Pure Red Cell Aplasia Encountered in a Tertiary Care Hematology Laboratory: A Series of Nine Distinctive Cases

Pure red cell aplasia (PRCA) is characterized by severe anemia with reticulocytopenia and bone marrow erythroblastopenia. The early erythroblasts are markedly decreased; however, in rare instances, they may be normal or raised in number. There are varied etiologies, namely congenital or acquired and primary or secondary. The congenital PRCA is known as “Diamond-Blackfan anemia.” Thymomas, autoimmune disease, lymphomas, infections, and drugs also may be familiar associates. However, the etiologies of PRCA are numerous, and many diseases/infections can be associated with PRCA. The diagnosis rests on clinical suspicion and appropriate laboratory workup. We evaluated nine cases of red cell aplasia, having severe anemia with reticulocytopenia. Nearly half of the cases showed adequate erythroid (> 5% of the differential count) but with a maturation arrest. The adequacy of the erythroid could confuse the hematologist and may even delay the diagnosis. Hence, it is empirical that PRCA could be considered a differential in every case of severe anemia with reticulocytopenia, even in the presence of adequate erythroid precursors in the bone marrow.

Liquid biopsy assay for lung carcinoma using centrifuged supernatants from fine-needle aspiration specimens

INTRODUCTION

Tumor mutation profiling is standard-of-care in lung carcinoma patients. However, comprehensive molecular profiling of small specimens, including core needle biopsy (CNB) and fine-needle aspiration (FNA) specimens, may often be inadequate due to limited tissue. Centrifuged FNA supernatants, which are typically discarded, have emerged recently as a novel liquid-based biopsy for molecular testing. In this study, we evaluate the use of lung carcinoma FNA supernatants for detecting clinically relevant mutations.

METHODS

Supernatants from lung carcinoma FNA samples (n = 150) were evaluated. Samples were further analyzed using next-generation sequencing (NGS) and ultrasensitive droplet digital PCR (ddPCR). Mutation profiles in a subset of samples were compared with results derived from paired tissue samples from the same patient (n = 67) and available plasma liquid biopsy assay (n = 45).

RESULTS

All 150 samples yielded adequate DNA and NGS were carried out successfully on 104 (90%) of 116 selected samples. Somatic mutations were detected in 82% of the samples and in 50% of these patients a clinically relevant mutation was identified that would qualify them for targeted therapy or a clinical trial. There was high overall concordance between the mutation profiles of supernatants and the corresponding tissue samples, with 100% concordance with concurrent FNA and 96% with concurrent CNB samples. Comparison of actionable driver mutations detected in supernatant versus plasma samples showed 84% concordance.

CONCLUSIONS

FNA supernatants can provide a valuable specimen source for genotyping lung carcinoma especially in patients with insufficient tumor tissue, thereby reducing multigene mutation profiling failure rates, improving turnaround times, and avoiding repeat biopsies.

A phase I study of panobinostat and ruxolitinib in patients with primary myelofibrosis (PMF) and post--polycythemia vera/essential thrombocythemia myelofibrosis (post--PV/ET MF)

Ruxolitinib, a selective JAK1/JAK2 inhibitor, is the current first line therapy for myelofibrosis (MF), which reduces symptomatology and splenomegaly, but does not clearly modify disease course. Panobinostat, a histone deacetylase inhibitor, was shown to be safe and tolerable in phase I and II trials and demonstrated clinical activity in approximately a third of treated patients. Combination therapy of ruxolitinib and panobinostat showed synergistic activity in a preclinical MF model, which prompted clinical evaluation of this combination in both ruxolitinib naïve and treated MF patients. Herein, we report the results of an investigator-initiated, dose escalation, phase I trial of ruxolitinib and panobinostat in 15 patients with primary MF and post-polycythemia vera/essential thrombocythemia MF. This combination treatment proved to be safe and tolerable without dose limiting thrombocytopenia and a maximum tolerated dose of both agents in combination was not determined. The majority of patients maintained stable disease with this combination treatment and 40 % attained a clinical improvement (spleen n = 5, anemia n = 1) by modified IWG-MRT at the end of 6 cycles. This is one of the first attempts of rationally designed, JAK inhibitor-based, combination therapy studies and exemplifies the feasibility of such an approach in patients with advanced MF.

Enhancing antimicrobial stewardship by strengthening the veterinary drug regulatory framework

Antimicrobial resistance is a major and growing public health threat. Recently, Health Canada introduced multiple regulatory changes to strengthen the oversight of antimicrobial drugs for veterinary use. These changes aim specifically at increasing control over importation of veterinary drugs and active pharmaceutical ingredients, mandatory reporting of antimicrobial sales data from manufacturers, importers and compounders and facilitating access to low risk veterinary health products. Additional policy changes under existing authorities are also being made to enhance veterinary supervision of antimicrobial use and to remove production claims for food animals from labels of medically important antimicrobial drugs. These important interlinked initiatives are aimed towards enhancing antimicrobial stewardship in Canada to preserve the effectiveness of existing antimicrobials and to protect the health of Canadians.

Spectrum of malabsorption syndrome among adults & factors differentiating celiac disease & tropical malabsorption

BACKGROUND & OBJECTIVES

Aetiology of malabsorption syndrome (MAS) differs in tropical and temperate countries over time; clinical and laboratory parameters may differentiate between various causes. This study was undertaken to investigate the spectrum of MAS among Indian adults and to find out the features that may help to differentiate between TM and celiac disease.

METHODS

Causes of MAS, and factors differentiating tropical malabsorption (TM) from celiac disease (CD) were determined in 275 patients.

RESULTS

Using standard criteria, causes in 275 patients [age 37.5+13.2 yr, 170, (61.5%) male] were, TM 101 (37%), CD 53 (19%), small intestinal bacterial overgrowth 28 (10%), AIDS 15 (5.4%), giardiasis 13 (5%), hypogammaglobulinemia 12 (4%), intestinal tuberculosis 7 (2.5%), strongyloidiasis 6 (2%), immunoproliferative small intestinal disease 5 (2%), Crohn's disease 6 (2%), amyloidosis 4 (1.5%), intestinal lymphangiectasia 3 (1%) and unknown 22 (8%). On univariate analysis, patients with CD were younger than TM (30.6+12 vs. 39.3+12.6 yr, P<0.001), had lower body weight (41.3+11.8 vs. 49.9+11.2 kg, P<0.001), longer diarrhoea duration (median 36 inter-quartile range 17.8-120 vs. 24-months, 8-48, P<0.01), lower stool frequency (6/day, 5-8 vs. 8, 5-10, P<0.05), lower haemoglobin (9.4+3.2 vs. 10.4+2.7 g/dl, P<0.05), higher platelet count (2,58,000, range 1,35,500-3,23,500 vs. 1,60,000, 1,26,000-2,58,000/mm 3 , P<0.05), and more often had hepatomegaly (9/53, 17% vs. 4/101, 4%, P<0.01), and subtotal or partial villous atrophy (36/50, 72% vs. 28/87, 32%, P<0.001). Younger age (<35 yr), longer diarrhoea duration, higher platelet count and villous atrophy were significant on multivariate analysis.

INTERPRETATION & CONCLUSIONS

TM and CD are common causes of MAS among Indian adults. Younger age (<35 yr), longer diarrhoea duration, higher platelet count and villous atrophy were found to be associated with CD.

Laparoscopic ventral/incisional hernia repair: a single centre experience of 1,242 patients over a period of 13 years

BACKGROUND AND PURPOSE

Laparoscopic technique is now well established for ventral/incisional hernia repair. However several issues such as optimal fixation technique, occult hernias, management of inadvertent enterotomies, postoperative seromas and recurrence require appraisal.

METHODS

A single centre retrospective review of 1,242 patients between January 1992 and June 2005 is described. All patients had laparoscopic ventral/incisional hernia repair (LVIHR) following a standardised protocol by five consultants and fellows in a dedicated minimal access surgery unit of a tertiary care hospital.

RESULTS

LVIHR was completed in 1,223 patients (98.5%). The average BMI was 32, mean defect size was 26.2 cm(2), mean operating time was 81 min and mean hospital stay was 1.9 days. The mean mesh to hernia ratio was 37.5. Occult hernias were observed in 203 (16.3%) patients and inadvertent enterotomies occurred in 21 (1.7%) patients. Mortality occurred in two patients, pulmonary embolism and cardiac dysrhythmia being the respective reasons. The most common sequel was early seroma formation (25%). Chronic pain occurred in 14.7% patients. Recurrence rate was 4.4%, which was associated with a higher BMI, use of staplers as fixation device, multiple defects and recurrent hernias. The mean follow up was 5.4 years; (range 2.4-10 years). The follow up rate was 78%.

CONCLUSION

LVIHR leads to low recurrence rates and low rates of wound and mesh infection. Occult hernias are diagnosed and optimally treated laparoscopically. However, chronic pain remains an unresolved issue.

Frequency of small intestinal bacterial overgrowth in patients with irritable bowel syndrome and chronic non-specific diarrhea

INTRODUCTION

Small intestinal bacterial overgrowth (SIBO) occurs in varying frequency in irritable bowel syndrome (IBS). We studied the frequency of SIBO in IBS and chronic non-specific diarrhea (CNSD).

METHODS

129 patients with IBS (Manning's criteria), 73 with CNSD (>/= 4 weeks diarrhea with two of these tests normal [urine D-xylose, fecal fat and duodenal biopsy]) and 51 healthy controls (HC) were evaluated for SIBO using glucose hydrogen breath test (GHBT). Diarrhea-predominant IBS (D-IBS) was grouped into CNSD. Rise in breath hydrogen 12 ppm above basal following 100 g glucose was diagnostic of SIBO.

RESULTS

Of 129 patients with IBS, 7 were constipation (C-IBS), and 122 were of indeterminate type (I-IBS). Patients with IBS were younger than HC and CNSD (IBS vs. HC: 36.6 yr +/- 11.4 vs. 44.1 yr +/- 13.6, p = 0.001; IBS vs. CNSD: 36.6 yr +/- 11.4 vs. 42 yr +/- 14.5, p = 0.003). Patients with CNSD were comparable to HC in age (42 yr +/- 14.5 vs. 44.1 yr +/- 13.6, p = ns). Patients with IBS were more often male than HC [108/129 (83.7%) vs. 34/51 (66.7%) p = 0.02]; gender of CNSD and HC was comparable [male 39/73 (53.4%) vs. 34/51 (66.7%) p = ns]. SIBO was commoner in CNSD than HC [16 (21.9%) vs. 1 (2%), p = 0.003], but was comparable in IBS and HC [11 (8.5%) vs. 1 (2%), p = 0.18]. Patients with CNSD more often had SIBO than IBS [16 (21.9%) vs. 11 (8.5%), p = 0.007].

CONCLUSIONS

SIBO was more common in CNSD including D-IBS than other types of IBS and HC.

Effects of prostaglandin E2 and lipopolysaccharide on osteoclastogenesis in RAW 264.7 cells

INTRODUCTION

Prostaglandins (PGs) can act on both hematopoietic and osteoblastic lineages to enhance osteoclast formation.

METHODS

We examined PGE2 stimulated osteoclastogenesis in RAW 264.7 cells and the role of endogenous PGE2 in lipopolysaccharide (LPS) stimulated osteoclastogenesis.

RESULTS

RANKL (1-100 ng/ml) increased formation of osteoclasts, defined as tartrate resistant acid phosphatase multinucleated cells, with peak effects at 30 ng/ml. Addition of PGE2 (0.01-1.0 microM) to RANKL (30 ng/ml) dose dependently increased osteoclast number 30-150%. Use of NS-398 (0.1 microM) or indomethacin (Indo, 1.0 micro M) to block endogenous PG synthesis had little effect on the response to RANKL alone but significantly decreased the response to PGE2. Addition of LPS (100 ng/ml) to RANKL increased osteoclast number 50%, and this response was significantly decreased by NS-398 and Indo. RANKL and PGE2 produced small, additive increases in COX-2 mRNA levels, while LPS produced a larger increase. PG release into the medium was not increased by RANKL and PGE2 but markedly increased by LPS.

CONCLUSION

We conclude that RANKL stimulated osteoclastogenesis can be enhanced by PGE2 and LPS though direct effects on the hematopoietic cell lineage and that these effects may be mediated in part by induction of COX-2 and enhanced intracellular PG production.

A prospective comparison of four techniques for diagnosis of paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal stem cell disorder with altered expression of glycosylphosphatidylinositol (GPI)-anchored proteins, resulting in the increased susceptibility of erythrocytes to complement-mediated lysis. This study compared the available laboratory methods for detection of PNH cells and evaluated their utility in routine clinical practice. Fifty patients were evaluated by flow cytometric immunophenotyping (FCMI) using CD55 and CD59 monoclonal antibodies, PNH gel card test (GCT), Ham test and sucrose lysis test (SLT). A PNH clone was detectable in erythrocytes in 14 (28%) patients by FCMI, 13 (26%) by GCT and 10 (20%) by Ham test and SLT. The GCT and lytic tests showed 100% specificity and sensitivity was 92.8% and 71.1%, respectively. The GCT results correlated with type III cells (positive for > or =3.21% type III cells) and lytic test results correlated with CD59(-) type III cells (positive for > or =5% CD59(-) type III cells). The GCT and lytic tests were comparable in their sensitivity to detect type II cells (positive for > or =18.5% type II cells). Among the available methods, FCMI is most sensitive, can quantify and delineate PNH cells with differential expression of GPI-anchored proteins. The GCT is a useful screening tool as it is fairly sensitive, easy to perform and interpret. Well-standardized lytic tests are fairly reliable as screening tests.

Day care laparoscopic cholecystectomy: a feasibility study in a public health service hospital in a developing country

BACKGROUND

Day care laparoscopic cholecystectomy (DCLC) has been shown to be safe in centers with adequate infrastructure for day care surgery in economically advanced countries. However, the feasibility of applying this concept in public health service hospitals in less developed and developing nation needs to studied. Unique protocols need to be developed and tested, taking into account local conditions and infrastructural constraints.

PATIENTS AND METHODS

Patients less than 60 years old, graded I and II on the American Society of Anesthesiologists (ASA) physical status score, living within one hour traveling time and willing to make their own arrangements for a return to hospital in case of problems, were selected for DCLC.

RESULTS

291 cases (78%) out of 373 laparoscopic cholecystectomies done in one calendar year were found suitable for DCLC. The most common cause for omitting from DCLC was that the patient lived out of the defined area (57%). Four of 291 (1.3%) cases were cancelled due to medical condition; 270/287 (96.1%) were discharged the same evening as surgery; 6 patients were converted to open surgery; and 11 did not meet the necessary discharge criteria. Eight of 270 (2.9%) required readmission out of which 3 (1.1%) required intervention. Overall, incidence of complication rate was 3.4%. Analysis of data showed that results were comparable to previously published studies, hence extrapolating that inclusion and discharge criteria used in the study are valid. However, there are certain social constraints which hinder truly universal application of DCLC.

CONCLUSIONS

DCLC is a safe and technically feasible concept, even in public health service centers without dedicated ambulatory surgery units. It has potential for much economical and social benefit in these countries.

Effect of oophorectomy on expression of calcium sensing receptor mRNA in rat duodenal mucosa

Calcium sensing receptor (CaR) in duodenal mucosa may be involved in active calcium absorption. Estrogen deficiency results in decreased intestinal calcium absorption. Effects of bilateral oophorectomy (OVX) have been studied on calcium homeostasis, bone mineral density (BMD) and CaR mRNA levels in duodenal mucosa at 4 weeks in adult female Sprague Dawley rats and compared with those in sham-operated and control group. There was no significant change in serum corrected calcium, inorganic phosphorous, calcidiol and intact parathyroid hormone in all the three groups. OVX rats had a significant decline in serum estrogen (E2) levels and alkaline phosphatase. They also had a significant decrease in BMD (DXA) at lumbar spine in vivo, and proximal and distal tibia in vitro while there was no significant change in serum E2 and BMD parameters in sham-operated and control rats. Northern blot analysis revealed no significant change in the CaR mRNA expression in duodenal mucosa in all three groups. The results suggests that CaR mRNA expression in duodenal mucosa is not affected by physiological circulating concentrations of estradiol in rats.

Short-term androgen deprivation does not alter CaR and VDR mRNA expression in duodenal mucosa in male rats

Androgen deprivation is associated with decline in intestinal calcium absorption. The effect of androgen on CaR and VDR intestinal mucosa has not yet been studied. Calcium homeostasis, a real bone mineral density (aBMD, dual energy X-ray absorptiometry) and expression of CaR and VDR mRNA in duodenal mucosa of orchidectomized (ORX) and sham operated (Sham) adult Sprague Dawley rats at 4 week have been studied. There was no significant difference in serum calcium, alkaline phosphatase, calcidiol and calcitriol levels between both the groups. Serum testosterone (T) (ng/dl) and inorganic phosphorous (iP) (mg/dl) levels were significantly lower in ORX rats. As compared to sham rats, ORX rats had significant decline in in-vitro aBMD at proximal, middle and distal tibia, proximal, mid and distal femur and femoral neck (P < 0.05). Northern blot analysis revealed no significant alteration in the CaR and VDR mRNA expression in duodenal mucosa in ORX rats. CaR and VDR mRNA expression in duodenal mucosa is therefore, not affected by physiological concentrations of testosterone in rats.

Strategies to optimize the impact of needle exchange programs

In the United States today, half of all new HIV infections are injection drug use-associated, many of which are a result of the reuse and sharing of contaminated syringes. Thus, providing access to sterile syringes for injection drug users is an important part of preventing HIV transmission. Needle exchange programs (NEPs) have been established as one successful approach to providing sterile injection equipment. The medical literature shows that these programs are effective in decreasing both syringe sharing and HIV incidence in injection drug users. In addition, many NEPs are also beneficial because they provide other injection drug use-relevant services. There are several strategies that can be adopted in order to optimize the impact of needle exchange programs, at both the community and national levels. These include establishing NEPs in communities that need them, expanding and improving those that already exist, and implementing such programs on a larger national scale with the provision of federal funds.

Multiplex PCR for detection of genes for Staphylococcus aureus enterotoxins, exfoliative toxins, toxic shock syndrome toxin 1, and methicillin resistance

A multiplex PCR assay for detection of genes for staphylococcal enterotoxins A to E (entA, entB, entC, entD, and entE), toxic shock syndrome toxin 1 (tst), exfoliative toxins A and B (etaA and etaB), and intrinsic methicillin resistance (mecA) was developed. Detection of femA was used as an internal positive control. The multiplex PCR assay combined the primers for sea to see and femA in one set and those for eta, etb, tst, mecA, and femA in the other set. Validation of the assay was performed using 176 human isolates of Staphylococcus aureus. This assay offers a very specific, quick, reliable, and inexpensive alternative to conventional PCR assays used in clinical laboratories to identify various staphylococcal toxin genes.

Relation of childhood malnutrition to parental education and mothers' nutrition related KAP

Severely malnourished children (26), weight for age 55.27 +/- 3.17, were identified in a colony of predominantly Muslim urban slum dwellers of low economic status. An equal number of normally nourished children matched for age, sex and per capita income were identified. A strong relation was found between nutritional status of the subjects and educational level of their mothers (P less than 0.025). Father's education was unrelated to childrens' nutritional status. A thirty seven point questionnaire was administered to the mothers to record their nutritional knowledge, attitudes and practices (KAP). Analysis revealed that better KAP in relation to 16 of these 37 questions was not associated with better nutritional status. Seven questions were found to have only a weak association. The remaining 14 questions were identified as important for a nutrition education programme. Comparison of nutritional KAP score based on these 14 questions in case of mothers of normal and severely malnourished children revealed a significantly higher score in the former. Questions related to growth monitoring and breast feeding were not found to be important. No significant association was found between mothers' KAP and educational level. It is concluded that (i) Maternal education and KAP are significantly and independently associated with childrens' nutritional status. (ii) The content areas of knowledge, attitudes and practices significantly associated with nutritional status pertain to nutritional requirements of children, nutritional value of foods, immunisation, hygiene, oral rehydration and diarrhea.

Effect of giardia infection on nutritional status of preschool children

Nutritional status of 34 children aged 24-72 months and infected with giardia was compared with that of 92 children matched for age, sex and income and 34 children matched for age, sex, income as well as birth order. Children without giardiasis were found to have better nutritional status in both comparisons. The difference was more pronounced in the second instance. Of the seven anthropometric parameters used for comparison, four were significantly lower (weight, weight for age, midarm circumference and midarm circumference for age), while two (height for age and weight for height) showed nonsignificant childhood malnutrition and that matching for birth order enhances the utility of case-control studies in children.

Role of calcium channel in postvagal potentiation of contraction as evident from the effects of Mn2+, La3+, D-600, and deoxycholate on isolated guinea pig atria-vagus nerve preparation

The role of the calcium channel in the first large contraction (postvagal potentiation, PVP) of the atria at the end of the inhibitory phase of its response (IPR) to vagal stimulation has been investigated by studying the effects of agents acting on the calcium channel (e.g., Ca2+, Mn2+, La3+, and D-600) or sarcoplasmic reticulum (SR) (e.g., deoxycholate (DOC)). IPR was potentiated by high [Ca2+]o (3-16 mM) and also by the calcium channel blockers, Mn2+ (1 microM-0.5 mM), La3+ (0.1 microM-0.5 mM), D-600 (1.0-10 microM), and DOC (1 microM-0.5 mM). PVP was also potentiated by enhanced [Ca2+]o, but the PVP ratio, which employs a correction for the simultaneous changes in the force of spontaneous contraction was inhibited. This indicated greater potentiation of contractility during spontaneous activity by Ca2+ than during PVP. Mn2+, La3+, and D-600 and even DOC in the above concentrations inhibited PVP but increased the PVP ratio. High concentrations of DOC (greater than 1 mM), which disrupt SR, strongly inhibited PVP. It is concluded that the calcium channel plays a more prominent role in spontaneous contractions than in PVP in guinea pig atria. PVP is suggested to be generated by excessive triggered release of Ca2+ from SR leading to a marked increase in [Ca2+]i. The calcium channel and the calcium trapped in the glycocalyx also play significant roles in PVP.

The myeloperoxidase-dependent metabolism of leukotrienes C4, D4, and E4 to 6-trans-leukotriene B4 diastereoisomers and the subclass-specific S-diastereoisomeric sulfoxides

The mechanism of the metabolic inactivation of leukotrienes C4, D4, and E4 by human polymorphonuclear leukocytes activated by phorbol myristate acetate has been analyzed with the use of activated cells, their supernatants, the isolated components of the myeloperoxidase system, and chemically synthesized hypochlorous acid (HOC1). The metabolic products were resolved by reverse-phase high performance liquid chromatography in one or more solvent systems, and each product was characterized relative to chemically synthesized standards by its reverse-phase high performance liquid chromatography retention time, UV absorption spectrum, nonvascular smooth muscle spasmogenic activity, and immunoreactivity. The phorbol myristate acetate-activated human polymorphonuclear leukocytes converted each of the sulfidopeptide leukotrienes to products identical with synthetic diastereoisomers of 6-trans-leukotriene B4 by the following criteria: retention times in two solvent systems, lambda max of 269 nm with shoulders at 259 and 279 nm, and mass spectral analysis. Each of the sulfidopeptide leukotrienes was simultaneously converted to subclass-specific S-diastereoisomeric sulfoxides which co-chromatographed with synthetic standards, exhibited a bathochromic shift to a lambda max at 284 nm, were fully immunoreactive, and possessed less than 5% spasmogenic activity of the corresponding sulfidopeptide leukotrienes. When the sulfidopeptide leukotrienes were incubated with supernatants of phorbol myristate acetate-activated cells in the presence of 0.1 mM H2O2, with a mixture of 100 milliunits of myeloperoxidase, 0.1 mM H2O2, and 10 mM Cl-, or with chemically prepared HOCl, the metabolic products formed were the same as those obtained with the activated cells, indicating that extracellular inactivation was due to HOCl produced by the action of released myeloperoxidase.