A 26-year-old assistant nurse suffered from acute lymphoblastic leukemia and was successfully treated with combination chemotherapy. 15 months later, she relapsed with a lump in her right breast. The significance of this finding is discussed.
A female Malay patient with acute lymphoblastic leukemia in remission for one year developed bilateral visual loss. The ophthalmoscopic appearance showed infiltration of optic nerves and retinae by leukemic cells. At that time, her blood, bone marrow and cerebral spinal fluid remained normal. She had received prophylactic cranial irradiation and intrathecal methotrexate as part of the treatment programme. It was likely therefore she had a leukemic relapse from a pharmacologic sanctuary in the eyes. She responded to local irradiation but did not regain her sight. Three months later, she had a bone marrow relapse.
Myelodysplastic syndromes appear to be a rare group of blood disorders in Malaysia. It usually affects the elderly and some of the cases were reported to evolve into acute leukemia. We describe our experience with five cases, seen and managed by us over a 5-year period. All patients receiving supportive therapy died with one of them definitely known to transform to acute leukemia. The patient who survives till the time of writing received low dose continuous cytosine arabinoside infusion.
The routine study of bone marrow trephine biopsies involves fixation, decalcification, paraffin-embedment, sectioning and staining. However, this process creates artifacts, produces shrinkage of tissue, consumes time and can result in sections of unsatisfactory cytological quality. It also renders the tissue unsuitable for enzyme-histochemical and immunohistochemical analyses. Frozen section of bone marrow without decalcification was evaluated as an alternative method for the study of bone marrow. This method was found to give sections with comparable cytological quality to that of paraffin-embedment, yielded sections for interpretation within 24 hours, and allowed enzyme-histochemical and immunohistochemical analyses to be applied successfully.
The Contraves Autolyzer 801 is a 20 parameter cell counter that operates on the principle of impedance. This evaluation study found that the within-batch precision for 5 of its parameters--WBC, RBC, Hb, Hct and Plt--had coefficients of variation below 5%, while the counts for red cell parameters were reproducible for up to 3 days. The analyser exhibited good linearity for all the parameters. When compared with 2 other counters--the Coulter S-Plus and the Coulter M350, some degree of proportional and constant bias due to unsuitable calibration were detected in the WBC, Hct and Plt parameters. Otherwise it showed generally good correlation in all the parameters and also with the manual PCV method. Carry over was negligible in the red cell parameters. The Contraves Autolyzer 801 is easy to operate and readily accepted by operators.
The 'Dextran' and the 'Buffy-coat' methods for isolation of human leucocytes for DNA extraction were compared on the basis of DNA yield from the same amounts (10 ml) of blood. Human leucocytes from a total of 11 samples were isolated using both methods for each sample after which DNA was extracted. Extracted DNA samples were treated with ribonucleases and proteinase K after which the yields were quantitated by measuring absorbance at 260 nm. The 'Buffy-coat' method yielded a mean concentration of DNA of 476.7 micrograms/ml (range: 212 to 700 micrograms/ml) while the 'Dextran' method yielded 188.4 micrograms/ml (range: 64 to 340 micrograms/ml). The difference was confirmed by subjecting the extracted DNA samples to agarose gel electrophoresis.
A 2-year study was carried out in the Maternity Hospital, Kuala Lumpur to determine the neonatal mortality rates. This Hospital functions both as the local service centre as well as the national referral centre in Malaysia. Its neonatal services, however, were equipped and manned at those below Level III perinatal centre. During the study period 52, 877 livebirths took place in the Hospital. In 1987 and 1988 respectively, the low birthweight (less than 2500 gm) rates were: 112.8 and 101.9 per 1000 livebirths, very low birthweight (less than 1500 gm) rates: 11.1 and 8.8 per 1000 livebirths, neonatal mortality rates: 12.5 and 10.7 per 1000 livebirths and neonatal mortality risk ratio: 1.15 and 1.27. There was significant difference in mortality rates among the Malay, Chinese and Indian babies born in this hospital: the Indians had the highest and the Chinese the lowest rates. Babies delivered by breech or lower segment Caesarean section (LSCS) also had significantly higher mortality than those delivered by other modes of delivery. Low birthweight neonates constituted less than 45% of the total special care nursery admission but contributed to more than 70% of the total neonatal deaths. The common causes of neonatal deaths were problems of prematurity, infection, asphyxia and congenital malformations. Preterm and low birthweight neonates died primarily from problems of prematurity or infection. Term and larger neonates died mainly from asphyxia. More than 75% of the neonatal deaths occurred before 7 days of life. Improvement of antenatal care in the community and upgrading of perinatal services in this Hospital could help to lower the morbidity and mortality due to preventable causes.
Most methods used in double esterase cytochemistry for the diagnosis and classification of acute myeloid leukaemias require double incubation and staining, using separate coupling reagents. We evaluated a method by Swirsky on our normal and abnormal blood and bone marrow smears where only a single incubation and the use of a single coupling reagent is required. Its short incubation period and its strong positive reaction for butyrate esterase in demonstrating cells of monocytic lineage gives it an advantage over the conventional double incubation technique.
Mixed reagents for the Glucose-6-phosphate dehydrogenase (G6PD) deficiency fluorescent screening test were freeze-dried in plastic tubes. The reagents were then reconstituted with distilled water and the test was performed in the usual way. Initial testing with the freeze-dried mixed reagents gave consistent positive reaction to 12 normal blood samples and negative reaction to 9 G6PD deficient blood samples. This will enable a laboratory with freeze-drying facilities to prepare reagent tubes in bulk. As these tubes can be kept at 4 degrees C and do not require to be stored at -20 degrees C, a major laboratory can prepare these tubes and supply small laboratories for screening purposes.
An in-house method which utilizes 14C-thymidine as a substrate was used to assay deoxythymidine kinase in serum. The method is sensitive enough to detect normal levels of serum deoxythymidine kinase and the assay procedure also enables rapid handling of multiple samples. With a total reaction volume of 60 ul, the enzyme reaction was found to be linear with concentrations for up to 650 U/L of TK activity. On studying serum deoxythymidine kinase (s-TK) activity with incubation time, there was a proportional increase in activity with the length of incubation time. "Within-batch" precision showed a coefficient of variation (CV) of 4.7% for serum with extremely high s-TK levels and a CV of 8.8% for serum with normal s-TK levels. S-TK showed a CV of less than 16.0% in its activity when stored at -8 degrees C and at -20 degrees C. The normal reference range obtained for s-TK activity was 8.6 +/- 7.5 U/L.
Immunophenotyping of acute leukaemias has become an important diagnostic tool in haematology laboratories as it is now well recognised that the presence of certain surface markers has prognostic significance. In 1988, we experimented with the alkaline phosphatase anti-alkaline phosphatase (APAAP) method for immunophenotyping of leukaemic cells in our laboratory. 48 cases of peroxidase-negative acute leukaemias were studied. Our study showed that 2 peroxidase-negative cases carried myeloid surface markers, 44% were negative for the markers studied and 5% were unclassified due to technical problems. We concluded that the APAAP method is a useful technique for demonstrating cell markers in leukaemic cells as the reaction is reddish and usually intense. We failed to demonstrate surface markers in 44% of the cases probably because of the choice of a limited panel of monoclonal antibodies.
The haematological findings and case history of 3 patients with the association of acute myeloid leukemia and translocation involving the long arm of chromosome no. 11 are presented. The recipient chromosome for the translocated material from chromosome 11 differs in all the three cases being namely chromosomes 1, 10 and 17.
A system for computerising histopathology records developed in-house using dBASE IV on IBM-compatible microcomputers in a local area network is described. The software package uses a horizontal main menu bar with associated pull-down submenus as interface between the machine and the user. It is very easy to use. The package provides options for selecting databases by years, entering/editing records, browsing data, making multi-characteristics searches/retrievals, printing data, and maintaining databases that includes backing-up and repairing corrupted databases.
A six year old Chinese boy with relapsed Acute Promyelocytic Leukaemia (APML) failed to respond to reinduction with Daunorubicin and Cytarabine infusion. He was successfully treated with all trans-Retinoic Acid (45 mg/m2/day) orally. After four weeks of treatment, he was in complete remission. The side effects of all trans-Retinoic Acid were negligible.
With the advent of new monoclonal antibodies that are applicable to formalin-fixed, paraffin embedded sections, immunophenotyping is becoming increasingly important in the diagnosis and classification of lymphomas. However, multiple factors such as fixation, trypsinization and even type of antibodies used have certain effects on the final outcome of the staining procedure. In this paper we report our experience and the problems encountered in our laboratory when we first tried to establish a workable immunostaining protocol for formalin-fixed, paraffin embedded tissue sections using the immunoalkaline phosphatase technique.
The distribution of immunoregulatory cells in the peripheral blood of an individual has now been established as an important tool in helping the management of several diseases. It is necessary to set the normal ranges of these cells for the laboratory. We have undertaken in this study to establish the reference ranges for normal Malaysian adults. We found that the mean percentages of T cells, B cells, T Helper cells (CD4), T suppressor cells (CD8), NK cells and the ratio of CD4/CD8 were 70.91%, 11.38%, 38.15%, 37.76%, 17.45%, and 1.00 respectively. There was no significant difference between the sexes. In certain parameters, there was significant differences between Malay, Chinese and Indians. The Chinese and Indians were significantly different in the distribution of B cells and in the CD4/CD8 ratio. In the case of CD4 and NK cells, the Indians were different from the other two groups.
DNA analysis for the diagnosis of beta-thalassaemia is a relatively new technique in Malaysia. This, combined with chorionic villus sampling, has enabled us to offer prenatal diagnosis in the first trimester for this common condition. To the best of our knowledge, this has not hitherto been reported in Malaysia.
The applications of antibodies, be it monoclonal or polyclonal, in the diagnostic and research fields are well established. The disadvantage is the high cost of commercially available antibodies. In a diagnostic establishment like ours which also functions as a training ground for laboratory related personnel, it is beneficial to be able to produce in-house reagents. Therefore, we have undertaken this project to produce a rabbit polyclonal antibody against B lymphocytes. We found that the rabbit was a good choice because the titre of antibody produced was high and positive reactions were still detected at a dilution of 1:38400. The antibody showed significant positive reaction only with the lymphocyte subpopulation. A positive reaction was observed between the immunized rabbit serum and B lymphocytes but not T lymphocytes. This shows that the antibody was B lymphocyte specific. There was a positive correlation between the percentage of B lymphocytes labelled using the commercial anti-CD19 monoclonal antibody and the in-house polyclonal antibody (n = 13, r = 0.7, p = 0.02). However, the percentage of cells labelled by the in-house polyclonal anti-B was lower than that by the commercial monoclonal anti-CD19. The fluorescence intensity of the polyclonal antibody was lower than that of the monoclonal. In general, the performance of the in-house polyclonal antibody can be considered as satisfactory. The rabbit serum was stored at -20 degrees C and no significant loss of activity was detected for over a period of 19 months.