1.Case report: induction of immune tolerance to factor VIII inhibitor after a major operation.
Liam-Pock HO ; Yoke-Kum HO ; Sim-Leng TIEN
Annals of the Academy of Medicine, Singapore 2007;36(6):431-434
INTRODUCTIONWe report a successful case of immune tolerance to factor VIII (FVIII) inhibitor after a major operation. An attempt was made to induce immune tolerance with inhibitor in a haemophilia A patient, who was required to undergo an above-knee amputation. We opted to give high-dose FVIII infusion with no immunosuppression.
OUTCOMEThe highest preoperative FVIII inhibitor level was 5 BU and the peak postoperative FVIII inhibitor level was 1.5 BU demonstrated on Day 9 post operation. High-dose FVIII support was provided during the perioperative period and continued with a low maintenance dose to achieve a FVIII level of 30% to 40%. The requirement of high-dose FVIII lasted from day 6 to 23 post operation and this was tailed down to a maintenance dose over the next 37 days. There were only 2 episodes of mild oozing from the wound at around Day 9, which coincided with the peak postoperative FVIII inhibitor level. Both bleeding episodes were arrested adequately by administering a single dose of FEIBA during each episode. Immune tolerance was demonstrated after around 3 months and a follow-up period of 233 days showed no recurrence of FVIII inhibitor with the normalisation of FVIII half-life study.
CONCLUSIONAfter immune tolerance, the patient suffered fewer episodes of joint haemorrhage and required a lower amount of FVIII infusion as well. The cost may be high initially but the longterm cost-effectiveness has to be carefully evaluated.
Adult ; Amputation ; Coagulants ; administration & dosage ; immunology ; Factor VIII ; administration & dosage ; immunology ; Hemophilia A ; complications ; Humans ; Immune Tolerance ; drug effects ; Male ; Perioperative Care ; Postoperative Care
2.Holoprosencephaly: an antenatally-diagnosed case series and subject review.
Alvin S T LIM ; Tse Hui LIM ; Su Keyau KEE ; Patrick CHIA ; Subramaniam RAMAN ; Elizabeth L P EU ; Jessie Y C LIM ; Sim Leng TIEN
Annals of the Academy of Medicine, Singapore 2008;37(7):594-597
INTRODUCTIONHoloprosencephaly (HPE) is an uncommon congenital failure of forebrain development. Although the aetiology is heterogeneous, chromosomal abnormalities or a monogenic defect are the major causes, accounting for about 40% to 50% of HPE cases. At least 7 genes have been positively implicated, including SHH, ZIC2, SIX3, TGIF, PTCH1, GLI2, and TDGF1.
CLINICAL PICTURETwelve antenatally- and 1 postnatally-diagnosed cases are presented in this study. These comprised 6 amniotic fluid, 3 chorionic villus, 2 fetal blood, 1 peripheral blood, and 1 product of conception.
OUTCOMEThe total chromosome abnormality rate was 92.3%, comprising predominantly trisomy 13 (66.7%). There was 1 case of trisomy 18, and 3 cases of structural abnormalities, including del13q, del18p, and add4q.
CONCLUSIONDespite the poor outcome of an antenatally-diagnosed HPE and the likely decision by parents to opt for a termination of pregnancy, karyotyping and/or genetic studies should be performed to determine if a specific familial genetic or chromosomal abnormality is the cause. At the very least, a detailed chromosome analysis should be carried out on the affected individual. If the result of high resolution karyotyping is normal, Fluorescence in situ hybridisation (FISH) and/or syndrome-specific testing or isolated holoprosencephaly genetic testing may be performed. This information can be useful in making a prognosis and predicting the risk of recurrence.
Adult ; Chromosome Aberrations ; Female ; Holoprosencephaly ; diagnosis ; genetics ; Humans ; Karyotyping ; Pregnancy ; Prenatal Diagnosis ; Trisomy
3.Validating lactate dehydrogenase (LDH) as a component of the PLASMIC predictive tool (PLASMIC-LDH)
Christopher Chin KEONG LIAM ; Jim Yu-Hsiang TIAO ; Yee Yee YAP ; Yi Lin LEE ; Jameela SATHAR ; Simon MCRAE ; Amanda DAVIS ; Jennifer CURNOW ; Robert BIRD ; Philip CHOI ; Pantep ANGCHAISUKSIRI ; Sim Leng TIEN ; Joyce Ching MEI LAM ; Doyeun OH ; Jin Seok KIM ; Sung-Soo YOON ; Raymond Siu-Ming WONG ; Carolyn LAUREN ; Eileen Grace MERRIMAN ; Anoop ENJETI ; Mark SMITH ; Ross Ian BAKER
Blood Research 2023;58(1):36-41
Background:
The PLASMIC score is a convenient tool for predicting ADAMTS13 activity of <10%.Lactate dehydrogenase (LDH) is widely used as a marker of haemolysis in thrombotic thrombocytopenic purpura (TTP) monitoring, and could be used as a replacement marker for lysis. We aimed to validate the PLASMIC score in a multi-centre Asia Pacific region, and to explore whether LDH could be used as a replacement marker for lysis.
Methods:
Records of patients with thrombotic microangiopathy (TMA) were reviewed. Patients’ ADAMTS13 activity levels were obtained, along with clinical/laboratory findings relevant to the PLASMIC score. Both PLASMIC scores and PLASMIC-LDH scores, in which LDH replaced traditional lysis markers, were calculated. We generated a receiver operator characteristics (ROC) curve and compared the area under the curve values (AUC) to determine the predictive ability of each score.
Results:
46 patients fulfilled the inclusion criteria, of which 34 had ADAMTS13 activity levels of <10%. When the patients were divided into intermediate-to-high risk (scores 5‒7) and low risk (scores 0‒4), the PLASMIC score showed a sensitivity of 97.1% and specificity of 58.3%, with a positive predictive value (PPV) of 86.8% and negative predictive value (NPV) of 87.5%. The PLASMIC-LDH score had a sensitivity of 97.1% and specificity of 33.3%, with a PPV of 80.5% and NPV of 80.0%.
Conclusion
Our study validated the utility of the PLASMIC score, and demonstrated PLASMIC-LDH as a reasonable alternative in the absence of traditional lysis markers, to help identify high-risk patients for treatment via plasma exchange.
4.Bone marrow cytogenetics workup: Application of lean management system to determine if additional cell workup is helpful and necessary to analysis.
Alvin S T LIM ; Ting Jie CHEN ; Tse Hui LIM ; Mary TAN ; Lai Ching LAU ; Ping LIM ; Geok Yee LEE ; Li Eng LOO ; Fiona P S LIAW ; Charles T H CHUAH ; Yeow Tee GOH ; Sim Leng TIEN
Annals of the Academy of Medicine, Singapore 2010;39(9):696-699
INTRODUCTIONHigh workload volumes in a Cytogenetics laboratory can lead to long result turn-around times (TAT). This study aimed to improve laboratory efficiency by adopting Lean Management System initiatives to increase productivity through the elimination of wastes. This study examined if the prerequisite 20-cell analysis was sufficient for a conclusive result or if additional cell workup was necessary to ascertain the presence of a previous chromosome abnormality among cases on follow-up, or when a single abnormal cell was encountered during the analysis to determine the presence of a clone.
MATERIALS AND METHODSThe karyotype results of cases that had additional workup were retrieved from among 8040 bone marrow cases of various haematological disorders performed between June 2003 and June 2008.
RESULTSOf 8040 cases analysed, 2915 cases (36.3%) had additional cell workup. Only 49 cases (1.7%) led to the establishment of a clone. The majority of these cases could have been resolved without the additional workup, especially if fluorescence in situ hybridization (FISH) or polymerase chain reaction (PCR)-based assays had been utilised.
CONCLUSIONThis study shows that the additional workup procedure is redundant. The time saved by discontinuing the workup procedure can be used to analyse other cases, leading to increased laboratory efficiency and a faster TAT without compromise to patient care. The practice of additional workup over and above the 20- cell analysis should be dispensed with as little benefit was derived for the amount of additional manpower expended. FISH or PCR-based assays should be utilised to elucidate a case further.
Adult ; Aged ; Aged, 80 and over ; Bone Marrow ; Bone Marrow Cells ; Cytogenetics ; Efficiency ; Efficiency, Organizational ; Female ; Hematologic Diseases ; diagnosis ; pathology ; Humans ; In Situ Hybridization, Fluorescence ; instrumentation ; methods ; Karyotyping ; instrumentation ; methods ; Male ; Polymerase Chain Reaction
5.Cytogenetic and molecular aberrations of multiple myeloma patients: a single-center study in Singapore.
Alvin Soon Tiong LIM ; Tse Hui LIM ; Karen Hsu Shien SEE ; Yit Jun NG ; Yu Min TAN ; Natasha Swee Lian CHOO ; Sherry Xin Er LIM ; Yenny YEE ; Lai Ching LAU ; Sim Leng TIEN ; Kumar SATHISH ; Daryl Chen Lung TAN
Chinese Medical Journal 2013;126(10):1872-1877
BACKGROUNDMuch is known about the cytogenetic lesions that characterize multiple myeloma (MM) patients from the USA, Europe, and East Asia. However, little has been published about the disease among Southeast Asians. The aim of this study was to determine the chromosomal abnormalities of MM patients in our Singapore population.
METHODSForty-five newly-diagnosed, morphologically confirmed patients comprising 18 males and 27 females, aged 46 - 84 years (median 65 years) were investigated by karyotyping and fluorescence in situ hybridization (FISH). FISH employing standard panel probes and 1p36/1q21 and 6q21/15q22 probes was performed on diagnostic bone marrow samples.
RESULTSThirty-four cases (75.6%) had karyotypic abnormalities. Including FISH, a total detection rate of 91.1% was attained. Numerical and complex structural aberrations were common to both hyperdiploid and non-hyperdiploid patients. Numerical gains of several recurring chromosomes were frequent among hyperdiploid patients while structural rearrangements of several chromosomes including 8q24.1 and 14q32 characterized non-hyperdiploid patients. With FISH, immunoglobulin heavy chain (IGH) gene rearrangements, especially fibroblast growth factor receptor 3 (FGFR3)/IGH and RB1 deletion/monosomy 13 were the most common abnormalities (43.4%). Amplification 1q21 was 10 times more frequent (42.5%) than del(1p36) and del(6q21).
CONCLUSIONSWe have successfully reported the comprehensive cytogenetic profiling of a cohort of newly-diagnosed myeloma patients in our population. This study indicates that the genetic and cytogenetic abnormalities, and their frequencies, in our study group are generally similar to other populations.
Aged ; Aged, 80 and over ; Chromosome Aberrations ; Cytogenetics ; Female ; Humans ; Immunoglobulin Heavy Chains ; In Situ Hybridization, Fluorescence ; Karyotyping ; Male ; Middle Aged ; Monosomy ; genetics ; Multiple Myeloma ; genetics ; pathology ; Receptor, Fibroblast Growth Factor, Type 3 ; genetics ; Retinoblastoma Protein ; genetics ; Singapore