Evaluation of the use of gel card system for assessment of direct coombs test: weighing the pros and cons.

A positive direct Coombs test (DCT) is the hallmark of diagnosis of immune hemolytic anemias. The reagent used for the test is the Antihuman globulin (AHG), which may be either 'Polyspecific' or 'Monospecific'. The advent of the Gel card systems has made the procedure and interpretation of DCT simpler. Aim of this study is to evaluate three of the various techniques used for the performance and interpretation of DCT. A total of 96 EDTA samples were included in the study. DCT was performed by (i) polyspecific AHG manual tube method (ii) polyspecific AHG Gel card method and (iii) monospecific AHG (Anti IgG and Anti Complement) manual tube method. In our study we considered positivity by monospecific AHG as the standard for diagnosis. Of the total 96 samples evaluated, 44 cases positive by Gel card method, were also positive for either one or both the monospecific AHG reagents. 17 cases positive by Gel card were negative by all manual methods. These false positive cases were attributed to reasons such as increased ESR, macrocytosis and marked leucocytosis. Nine cases were negative by Gel card but were positive with the Monospecific AHG. The sensitivity of DCT done by the Gel card technique was 83.01% and the specificity was 60.46%. Use of Gel card technique to perform and interpret DCT is easier than manual tube methods, but positivity by Gel card needs to be correlated with clinical presentation of the patient and other laboratory findings. Monospecific antisera can be used to confirm cases that are positive by the Gel card systems.

ABO blood groups and malaria related clinical outcome.

OBJECTIVES: The study was undertaken to correlate the blood groups and clinical presentations in malaria patients and to understand the differential host susceptibility in malaria. METHODS: From October 2007 to September 2008, malaria positive patients' samples were evaluated in this study. Hemoglobin, total leukocyte count, and platelet count of each patient were done on an automated cell counter. After determining the blood groups, malarial species and the severity of clinical course were correlated. RESULTS: A total of 100 patients were included in the study, of which 63 cases were positive for Plasmodium falciparum and 37 cases were positive for P. vivax infection and 11 patients had mixed infection. The results of the blood groups showed 22 - 'A' group, 42 - 'B' group, 35 - 'O' group and 1 was 'AB' group. When the clinical courses between different groups were compared using the following parameters for severe infection--a parasitic load of >10/1000 RBCs, severe anemia with hemoglobin < 6 g%, platelet count of <10,000/mm3, hepato or splenomegaly or clinical signs of severe malaria such as fever >101°F and other organ involvement, it was observed that 'O' group had an advantage over other the groups. The difference in rosetting ability between red blood cells of different 'ABO' blood groups with a diminished rosetting potential in blood group 'O' red blood cells was due to the differential host susceptibility. CONCLUSION: 'O' group had an advantage over the other three blood groups. Based on literature and the results of this study, the diminished rosetting potential in blood group 'O' red blood cells is suggested as the basis for the differential host susceptibility.

Clinical patterns and hematological spectrum in autoimmune hemolytic anemia.

BACKGROUND: Autoimmune hemolytic anemia (AIHA) results from red cell destruction due to circulating autoantibodies against red cell membrane antigens. They are classified etiologically into primary and secondary AIHAs. A positive direct antiglobulin test (DAT) is the hallmark of diagnosis for AIHA. METHODS AND RESULTS: One hundred and seventy-five AIHA cases diagnosed based on positive DAT were included in the study. The cases showed a female predilection (M: F = 1:2.2) and a peak incidence in the third decade. Forty cases were found to be due to primary AIHA, while a majority (n = 135) had AIHA secondary to other causes. The primary AIHA cases had severe anemia at presentation (65%) and more often showed a blood picture indicative of hemolysis (48%). Forty-five percent of primary AIHAs showed positivity for both DAT and indirect antiglobulin test (IAT). Connective tissue disorders were the most common associated etiology in secondary AIH A0 (n = 63). CONCLUSION: AIHAs have a female predilection and commonly present with symptoms of anemia. AIHA secondary to other diseases (especially connective tissue disorders) is more common. Primary AIHAs presented with severe anemia and laboratory evidence of marked hemolysis.

Hunt for the hidden trait.

OBJECTIVE: To assess the efficacy of a peripheral smear examination as a screening tool for ß-thalassemia trait. MATERIALS AND METHODS: 17 623 Leishman-stained peripheral smears were evaluated during the period from July 2006 to September 2007. The following parameters were studied: hemoglobin, red blood cell count, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration and red cell distribution width. All the cases that showed microcytosis, hypochromia, erythrocytosis and absence of anisopoikilocytosis were suspected of having the thalassemia trait (TT), and all these cases were further evaluated with Alkaline Hemoglobin Electrophoresis for confirmation. RESULTS: Of the 17 623 smears examined, 60 cases were considered suspicious of having TT. Alkaline hemoglobin electrophoresis carried out on all these cases revealed an elevated HbA(2) (Mean = 7.5%). Five cases evaluated were found to have other hemoglobinopathies (1 Sickle cell trait, 3 Hb-E, 1 thalassemia intermedia). CONCLUSION: Careful screening of peripheral smear is an invaluable screening tool for thalassemia trait (PPV - 95%). There must be awareness among the peripheral centers about the importance of peripheral smear screening and the affected persons should be counseled.

The MAHA clue - A case report.

Microangiopathic hemolytic anemia (MAHA), is one of the causes of extra vascular hemolysis. It is seen in settings with pathologically altered small blood vessels. Disseminated carcinomas may rarely present as MAHA. A case of a 28 year old female with carcinoma stomach, who presented with MAHA as a first manifestation is reported. Acute onset of MAHA, may be the first manifestation of malignancy. In the absence of relatively common causes like disseminated intravascular coagulation,/Hemolytic uremic syndrome/thrombotic thrombocytopenic purpura, MAHA warrants extensive rapid investigations including bone marrow aspiration for possible metastatic deposits.

Salivary duct carcinoma of the parotid gland: the cytohistological features.

A 62-year-old man presented with rapidly growing tumour in the right parotid region with associated pain and facial nerve palsy. Based on the fine needle aspiration cytology report of high-grade mucoepidermoid carcinoma, parotidectomy was performed which showed features of salivary duct carcinoma. The smears were reviewed to identify the potential pitfalls in the cytological diagnosis of salivary duct carcinoma.