Obsessive-compulsive disorder following severe traumatic brain injury

Obsessive-compulsive disorder (OCD) as a consequence of severe traumatic brain injury (TBI) has been reported in a limited number of case studies. Informed by CARE guidelines, we present the case of a boy in his late adolescence who sustained a severe TBI from a motor vehicle crash. His injuries required a prolonged stay in the hospital, including 3 weeks in the intensive care unit and a craniotomy to evacuate a large subdural haematoma. Obsessive-compulsive behaviours were first observed on discharge from the hospital and became worse over time. Compulsive behaviours were considered in light of a neuropsychological examination, and a diagnosis of OCD was attained. Sertraline was prescribed and effectively reduced the severity of OCD symptoms. Given the challenges comorbid conditions can pose to neurorehabilitation, a better understanding of patterns in OCD symptoms and brain lesions among reported cases will help guide the diagnosis of OCD among individuals with severe TBI.

Saliva Cortisol as a Biomarker of Injury in Youth Sport-Related Concussion

Increasing rates of sport-related concussion (SRC) in youth impose a significant burden on public health systems and the lives of young athletes. Accurate prediction for those likely to develop persistent post-concussion symptomology (PPCS) using a fluid biomarker, reflecting both acute injury and recovery processes, would provide the opportunity for early intervention. Cortisol, a stress hormone released through the hypothalamic-pituitary-adrenal (HPA) axis following injury, may provide a missing physiological link to clinical recovery. This cohort study investigated the change in saliva cortisol following SRC and the association between cortisol and symptom burden in pediatric ice hockey players. Further, the association between cortisol levels and medical clearance to return to play was explored. In total, cortisol samples from 233 players were included; 165 athletes (23.6% female) provided pre-injury saliva and 68 athletes (19.1% female) provided post-SRC saliva samples for cortisol analysis. Quantile (median) regressions were used to compare cortisol between pre-injury and post-SRC groups, and the association between total symptoms (/22) and symptom severity scores (/132) reported on the Sport Concussion Assessment Tool (SCAT)3/SCAT5 and post-SRC cortisol (adjusting for age, sex, history of concussion, and time from injury to sample collection). Results demonstrated significantly lower saliva cortisol in post-SRC athletes compared with the pre-injury group (β = -0.62, 95% confidence interval [CI; -1.08, -0.16], p = 0.009). Post-SRC cortisol was not significantly associated with the SCAT3/SCAT5 symptom totals or symptom severity scores; however, females were found to report more symptoms (β = 6.95, 95% CI [0.35, 13.55], p = 0.040) and greater symptom severity (β = 23.87, 95% CI [9.58, 38.15], p = 0.002) compared with males. Exploratory time-to-event analysis revealed a point estimate suggesting a potential association between low cortisol levels and days to medical clearance to return to play. Although preliminary, these findings suggest that the HPA axis may be dysregulated post-SRC. Further, our exploratory analysis and case presentation of post-injury outliers highlight the need to further research cortisol as a prognostic biomarker to inform individualized sex-specific care after SRC.

Determining the Agreement Between Common Measures Related to Vestibulo-ocular Reflex Function After a Mild Traumatic Brain Injury in Children and Adolescents

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A battery of complementary tests is needed to assess vestibulo-ocular reflex (VOR) in pediatric mild traumatic brain injury (mTBI).

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This battery should include both symptom- and performance-based measures.

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Best practice recommendation is needed for such a battery in clinical settings.

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Cervical injury presence may influence symptoms induced during VOR testing.

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There is value of assessing for cervical injury post pediatric mTBI.

Objective

To (1) determine the level of agreement between symptom provocation and performance-based tests of vestibulo-ocular reflex (VOR) function after pediatric mild traumatic brain injury (mTBI) and (2) describe the level of symptom provocation induced by a VOR task in individuals with and without cervical findings.

Design

Cross-sectional.

Setting

This study was conducted at a tertiary care pediatric hospital.

Participants

A total of 101 participants (N=101) aged 6-18 years within 3 weeks of mTBI diagnosis were included (54.5% female; mean age, 13.92±2.63 years; mean time since injury at assessment, 18.26±6.16 days).

Interventions

None.

Main Outcome Measures

Symptom provocation (Vestibular/Ocular Motor Screening tool), performance (clinician-observed VOR performance, head thrust test [HTT], computerized dynamic visual acuity test, video head impulse test), and cervical impairment (cervical flexion-rotation test, range of motion test, self-reported neck pain). Agreement was evaluated using Cohen's κ statistic.

Results

No outcomes demonstrated agreement with symptom provocation (κ=−0.15 to 0.14). Fair agreement demonstrated between clinician-observed VOR performance and HTT (κ=0.32), with little to no agreement demonstrated between other measures. Proportions reporting test-induced dizziness and headache were greater among individuals with cervical findings (29.1%-41.8%) than without (2.3%-6.8%).

Conclusions

Findings support that symptom provocation and performance-based tests measure different constructs and thus have distinct roles when assessing VOR function. Findings suggest results from measures of symptom provocation may be influenced by coexisting cervical impairments, underlining the value of assessing for cervical injury after pediatric mTBI.

Characterizing the evolution of oculomotor and vestibulo-ocular function over time in children and adolescents after a mild traumatic brain injury

Background

Impairments to oculomotor (OM) and vestibulo-ocular reflex (VOR) function following pediatric mTBI have been demonstrated but are poorly understood. Such impairments can be associated with more negative prognosis, affecting physical and mental wellbeing, emphasizing the need to more fully understand how these evolve.

Objectives

to determine i) the extent to which performance on clinical and computerized tests of OM and VOR function varies over time in children and adolescents at 21 days, 3-, and 6-months post-mTBI; ii) the proportion of children and adolescents with mTBI presenting with abnormal scores on these tests at each timepoint.

Design

Prospective longitudinal design.

Setting

Tertiary care pediatric hospital.

Participants

36 participants with mTBI aged 6 to18.

Procedures

Participants were assessed on a battery of OM and VOR tests within 21 days, at 3- and 6-months post injury.

Outcome measures

Clinical measures: Vestibular/ocular motor screening tool (VOMS) (symptom provocation and performance); Computerized measures: reflexive saccade test (response latency), video head impulse test (VOR gain), and dynamic visual acuity test (LogMAR change).

Analysis

Generalized estimating equations (parameter estimates and odd ratios) estimated the effect of time. Proportions above and below normal cut-off values were determined.

Results

Our sample consisted of 52.8% females [mean age 13.98 (2.4) years, assessed on average 19.07 (8–33) days post-injury]. Older children performed better on visual motion sensitivity (OR 1.43, p = 0.03) and female participants worse on near point of convergence (OR 0.19, p = 0.03). Change over time (toward recovery) was demonstrated by VOMS overall symptom provocation (OR 9.90, p = 0.012), vertical smooth pursuit (OR 4.04, p = 0.03), voluntary saccade performance (OR 6.06, p = 0.005) and right VOR gain (0.068, p = 0.013). Version performance and VOR symptom provocation showed high abnormal proportions at initial assessment.

Discussion

Results indicate impairments to the VOR pathway may be present and driving symptom provocation. Vertical smooth pursuit and saccade findings underline the need to include these tasks in test batteries to comprehensively assess the integrity of OM and vestibular systems post-mTBI.

Implications

Findings demonstrate 1) added value in including symptom and performance-based measures in when OM and VOR assessments; 2) the relative stability of constructs measured beyond 3 months post mTBI.

The impact of the COVID-19 pandemic on the well-being of individuals with persistent post-concussive symptoms: a qualitative study

Background

In response to the COVID‐19 pandemic, public health measures were implemented that closed essential businesses, mandated social distancing, and imposed substantial changes to the routine care experienced by patients with mild traumatic brain injury (mTBI) and persistent postconcussive symptoms (PPCS). Patients with PPCS often rely on a comprehensive care team, requiring in‐person treatments and consistent care. Little information exists regarding how access to these services have been affected by public health measures and what outcome the measures have had on the recovery of patients with PPCS.

Objective

To explore the impact of the restriction of in‐person treatments, shifts to virtual care, and global public health measures on the recovery and psychological well‐being of patients with PPCS.

Design

Qualitative interviews were recorded, transcribed, and analyzed using a reflexive thematic analysis approach to identify the main impacts of the public health measures on participants with PPCS.

Setting

Participant interviews were completed remotely via telephone or video‐calling software during province‐wide shutdowns.

Participants

20 individuals with PPCS who attended the institution's Brain Injury Program consented to participate.

Interventions

Not applicable.

Results

The impacts of the public health measures emerged most prominently in three main categories: (1) day‐to‐day lived experiences, (2) personal health status, and (3) health service experiences and barriers.

Conclusions

This in‐depth investigation of the lived experiences of patients with PPCS outlines how the COVID‐19 public health measures negatively affected their care and well‐being. The analysis identified that through increasing social support systems, providing better access to standard or remote treatment, and developing more effective telehealth strategies, this population could be better supported in the event of future public health measures.

Factors Associated With Clinical Recovery After Concussion in Youth Ice Hockey Players

Background:

The identification of factors associated with clinical recovery in youth after sports-related concussion could improve prognostication regarding return to play (RTP).

Purpose:

To assess factors associated with clinical recovery after concussion in youth ice hockey players.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

Participants were part of a larger longitudinal cohort study (the Safe to Play study; N = 3353). Included were 376 ice hockey players (age range, 11-17 years) from teams in Calgary and Edmonton, Canada, with 425 physician-diagnosed ice hockey–related concussions over 5 seasons (2013-2018). Any player with a suspected concussion was referred to a sports medicine physician for diagnosis, and a Sport Concussion Assessment Tool (SCAT) form was completed. Time to clinical recovery was based on time between concussion and physician clearance to RTP. Two accelerated failure time models were used to estimate days to RTP clearance: model 1 considered symptom severity according to the SCAT3/SCAT5 symptom evaluation score (range, 0-132 points), and model 2 considered responses to individual symptom evaluation items (eg, headache, neck pain, dizziness) of none/mild (0-2 points) versus moderate/severe (3-6 points). Other covariates were time to physician first visit (≤7 and >7 days), age group (11-12, 13-14, and 15-17 years), sex, league type (body checking and no body checking), tandem stance (modified Balance Error Scoring System result ≥4 errors out of 10), and number of previous concussions (0, 1, 2, and ≥3).

Results:

The complete case analysis (including players without missing covariates) included 329 players (366 diagnosed concussions). The median time to clinical recovery was 18 days. In model 1, longer time to first physician visit (>7 days) (time ratio [TR], 1.637 [95% confidence interval (CI), 1.331-1.996]) and greater symptom severity (TR, 1.016 [95% CI, 1.012-1.020]) were significant predictors of longer clinical recovery. In model 2, longer time to first physician visit (TR, 1.698 [95% CI, 1.399-2.062]), headache (moderate/severe) (TR, 1.319 [95% CI, 1.110-1.568]), and poorer tandem stance (TR, 1.249 [95% CI, 1.052-1.484]) were significant predictors of longer clinical recovery.

Conclusion:

Medical clearance to RTP was longer for players with >7 days to physician assessment, poorer tandem stance, greater symptom severity, and moderate/severe headache at first visit.

μDrop: Multi-analyte portable electrochemical-sensing device for blood-based detection of cleaved tau and neuron filament light in traumatic brain injury patients

Over 27 million individuals are affected every year worldwide with central nervous system (CNS) injuries. These injuries include but are not limited to traumatic brain injury (TBI) and spinal cord injury (SCI). CNS injuries remain a significant public health concern which demands reliable tools for rapid, on-sight, on-field, and point-of-care diagnostic (POC) solutions. To address these challenges, we developed a low-cost, open-source, hand-held, portable, and POC detection technology, termed as MicroDrop (μDrop), which can simultaneously detect up to eight target biomolecules and display results in both analog and digital formats. The data acquired is stored wirelessly in a cloud server for further investigation and statistical analysis. Multiplexing capability of μDrop and immuno-biosensors detects and quantifies Cleaved-Tau Protein (C-Tau) and Neuron-Filament (NFL) proteins in the blood of TBI patients. Immuno-biosensors rapidly sense the two target proteins in less than 30 min, with μDrop and a conventional potentiostat. C-Tau and NFL were selectively detected with μDrop within the dynamic range of 10 pg/mL - 100 ng/mL and the sensitivity range of 47 μA/pg mm² - 65 μA/pg mm². Comparing the biosensing performance with enzyme-linked immunosorbent assays (ELISA) shows that the immuno-biosensors combined with μDrop could successfully differentiate between clinical controls and injured patients.

Early Supported Discharge for Neurorehabilitation Following Acquired Brain Injury

Introduction: Early Supported Discharge (ESD) is a clinical flow management service offering interdisciplinary rehabilitation, wherein patients are provided supported in-home rehabilitation treatment; in comparison to conventional hospital-based rehabilitation model of service delivery. There has been little research into the functional outcomes for other types of acquired brain injury (ABI).

Methods: In this prospective cohort study, ABI patients presenting at a level I trauma center in Calgary, Canada were placed in either an ESD program or conventional inpatient rehabilitation (IPR) program based on their medical history and presentation. A small number of patients completed both programs (ESD+IPR group). ESD therapies were designed to emulate IPR. Participants completed professionally-rated Mayo-Portland Adaptability Index-4 (MPAI), Quality of Life after Brain Injury (QOLIBRI), Generalized Anxiety Questionnaire-7 (GAD7), Montreal Cognitive Assessment (MoCA), and Patient Health Questionnaire-9 (PHQ9) surveys at 1, 3, and 6 months following initial assessment pre-rehabilitation. Caregivers completed the Zarit Burden Interview (ZBI) at the same time points. The Supervision Rating Scale (SRS) and Disability Rating Scale (DRS) were completed at admission to rehabilitation and all follow-ups. Generalized estimate equations models were used to describe the three groups over time, including age as a covariate.

Results: Significant effects of time were reported in the MPAI participant sub-score in the ESD and IPR groups (χ(2)2 = 42.429, p < 0.000; χ(2)2 = 9.773, p = 0.008), showing significantly higher scores between 1 and 3 month timepoints for both groups. ZBI scores were significantly lower in the ESD group at 1 month compared to 3 and 6 months (χ(2)2 = 31.252, p < 0.001). The proportion of patients with medical complications during rehabilitation was 25.3% in ESD compared to 74.7% patients in IPR.

Conclusions: Improvements in functional outcomes were evident in patients participating in ESD and IPR, with more medical complications reported in the IPR group. Caregiver burden lessened over time in the ESD group but not in the IPR group. Both ESD and ESD+IPR groups can be considered viable alternatives to traditional inpatient rehabilitation. A randomized control trial would be required to properly compare rehabilitation streams. Further investigation into affective and lifestyle elements of ABI recovery would also improve our understanding of targeted neurorehabilitation in this population.

Treatment of Persistent Post-Traumatic Headache and Post-Concussion Symptoms Using Repetitive Transcranial Magnetic Stimulation: A Pilot, Double-Blind, Randomized Controlled Trial

Persistent post-traumatic headache (PTH) after mild traumatic brain injury is one of the most prominent and highly reported persistent post-concussion symptoms (PPCS). Non-pharmacological treatments, including non-invasive neurostimulation technologies, have been proposed for use. Our objective was to evaluate headache characteristics at 1 month after repetitive transcranial magnetic stimulation (rTMS) treatment in participants with PTH and PPCS. A double-blind, randomized, sham-controlled, pilot clinical trial was performed on 20 participants (18-65 years) with persistent PTH (International Classification of Headache Disorders, 3rd edition) and PPCS (International Classification of Diseases, Tenth Revision). Ten sessions of rTMS therapy (10 Hz, 600 pulses, 70% resting motor threshold amplitude) were delivered to the left dorsolateral pre-frontal cortex. The primary outcome was a change in headache frequency or severity at 1 month post-rTMS. Two-week-long daily headache diaries and clinical questionnaires assessing function, PPCS, cognition, quality of life, and mood were completed at baseline, post-treatment, and at 1, 3, and 6 months post-rTMS. A two-way (treatment × time) mixed analyisis of variance indicated a significant overall time effect for average headache severity (F_(3,54) = 3.214; p = 0.03) and a reduction in headache frequency at 1 month post-treatment (#/2 weeks, REAL -5.2 [standard deviation {SD} = 5.8]; SHAM, -3.3 [SD = 7.7]). Secondary outcomes revealed an overall time interaction for headache impact, depression, post-concussion symptoms, and quality of life. There was a significant reduction in depression rating in the REAL group between baseline and 1 month post-treatment, with no change in the SHAM group (Personal Health Questionnaire-9; REAL, -4.3 [SD = 3.7[ p = 0.020]; SHAM, -0.7 [SD = 4.7; p = 1.0]; Bonferroni corrected). In the REAL group, 60% returned to work whereas only 10% returned in the SHAM group (p = 0.027). This pilot study demonstrates an overall time effect on headache severity, functional impact, depression, PPCS, and quality of life after rTMS treatment in participants with persistent PTH; however, findings were below clinical significance thresholds. There was a 100% response rate, no dropouts, and minimal adverse effects, warranting a larger phase II study. Clinicaltrials.gov: NCT03691272.

Polyethylenimine Modified Graphene-Oxide Electrochemical Immunosensor for the Detection of Glial Fibrillary Acidic Protein in Central Nervous System Injury

Glial fibrillary acidic protein (GFAP) is as an intermediate filament protein expressed by certain cells in the central nervous system (CNS). GFAP has been recognized as a reliable biomarker of CNS injury. However, due to the absence of rapid and easy-to-use assays for the detection of CNS injury biomarkers, measuring GFAP levels to identify CNS injury has not attained widespread clinical implementation. In the present work, we developed a polyethylenimine (PEI) coated graphene screen-printed electrode and used it for highly sensitive immunosensing of GFAP. Covalent binding of GFAP antibody to the PEI-modified electrode surface along with electrochemical impedance spectroscopy was used for detecting the change in the electrical conductivity of the electrodes. A highly linear response was recorded for various GFAP concentrations. Quantitative, selective, and label-free detection was achieved in the dynamic range of 1 pg mL^-1 to 100 ng mL^-1 for GFAP spiked in phosphate buffer saline, artificial cerebrospinal fluid, and human blood serum. The performance of the immunosensor was further validated and correlated by testing samples with the commercially available enzyme-linked immunosorbent assay method. This functionalized electrode could be used clinically for rapid detection and monitoring of CNS injury.

Knowing What We Don't Know: Long-Term Psychiatric Outcomes following Adult Concussion in Sports

OBJECTIVE

Amidst a growing concern regarding concussion in sports, there is an emerging link between sport concussion and mental health outcomes. This review summarizes the current literature addressing long-term psychiatric sequelae associated with sport concussion in adults.

METHOD

Several databases were searched using a broad list of keywords for each of concussion, sports, and mental health, with a resultant 311 studies for initial review. After limiting studies based on duplication, appropriateness of data, and relevance, 21 studies remained pertaining to depression, anxiety, substance use, and behavioural changes, including those highlighting chronic traumatic encephalopathy (CTE).

RESULTS

Most studies identified suggested an increased prevalence of depressive symptoms related to concussion history. A conference abstract and qualitative study suggested increasing anxiety related to concussion history; however, a PhD dissertation found no relationship. In reviewing substance use, several studies mentioned use in athletes suspected of having concussion histories, although no link was established, while another noted undiagnosed concussion as leading to current substance misuse. Regarding behavioural changes, all studies identified occurrences of behaviour and/or cognitive changes in participants, with 2 studies suggesting a link with concussion history. With respect to CTE, concerns with mood, behaviour, cognition, and substance use were consistently highlighted, suggesting relations to previous sport concussion; however, the notion of different CTE subtypes and clear aetiology behind concussion severity or frequency was not consistently elucidated.

CONCLUSION

There appears to be a growing body of evidence supporting the presence of long-term psychiatric and psychological sequelae following sport concussion in adults.

Incidence and characterization of MLL gene (11q23) rearrangements in acute myeloid leukemia M1 and M5

To determine the incidence of MLL rearrangement in acute myeloid leukemia (AML) French-American-British (FAB) type M1 and to evaluate optimal screening strategies for the characterization of such abnormalities, we analyzed specimens from 41 patients with AML by Southern blotting with two MLL genomic probes and compared the capacities of reverse transcription-polymerase chain reaction (RT-PCR) and fluorescent in situ hybridization (FISH) to identify the types of rearrangement found in AML M1 with those observed in AML M5. MLL rearrangement was found in 6 of 29 (20%) AML M1 and 6 of 10 AML M5 cases. RT-PCR characterization of 11 cases showed four MLL self-fusions, four MLL-AF6, two MLL-AF9, including a novel AF9 breakpoint, and one uncharacterized t(11:19). Only 5 of 10 MLL-rearranged cases tested demonstrated karyotypic 11q23 abnormalities. FISH analysis of nine cases with an MLL-specific yeast artificial chromosome (YAC) confirmed the cytogenetic abnormalities in two cases, clarified them in one, and did not detect six cases, including three MLL self-fusions, one case with a probable MLL-rearranged subclone not represented karyotypically, and twoMLL-AF6. A whole chromosome 11 paint detected one of these MLL-AF6, and an AF6 cosmid demonstrated that the other was probably due to insertion of a submicroscopic portion of chromosome 6, including part of AF6, into an apparently normal chromosome 11. We conclude that MLL rearrangements are common in adult AML M1, that MLL self-fusion and MLL-AF6 are the most frequent types of abnormalities, and that RT-PCR is preferable to 11q23 FISH analysis for their characterization.

Detection of clonal CD34+19+ progenitors in bone marrow of BCL2-IgH-positive follicular lymphoma patients

The frequent occurrence of BCL2-IgH rearrangements in follicular lymphoma (FL) makes detection of low numbers of tumor cells possible by polymerase chain reaction (PCR). The presence of BCL2-IgH in the bone marrow (BM) and peripheral blood of many FL patients at the time of autografting has led to the suggestion that selection of the CD34-enriched fraction may lead to reinfusion of lower numbers of tumor cells. To address this issue, we PCR-amplified BCL2-IgH from fluorescence-activated cell sorting (FACS)-purified BM CD34+ and CD34- fractions in seven FL patients showing a PCR-detectable translocation in the major breakpoint region of BCL2, five of which showed morphological BM involvement. The total CD34+ fraction showed diminished but residual positivity in the first two cases tested. Therefore, BM cells from the remaining five patients were sorted for the CD34+19- immature population, the CD34+19+ B-cell precursors, and the CD34-19+ mature B-cell fraction. The CD34+19- subpopulation was negative in four of five, despite evident BM infiltration in three cases. In contrast, the CD34+19+ fraction was positive in all three cases tested. These cells represented 0% to 50% (mean, 18%) of the total CD34+ population, suggesting that, if reinfusion of BCL2-IgH-positive cells plays a role in postautograft relapse in FL, therapeutic CD34 selection procedures should include additional purging of the CD34+19+ B-cell precursors or, at least, assessment of the proportion of CD19+ cells in the CD34+ fraction and its correlation with clinical outcome postreinfusion.

Highly purified primitive hematopoietic stem cells are PML-RARA negative and generate nonclonal progenitors in acute promyelocytic leukemia

The hierarchical level of stem cell involvement in acute promyelocytic leukemia (APL) characterized by the pathognomonic PML-RARA fusion gene is unknown. To determine if the cells of the primitive hematopoietic stem cell compartment are involved in the leukemic process, we have used molecular and cell sorting techniques in peripheral blood and bone marrow (BM) cells at diagnosis from three patients with APL and t(15; 17). In two of them, clonality analysis was also possible using the BstXI polymorphic site of the PGK gene. The PML-RARA fusion gene was readily identified by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of BM cells obtained at diagnosis in all three patients. These same samples were then used to sort CD34+ cells and their CD38+ and CD38- subsets by fluorescence-activated cell sorting. In both female patients, CD34+/CD38+ and CD34+/CD38- cell fractions were polyclonal using PCR, whereas a monoclonal pattern was identified at the BM sample obtained at diagnosis either by Southern blotting or by PCR. Because of the high sensitivity of the PCR analysis, the polyclonal pattern of these cell populations could mask the presence of a minor clone. To detect this clone, we preformed RT-PCR analysis for t(15; 17). In one female patient, the abnormal PML-RAR fusion gene was found only in the more mature CD34+/CD38+ cell fraction using a nested PCR approach, whereas the polyclonal CD34+/CD38- fraction was PML-RARA negative. These findings were confirmed in a third patient with APL in whom the PML-RARA transcripts were absent in the CD34+/CD38- cell fraction. To study the clonality at the level of clonogenic progenitors, we used in one patient PGK analysis by PCR of individual burst-forming units-erythroid and colony-forming units-granulocyte-macrophage obtained from the CD34+/CD38- and CD34+/CD38+ cell populations at diagnosis and from the BM sample obtained during remission. The two highly purified cell populations gave rise to morphologically normal colonies clonal for both the BstXI site containing (A) and the BstXI site lacking (B) PGK allelles, indicating their polyclonal content, a pattern that was also found in clonogenic progenitors obtained at remission. These findings strongly suggest that the primitive hematopoietic stem cells as defined by the CD34+/CD38- antigens are not involved by the neoplastic process in APL. These results may have important implications for autografting strategies of retinoic acid/chemotherapy-resistant or relapsed patients.

Description of a novel FR1 IgH PCR strategy and its comparison with three other strategies for the detection of clonality in B cell malignancies

PCR amplification of IgH gene V-D-J junctional variability (IgH PCR) is increasingly replacing Southern analysis for the detection of clonal lymphoid populations in cases presenting diagnostic difficulties. In order to determine the most efficient strategy, we have compared three known methods, using consensus primers against the VH FR3 or FR2 (FR256) regions, or a mix of six primers against the FR1 region (FR1f), with a new approach using a consensus primer against FR1 (FR1c), never previously described for diagnostic purposes, on DNA from 89 monoclonal B-cell proliferations (16 ALL, 28 CLL/PLL, 15 myelomas, 30 NHL). We obtained a detection rate of 70% for FR3, 64% for FR1f and 77% and 78% for FR256 and FR1c, respectively. Polyclonal lymphocytes and mature T cell malignancies tested negative for all systems. Differences in the detection rate were related not only to the choice of VH primer but also the JH primer(s) used and the pathological subtype. All strategies led to adequate detection of leukaemic DNA, whereas the detection rate in myeloma varied between strategies from 47 to 80% and that of follicular lymphoma from 13 to 63%. The lowest detection rates were observed in follicular lymphoma and in mature CD5 negative proliferations, reflecting the probable correlation between somatic mutation and PCR false-negativity. The combined use of FR1c and FR256 allowed detection in at least one system of 92% of cases overall and at least 75% in all pathological subtypes, thus providing a simple, reliable and rapid non-radioactive system for the detection of B cell clonality.

Persistent polyclonal lymphocytosis with binucleated B lymphocytes: a genetic predisposition

Persistent lymphocytosis is usually associated with a malignant lymphoproliferative disease (MLPD). We report six female patients presenting a chronic, moderate lymphocytosis of 2-16 years duration with atypical binucleated lymphocytes on peripheral blood smears. Further investigation showed a polyclonal increase in serum IgM and HLA-DR7 phenotype in all patients. The B cells were polyclonal because Southern hybridization of DNA and polymerase chain reaction failed to demonstrate a clonal rearrangement of immunoglobulin heavy chain genes. Peripheral blood examination showed binucleated lymphocytes in a family member of two of the cases; taken together with the association with HLA-DR7 these data suggest a genetic predisposition. The identification of this benign syndrome is important in order to prevent its misdiagnosis as a MLPD.