Prolonged response after TPO-RA discontinuation in primary ITP: results of a prospective multicenter study.

Sustained response off treatment (SROT) after thrombopoietin receptor agonist (TPO-RA) discontinuation has been reported in immune thrombocytopenia (ITP). This prospective multicenter interventional study enrolled adults with persistent or chronic primary ITP and complete response (CR) on TPO-RAs. The primary end point was the proportion of patients achieving SROT (platelet count >30 × 109/L and no bleeding) at week 24 (W24) with no other ITP-specific medications. Secondary end points included the proportion of sustained CR off-treatment (SCROT, platelet count >100 × 109/L and no bleeding) and SROT at W52, bleeding events, and pattern of response to a new course of TPO-RAs. We included 48 patients with a median age of 58.5 years; 30 of 48 had chronic ITP at TPO-RA initiation. In the intention-to-treat analysis, 27 of 48 achieved SROT, 15 of 48 achieved SCROT at W24; 25 of 48 achieved SROT, and 14 of 48 achieved SCROT at W52. No severe bleeding episode occurred in patients who relapsed. Among patients rechallenged with TPO-RA, 11 of 12 achieved CR. We found no significant clinical predictors of SROT at W24. Single-cell RNA sequencing revealed enrichment of a tumor necrosis factor α signaling via NF-κB signature in CD8+ T cells of patients with no sustained response after TPO-RA discontinuation, which was further confirmed by a significant overexpression of CD69 on CD8+ T cells at baseline in these patients as compared with those achieving SCROT/SROT. Our results strongly support a strategy based on progressive tapering and discontinuation of TPO-RAs for patients with chronic ITP who achieved a stable CR on treatment. This trial was registered at www.clinicaltrials.gov as #NCT03119974.

Risk of fractures and use of bisphosphonates in adult patients with immune thrombocytopenia-A nationwide population-based study.

Corticosteroids remain the first-line treatment of immune thrombocytopenia (ITP), but increase the risk of osteoporosis and fractures. Bisphosphonates are used for the treatment of osteoporosis, but their usage among patients with ITP has not been systemically described. We investigated the risk of fractures and the use of bisphosphonates in adult patients with primary (pITP) and secondary ITP (sITP) compared with matched comparators in a nationwide registry-based cohort study. We identified 4030 patients with pITP (median age 60 years [IQR, 40-74]), 550 with sITP (median age 59 years [IQR, 43-74]) and 182 939 age-sex-matched general population comparators. All individuals were followed for incident fractures. Bisphosphonate use was estimated for calendar-years and in temporal relation to the ITP diagnosis. Adjusted cause-specific hazard ratio (csHR) for any fracture was 1.37 (95% confidence interval [CI] 1.23; 1.54) for pITP and 1.54 (1.17; 2.03) for sITP. The first-year csHR was 1.82 (1.39; 2.40) for pITP and 2.78 (1.58; 4.91) for sITP. Bisphosphonate use over calendar-years and in the early years following ITP diagnosis was higher among patients with ITP diagnosis compared with the general population. In conclusion, the risk of fractures and the use of bisphosphonates are higher in patients with ITP compared with the general population.

Primary autoimmune haemolytic anaemia is associated with increased risk of ischaemic stroke: A binational cohort study from Denmark and France.

Primary autoimmune haemolytic anaemia (AIHA) causes the destruction of red blood cells and a subsequent pro-thrombotic state, potentially increasing the risk of ischaemic stroke. We investigated the risk of ischaemic stroke in patients with AIHA in a binational study. We used prospectively collected data from nationwide registers in Denmark and France to identify cohorts of patients with primary AIHA and age- and sex-matched general population comparators. We followed the patient and comparison cohorts for up to 5 years, with the first hospitalization of a stroke during follow-up as the main outcome. We estimated cumulative incidence, cause-specific hazard ratios (csHR) and adjusted for comorbidity and exposure to selected medications. The combined AIHA cohorts from both countries comprised 5994 patients and the 81 525 comparators. There were 130 ischaemic strokes in the AIHA cohort and 1821 among the comparators. Country-specific estimates were comparable, and the overall adjusted csHR was 1.36 [95% CI: 1.13-1.65], p = 0.001; the higher rate was limited to the first year after AIHA diagnosis (csHR 2.29 [95% CI: 1.77-2.97], p < 10-9 ) and decreased thereafter (csHR 0.89 [95% CI: 0.66-1.20], p = 0.45) (p-interaction < 10-5 ). The findings indicate that patients diagnosed with primary AIHA are at higher risk of ischaemic stroke in the first year after diagnosis.

Difficult-to-treat primary immune thrombocytopenia in adults: Prevalence and burden. Results from the CARMEN-France registry.

The aim of this study was to assess the prevalence and the burden of difficult-to-treat primary ITP (pITP), defined by the need for another ITP treatment after romiplostim and eltrombopag. Adult patients were selected in the prospective, real-world CARMEN-France registry up to December 2021. Out of 821 adult patients with pITP, 29 had difficult-to-treat ITP (3.5%; 95% confidence interval [CI]: 2.3%-4.8% in total; 7.6%; 95% CI: 4.9%-10.2% of patients needing ≥2nd line treatment). The 3-year cumulative incidence of bleeding, infection and thrombosis was 100%, 24.1% and 13.8% respectively. The median cumulative duration of hospital stays was 31 days (median follow-up: 30.3 months).

Risk of vaso-occlusive episode after exposure to corticosteroids in patients with sickle cell disease.

Vaso-occlusive episodes (VOEs) are a major concern in patients with sickle cell disease (SCD). Exposure to systemic corticosteroids has been suspected to increase the occurrence of VOEs in case reports or series. No comparative study has been conducted to investigate this risk, which is still debated. Several clinical trials demonstrated the effectiveness of corticosteroids for the treatment of VOEs, but with increased rates of readmission. The aim of the study was to assess the risk of hospitalization for VOE associated with exposure to systemic corticosteroids in patients with SCD. We used a case-case-time-control design in a nationwide population-based cohort built in the French national health insurance database between 2010 and 2018. The population included all patients with SCD with at least 1 hospitalization for VOE. Corticosteroids were identified using out-of-hospital dispensing data. The outcome was the first hospitalization for VOE. The case-case-time-control design induces self-adjustment for time-invariant confounders, including genotype. Analyses were adjusted for time-dependent confounders (infections, red blood transfusions) and stratified by exposure to hydroxyurea. Overall, 5151 patients were included in the main analysis. Corticosteroid exposure was significantly associated with the occurrence of hospitalizations for VOEs: adjusted odds ratio, 3.8; 95% confidence interval [CI], 2.4-5.6). In patients exposed to hydroxyurea, the adjusted odds ratio was 2.6 (95% CI, 1.1-6.4); it was 4.0 (95% CI, 2.5-6.3) in unexposed patients. These results were consistent in children and adults. In conclusion, systemic corticosteroids were associated to an increased risk of hospitalization for VOEs and should be limited in patients with SCD.

Markers of refractory primary immune thrombocytopenia.

Refractory immune thrombocytopenia (ITP) is a challenging disease that can be defined by refractoriness to second-line treatments. In this review, we list and comment available evidence about clinical and biological factors associated with refractoriness to splenectomy, thrombopoietin receptor agonists (TPO-RAs), rituximab and fostamatinib, as well as those associated with multirefractory ITP (active disease with failure of rituximab, TPO-RAs and splenectomy).

Clinical significance of antinuclear antibodies in primary immune thrombocytopenia.

There are discrepancies across guidelines about whether the dosage of antinuclear antibodies (ANAs) is of use at the diagnosis of primary immune thrombocytopenia (ITP). This review describes the current knowledge about ANA prevalence in patients with primary ITP, and their potential usefulness as biomarkers for ITP evolution, response to treatments and increased risk of subsequent development of systemic lupus and thrombosis.

Chronic refractory immune thrombocytopenia in adolescents and young adults.

Defining immune thrombocytopenia (ITP) in two age groups-children and adults-overlooks the specific clinical features and needs of adolescents and young adults (AYAS). We previously reported a high risk of chronic disease at 12 months (50%); however, data on the course of chronic ITP, the risk of refractoriness and treatment strategies in AYAS are limited. Data from patients aged 12-25 years with chronic primary ITP at 12 months were extracted from three large registries between 2004 and 2021. Clinical and laboratory data were evaluated until 48 months of follow-up (FU). Refractory ITP was defined as the administration of ≥3 different lines of therapy. A total of 427 AYAS (64% female) with chronic ITP were included. Overall, 7% and 14% were classified as 'refractory' at 12 and 48 months of FU respectively. The proportion of males was greater in the refractory group than in the non-refractory group (43% vs. 35%). AYAS with refractory disease displayed lower median platelet counts, more bleeding and a higher need for treatment at initial diagnosis and FU than non-refractory patients. This study reveals that refractory ITP is uncommon in AYAS; however, AYAS with refractory ITP display a high disease burden at all time points, including at initial diagnosis.

Combining thrombopoietin receptor agonists with immunosuppressive drugs in adult patients with multirefractory immune thrombocytopenia, an update on the French experience.

Combining drugs could be an effective option for treating multirefractory ITP, that is, patients not responding to rituximab, thrombopoietin receptor agonists (TPO-RA) and splenectomy. We conducted a retrospective, multicenter, observational study including multirefractory ITP patients who received a combination of a TPO-RA and an immunosuppressive drug. We included 39 patients (67% women, median age 59 years [range 21-96]), with a median ITP duration of 57 months [3-393] and a median platelet count at initiation of 10 × 109 /L [1-35]. The combination regimen was given for a median duration of 12 months [1-103] and included eltrombopag (51%) or romiplostim (49%), associated with mycophenolate mofetil (54%), azathioprine (36%), cyclophosphamide (5%), cyclosporin (3%) or everolimus (3%). Overall, 30 patients (77%) achieved at least a response (platelet count ≥30 × 109 /L and at least doubling baseline during at least 3 months), including 24 complete responses (platelet count >100 × 109 /L during at least 3 months) with a median time to response of 30 days [7-270] and a median duration of response of 15 months [4-63]. Severe adverse event related to ITP treatment was observed in 31%. In conclusion, this study confirms that some patients with multirefractory ITP can achieve long lasting response with this combination.

Adolescents and young adults with newly diagnosed primary immune thrombocytopenia.

Current immune thrombocytopenia (ITP) guidelines target children and adults, leading to oversimplification. Adolescents and young adults (AYAS) comprise a separate group with distinct health and psychosocial issues. This study aimed to describe the clinical presentation and therapeutic strategies of ITP among AYAS. We analyzed data from two large ITP registries (PARC-ITP; CARMEN-France) and included newly diagnosed ITP patients (aged 12-25 years) with an initial platelet counts of <100×109/L. Patients with secondary ITP or non-immune thrombocytopenia (n=57) and pregnant women (n=10) were excluded. Of the 656 cases of AYAS with primary ITP registered from 2004 up to 2021, 12-month follow-up data were available for 72%. The initial median platelet count was 12×109/L. In 109 patients (17%), the diagnosis was incidental, without documented bleeding. Apart from gynecological bleeding, the clinical and therapeutical characteristics of females and males were similar. Platelet-enhancing drugs were reported in 66%, 45%, and 30% of patients at diagnosis, 1-6 months, and 6-12 months after diagnosis, respectively. Corticosteroids were the preferred treatment at all time points. At 12 months, 50% of all patients developed chronic ITP. In the subgroup of patients with initial severe thrombocytopenia (<20×109/L), those receiving frontline treatment had a higher remission rate at 1 year than those who followed an initial watch-and-wait strategy (53% and 32%; P<0.05). Our analysis indicates that the remission rate at 1 year may be associated with the initial treatment strategy. This hypothesis must be confirmed in prospective studies.

Primary immune thrombocytopenia in very elderly patients: particularities in presentation and management: results from the prospective CARMEN-France Registry.

Data about the presentation and the management of primary immune thrombocytopenia (ITP) in very elderly patients (VEPs; aged ≥80 years) are lacking. The aim of the present study was to describe ITP in this subgroup. The data source was the prospective CARMEN-France registry. Patients included between 2013 and 2018 were selected. ITP presentation and management in VEPs was compared to elderly patients (EPs; aged 65-79 years). We assessed factors associated with bleeding at ITP onset in VEPs. Of 541 patients, 184 were included: 87 in the VEP group and 97 in the EP group. The mean age was 85·7 years in the VEP group. Comorbidities were more frequent in the VEP group (67·4% vs. 47·9%). The median platelet count at ITP onset was similar but severe bleeding tended to be more frequent in VEPs (10·3% vs. 4·1%, P = 0·1) as well as mortality. Exposure to ITP drugs, response to first-line treatment, need of second-line treatment, evolution towards persistency, occurrence of bleeding, infection and thrombosis did not differ between groups. In VEPs, factors associated to bleeding were female sex [odds ratio (OR) 4·75, 95% confidence interval (CI) 1·31-17·32] and platelet count of <20 × 109 /l (OR 10·05, 95% CI 4·83-67·39). Exposure to anticoagulants was strongly associated with severe bleeding (OR 7·61, 95% CI 1·77-32·83).

IgA vasculitis in patients with inflammatory bowel disease: new insights into the role of TNF-α blockers.

OBJECTIVE: The association of IgA vasculitis (IgAV) and IBD is rarely described, mainly during anti-TNF-α therapy. We aimed to describe the association of IgAV and IBD. METHODS: We retrospectively analysed the association of IgAV and IBD through the implication of the GETAID and FVSG networks. Characteristics of IBD and IgAV were collected using a standardized case report form. RESULTS: Forty-three cases were included. IBD [mainly Crohn's disease (CD) in 58%] preceded IgAV in 38 (88%), with median interval of 9.2 (IQR 5.4-15.4) years. In these 38 patients, at IgAV diagnosis, five (13%) had active IBD and 28 (74%) were treated with anti-TNF-α for a median duration of 31.5 (IQR 19-56) months. Main IgAV manifestations were purpura all patients (100%), joints in 20/35 (57%), renal in 15/35 (43%) and gastrointestinal in 11/35 (31%) involvement. IgAV was treated with glucocorticoids in 25 (66%), colchicine in six (16%), CYC in six (16%) and anti-TNF-α were discontinued in 15/28 (54%). No IgAV relapse occurred when TNF-α blockers were stopped, vs 23% in patients pursuing it. Conversely, five (33%) had IBD flare or complication after anti-TNF-α cessation vs one (8%) in those continuing biologics. Anti-TNF-α were resumed in six (40%), with subsequent IgAV relapse in four (67%). CONCLUSIONS: This large cohort suggests that TNF-α blockers may promote the onset of IgAV in IBD. Discontinuation of anti-TNF-α was associated with vasculitis remission but increased risk of IBD relapses, whereas continuation of anti-TNF-α was associated with IBD remission but vasculitis relapse.

Association between megakaryocyte abnormalities on bone marrow smear and response to thrombopoietin receptor agonists in adult patients with primary immune thrombocytopenia.

Impaired platelet production is a mechanism of immune thrombocytopenia (ITP). Morphological abnormalities of megakaryocytes (MKs) are sometimes observed in this disease. Two studies have suggested an association between MK abnormalities and response to corticosteroids in primary ITP, but none have investigated this association for thrombopoietin-receptor agonists (TPO-RAs). This was the aim of this study. The source of population was the French CARMEN registry with prospective follow-up of adult patients with incident ITP. We included patients with primary ITP, treated by TPO-RA and with a bone marrow smear before initiating TPO-RA. MK abnormalities were categorized by the presence of dysplasia and by the stage of maturation. Among 451 patients screened, 38 were included in the analysis. There was no difference in the median percentage of dysplastic MKs between responders to TPO-RA (4.0%, 95% confidence interval - CI: 2.3-6.4) and non-responders (4.5%, 95% CI: 0.7-7.1). There was a slightly higher proportion of granular MKs (4.5%, 95% CI: 3-6) and basophilic MKs (30.1%, 95% CI: 21.9-39.1) in non-responders compared to responders (granular: 2.0%, 95% CI: 0-4.1; basophilic: 21.3%, 95% CI: 11.4-40.7). In conclusion, MK abnormalities were not associated with response achievement in ITP patients treated with TPO-RA in this series of 38 patients.

Risk factors of hospitalisation for thrombosis in adults with primary immune thrombocytopenia, including disease-specific treatments: a French nationwide cohort study.

We aimed to assess the risk factors of venous thrombosis (VT) and arterial thrombosis (AT) in adults with primary immune thrombocytopenia (ITP), particularly in relation to treatments. The population comprised all incident primary ITP adults in France between 2009 and 2017 (FAITH cohort; NCT03429660) built in the national health database. Outcomes were the first hospitalisation for VT and AT. Multivariable Cox regression models included baseline risk factors, time-varying exposure to ITP drugs, splenectomy and to cardiovascular drugs. The cohort included 10 039 patients. A higher risk of hospitalisation for VT was observed with older age, history of VT, history of cancer, splenectomy [hazard ratio (HR) 3·23, 95% confidence interval (CI) 2·26-4·61], exposure to corticosteroids (HR 3·55, 95% CI 2·74-4·58), thrombopoietin-receptor agonists (TPO-RAs; HR 2·28, 95% CI 1·59-3·26) and intravenous immunoglobulin (IVIg; HR 2·10, 95% CI 1·43-3·06). A higher risk of hospitalisation for AT was observed with older age, male sex, a history of cardiovascular disease, splenectomy (HR 1·50, 95% CI 1·12-2·03), exposure to IVIg (HR 1·85, 95% CI 1·36-2·52) and TPO-RAs (HR 1·64, 95% CI 1·26-2·13). Rituximab was not associated with an increased risk. These findings help to estimate the risk of thrombosis in adult patients with ITP and to select treatment.

Impact of aging on phenotype and prognosis in IgA vasculitis.

OBJECTIVES: Immunoglobulin A vasculitis (IgAV) is a small-vessel vasculitis most frequently benign in children while more severe in adults. We aimed to study the impact of age on presentation and outcome of adult IgAV. METHODS: We conducted a nationwide retrospective study including 260 IgAV patients. Patients were divided into four quartiles according to the age at IgAV diagnosis: <36, 36 ≤ age < 52; 52 ≤ age < 63 and ≥63 years. Comparison of presentation and outcome were performed according to age of disease onset. RESULTS: Mean age at diagnosis was 50.1 (18) years and 63% were male. IgAV diagnosed in the lowest quartile of age was associated with more frequent joint (P < 0.0001) and gastrointestinal involvement (P = 0.001). In contrast, the oldest patients had more severe purpura with necrotic lesions (P = 0.001) and more frequent renal involvement (P < 0.0001), with more frequent haematuria, renal failure, higher urine protein excretion and more frequent tubulointerstitial lesions. Patients were treated similarly in all groups of age, and clinical response and relapse rates were similar between groups. In the 127 treated patients with follow-up data for >6 months, clinical response and relapse rates were similar between the four groups. Median follow-up was of 17.2 months (9.1-38.3 months). Renal failure at the end of follow-up was significantly more frequent in the highest quartile of age (P = 0.02), but the occurrence of end-stage renal disease was similar in all groups. Last, overall and IgAV-related deaths were associated with increase in age. CONCLUSION: Aging negatively impacts the severity and outcome of IgAV in adults. Younger patients have more frequent joint and gastrointestinal involvement, while old patients display more frequent severe purpura and glomerulonephritis.

Clinical spectrum, outcome and management of immune thrombocytopenia associated with myelodysplastic syndromes and chronic myelomonocytic leukemia.

Myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML) are associated with systemic inflammatory or autoimmune diseases in 10-20 % of cases. Among them, immune thrombocytopenia (ITP) has been reported but large studies assessing this association are missing. Whether such patients have a particular phenotype and require particular management is unclear. This study analyzes the clinical spectrum, outcome and therapeutic management of patients with ITP associated with MDS or CMML, in comparison (i) to patients with primary ITP without MDS/CMML and (ii) to patients with MDS/CMML without ITP. Forty-one MDS/CMML-associated ITP patients were included, with chronic ITP in 26 (63%) patients, low-risk myelodysplasia in 30 (73%) patients and CMML in 24 (59%) patients. An associated autoimmune disease was noted in 10 (24%) patients. In comparison to primary ITP patients, MDS/CMML-associated ITP patients had a higher occurrence of severe bleeding despite similar platelet counts at diagnosis. First-line treatment consisted of glucocorticoids (98%) and intravenous immunoglobulin (IVIg) (56%). Response achievement with IVIg was more frequent in primary ITP than in MDS/CMML-associated ITP patients. Response rates to second-line therapies were not statistically different between primary ITP and MDS/CMMLassociated ITP patients. Ten percent (n=4) of patients with MDS/CMML-associated ITP had multirefractory ITP versus none in primary ITP controls. After a median follow-up of 60 months, there was no difference in overall survival between MDS/CMML-associated ITP and primary ITP patients. Leukemia-free-survival was significantly better in MDS/CMMLassociated ITP patients than in MDS/CMML without ITP MDS/CMML-associated ITP have a particular outcome with more severe bleeding and multirefractory profile than primary ITP, similar response profile to primary ITP therapy except for IVIg, and less progression toward acute myeloid leukemia than MDS/CMML without ITP.

High rate of indeterminate results of the QuantiFERON-TB Gold in-tube test, third generation, in patients with systemic vasculitis.

OBJECTIVES: To describe the frequency of QuantiFERON-TB Gold in-tube test® (QFT-GIT) indeterminate results due to no response to phytohaemagglutinin A stimulation in the control tube in vasculitis patients prior to immunosuppressant therapy; and to compare it with other groups of patients. METHODS: This was a single-centre, retrospective study. Patients and controls were included between 1 January 2008 and 31 December 2015. We assessed the rate of indeterminate results of the QFT-GIT in 38 patients with systemic vasculitis prior to any corticosteroid or immunosuppressant therapy, compared with 40 non-vasculitis patients with biological inflammatory syndrome, and 310 non-immunosuppressed patients matched for gender and age. RESULTS: Indeterminate results due to no response to phytohaemagglutinin A were more frequent in vasculitis patients (21.1%) compared with non-vasculitis patients with biological inflammatory syndrome (7.5%) (Fisher's exact test: P = 0.11) and to anonymized controls (7%) (P = 0.009). Responses to phytohaemagglutinin A were significantly lower in vasculitis patients compared with other groups (Kruskal-Wallis test: P < 0.0001) and compared with non-vasculitis patients with biological inflammatory syndrome (P = 0.0015). The multivariable analysis identified as independent predictors of an indeterminate result of the QFT-GIT: the presence of systemic vasculitis (odds ratio 9.64 [1.14-81.3], P = 0.037) and a high neutrophil-to-lymphocyte ratio (odds ratio 1.70 [1.21-2.37], P = 0.002). One patient with an indeterminate result of QFT-GIT developed active tuberculosis after one year of corticosteroid therapy for giant cell arteritis. CONCLUSION: Our results question the reliability of QFT-GIT to rule out latent tuberculosis in vasculitis patients at diagnosis, prior to immunosuppressant therapy.

Gastrointestinal involvement in adult IgA vasculitis (Henoch-Schönlein purpura): updated picture from a French multicentre and retrospective series of 260 cases.

OBJECTIVES: To describe the clinical presentation, treatments and prognosis of gastrointestinal (GI) involvement in adult IgA vasculitis (IgAV). METHODS: Data from 260 adults with IgAV included in a French multicentre retrospective survey were analysed. Presentation and outcomes of patients with (GI+) and without (GI-) GI involvement were compared. RESULTS: One hundred and thirty-seven (53%) patients had GI involvement. Initial manifestations were abdominal pain in 99%, intestinal bleeding in 31%, diarrhoea in 26% and acute surgical abdomen in only 4%. Abdominal imaging revealed thickening of intestinal wall in 61%, and endoscopies revealed abnormalities in 87%, mostly mucosal ulcerations. GI+ vs GI- patients were younger (46 ± 18 vs 54 ± 18 years; P = 0.0004), had more constitutional symptoms (43% vs 23%; P = 0.0005) and joint involvement (72 vs 50%; P = 0.0002), and higher CRP levels (3.7 vs 1.9 mg/dl; P = 0.001). Clinical response and relapse rates were comparable between groups, and all causes mortality (2 vs 4%) and IgAV-related mortality (1% vs 2%) as well. GI-related deaths were due to intestinal perforation and mesenteric ischaemia. CONCLUSION: GI involvement is frequent in adult IgAV. GI involvement is frequent in adult IgAV. Mortality is not uncommon but does not seem to be specifically related to GI. Immunosuppressants should not be preferred as first-line therapy for GI+ patients but may be required in case of acute surgical abdomen.

Platelet counts of adults upon acute hospital admission to internal medicine units are a predictor of mortality.

The objective of this cohort study was to examine the association between platelet counts upon acute hospitalization and mortality. The study included all adults in North and Central Denmark Regions with a first acute admission to an internal medicine unit during 2006-2012, categorized by first platelet count within +/-24 hours of admission. We assessed the association between platelet count and in-hospital, 30-day, 90-day, and 365-day mortality using age- and sex-adjusted Cox models. We also stratified analyses by presence/absence of comorbidity and performed additional analyses restricted to patients with a primary discharge diagnosis of cardiovascular disease or infection. Among the 274,148 study patients, the 1-year mortality was 12.6%. The association between platelet count and mortality took the form of an asymmetric U-shaped curve. For 30-day mortality, hazard ratios (HRs) were 5.24 (95% CI: 4.60-5.97) for platelet count < 50 × 109/L and 2.50 (95% CI: 2.33-2.69) for platelet count ≥ 500 × 109/L, compared with a normal platelet count (150-400 × 109/L). A slightly increased risk of mortality was observed for platelet counts < 200 × 109/L and ≥ 250 × 109/L. A similar pattern was observed for 30-day, 90-day, and 365-day mortality and in all subgroups except patients with a primary discharge diagnosis of infection. In this case, patients with a platelet count between 150 × 109/L and 199 × 109/L had the lowest mortality. Platelet counts in adults upon acute hospital admission to internal medicine units, including counts within the normal range, are a predictor of mortality.