups based on operative condition: platelet ≤ 119×109/L with operation,n=18, without operation,n=18; platelet > 119×109/L with operation,n=96, without operation,n=51. The basic information at admission including platelet counts, WBC and D-dimer were studied in all groups, the primary endpoint was in-hospital mortality. Results: The overall in-hospital mortality was 14.3%. Compared with In-hospital surviving group, the In-hospital mortality group had decreased platelet counts, lower blood pressure and higher level of D-dimer. The mortality in Q1 group (38.9%) was higher than those in Q2, Q3, Q4 and Q5 groups (10.8%, 11.1%, 8.1% and 2.7%), allP<0.001. The risk of death in Q5 group was higher than Q1 group (HR=11.2, 95% CI 2.13-123.3,P=0.007). With adjusted age, gender and other relevant factors, when platelet counts ≤ 119×109/L, the risk of in-hospital mortality with Cox multivariate model I analysis was (HR3.90, 95% CI 1.67-9.09,P=0.002), with Cox model II was (HR=2.67, 95% CI 1.15 -6.19,P=0.023). Conclusion: AAD patients with admission platelet counts ≤ 119×109/L had the high risk of in-hospital death, even with operation, lower platelet counts was still related to in-hospital death.

Clinical analysis for fungal septicemia in 23 neonates / 临床儿科杂志

Objective To investigate the risk factors, pathogens spectrum and antimicrobial susceptibility of neonatal fungal septicemia. Methods Medical records of 23 neonates with fungal septicemia from May 2009 to August 2013 were analyzed retrospectively. Results A total of 36 strains of fungi including 20 strains of Candidaparapsilosis (55.6%) and 11 strains of Candidaalbicans (30.6%) were isolated from 23 patients. Fungal pathogens were susceptible to amphotericin and lfuorouracil, with susceptibility being 69.4%-77.8%. Prematurity, low birth weight, application of broad-spectrum antibiotics and invasive operation might be the risk factors of fungal septicemia. Fifteen cases (65.2%) had good outcomes (survival or partial restoration), while 8 cases (34.8%) had poor outcomes (withdrawing therapy or death). The duration of antifungal therapy in good prognosis group was longer than that in poor prognosis group (t=2.982, P<0.05). No significant difference in indicators of liver and kidney function was observed between before antifungal therapy and within 2 weeks after treatment. Meanwhile, no signiifcant difference of WBC was found between before antifungal therapy and within 2 weeks after treatment. The platelet counts were increased within one week after initial antifungal therapy (P<0.05). Conclusions Candida is the main pathogen of neonatal fungal septicemia and sensitive to amphotericin B. Long enough course of antifungal therapy is necessary to improve the cure rate.

Gingival inflammation and platelet count in patients with leukemia: preliminary results

Leukemia has been associated with oral manifestations. However, the available literature on this topic consists of mostly reports of cases, without data about the periodontal parameters that may be under the influence of hematologic factors. The aim of this cross-sectional study was to assess the correlation between the Gingival Index and Bleeding on Probing with the platelet count in patients with leukemia. Patients with diagnosis of any kind of leukemia, at any stage of treatment, having a minimum age of 14 years, treated at the Department of Hematology-Oncology of the University Hospital of Santa Maria, Brazil, between December 2009 and March 2010, were assessed. Excluded patients were: edentulous, with orthodontic appliances, with psychomotor disturbances, requiring antibiotic prophylaxis for the examinations, or those using medications associated with gingival swelling. Two trained and calibrated examiners evaluated the Plaque Index, Gingival Index (GI), Probing depth, Bleeding on Probing (BOP), and Clinical Attachment Loss. Hematologic data were collected from a blood test performed on the same day as the periodontal examination. Thirty-seven patients (26 males), aged between 15 and 80 years (mean age 41.7 ± 18.31) were evaluated. Correlation between platelet count and BOP (p > 0.05), or between platelet count and GI (p > 0.05), were both weak (Pearson's correlation coefficient r = 0.171 and r = -0.003, respectively) and not statistically significant. It can be concluded from the preliminary results that the low platelet count was not correlated with the higher prevalence of gingival and periodontal bleeding in patients with leukemia.

A standardized research protocol for platelet-rich plasma (PRP) preparation in rats

Introduction: The urgent need for studies using standardized protocols to evaluate the real biological effects of PRP has been emphasized by several authors. Objective: The purpose of this study was to standardize a methodology for autologous Platelet-Rich Plasma (PRP) preparation in rats. Material and methods: Twenty-four, 5 to 6-month-old, male rats, weighing 450 to 500 g were used. After general anesthesia, 3.15 ml of blood was collected from each animal, via cannulation of the jugular vein. A standardized technique of double centrifugation was used to prepare PRP. PRP samples and peripheral blood platelets were then manually counted using a Neubauer chamber. Student’s t-test was used to compare the differences between the number of platelets in peripheral blood and PRP samples (p < 0.05). In addition, PRP and peripheral blood smears were stained to see platelets’ morphology. Results: All surgical procedures were well tolerated by the animals and they were healthy during the entire experimental period. PRP samples showed higher significantly platelet concentrations than peripheral blood samples (2,677,583 and 683,680 respectively). Conclusion: Within the limits of this study, it can be concluded that the method used produced autologous PRP with appropriated platelet quantity and quality, in rats.

Effects of Helicobacter pylori eradication in patients with immune thrombocytopenic purpura

BACKGROUND: The relationship between Helicobacter pylori (H. pylori) infection and chronic idiopathic thrombocytopenic purpura (ITP) has been confirmed; however, no clear evidence for the effectiveness of H. pylori eradication on ITP exists thus far. The purpose of this study was to investigate platelet recovery in chronic ITP after H. pylori eradication. METHODS: A total of 25 patients (18 male, 7 female; the median age of 55 years) diagnosed with ITP, whose platelet counts were less than 100x10(3)/microliter, were enrolled. They were tested for H. pylori infection by the rapid urea test or urea breath test. All patients received triple therapy for 7 or 14 days to eradicate H. pylori infection. RESULTS: Of the 25 patients, 23 (92%) were diagnosed with H. pylori infection. Of all the ITP patients, 11 (44%) exhibited a complete response (CR) to H. pylori eradication therapy; 6 (24%), a partial response (PR); and 8 (32%) were nonresponsive (NR). Predictive factors of response after H. pylori eradication therapy were platelet counts at the initial response (27.3% responders among patients with platelet counts or =100x10(3)/microliter, P<0.001) and H. pylori infectivity (73.9% responders among the H. pylori positive patients vs 0% responders among the H. pylori negative patients, P=0.032). CONCLUSION: This study confirmed the efficacy of H. pylori eradication in increasing the platelet count in ITP patients. Further studies with a larger number of patients are necessary to identify the crucial predictive factors responsible for platelet recovery in chronic ITP patients with the H. pylori infection.

Platelet Counts in Healthy Premature Infants

Serial platelet counts performed at four day intervals on forty two healthy premature infants whose birth weights were less than 2200 grams. The forty two infants were divided into two groups: twelve premature infants weighing less than 1700 grams, and thirty prematures infants weighing over 1700 grams at birth. We evaluated the length of time for the platetet counts of the premature infants to equal that of the full-term infants. Platelet counts also were determined on ninety-nine healthy full-term infants during twenty one days of age. The platelet counts were repeated twice a day. The counts of the twenty-four healthy premature infants and the twenty-two healthy full term infants were compared using the Brecher-Cronkite method. 1) There was no significant differnce in platelet counts between twenty four healthy premature infants and twenty two healthy full-term infants obtained at birth and four hour of life by the method of Brecher-Cronkite and the error of platelet Counts was within 2.4 percent. 2) There was no significant difference in the mean platelet values between premature infants weighing less than 1700 grams(21200/mm3) and weighing over 1700 grams (21900/mm3)during first day of life. It was noted the mean platelet values of forty two premature infants were significantly lower than that of sixty eight full term infants which was 27500/mm3. 3) At nine days of life, the mean platelet values of the forty two premature infants equaled that of the sixty eight full term infants at leveles of 27500/mm3. The platelet values were increase continuously and reached peak level of 370000/mm3at the age of three weeks. Increase of platelet values in premature infants weighing less than 1700 grams at birth was delayed about one week compared with that of the infants over 1700 grams at birth.