A Network Meta-Analysis of Two Doses of Recombinant Human Thrombopoietin for Treating Sepsis-Related Thrombocytopenia.

Previous studies suggest that sepsis remains a common critical illness with a global incidence of 31.5 million. The aim of this study was to evaluate the comparative therapeutic value of recombinant human thrombopoietin (rhTPO) in treating sepsis patients with thrombocytopenia. We conducted a comprehensive electronic search of PubMed, EMBASE, the Cochrane Library, and CNKI from its inception through December 31, 2021. Thirteen randomized controlled trials (RCTs) involving 963 patients were included. Network meta-analyses showed that rhTPO 300 U/kg/day and rhTPO 15000 U/day significantly increased the platelet (PLT) levels on the 7th day and decreased the requirement of transfusion of red blood cells (RBCs), plasma, and PLT compared with IVIG and NAT. SUCRA showed that rhTPO 300 U/kg/day ranked first in terms of 28-day mortality (85.5%) and transfusion, including RBC (88.7%), plasma (89.6%), and PLT (95.2%), while rhTPO 15000 U/day ranked first for the length of the intensive care unit (ICU) stay (95.9%) and PLT level at day 7 (91.6%). rhTPO 300 U/kg/day may be the optimal dose to reduce 28-day mortality and transfusion requirements. However, rhTPO 15000 U/day may be the optimal dose for shortening the ICU stay and increasing the PLT level on the 7th day. However, additional studies to further validate our findings are needed.

Rare case of severe rhabdomyolysis secondary to human granulocytic anaplasmosis.

Anaplasma phagocytophilum (AP) is the causative agent of human granulocytic anaplasmosis (HGA), a tick-borne illness with highest incidence in north-eastern regions of the United States. This condition presents with vague constitutional symptoms and has been associated with laboratory derangements such as leukopenia, thrombocytopenia and transaminitis1. Rhabdomyolysis, however, is not one of these associations. We report a case of confirmed HGA associated with severe rhabdomyolysis, where no other cause was identified. The etiology of rhabdomyolysis secondary to AP infection is still unknown. A presumptive diagnosis of HGA can be made in the presence of fever, non-specific symptoms such as myalgias, laboratory derangements such as leukopenia and thrombocytopenia in an individual residing in an endemic area3. Serological confirmation should not delay treatment, given the rapid progression of this dangerous infection. Rhabdomyolysis should also be considered as part of supporting data in the diagnostic consideration for HGA.

Hepatic Campylobacter jejuni infection in patients with Castleman-Kojima disease (idiopathic multicentric Castleman disease with thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly (TAFRO) syndrome).

Castleman-Kojima disease, also known as idiopathic multicentric Castleman disease with TAFRO syndrome (iMCD-TAFRO), is a recently recognized systemic inflammatory disorder with a characteristic series of clinical symptoms, including thrombocytopenia (T), anasarca (A), fever (F), reticulin fibrosis (R), and organomegaly (O). Patients with iMCD-TAFRO often develop severe abdominal pain, elevated alkaline phosphatase levels, and systemic inflammation, but the etiological factors are unknown. To investigate the potential role of bacterial infection in the pathogenesis of iMCD-TAFRO, we performed polymerase chain reaction (PCR) for the bacterial 16S rRNA gene with DNA extracted from liver specimens of three patients with iMCD-TAFRO, four patients with amyotrophic lateral sclerosis, and seven patients with inflammatory conditions. Sequencing of the PCR product showed 99% DNA sequence identity with Campylobacter jejuni in all three patients with iMCD-TAFRO and in two patients with inflammatory conditions. Immunohistochemical and electron microscopy analyses could not identify C. jejuni in patients with iMCD-TAFRO. The findings indicated that C. jejuni infection is not the pathological cause of iMCD-TAFRO; however, this ubiquitous bacterium may play a role in uncontrolled systemic hypercytokinemia, possibly through the development of cross-reactive autoantibodies.

A Severe Case of Murine Typhus Presenting With Anemia and Severe Thrombocytopenia.

We discuss a child with severe thrombocytopenia and mild anemia admitted to the Hematology service who quickly deteriorated to a life-threatening state. However, once rickettsial disease was considered in the differential diagnosis and empiric doxycycline begun, she quickly and fully recovered. A diagnostic panel, including Rickettsia typhi serology, confirmed the diagnosis of murine typhus but this occurred weeks after she had recovered. Given the potential severity of rickettsial diseases and the ease of modern travel across geographic borders, hematology-oncology providers everywhere must consider rickettsial diseases in their differential diagnosis of critically ill children and begin empiric therapy with doxycycline promptly.

A Case Report and Literature Review of Scrub Typhus With Acute Abdomen and Septic Shock in a Child-The Role of Leukocytoclastic Vasculitis and Granulysin.

Scrub typhus is becoming a clinically important cause of acute undifferentiated febrile illness in Taiwan. The incubation period is between 6 and 21 days after exposure. It is transmitted by chiggers (larva of trombiculid mite) in long grasses and in dirt-floor homes, with infection characterized by a flu-like illness of fever, headache, and myalgia lasting approximately 1 week. It has various systemic manifestations, including GI symptoms. In some, the illness progresses to multiorgan dysfunction syndrome and death. We report on a 13-year-old boy who lived in Taipei City and who had initially tentative diagnosis of acute pyrexia of unknown origin with high fever up to 40.3°C for 1 week, but later had thrombocytopenia and diffuse abdominal pain with peritoneal sign suspected acute appendicitis. During the clinical course, septic shock and disseminated intravascular coagulopathy (DIC) were noted. There were skin rash in his trunk and extremities and an eschar with black crust surrounded by a scaling erythematous rim on his right buttock. In addition, we got the information of his travel history in Green Island and Orchid Island for 10 days.With the correct antibiotics, vancomycin, meropenem, and doxycycline, the patient was getting better and corresponding with high level of granulysin and tumor necrosis factor-alpha. The diagnosis of scrub typhus was confirmed by the biopsy of eschar and high quantitative real-time polymerase chain reaction values of Orientia tsutsugamushi (16sRNA and 56 kDa) tested by Centers for Disease Control and Prevention, Taiwan. Histopathological findings of the eschar revealed the leukocytoclastic vasculitis, crust and thrombus formation with many gram-negative microorganisms, O. tsutsugamushi demonstrated by 47 kDa monoclonal antibody immunohistochemical stain and electromicroscopy. OUTCOMES: After the careful selection of appropriate antibiotics including meropenem, vancomycin, and doxycycline, he recovered and was subsequently discharged 7 days after admission. LESSON SUBSECTIONS: This case highlights that scrub typhus infection can mimic acute abdomen and septic shock with DIC. This rare presentation of acute abdomen and septic shock with thrombocytopenia and DIC caused by scrub typhus should remind physicians to be alert to the possibility of acute abdomen and febrile illness resulting from scrub typhus.

Thrombocytopenia in hospitalized patients with severe clostridium difficile infection.

Clostridium difficile infection (CDI) is a common cause of nosocomial diarrhea and colitis. The incidence and prognostic significance of thrombocytopenia as related to mode of acquisition (hospital vs. community), NAP1/027 strain, and disease severity has not been examined. We performed a single-institution retrospective analysis of all adult inpatients from 2013 to 2014 diagnosed with CDI during their hospitalization to document the incidence/prevalence of thrombocytopenia and associated outcomes. Severe disease was defined by a composite endpoint of inpatient death, death within 30 days of discharge, presence of septic shock, or need for colectomy during hospitalization. Of the 533 patients diagnosed with CDI, moderate thrombocytopenia (platelet count <100 × 109/L at time of CDI diagnosis) was present in 15 % of the total cohort and incident thrombocytopenia developed in 3 % of patients after admission. Thrombocytopenia was more common in hospital-acquired disease and associated with increased length of stay, but was not associated with treatment failure. Those with moderate thrombocytopenia were more likely to have severe disease, after controlling for white blood cell count, albumin, and creatinine. Moderate thrombocytopenia is associated with poor prognosis and is a potential risk stratification tool for severe CDI.

Strains of Group B streptococci from septic patients induce platelet activation via Toll-like Receptor 2.

Group B Streptococcus (GBS) causes life-threatening bacterial sepsis, especially in newborns and pregnant women. Patients suffering from sepsis often display low platelet counts, characterized by thrombocytopenia, because of platelet activation. In the present study, the roles of six GBS strains from septic patients in platelet aggregation, as well as the underlying mechanisms, were investigated. Incubation of platelets with three of the strains induced platelet aggregation, increased the secretion of cellular adhesin molecule CD62P and activation of GPIIb/IIIa. Furthermore, the GBS strains that induced platelet activation also caused an increase in the expression of Toll-like receptor (TLR) 2 in platelets. Pre-incubation of platelets with anti-TLR2 monoclonal antibody, but not anti-TLR4 monoclonal antibody, inhibited these functional responses induced by GBS. TLR2 stimulation also activated the phosphoinositide 3-kinase (PI3-K)/Akt signalling pathway in platelets, and inhibition of PI3-K significantly reduced GBS-induced platelet responses. Our results indicate that three of the GBS strains from the septic patients can trigger platelet activation by interacting with platelets, which involves the elevation of platelet TLR2 expression.

Helicobacter pylori infection is not correlated with subclinical thrombocytopenia: a cross-sectional study.

In a small percentage of patients with immune thrombocytopenia (ITP), H. pylori eradication has a positive effect on platelet counts. Whether H. pylori infection is associated with a lower thrombocyte count in persons without clinical ITP is unknown. We performed a cross-sectional study to compare thrombocyte count between H. pylori infected (n=108) and H. pylori non-infected patients (n=600) who underwent a diagnostic gastroscopy. The mean thrombocyte count in H. pylori negative patients was 257 × 10(9)/l, in H. pylori positive patients 252 × 10(9)/l (mean difference 5 × 10(9)/l, 95% CI: -23 to 14). Subgroup analysis did not show significant differences either. In the patient group without apparent comorbidity, there were no subjects with thrombocyte counts <120. In 36 H. pylori positive patients in whom data post-eradication was available, platelet counts pre- and post-eradication were similar. In conclusion, this study could not demonstrate a lower thrombocyte count in H. pylori infected patients or in subgroups of H. pylori infected patients compared to non-infected subjects.

Quantitative changes in platelet count in response to different pathogens: an analysis of patients with sepsis in both retrospective and prospective cohorts.

BACKGROUND: Thrombocytopenia is commonly observed in patients with sepsis and is an independent risk factor for poor prognosis. However, the changes of platelet count caused by different pathogens can vary significantly. Our study aims to evaluate the quantitative changes in platelet count in response to various pathogens. MATERIAL AND METHODS: We retrospectively analysed data of 3044 patients with sepsis from Medical Information Mart for Intensive Care (MIMIC, 2008-2019) database and prospectively collected data of 364 patients with sepsis from our local cohort of the Shandong Bloodstream Infection and Sepsis Collaboration Study (SBISC, 2020-2022). Propensity score matching (PSM) was employed to control for baseline differences in variables, except for the causative pathogen. RESULTS: Multivariate logistic analyses of both original and PSM populations identified Candida, Escherichia, Klebsiella, and Serratia species posing a higher risk for thrombocytopenia compared to others. Restricted cubic spline (RCS) curves showed L- or U-shaped associations between platelet count and 28-mortality with various cut-off values among different pathogens: ranging from 96 × 109/L in Candida species - 190 × 109/L in Klebsiella species. CONCLUSION: Our present findings indicate a pathogen-specific effect on platelet count, highlighting the importance of monitoring thrombocytopenia in patients infected with above microorganisms. Clinicians need to consider pathogen-specific thresholds when intervene on platelet count.

This study validated the differential incidence of thrombocytopenia among various pathogens within two distinct populations.Candida, Escherichia, Klebsiella, and Serratia species were identified as having a notably higher risk of causing thrombocytopenia compared to other pathogens.We observed L- or U-shaped relationships between platelet counts and 28-day mortality in Candida species, Enterococcus species, Escherichia species, Enterobacter species, Staphylococcus species, and Klebsiella species with platelet count cutoff values of 96 × 10⁹/L, 100 × 10⁹/L, 100 × 10⁹/L, 146 × 10⁹/L, 152 × 10⁹/L, and 190 × 10⁹/L, respectively.

Two patients with history of STEC-HUS, posttransplant recurrence and complement gene mutations.

Hemolytic uremic syndrome (HUS) is a disease of microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure. About 90% of cases are secondary to infections by Escherichia coli strains producing Shiga-like toxins (STEC-HUS), while 10% are associated with mutations in genes encoding proteins of complement system (aHUS). We describe two patients with a clinical history of STEC-HUS, who developed end-stage renal disease (ESRD) soon after disease onset. They received a kidney transplant but lost the graft for HUS recurrence, a complication more commonly observed in aHUS. Before planning a second renal transplantation, the two patients underwent genetic screening for aHUS-associated mutations that revealed the presence of a heterozygous CFI mutation in patient #1 and a heterozygous MCP mutation in patient #2, and also in her mother who donated the kidney. This finding argues that the two cases originally diagnosed as STEC-HUS had indeed aHUS triggered by STEC infection on a genetic background of impaired complement regulation. Complement gene sequencing should be performed before kidney transplantation in patients who developed ESRD following STEC-HUS since they may be undiagnosed cases of aHUS, at risk of posttransplant recurrence. Furthermore, genetic analysis of donors is mandatory before living-related transplantation to exclude carriers of HUS-predisposing mutations.

Virulence gene and expression analysis of community-associated methicillin-resistant Staphylococcus aureus causing iliopsoas abscess and discitis with thrombocytopenia.

Iliopsoas abscesses (IPAs) from methicillin-resistant Staphylococcus aureus (MRSA) are rare; however, IPAs from community-associated MRSA (CA-MRSA) may be increasing. In Japan, we previously described an adolescent athlete case of Panton-Valentine leukocidin (PVL)-positive ST30 CA-MRSA (strain NN12). In this study, we describe an IPA and discitis case from a variant of the successful PVL-negative CA-MRSA clone (ST8 CA-MRSA/J) in Japan. The patient was a 62-year-old man with intractable eczema, who had been diagnosed with IPAs and discitis (L1-L2). CA-MRSA (strain NN55) was isolated from blood, pus, and joint fluid. The invasive infections seemed to have originated in his intractable eczema, and the characteristics of this case, systemic myalgia and marked thrombocytopenia, seemed to have been caused by an exotoxin. Molecular genetic analysis revealed that NN55 possessed genotype ST8/spa606(t1767)/agr1/CoaIII and SCCmecIV of a novel subtype (encoding new cell-wall-anchored surface protein/J [CWASP/J]), exhibited enhanced expression of the cytolytic peptide genes, psmα and hld, and was resistant to gentamicin (caused by aacA-aphD), similar to ST8 CA-MRSA/J; however, NN55 lacked pathogenicity island SaPIj50 [carrying tst, encoding toxic shock syndrome toxin-1 (TSST-1)] of ST8 CA-MRSA/J, suggesting a variant (ST8 CA-MRSA/Jv). Strains NN12 and NN55 both caused bacteremia, IPAs, and adjacent musculoskeletal infections, preceded by intractable skin infections, and possessed high potential for adherence and enhanced expression of psmα and hld. The data suggest the role of a combination of CA-MRSA adhesin/cytolytic peptides (not PVL or TSST-1) in the pathogenesis of IPAs (and perhaps of systemic myalgia and marked thrombocytopenia).

Immunomodulatory and protective roles of quorum-sensing signaling molecules N-acyl homoserine lactones during infection of mice with Aeromonas hydrophila.

Aeromonas hydrophila leads to both intestinal and extraintestinal infections in animals and humans, and the underlying mechanisms leading to mortality are largely unknown. By using a septicemic mouse model of infection, we showed that animals challenged with A. hydrophila die because of kidney and liver damage, hypoglycemia, and thrombocytopenia. Pretreatment of animals with quorum-sensing-associated signaling molecules N-acyl homoserine lactones (AHLs), such as butanoyl and hexanoyl homoserine lactones (C(4)- and C(6)-HSLs), as well as N-3-oxododecanoyl (3-oxo-C(12))-HSL, prevented clinical sequelae, resulting in increased survivability of mice. Since little is known as to how different AHLs modulate the immune response during infection, we treated mice with the above AHLs prior to lethal A. hydrophila infection. When we compared results in such animals to those in controls, the treated animals exhibited a significantly reduced bacterial load in the blood and other mouse organs, as well as various levels of cytokines/chemokines. Importantly, neutrophil numbers were significantly elevated in the blood of C(6)-HSL-treated mice compared to those in animals given phosphate-buffered saline and then infected with the bacteria. These findings coincided with the fact that neutropenic animals were more susceptible to A. hydrophila infection than normal mice. Our data suggested that neutrophils quickly cleared bacteria by either phagocytosis or possibly another mechanism(s) during infection. In a parallel study, we indeed showed that other predominant immune cells inflicted during A. hydrophila infections, such as murine macrophages, when they were pretreated with AHLs, rapidly phagocytosed bacteria, whereas untreated cells phagocytosed fewer bacteria. This study is the first to report that AHL pretreatment modulates the innate immune response in mice and enhances their survivability during A. hydrophila infection.

Chronic liver disease increases the risk of linezolid-related thrombocytopenia in methicillin-resistant Staphylococcus aureus-infected patients after digestive surgery.

Linezolid is an effective antibiotic for treatment of infections caused by resistant Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). However, thrombocytopenia has been reported in a certain proportion of patients receiving linezolid treatment. We investigated the risk factors for linezolid-related thrombocytopenia in MRSA-infected patients after digestive surgery. Forty-three patients who were treated with linezolid for postoperative MRSA infection were enrolled. We compared the characteristics of the patients who developed thrombocytopenia during linezolid therapy with those of the patients who did not. Thrombocytopenia was defined as a platelet ratio (post/pre-treatment with linezolid) of < 0.7. Twenty-one (48.8%) patients developed thrombocytopenia. In univariate analysis, long treatment duration, high pre-treatment levels of total-bilirubin and transaminases, and the coexistence of chronic liver disease (CLD) were found to be significant risk factors for development of thrombocytopenia. Other factors, for example pre-treatment platelet count, serum creatinine and albumin levels, and previous hepatic resection were not associated with thrombocytopenia. In the multivariate regression analysis, only CLD remained as an independent factor associated with thrombocytopenia. In addition, thrombocytopenia was more common among patients with indocyanine green retention at 15 min (ICG-R15) of more than 10% than in those with an ICG-R15 of 10% or less. Our results suggest that patients with CLD are at high risk of developing linezolid-related thrombocytopenia. Therefore, they should be targeted for more intense platelet count monitoring during linezolid therapy.

Platelet Deficiency Represents a Modifiable Risk Factor for Periprosthetic Joint Infection in a Preclinical Mouse Model.

BACKGROUND: Well known for their hemostatic function, platelets are increasingly becoming recognized as important immunomodulators. The purpose of the present study was to assess the impact of platelet depletion on antimicrobial host defense in a mouse model of periprosthetic joint infection (PJI). METHODS: Thrombocytopenia (TCP) was induced in C57BL/6 mice with use of a selective antibody against platelet CD41 (anti-CD41). Whole blood from pre-treated mice was incubated with Staphylococcus aureus to assess antimicrobial efficacy with use of bioluminescent imaging, quantitative histological staining, and colony forming unit (CFU) quantification. In parallel, untreated heterologous platelets were added to TCP blood to assess potential rescue of antimicrobial efficacy. In vivo, TCP and control mice underwent placement of a titanium implant in the femur inoculated with bioluminescent Xen36 S. aureus. Longitudinal bioluminescent imaging was performed postoperatively to quantify the evolution of bacterial burden, which was confirmed via assessment of S. aureus CFUs on the implant and in peri-implant tissue on postoperative day (POD) 28. RESULTS: Anti-CD41 treatment resulted in significant dose-dependent reductions in platelet count. Ex vivo, platelet-depleted whole blood demonstrated significantly less bacterial reduction than control blood. These outcomes were reversed with the addition of untreated rescue platelets. In vivo, infection burden was significantly higher in TCP mice and was inversely correlated with preoperative platelet count (r2 = 0.63, p = 0.037). Likewise, CFU quantification on POD28 was associated with increased bacterial proliferation and severity of periprosthetic infection in TCP mice compared with controls. CONCLUSIONS: Thrombocytopenia resulted in an increased bacterial burden both ex vivo and in vivo in a mouse model of PJI. CLINICAL RELEVANCE: In orthopaedic patients, deficiencies in platelet quantity or function represent an easily modifiable risk factor for PJI.

Bronchoalveolar lavage fluid analysis and mortality risk in systemic lupus erythematosus patients with pneumonia and respiratory failure.

BACKGROUND: Our aim was to characterize etiologic diagnoses obtained from bronchoalveolar lavage fluid (BALF) and blood specimens, and to identify risk factors for mortality in systemic lupus erythematosus (SLE) patients with pneumonia and respiratory failure. METHODS: We conducted a retrospective analysis of SLE patients with pneumonia and respiratory failure. Clinical characteristics, laboratory profiles, and microbiology in BALF and blood samples were evaluated. We performed univariable analyses to identify mortality risk factors. RESULTS: All 24 patients (F:M = 21:3, median age 46.5 years; disease duration 11 years) received mechanical ventilation (median duration: 11 days). Pathogens identified in BALF included Pneumocystis jiroveci (12 patients [50%]), cytomegalovirus (CMV, 7 patients [29.2%]), and bacteria (11 patients [45.8%]). Thirteen patients (54.2%) yielded pathogens in blood (CMV in 8 patients [33.3%] and Escherichia coli in 5 patients [20.8%]). Eight developed septic shock, and 9 died within 30 days. Univariable analysis identified thrombocytopenia (odds ratio [OR]: 8.0, 95% confidence interval [CI]: 1.23-52.25), bacteremia within 30 days before or after endotracheal intubation (OR: 8.0, 95% CI: 1.23-52.5), and P. jiroveci pneumonia (PJP, OR: 7.0, 95% CI: 1.04-46.95) as risk factors for 30-day mortality. Kaplan-Meier analysis confirmed an increased risk of 30-day mortality with thrombocytopenia and bacteremia. CONCLUSION: There are high prevalence rates of PJP and CMV infections as evidenced by BALF analyses in SLE patients with pneumonia and respiratory failure. BALF analysis can facilitate rescue therapy per pathogen. Thrombocytopenia, bacteremia, and PJP in SLE patients can increase their 30-day mortality, so warrant early and aggressive treatments.

Genetic control of the innate immune response to Borrelia hermsii influences the course of relapsing fever in inbred strains of mice.

Host susceptibility to infection is controlled in large measure by the genetic makeup of the host. Spirochetes of the genus Borrelia include nearly 40 species of vector-borne spirochetes that are capable of infecting a wide range of mammalian hosts, causing Lyme disease and relapsing fever. Relapsing fever is associated with high-level bacteremia, as well as hematologic manifestations, such as thrombocytopenia (i.e., low platelet numbers) and anemia. To facilitate studies of genetic control of susceptibility to Borrelia hermsii infection, we performed a systematic analysis of the course of infection using immunocompetent and immunocompromised inbred strains of mice. Our analysis revealed that sensitivity to B. hermsii infections is genetically controlled. In addition, whereas the role of adaptive immunity to relapsing fever-causing spirochetes is well documented, we found that innate immunity contributes significantly to the reduction of bacterial burden. Similar to human infection, the progression of the disease in mice was associated with thrombocytopenia and anemia. Histological and fluorescence in situ hybridization (FISH) analysis of infected tissues indicated that red blood cells (RBCs) were removed by tissue-resident macrophages, a process that could lead to anemia. Spirochetes in the spleen and liver were often visualized associated with RBCs, lending support to the hypothesis that direct interaction of B. hermsii spirochetes with RBCs leads to clearance of bacteria from the bloodstream by tissue phagocytes.