Genetic determinants of cocaine-associated agranulocytosis

Risk assessment of substance use disorders based on the human leukocyte antigen (HLA)

Substance use disorders (SUDs) are common and costly conditions that are partially attributable to genetic factors. In light of immune system influences on neural and behavioral aspects of addiction, the present study evaluated the influence of genes involved in the human immune response, human leukocyte antigen (HLA), on SUDs. We used an immunogenetic epidemiological approach to evaluate associations between the population frequencies of 127 HLA alleles and the population prevalences of six SUDs (alcohol, amphetamine, cannabis, cocaine, opioid, and "other" dependence) in 14 countries of Continental Western Europe to identify immunogenetic profiles of each SUD and evaluate their associations. The findings revealed two primary groupings of SUDs based on their immunogenetic profiles: one group comprised cannabis and cocaine, whereas the other group comprised alcohol, amphetamines, opioids, and "other" dependence. Since each individual possesses 12 HLA alleles, the population HLA-SUD scores were subsequently used to estimate individual risk for each SUD. Overall, the findings highlight similarities and differences in immunogenetic profiles of SUDs that may influence the prevalence and co-occurrence of problematic SUDs and may contribute to assessment of SUD risk of an individual on the basis of their HLA genetic makeup.

Effects of circadian variation, lifestyle and environment on hematological parameters: A narrative review

The complete blood count (CBC) is the most widely prescribed laboratory test. It plays a key role in screening, diagnosing, and monitoring a variety of medical disorders. Preanalytical and analytical variables are responsible for more than 50% of laboratory errors that may lead to spurious CBC results. The effects of blood sampling, transport, storage, and analytical errors on hematological parameters have been well described. Circadian variation and changes in lifestyle and environment can also affect blood cells. It has been extensively studied in the past, but highly variable methodology and the presence of confounding factors have provided scattered and inconsistent results. We have investigated the literature to define the impact of circadian variation, modification of the sleep-wake cycle, acute and chronic exercise, eating habits, alcohol, tobacco, drugs of abuse, high-altitude, heat/cold exposure, and air pollution on CBC results. The affected cell type along with the intensity and duration of changes are detailed for each condition. We aim at providing a comprehensive overview of which situations may induce clinically significant changes and have to be taken into account by healthcare professionals before considering a hematological parameter as pathological and requesting complementary tests.

Cocaine/levamisole-associated autoimmune syndrome: a disease of neutrophil-mediated autoimmunity

PURPOSE OF REVIEW

Levamisole was previously used for its immunomodulatory properties to treat rheumatoid arthritis and some cancers. However, because of serious side-effects, it was taken off the market in the United States. Recently, levamisole has reemerged as a popular cocaine adulterant. Some individuals who consume levamisole-adulterated cocaine can develop a life-threatening autoimmune syndrome. In this review, the medical consequences of levamisole exposure and postulated mechanisms by which levamisole induces these adverse effects are discussed.

RECENT FINDINGS

Although agranulocytosis and cutaneous vasculitis are the major findings in patients who develop cocaine/levamisole-associated autoimmune syndrome (CLAAS), more recent experience indicates that other organ systems can be involved as well. Current studies point to neutrophil activation and neutrophil extracellular trap formation with subsequent antineutrophil cytoplasmic antibody-mediated tissue injury as a possible mechanism of CLAAS.

SUMMARY

In the past decade, the detrimental effects of levamisole have reemerged because of its popularity as a cocaine adulterant. Although infrequent, some individuals develop a systemic autoimmune syndrome characterized by immune-mediated agranulocytosis and antineutrophil cytoplasmic antibody-mediated vasculitis. Mechanistically, neutrophil antigens appear to be a major player in inducing CLAAS. Prompt cessation of levamisole exposure is key to treatment, although relapses are frequent because of the addictive effects of cocaine and the high prevalence of levamisole within the cocaine supply.

GSTP1 rs1695 is associated with both hematological toxicity and prognosis of ovarian cancer treated with paclitaxel plus carboplatin combination chemotherapy: a comprehensive analysis using targeted resequencing of 100 pharmacogenes

Purpose

To find genetic variants that predicted toxicity and/or efficacy of paclitaxel plus carboplatin combination therapy (TC therapy).

Patients and methods

In a retrospective case-control study, we analyzed 320 patients who had received TC therapy for gynecological cancers (ovarian, fallopian tube, peritoneal, uterine, and cervical cancers) and collected their germline DNA. We performed a comprehensive pharmacogenomic analysis using a targeted resequencing panel of 100 pharmacogenes. For 1,013 variants passing QC, case-control association studies and survival analyses were conducted.

Results

GSTP1 rs1695 showed the smallest p value for hematotoxicity association, and the ¹⁰⁵Ile wild type allele had a significantly higher risk of severe hematotoxicity (neutropenia G4, thrombocytopenia ≥ G3 and anemia ≥ G3) than the ¹⁰⁵Val allele (p=0.00034, odds ratio=5.71 (95% confidence interval:1.77-18.44)). Next, we assessed 5-year progression-free survival (PFS) and overall survival (OS) in 56 advanced ovarian cancer patients who received tri-weekly TC as a first-line chemotherapy. Patients with the ¹⁰⁵Ile/¹⁰⁵Ile genotype showed significantly better PFS (p=0.00070) and OS (p=0.0012) than those with the ¹⁰⁵Ile/¹⁰⁵Val or ¹⁰⁵Val/¹⁰⁵Val genotype.

Conclusion

Our study indicates that the GSTP1 rs1695 ¹⁰⁵Ile/¹⁰⁵Ile genotype is associated with both severe hematotoxicity and high efficacy of TC therapy, identifying a possible prognostic indicator for patients with TC therapy.

Recurrent Levamisole-Induced Agranulocytosis Complicated by Bowel Ischemia in a Cocaine User

BACKGROUND Levamisole is a common adulterant of cocaine and up to 69% of seized cocaine in United States contains levamisole. It is a synthetic imidazothiazole derivative which was previously used as an immunomodulating agent for treatment of various connective tissue disorders and colorectal carcinoma. However, it was withdrawn later from the market due to significant toxicity associated with it. CASE REPORT We present the case of a 59-year-old male patient with a history of active cocaine use who presented to the hospital with febrile neutropenia and agranulocytosis. He underwent extensive work-up for neutropenia and was suspected to have it secondary to levamisole-adulterated cocaine. He was treated with antibiotics and granulocyte-stimulating factor. His white cell count improved and he was discharged home. He continued to use cocaine after discharge from the hospital. He returned to the hospital 3 weeks later with recurrent neutropenia and agranulocytosis complicated by septic shock and bowel necrosis which required prolonged antibiotics and a bowel resection. CONCLUSIONS Levamisole-induced agranulocytosis should be considered in patients who present with neutropenia and a history of cocaine use. Physicians should have high clinical suspicion and consider it a potential etiology of agranulocytosis when other causes have been excluded.

A Case of Levamisole-Induced Agranulocytosis

A sixty-eight-year-old male with a past medical history of recurrent cocaine use presented to the emergency department with recurrent diarrhea and was found to have a white blood cell (WBC) count of 1.9 × 10⁹/L with agranulocytosis (absolute neutrophil count (ANC) of 95 cell/mm³). At admission, the patient disclosed that he used cocaine earlier during the day, and a urine drug screen tested positive for this. On hospital day one, the patient was found to have a fever with a maximum temperature of 313.6 K. After ruling out other causes and noting the quick turnaround of his neutropenia after four days of cocaine abstinence, the patient's neutropenia was attributed to levamisole-adulterated cocaine.

Association of HLA-B and HLA-DRB1 polymorphisms with antithyroid drug-induced agranulocytosis in a Han population from northern China

Antithyroid drug (ATD)-induced agranulocytosis is associated with human leukocyte antigen (HLA) and nearby genes in Southeast Asian and European populations. The susceptibility of the Han population from northern China to ATD-induced agranulocytosis has not been reported. We evaluated the associations of genetic variants at the HLA-B and HLA-DRB1 loci and 32 candidate single nucleotide polymorphisms (SNPs) with agranulocytosis in 29 patients with ATD-induced agranulocytosis and in 140 patients with Graves’ disease (GD) as controls. All subjects were of Han descent from northern China. HLA-B*27:05 (P = 1.10 × 10⁻⁴), HLA-B*38:02 (P = 2.41 × 10⁻⁴) and HLA-DRB1*08:03 (P = 1.57 × 10⁻³) were susceptibility HLA variants for ATD-induced agranulocytosis. All subjects carrying the HLA-B*27:05 allele had agranulocytosis. The odds ratios (ORs) comparing allele carriers to non-carriers were 66.24 (95% confidence interval (CI): 3.54–1239.66) for HLA-B*27:05, 7.525 (95% CI: 2.294–24.68) for HLA-B*38:02 and 4.316 (95% CI: 1.56–11.93) for HLA-DRB1*08:03. Two SNPs, rs2596487 (OR = 4.196, 95% CI = 2.086–8.441, P = 2.08 × 10⁻⁵) and rs2228391 (OR = 3.621, 95% CI = 1.596–8.217, P = 1.2 × 10⁻³), were independently associated with ATD-induced agranulocytosis. Subjects carrying the ‘A’ allele of rs1811197 or HLA-B*38:02 showed lower minimum granulocyte counts than non-carriers (P = 4.74 × 10⁻⁴ and P = 7.39 × 10⁻⁴, respectively). Our findings support the association between genetic variations of HLA-B and HLA-DRB1 with ATD-induced agranulocytosis in a Han population from northern China.

Levamisole: A High Performance Cutting Agent

Levamisole is an imidazothiazole chemical most frequently used as an antihelminthic agent in cattle. Over the last decade, levamisole has been increasingly encountered as an additive in both powder and crack cocaine. A white powder with a "fish scale" appearance, the chemical is physically similar to powder cocaine. In vivo, levamisole is metabolized to aminorex, a compound with amphetamine-like psychostimulatory properties and a long half-life; a priori, this property allows levamisole to potentiate and prolong the stimulatory effects of cocaine while bulking up the drug to increase profit for the dealer. As use of cocaine cut with levamisole becomes more prevalent, complications directly attributable to the chemical are increasingly being recognized.

Genetic variants associated with antithyroid drug-induced agranulocytosis: a genome-wide association study in a European population

BACKGROUND

Drug-induced agranulocytosis is a potentially life-threatening adverse reaction. Genome-wide association studies (GWASs) in ethnic Chinese people in Taiwan and Hong Kong have shown an association between agranulocytosis induced by antithyroid drugs and the HLA alleles HLA-B*38:02 and HLA-DRB1*08:03. We aimed to identify genetic variants associated with antithyroid drug-induced agranulocytosis in a white European population.

METHODS

We did a GWAS in 234 European adults with any non-chemotherapy drug-induced agranulocytosis (absolute neutrophil count ≤0·5 × 10(9)/L [≤500/μL]) and 5170 population controls. 39 of the 234 patients had agranulocytosis that was induced by antithyroid drugs (thiamazole [methimazole], carbimazole, or propylthiouracil). After imputation and HLA allele prediction, 9 380 034 single nucleotide polymorphisms (SNPs) and 180 HLA alleles were tested for association. The genome-wide significance threshold was p<5 × 10(-8).

FINDINGS

Agranulocytosis induced by non-chemotherapy drugs in general was significantly associated with the HLA region on chromosome 6, with odds ratios (ORs) of 3·24 (95% CI 2·31-4·55, p=1·20 × 10(-11)) for HLA-B*27:05 and 3·57 (2·61-4·90, p=2·32 × 10(-15)) for the top SNP (rs114291795). Drug-specific analysis showed that the association with HLA-B*27:05 was largely driven by cases induced by antithyroid drugs. In a multiple logistic regression model, the OR for HLA-B*27:05 was 7·30 (3·81-13·96) when antithyroid drug-induced agranulocytosis was compared with population controls (p=1·91 × 10(-9)) and 16·91 (3·44-83·17) when compared with a small group of hyperthyroid controls (p=5·04 × 10(-4)). Three SNPs were strongly associated with antithyroid drug-induced agranulocytosis: rs652888 (OR 4·73, 95% CI 3·00-7·44, p=1·92 × 10(-11)) and rs199564443 (17·42, 7·38-41·12, p=7·04 × 10(-11)), which were independent of HLA-B*27:05, and rs1071816 (5·27, 3·06-9·10, p=2·35 × 10(-9)) which was in moderate linkage disequilibrium with HLA-B*27:05. In heterozygous carriers of all three SNPs, the predicted probability of antithyroid drug-induced agranulocytosis was about 30% (OR 753, 95% CI 105-6812). To avoid one case of agranulocytosis, based on the possible risk reduction if all three SNPs are genotyped and carriers are treated or monitored differently from non-carriers, roughly 238 patients would need to be genotyped.

INTERPRETATION

In white European people, antithyroid drug-induced agranulocytosis was associated with HLA-B*27:05 and with other SNPs on chromosome 6. In the future, carriers of these variants could be placed under intensified monitoring or offered alternative treatment for hyperthyroidism.

FUNDING

Swedish Research Council, Swedish Heart and Lung Foundation, Clinical Research Support at Uppsala University, German Federal Institute for Drugs and Medical Devices, Carlos III Spanish Health Institute, European Regional Development Fund, UK National Institute for Health Research, The Selander's Foundation, Thuréus Foundation, European Commission, and Science for Life Laboratory.