A Case of Acquired Amegakaryocytic Thrombocytopenia with Anti-c-mpl Autoantibody: Comparison with Idiopathic Thrombocytopenic Purpura

Acquired amegakaryocytic thrombocytopenia (AAMT) is a rare disease that causes severe bleeding. The pathogenesis and treatment of AAMT have not yet been defined. We report the case of a 60-year-old woman diagnosed with AAMT, who presented with severe thrombocytopenia, gastroin-testinal bleeding, and significantly reduced bone marrow megakaryocytes. The patient was treated with methylprednisolone, cyclosporin, and intravenous immunoglobulin. After 2 weeks of treatment, her platelet count started to increase, and her bone marrow megakaryocyte count had normalized 3 months after diagnosis. At the time of diagnosis, the patient was seropositive for anti-c-mpl antibody but was seen to be seronegative once the platelet count recovered. In contrast, anti-c-mpl antibodies were not detected in the serum of 3 patients with idiopathic thrombocytopenic purpura. This case study suggests that anti-c-mpl antibody plays an important role in the development of AAMT, and that intensive immunosuppressive treatment is required for autoantibody clearance and recovery of megakaryocyte count.

Thrombotic Microangiopathy and the Kidney

Thrombotic microangiopathy can manifest in a diverse range of diseases and is characterized by thrombocytopenia, microangiopathic hemolytic anemia, and organ injury, including AKI. It can be associated with significant morbidity and mortality, but a systematic approach to investigation and prompt initiation of supportive management and, in some cases, effective specific treatment can result in good outcomes. This review considers the classification, pathology, epidemiology, characteristics, and pathogenesis of the thrombotic microangiopathies, and outlines a pragmatic approach to diagnosis and management.

Acquired amegakaryocytic thrombocytopenia previously diagnosed as idiopathic thrombocytopenic purpura in a patient with hepatitis C virus infection

We report the first case of a patient with hepatitis C virus (HCV) infection and idiopathic thrombocytopenic purpura (ITP), who later developed acquired amegakaryocytic thrombocytopenia (AAMT), with autoantibodies to the thrombopoietin (TPO) receptor (c-Mpl). A 64-year-old woman, with chronic hepatitis C, developed severe thrombocytopenia and was diagnosed with ITP. She died of liver failure. Autopsy revealed cirrhosis and liver carcinoma. In the bone marrow, a marked reduction in the number of megakaryocytes was observed, while other cell lineages were preserved. Therefore, she was diagnosed with AAMT. Additionally, autoantibodies to c-Mpl were detected in her serum. Autoantibodies to c-Mpl are one of the causes of AAMT, acting through inhibition of TPO function, megakaryocytic maturation, and platelet formation. HCV infection induces several autoantibodies. HCV infection might also induce autoantibodies to c-Mpl, resulting in the development of AAMT. This mechanism may be one of the causes of thrombocytopenia in patients with HCV infection.

Rifampcin-induced Thrombocytopaenia Purpura

We report the case of a 28-year-old resident doctor with no past history of having taken rifampicin, who presented with thrombocytoapaenic purpura occurring after the initiation of anti-tuberculosis therapy (isoniazid, rifampicin, pyrazinamide and ethambutol) for tubercular lymphadenopathy.

Genotyping of Human Platelet Antigens by BeadChip Microarray Technology

Human platelet antigen (HPA) typing plays a critical role in the diagnosis of fetal/neonatal alloimmune thrombocytopenia, and the prevention of posttransfusion purpura and refractoriness to platelet transfusions. The recent development of high-throughput genotyping methods, allowing simultaneous genotyping of as many as 17 HPAs, is of utmost interest for saving time and money. Here, we describe a microarray technology named "BeadChip," designed for HPA-1 to -9, -11, and -15 genotyping of up to 96 individuals, in approximately 5 h. This technology was used to study allele frequencies in Brazilian blood donors, considering the heterogeneous ethnic composition.

Purpura thrombopénique amégacaryocytaire acquis: penser au lupus érythémateux systémique

L'amegacaryocytose acquise est exceptionnellement décrite au cours d'un Lupus Erythémateux Systémique (LES) à Madagascar. Nous rapportons la première observation d'un Purpura Thrombopénique Amegacaryocytaire Acquis (PTAA) simulant un Purpura Thrombopénique Idiopathique (PTI) révélateur d'un LES. Il s'agissait d'une femme de 24 ans, sans antécédents particuliers. Elle présentait un syndrome hémorragique avec une thrombopénie à 10 000/mm³. Le diagnostic de PTI était retenu avant l'hospitalisation. Elle avait reçu une corticothérapie mais ceci n’était pas suivi d'amélioration. A l'unité de Dermatologie, elle se plaignait d'une baisse de l'acuité visuelle. Elle était en bon état général. On retrouvait une tachycardie à 110 bpm, un érythème malaire en verspertilio typique et une pâleur cutanéo-muqueuse. Une hémorragie oculaire bilatérale était objectivée à l'examen ophtalmologique. Les examens paracliniques montraient une thrombopénie à 31000/mm³, une anémie microcytaire à 48g/dL. Les examens immunologiques étaient non réalisés. Un LES avec atteinte cutanée et hématologique était retenu. Un bolus de corticothérapie était administrée associée à une transfusion sanguine. L’évolution était marquée par l'apparition d'un signe d'engagement cérébral faisant suspecter un neurolupus. Le scanner cérébral révélait une hémorragie cérébrale avec une hydrocéphalie aigue traitée par un inhibiteur de l'anhydrase carbonique mais le neurolupus n’était pas écarté. L'anémie disparaissait par contre la thrombopénie s'aggravait à 16000/mm³. Le médullogramme montrait l'absence des mégacaryocytes. L’évolution était favorable à huit mois de suivi après un relais per os de la corticothérapie par la dose de 1 mg/kg/j à dose dégressive à huit mois de suivi. Les atteintes neurologiques, ophtalmologiques et hématologiques étaient compatible avec le diagnostic d'un LES. La persistance d'une thrombopénie doit faire suspecter une amegacaryocytose. Le myélogramme était indispensable pour poser le diagnostic

Drug-induced immune thrombocytopenia: incidence, clinical features, laboratory testing, and pathogenic mechanisms

Drug-induced immune thrombocytopenia (DIIT) is a relatively uncommon adverse reaction caused by drug-dependent antibodies (DDAbs) that react with platelet membrane glycoproteins only when the implicated drug is present. Although more than 100 drugs have been associated with causing DIIT, recent reviews of available data show that carbamazepine, eptifibatide, ibuprofen, quinidine, quinine, oxaliplatin, rifampin, sulfamethoxazole, trimethoprim, and vancomycin are probably the most frequently implicated. Patients with DIIT typically present with petechiae, bruising, and epistaxis caused by an acute, severe drop in platelet count (often to <20,000 platelets/pL). Diagnosis of DIIT is complicated by its similarity to other non-drug-induced immune thrombocytopenias, including autoimmune thrombocytopenia, posttransfusion purpura, and platelet transfusion refractoriness, and must be differentiated by temporal association of exposure to a candidate drug with an acute, severe drop in platelet count. Treatment consists of immediate withdrawal of the implicated drug. Criteria for strong evidence of DIIT include (1) exposure to candidate drug-preceded thrombocytopenia; (2) sustained normal platelet levels after discontinuing candidate drug; (3) candidate drug was only drug used before onset of thrombocytopenia or other drugs were continued or reintroduced after resolution of thrombocytopenia, and other causes for thrombocytopenia were excluded; and (4) reexposure to the candidate drug resulted in recurrent thrombocytopenia. Flow cytometry testing for DDAbs can be useful in confirmation of a clinical diagnosis, and monoclonal antibody enzyme-linked immunosorbent assay testing can be used to determine the platelet glycoprotein target(s), usually GPIIb/IIIa or GPIb/IX/V, but testing is not widely available. Several pathogenic mechanisms for DIIT have been proposed, including hapten, autoantibody, neoepitope, drug-specific, and quinine-type drug mechanisms. A recent proposal suggests weakly reactive platelet autoantibodies that develop greatly increased affinity for platelet glycoprotein epitopes through bridging interactions facilitated by the drug is a possible mechanism for the formation and reactivity of quinine- type drug antibodies.

Alternative diagnosis to heparin-induced thrombocytopenia in two critically ill patients despite a positive PF4/heparin-antibody test

Thrombocytopenia can cause diagnostic challenges in patients who have received heparin. Heparin-induced thrombocytopenia (HIT) is often considered in the differential diagnosis, and a positive screening can be mistaken as confirmation of the disorder. We present two patients who both received low-molecular-weight heparin for several days. In the first patient, clinical judgment rejected the suspicion of HIT despite a positive screening assay, and treatment for the alternative diagnosis of post-transfusion purpura was correctly initiated. In the second patient, the inaccurate diagnosis HIT was pursued due to a positive screening assay, while the alternative diagnosis of drug-dependent thrombocytopenia caused by piperacillin/tazobactam was rejected. This resulted in re-exposure to piperacillin/tazobactam which caused a second episode of severe thrombocytopenia. A positive screening assay for platelet factor 4/heparin-antibody should be verified by a functional assay, especially in patients with low pretest probability for HIT.

Acquired amegakaryocytic thrombocytopenia purpura in a Rhesus macaque (Macaca mulatta)

A 10-y-old multiparous rhesus macaque presented for an annual routine physical examination. Clinically, the animal had pale mucous membranes, petechial and ecchymotic hemorrhages in multiple sites, and a laceration at the tail base. Severe pancytopenia was noted on hematologic evaluation. The monkey was seronegative for SIV, simian T-lymphotropic virus, simian retrovirus type D, and Macacine herpesvirus 1. Bone marrow evaluation revealed a paucity of megakaryocytic precursors in a hypercellular marrow with marked erythroid hyperplasia. In light of these findings, the diagnosis was acquired amegakaryocytic thrombocytopenia purpura. Due to the poor prognosis of the syndrome and clinical deterioration of the monkey, euthanasia was elected. A definitive cause of the thrombocytopenia was not identified; however, the syndrome may have developed secondary to a recent spontaneous abortion. To our knowledge, this case represents the first reported observation of acquired amegakaryocytic thrombocytopenia purpura in a rhesus monkey.

Diabetic ketoacidosis preceding thrombocytopenia associated multiple organ failure in a child

CONTEXT

Thrombocytopenia associated multiple organ failure is a rare but increasingly recognized condition in children. Diabetic ketoacidosis preceding thrombocytopenia associated multiple organ failure is previously unreported in pediatric patients.

CASE REPORT

A 12-year-old female presented with diabetic ketoacidosis along with acute pancreatitis. She further developed thrombocytopenia and renal failure over the next two days. Although hemolytic uremic syndrome/thrombotic thrombocytopenic purpura spectrum was considered, the clinical picture seemed most consistent with thrombocytopenia associated multiple organ failure. The patient was treated with serial therapeutic plasma exchanges and made a complete recovery.

CONCLUSION

A high index of suspicion of thrombocytopenia associated multiple organ failure is required in patients with diabetic ketoacidosis or pancreatitis who present with thrombocytopenia and renal failure. Plasma exchange is a life-saving intervention in such cases.

Renal thrombotic microangiopathy revisited: when a lesion is not a clinical finding

Despite advances in the field of thrombotic microangiopathy (TMA) and associated syndromes such as thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS), they still leave several issues unresolved. For instance, actual diagnostic criteria on which therapeutic decisions rely are relatively narrow and focused on TTP-HUS, with the consequence that non-idiopathic and atypically-presenting TMA are overlooked. In addition, nosologic classifications of TMA disorders have varied substantially over the years, but are still devised from historical rather than mechanistic data. As such, it is perhaps not surprising that even today TMA is erroneously used as an interchangeable term with TTP-HUS, and missed or inappropriately diagnosed on various occasions. Yet, recognizing TMA is of crucial importance given that this lesion often manifests with potentially reversible renal failure. In this editorial, which is presented from a Nephrologist's perspective, we propose that TMA disorders need to be reclassified to include most types of presentations and confirmed or excluded through more elaborate diagnostic approaches.

[Acute secondary iatrogenic thrombocytopenia in middle-aged patients]

Iatrogenic blood diseases are a primary concern for both patients and physicians. Pathology of blood coagulation system associated with pharmacotherapy has been studied in Samara regional Hemostasiological Centre during the last 30 years. A clinical case of secondary iatrogenic thrombopenic purpura is reported in a patient with a history of uncomplicated allergologic disorder. The disease developed after intake of several drugs at non-toxic doses.

A case of newly diagnosed metastatic pancreatic cancer presenting with associated immune thrombocytopenic purpura

Metastatic pancreatic adenocarcinoma presenting with immune thrombocytopenic purpura is a very rare association. To date, only 1 case report found in the literature delineates such an association. We present a case of a patient with newly diagnosed, biopsy-proven metastatic pancreatic adenocarcinoma with new-onset immune thrombocytopenic purpura. The patient's platelet count returned to normal limits after being treated with oral corticosteroid therapy. In conclusion, immune thrombocytopenic purpura can be associated with metastatic pancreatic adenocarcinoma and responds well to corticosteroid therapy.

[Thrombotic microangiopathies]

The thrombotic microangiopathic diseases, which include acquired and congenital TTP and HUS, are most frequently acute disease entities. Untreated, these diseases are associated with a lethal course in many cases. Deficiency of the von Willebrand cleaving enzyme, ADAMTS13, is a decisive pathophysiological defect in most cases of thrombotic microangiopathic diseases. Early recognition and a secure distinction from other conditions that resemble TMA diseases is essential in order to institute adequate treatment and to obtain a favourable outcome in terms of both survival and development of serious sequelae.

Myasthenia gravis and Werlhof's disease

A case of Werlhof's disease (immune thrombocytopenia) associated with myasthenia gravis is described. The two disorders developed within a few months of each other. The immunological and practical aspects of the association are discussed.

Immune thrombocytopenic purpura among the children attending at two teaching hospitals

The presenting features, diagnostic evaluation, seasonal variation and management performed in 110 children with immune thrombocytopenic purpura (ITP) attending at two tertiary level hospitals were evaluated. A peak incidence of children with ITP was observed during the month of June, July and the first step was found in May and lowest in the month of October to December. Mean initial platelet count was 65.5 x 10(9)/L. 35 patients with ITP did not require any treatment who were kept under observation and the rest 75 children who were admitted to hospital given platelet count enhancing treatment- intravenous immunoglobulin in 9, corticosteroids in 60 or both in 6 children with ITP. Intracranial hemorrhages were noticed in two children with ITP. So, this study suggests that ITP had special predilection during summer season and the least in winter along with variable approaches to management of these children.

[Combined indicators for diagnosing immune thrombocytopenic purpura]

OBJECTIVE

To search for the best combined indicators for diagnosing immune thrombocytopenic purpura (ITP).

METHODS

Reticulated platelet (RP), thrombopoietin (TPO), platelet-associated immunoglobulins (PAIgG, by ELISA), mean platelet volume (MPV), platelet distribution width (PDW), platelet-large cell ratio(P-LCR) by flow cytometry), and automated blood cytometer were tested in three groups of people: patients with ITP (n=45), healthy people (n=45), and patients without ITP (n=42). Receiver operating characteristic (ROC) curve, LSD-t test, logistic regression, and correlation analysis were performed to identify the best indicators for diagnosing ITP.

RESULTS

The patients with ITP had higher levels of RP, MPV, PDW, P-LCR, and PAIgG than the healthy people and the patients without ITP (P<0.05). The patients without ITP had higher TPO than the healthy people and the patients with ITP (P<0.05). RP and PAIgG were sensitive indicators to ITP. PR was correlated to the diagnosis of ITP (chi2=10.458, P=0.001).

CONCLUSION

Individual indicator has limited diagnostic values for ITP, which could be improved by a combination of the indicators.

Evaluation of clinical characteristics, diagnosis and management in childhood immune thrombocytopenic purpura: a single center's experience

Diagnostic evaluation and management in childhood immune thrombocytopenic purpura (ITP) are controversial. We reviewed the files of 162 children with ITP to evaluate clinical characteristics, response to treatment and outcome. History of antecedent infection, vaccination and serologic evidence for acute viral infection were present in 48%, 5% and 17% of the patients, respectively. At diagnosis, two-thirds of the patients had a platelet count of <10,000/microl but only 10% had major bleedings. Intracranial hemorrhage was seen in two patients (1.2%) with a mortality rate of 0.6%. Sixteen percent developed chronic ITP. The rate of platelet recovery with mega-dose methylprednisolone (30 mg/kg/d for 3 and 20 mg/kg/d for 4 days) was similar to that obtained with intravenous immunoglobulin or oral prednisolone. Four of seven patients with ITP responded to splenectomy. These data show that mode of treatment has no effect on the clinical course and prognosis of childhood ITP.

An unusual case of severe neonatal thrombocytopenia

Neonatal alloimmune thrombocytopenia (NAIT) occurs when maternal antibodies are directed against antigens on fetal and paternal but not maternal platelets. Most cases of NAIT arise when platelets of the father (and the fetus) express the human platelet antigen (HPA)1a and the mother's platelets expresses HPA-1b. A female patient presented with congenital severe thrombocytopenia and received 4 platelet transfusions, on days 2, 7, 16, and 28. This appeared to be a case of NAIT; however, extensive serologic evaluation by 2 reference laboratories failed to reveal the offending platelet antigen. Consistent with NAIT, the condition resolved by 6 weeks of age. By patient day of life 42, the platelet count had increased without additional need for transfusions, and by 16 weeks, the patient had a completely normal platelet count of 437,000/microL. The patient's platelet count remains normal at a 2-year follow-up. This case is reported as an instructive atypical case of NAIT, in which the relevant platelet antigen could not be identified.

Chronic ITP: analysis of various factors at presentation which predict failure to first line treatment and their response to second line therapy

OBJECTIVE

To observe the significance of various factors in chronic idiopathic thrombocytopenic purpura (ITP) which predict the response of first line (corticosteroids) and second line therapy (splenectomy) and to evaluate their response to second line therapy.

METHODS

This was a descriptive, prospective study conducted from August 2004 till January 2006. Patients of all age groups and both genders with diagnosis of chronic ITP were included. Treatment protocol and criteria for response assessment was explained.

RESULTS

During 17 months period, 86 patients with chronic ITP were analyzed. Non-responders to first line therapy were 74 patients who ultimately required splenectomy. Complete response (CR) was had in 37 (50.7%) patients, 10 (13.7%) and 27 (36.5%) had partial response (PR) and no response (NR) respectively. Analysis of variables like younger age, sex and low platelet count at presentation failed to show any significant influence on response to first line treatment. However response to splenectomy was found to be higher in patients who had initial complete or partial response with steroids and later relapsed and the platelet count was more than 300x10(9)/L on day 14 of surgery.

CONCLUSION

Splenectomy remains the most effective treatment of chronic ITP. No significant factor was identified which predicted initial response to first line treatment. However patients who initially responded to steroids and had platelet counts above 300 X109/L about a fortnight after splenectomy showed promising results post-operatively (p=0.003 and p=0.001).

[The case of spleen's tumor and trombocytopenia in pregnant women]

The women with spleen's tumor and trombocytopenia was diagnosed and observed during pregnancy, labour and puerperium. The lowest level of thrombocytes (50 K/microl) was detected in 32nd week of pregnancy. Termination of the pregnancy by cesarean section was performed because of a big risk for the mother and child (tumor's crack, haemorrhage, infection). The same time the splenectomy was conducted. The results were successful.

Initial management of children with newly diagnosed idiopathic thrombocytopenic purpura in the Nordic countries

AIM

To describe the management practices of newly diagnosed childhood idiopathic thrombocytopenic purpura (ITP) in the Nordic countries.

METHODS

A prospective registration was done from 1998 to 2000, including all children with newly diagnosed ITP aged 0-14 years and at least one platelet count < 30 x 10(9)/L.

RESULTS

506 children from 98 departments were registered. A diagnostic bone marrow aspiration was obtained within 14 days in 33%. Platelet and/or red blood cell transfusion was given in 11%. 287 children (57%) received platelet-enhancing therapy with intravenous immune globulin (IVIG) or corticosteroids within 14 days of diagnosis, IVIG being the first line choice in over 90% of the cases. There were noticeable national differences in the management. The decision to start drug treatment within two days of diagnosis was influenced mainly by the platelet count. Neither early treatment nor response to treatment changed the risk of chronic disease.

CONCLUSION

This study has shown a great variation in the management practices of children with newly diagnosed ITP. Prospective studies are required to produce evidence-based recommendations for this patient group.

Acquired amegakaryocytic thrombocytopenic purpura

Acquired amegakaryocytic thrombocytopenia is an unusual hematologic disorder characterized by thrombocytopenia in association with markedly diminished bone marrow megakaryocytes. We report a case that responded to treatment with cyclosporine but not to IL-11. The bone marrow biopsy, repeated after resolution of thrombocytopenia, showed normal number of megakaryocytes.

Kaposi's sarcoma with thrombocytopenia in a heterosexual Asian Indian male

A 45-year-old heterosexual male patient with retroviral disease since 12 years presented with hyperpigmented lesions, misdiagnosed initially as purpura due to an associated thrombocytopenia, but was biopsy proven to be Kaposi's sarcoma (KS). Bone marrow examination revealed excess megakaryocytes. Low CD4 count and absence of platelet specific IgG reduced the likelihood of immune thrombocytopenia (ITP). However after 6 weeks of antiretroviral therapy the patient's lesions have reduced and platelet counts are improving, possibly suggesting a sequestration thrombocytopenia in the abnormal tumor vessels of KS.

Cutaneous manifestations of systemic disease

BACKGROUND

While most patients who present with a rash have no associated systemic illness, many systemic illnesses have skin manifestations at some stage.

OBJECTIVE

This article uses case vignettes to illustrate a problem oriented approach to five commonly presented skin conditions that have common and varied systemic associations. A logical sequence of management for each case is provided.

DISCUSSION

Often the skin manifestations of systemic disease are vague and nonspecific such as the toxic erythema that might follow a viral infection or a drug eruption. Sometimes it is the systemic manifestations that are vague and nonspecific, while the skin manifestations are highly specific and define the illness. There is currently no useful classification for cutaneous manifestations of systemic disease.

The role of antiplatelet autoantibody assays in the diagnosis of immune thrombocytopenic purpura

Immune thrombocytopenic purpura (ITP) is a disorder almost always manifested by antibody-induced thrombocytopenia. In 1987, two clinically useful antigen-specific assays were reported, the immunobead assay and the monoclonal antibody-specific immobilization of platelet antigens (MAIPA) assay. These two assays and their variations give similar results and can measure both platelet-associated and plasma antibodies. Three prospective studies have reported assay results with sensitivities ranging from 49% to 66% and specificities ranging from 78% to 93%. Most antibodies react with either platelet glycoprotein (GP) IIb/IIIa or GPIb/IX. Recent evidence suggests that antiplatelet antibody assays may also be useful in predicting disease prognosis. Rare ITP patients have bleeding with normal or near-normal platelet counts, a prolonged bleeding time, and aggregation abnormalities due to autoantibodies that affect platelet function. Incubation of patient plasma, IgG or eluate with normal platelet-rich plasma reproduces the patient's aggregation abnormalities.

[Study on the direct MAIPA technique in the differential diagnosis of immune and non-immune thrombocytopenia]

OBJECTIVE

To evaluate the clinical usefulness of direct monoclonal antibody immobilization of platelet antigen (MAIPA) technique in the differential diagnosis of immune and non-immune thrombocytopenia.

METHODS

Platelet-bound autoantibodies in thrombocytopenic patients (immune and non-immune) were measured by direct MAIPA. Monoclonal antibodies against GP II b/III a, GPIb and GP I a/II a were used.

RESULTS

The positive rates of platelet-bound GP-specific autoantibodies between immune (76.4%) and non-immune thrombocytopenia (3.6%) were significantly different (P < 0.05). The direct MAIPA had a sensitivity of 76.4%, a specificity of 96.4%, and a positive predictive value of 97.1% for the diagnosis of immune thrombocytopenia. There was a significant inverse correlation between platelet-bound GP II b/III a specific autoantibody levels and platelet counts (r = -0.338, P < 0.05).

CONCLUSION

The direct MAIPA technique can be used to differentiate immune from non-immune thrombocytopenias.

Relapse of idiopathic thrombocytopenic purpura caused by influenza A virus infection: a case report

We report a patient with idiopathic thrombocytopenic purpura (ITP) in remission, who relapsed as a result of an influenza A virus infection. A 41-year-old woman presented with fever elevation, coughing, and generalized petechiae. Her platelet count had decreased to 1 x 10(9)/l. She had been diagnosed with ITP at age 23, and continuous complete remission had followed steroid therapy and splenectomy. Influenza A antigen was positive in her pharyngeal aspirate, and oseltamivir was effective for her symptoms. Findings of a bone marrow smear were typical for ITP. Steroid therapy resulted in a second complete remission. Although the development of ITP caused by influenza infection and a relapse caused by an influenza vaccination have been previously described, a relapse caused by a sporadic infection has never been documented to our knowledge. Physicians should carefully monitor the hematological data of influenza patients, especially those with ITP, even in remission.

Defining the learning curve for laparoscopic splenectomy for immune thrombocytopenia purpura

BACKGROUND

The current study was undertaken to define the learning curve for laparoscopic splenectomy (LS) in patients with immune thrombocytopenic purpura (ITP).

METHODS

The data of 50 patients who underwent LS for ITP between March 1996 and February 2003 were reviewed. Patients were divided into sequential groups of 10. Operative time, estimated blood loss, conversion to open procedure, length of stay (LOS), time to oral intake, complications, and mortality rates were analyzed.

RESULTS

The mean OR time in the 3rd, 4th, and 5th groups of 10 were significantly shorter than the 1st and 2nd groups of 10. There were no significant differences in estimated blood loss, LOS, or time to oral intake between the groups. Three conversions to open splenectomy occurred; one each in the 2nd, 3rd, and 4th groups of 10. Complications were evenly distributed between groups. There were no deaths.

CONCLUSION

The learning curve for LS in patients with ITP is a minimum of 20 cases.

Real-time PCR genotyping of human platelet alloantigens HPA-1, HPA-2, HPA-3 and HPA-5 is superior to the standard PCR-SSP method

Genotyping of the human platelet alloantigens (HPA) is useful for the diagnosis and therapy of the patients with alloimmune thrombocytopenic syndromes, such as post-transfusion refractoriness to platelets, post-transfusion thrombocytopenic purpura and foetomaternal alloimmune thrombocytopenia. We have developed, optimized and validated a new method for simultaneous genotyping of HPAs - HPA-1, HPA-2, HPA-3 and HPA-5 - by using the real-time polymerase chain reaction (PCR) based on TaqMan technology. Its performances were compared to those of the standard PCR-sequence-specific primers (SSP) method by testing 120 DNA samples. Several discrepancies between the two methods have been observed, especially in the HPA-3 genotyping. Evidently, the PCR-SSP method produced several false positive results due to its technical drawbacks. Based on our comparison, we believe that the new real-time TaqMan PCR assay for the HPA-1, HPA-2, HPA-3 and HPA-5 genotyping is faster, more reliable and reproducible, compared to the standard PCR-SSP.

Cardiobacterium hominis endocarditis associated with very severe thrombocytopenia and platelet autoantibodies

Severe thrombocytopenia is a life-threatening condition. It is often associated with immune-mediated platelet destruction or myeloablative chemotherapy. Infective endocarditis has been associated with thrombocytopenia, which, as in sepsis, tends to be mild and is often the result of several pathological mechanisms. We report a case of Cardiobacterium hominis endocarditis associated with very severe thrombocytopenia and bleeding in a patient who refused platelet transfusion. Platelet autoantibodies directed against glycoprotein (Gp) IIb/IIIa and Gp Ib/IX were detected during active infection using a glycoprotein-specific assay. Successful treatment of C. hominis endocarditis was associated with loss of platelet autoantibodies and recovery of the platelet count. This report illustrates that the development of platelet autoantibodies can contribute to very severe thrombocytopenia in occasional patients with infective endocarditis.