Outcome of Referrals for Non-Responsive Celiac Disease in a Tertiary Center: Low Incidence of Refractory Celiac Disease in the Netherlands.

OBJECTIVES: Refractory celiac disease (RCD) is a severe cause of non-responsive celiac disease (CD) due to its association with the enteropathy associated T-cell lymphoma (EATL). Conflicting data exist on the prevalence and the clinical manifestations of RCD type I (RCD I) and type II (RCD II). The aim of the current study was to provide insight in the incidence of RCD and in the distinction with other causes of non-responsive CD. METHODS: A total of 106 CD patients were referred to our tertiary referral center between January 2006 and December 2011 for evaluation of non-responsive CD. In addition, a questionnaire was sent to all 82 gastroenterology departments in the Netherlands to reveal whether a patient with RCD was currently being evaluated or had been treated between 2006 and 2012. RESULTS: During a 6 year period, a total of 31 patients were diagnosed with RCD (19 RCD I and 12 RCD II). The nationwide survey revealed 5 additional patients with RCD I and one patient with RCD II. This leads to an annual incidence of RCD of 0.83/10.000 CD patients. The remaining patients were diagnosed with involuntary gluten ingestion (21.7%), delayed mucosal recovery (11.3%), enteropathy associated T-cell lymphoma (7.5%) and autoimmune enteropathy (1.8%). CONCLUSIONS: This nationwide study reveals a low incidence of RCD in the Netherlands. Nevertheless, RCD is a clinically relevant disease entity in CD patients non-responsive to the gluten-free diet.

Ageing and obesity similarly impair antibody responses.

Ageing is characterized by increased low-grade chronic inflammation, which is a significant risk factor for morbidity and mortality of elderly individuals. Similar to ageing, obesity is considered to be an inflammatory predisposition associated with chronic activation of immune cells and consequent local and systemic inflammation. Both ageing and obesity are characterized by reduced innate and adaptive immune responses. This review focuses on B cells, how they may contribute, at least locally, to low-grade chronic inflammation in ageing and obesity and on the mechanisms involved.

Immunostimulatory capacity of dental casting alloys on endotoxin responsiveness.

STATEMENT OF PROBLEM: Oral metal exposure has been associated with systemic and local adverse reactions, probably due to elemental release from the alloys. Although supraphysiological concentrations of salts from dentally applied metals can activate innate cells through TLR4 (Ni, Co, Pd) and TLR3 (Au), whether direct exposure to solid alloys can also trigger innate immune reactivity is still unknown. PURPOSE: The purpose of this in vitro study was to determine whether dental cast alloy specimens can activate innate cells and influence their responsiveness to bacterial endotoxin. MATERIAL AND METHODS: Human monocyte-derived dendritic cells (MoDC) and THP-1 cells were cultured on top of different alloy specimens (Ni-Cr, Co-Cr, Pd-Cu, Pd-Ag, Ti-6Al-4V, amalgam, gold, and stainless steel) or in alloy-exposed culture medium with or without endotoxin (lipopolysaccharide [LPS]; Escherichia coli 055:B5). Interleukin-8 (IL-8) production was used as the parameter for innate stimulation and evaluated by enzyme-linked immunosorbent assay after 24 hours of culture. The statistical significance of the effects of various casting alloys on the secretion of IL-8 was analyzed by using the nonparametric Wilcoxon rank sum test (α=.05). RESULTS: Dental cast alloys induced IL-8 production in MoDC and THP-1 cells, with Au and Pd-Cu providing the strongest stimulation. The alloy-exposed culture media tested contained sufficient stimulatory metal ions to induce detectable IL-8 production in THP-1 cells, except for the Ni-Cr and stainless steel exposed media. Au and Pd-Cu alloys were also most effective in potentiating LPS responsiveness as measured by IL-8 production. CONCLUSIONS: Using an in vitro culture system to expose MoDC and THP-1 cells to different alloy specimens this study showed that contact with the solid alloys, in particular when they contain Pd or Au, can trigger innate immune responses and augment responsiveness to bacterial endotoxin.

Multidrug-resistant tuberculosis in Norway: a nationwide study, 1995-2014.

SETTING: The management of multidrug-resistant tuberculosis (MDR-TB) is strictly regulated in Norway. However, nationwide studies of the epidemic are lacking. OBJECTIVE: To describe the MDR-TB epidemic in Norway over two decades. DESIGN: Retrospective analysis of data on MDR-TB cases in Norway, 1995-2014, obtained from the national registry, patient records and the reference laboratory, with genotyping and cluster analysis data. Data for non-MDR-TB cases were collected from the national registry. RESULTS: Of 4427 TB cases, 89 (2.0%) had MDR-TB, 7% of whom had extensively drug-resistant TB (XDR-TB) and 24% pre-XDR-TB. Of the 89 MDR-TB cases, 96% were immigrants, mainly from the Horn of Africa or the former Soviet Union (FSU); 37% had smear-positive TB; and 4% were human immunodeficiency virus co-infected. Of the 19% infected in Norway, the majority belonged to a Delhi/Central Asian lineage cluster in a local Somali community. Among the MDR-TB cases, smear-positive TB and FSU origin were independent risk factors for XDR/pre-XDR-TB. Treatment was successful in 66%; 17% were lost to follow-up, with illicit drug use and adolescence being independent risk factors. Forty-four per cent of patients treated with linezolid discontinued treatment due to adverse effects. CONCLUSION: MDR-TB is rare in Norway and is predominantly seen in immigrants from the Horn of Africa and FSU. Domestic transmission outside immigrant populations is minimal.

Metal ions potentiate microglia responsiveness to endotoxin.

Oral metal exposure has been associated with diverse adverse reactions, including neurotoxicity. We showed previously that dentally applied metals activate dendritic cells (MoDC) via TLR4 (Ni, Co, Pd) and TLR3 (Au). It is still unknown whether the low levels of dental metals reaching the brain can trigger local innate cells or prime them to become more responsive. Here we tested whether dentally applied metals (Cr, Fe, Co, Ni, Cu, Zn, Au, Hg) activate primary human microglia in vitro and, as a model, monocytic THP-1-cells, in high non-toxic as well as near-physiological concentrations. In addition the effects of 'near-physiological' metal exposure on endotoxin (LPS) responsiveness of these cells were evaluated. IL-8 and IL-6 production after 24h was used as read out. In high, non-toxic concentrations all transition metals except Cr induced IL-8 and IL-6 production in microglia, with Ni and Co providing the strongest stimulation. When using near-physiological doses (up to 10× the normal plasma concentration), only Zn and Cu induced significant IL-8 production. Of note, the latter metals also markedly potentiated LPS responsiveness of microglia and THP-1 cells. In conclusion, transition metals activate microglia similar to MoDCs. In near-physiological concentrations Zn and Cu are the most effective mediators of innate immune activation. A clear synergism between innate responses to Zn/Cu and LPS was observed, shedding new light on the possible relation between oral metal exposure and neurotoxicity.

Dental metal-induced innate reactivity in keratinocytes.

Gold, nickel, copper and mercury, i.e. four metals frequently used in dental applications, were explored for their capacity to induce innate immune activation in keratinocytes (KC). Due to their anatomical location the latter epithelial cells are key in primary local irritative responses of skin and mucosa. Fresh foreskin-derived keratinocytes and skin and gingiva KC cell lines were studied for IL-8 release as a most sensitive parameter for NF-kB activation. First, we verified that viral-defense mediating TLR3 is a key innate immune receptor in both skin- and mucosa derived keratinocytes. Second, we found that, in line with our earlier finding that ionized gold can mimic viral dsRNA in triggering TLR3, gold is very effective in KC activation. It would appear that epithelial TLR3 can play a key role in both skin- and mucosa localized irritation reactivities to gold. Subsequently we found that not only gold, but also nickel, copper and mercury salts can activate innate immune reactivity in keratinocytes, although the pathways involved remain unclear. Although current alloys have been optimized for minimal leakage of metal ions, secondary factors such as mechanical friction and acidity may still facilitate such leakage. Subsequently, these metal ions may create local irritation, itching and swelling by triggering innate immune reactions, potentially also facilitating the development of metal specific adaptive immunity.

Serological Screening for Celiac Disease in Adult Chinese Patients With Diarrhea Predominant Irritable Bowel Syndrome.

Celiac disease (CD) is common in Caucasians, but thought to be rare in Asians. Our aim was to determine the prevalence of CD in Chinese patients with chronic diarrhea predominant irritable bowel syndrome (IBS-D).From July 2010 to August 2012, 395 adult patients with IBS-D and 363 age and sex-matched healthy controls were recruited in Zhongnan Hospital of Wuhan University and Xiaogan Central Hospital in Hubei province, central China. Patients with IBS-D were diagnosed according to the Rome III criteria. Serum Immunoglobulin (IgA/IgG) anti-human tissue transglutaminase (anti-htTG)-deamidated gliadin peptide (DGP) antibodies were measured in a single ELISA (QUANTA Lite h-tTG/DGP Screen). Upper endoscopy with duodenal biopsies and HLA-DQA1 and HLA-DQB1 genotyping were performed in seropositive subjects and a gluten-free diet was prescribed.Seven IBS-D patients (7/395, 1.77%) and 2 healthy controls (2/363, 0.55%), were positive for anti-htTG/DGP antibodies. Of these 9 cases, 1 was lost to follow-up, 3 were suspected to have CD and 5 were eventually diagnosed as CD with intestinal histological lesions classified as Marsh Type II in 2 and Type III in 3. Of these 5 diagnosed CD patients, 4 (4/395, 1.01%) were from the IBS-D group and 1 (1/363, 0.28%) from the healthy control had asymptomatic CD. Two Type III CD patients with relatively high titers in the serologic assay were homozygous and heterozygous for haplotype HLA-DQA1*03-DQB1*03:03 (HLA-DQ9.3), respectively.In the present study, CD was present in 1.01% of patients with IBS-D and in 0.28% of the control group. We like to suggest that the haplotype HLA-DQA1*03-DQB1*03:03 (HLA-DQ9.3), which is common in Chinese, is a new susceptibility factor for CD in China. Larger screening and genetic studies are needed in the Chinese population of different regions.

Continuing the quest for autoimmunity due to oral metal exposure.

AIM: The role of metal exposure in the development of autoimmune disease (AID) is still controversial. Here, we studied the relationship between oral metal exposure, metal allergy and autoimmunity. METHODS: A mixed population (n = 78) of non-allergic volunteers, metal-allergic patients and patients with oral problems putatively due to metal alloys was evaluated for oral Ni, Pd, Au and Hg exposure and skin hypersensitivity. Clinical autoimmune parameters were based on medical histories; additionally, serum levels of the four most common autoantibodies were measured. RESULTS: Skin hypersensitivity, as seen mainly for Ni and/or Pd, was not positively associated with autoimmune parameters. In contrast, metal hypersensitive individuals showed an extremely low frequency of thyroid autoantibodies (3% vs 20% in non-hypersensitive controls). Next, the relation between metal exposure and autoimmunity was evaluated in individuals >35 years (n = 58), since from that age on metal exposure had plateaued and was not correlated with age. In this subgroup, oral Ni exposure was associated (p < 0.01) with self-reported AID, irrespective of autoantibody levels. These unexpected findings warrant further confirmation in a larger test group. Of note, oral Pd, Au or Hg contacts were not associated with any of the clinical or serological autoimmune phenomena tested. CONCLUSION: The results of this study support the view that development of metal contact allergies may prevent autoimmune activation, and, second, that oral exposure to Pd, Au or Hg does not facilitate the development of AID.

Innate stimulatory capacity of high molecular weight transition metals Au (gold) and Hg (mercury).

Nickel, cobalt and palladium ions can induce an innate immune response by triggering Toll-like receptor (TLR)-4 which is present on dendritic cells (DC). Here we studied mechanisms of action for DC immunotoxicity to gold and mercury. Next to gold (Na3Au (S2O3)2⋅2H2O) and mercury (HgCl2), nickel (NiCl2) was included as a positive control. MoDC activation was assessed by release of the pro-inflammatory mediator IL-8. Also PBMC were studied, and THP-1 cells were used as a substitution for DC for evaluation of cytokines and chemokines, as well as phenotypic, alterations in response to gold and mercury. Our results showed that both Na3Au (S2O3)2⋅2H2O and HgCl2 induce substantial release of IL-8, but not IL-6, CCL2 or IL-10, from MoDc, PBMC, or THP-1 cells. Also gold and, to a lesser extent mercury, caused modest dendritic cell maturation as detected by increased membrane expression of CD40 and CD80. Both metals thus show innate immune response capacities, although to a lower extent than reported earlier for NiCl2, CoCl2 and Na2 [PdCl4]. Importantly, the gold-induced response could be ascribed to TLR3 rather than TLR4 triggering, whereas the nature of the innate mercury response remains to be clarified. In conclusion both gold and mercury can induce innate immune responses, which for gold could be ascribed to TLR3 dependent signalling. These responses are likely to contribute to adaptive immune responses to these metals, as reflected by skin and mucosal allergies.

Optimal strategies to identify aberrant intra-epithelial lymphocytes in refractory coeliac disease.

INTRODUCTION: Different strategies have been developed to identify those refractory celiac disease (RCD) patients who are at risk to develop an enteropathy associated T-cell lymphoma (EATL). Flow cytometric analysis of intra-epithelial lymphocytes (IEL) with an aberrant phenotype is considered the golden standard but is not widely available. Immunohistochemistry (IHC) and T-cell receptor (TCR) rearrangement studies are commonly available but may lack sensitivity and specificity. Here, we compared the three different methods in the workup of patients suspected for RCD. METHODS: Duodenal biopsies from control patient (n = 5), RCD patients with moderately increased aberrant IEL populations (20-50 %: n = 14), and RCD patients with high numbers of aberrant IEL (>50 %: n = 5) as determined by flow cytometry were analysed by IHC and TCR-γ chain rearrangement analysis. Three pathologists scored the slides independently. RESULTS: Sensitivity of IHC and TCR-γ rearrangement analysis in RCD patients with high numbers of aberrant IELs was 100 and 71 %, respectively. RCD patients with aberrant cells between 25 and 50 % however, were missed by IHC and TCR in 50 and 57 % of cases, respectively. In addition, inter-rater reliability analysis of the IHC scoring revealed coder-pair Kappa coefficients between 0.28 and 0.85. CONCLUSION: Immunohistochemistry and to a lesser extent TCR-γ clonality analysis are sensitive in identifying patients with high numbers of aberrant IEL populations, yet miss half of RCD patients with moderately increased numbers. In addition, IHC has a high inter-observer variability. Therefore, patients suspected for RCD should undergo flow cytometric analysis of the duodenum.

Increased IgA glycoprotein-2 specific antibody titres in refractory celiac disease.

BACKGROUND & AIMS: In most cases celiac disease (CD) is successfully treated with a gluten-free diet (GFD). However, some patients become refractory to the GFD. Refractory CD (RCD) patients have an increased risk for developing enteropathy associated T-cell lymphoma and early diagnosis is therefore of importance. Currently, RCD diagnosis relies on endoscopy and adequate serological markers are lacking. Antibodies against glycoprotein-2 (GP2A) were described in Crohn's disease (CrD) and active CD but not in ulcerative colitis (UC), suggesting this is a specific marker for small intestinal lesions. METHODS: Sera obtained from patients visiting our outpatient clinic for routine serological tests for diagnosis and/or follow-up of inflammatory bowel disease (n=78), active CD (n=45), GFD (n=34) and RCD (n=15) were analysed for GP2A titres. RESULTS: Increased GP2A-IgA levels in CrD and active CD as compared to controls (p<0.001) and lack thereof in UC was confirmed. However, we could not confirm the association with small bowel localization within the CrD patient group. Within CD patients, we demonstrated a significant decrease of GP2A-IgA titres upon a GFD and increased levels in RCD patients as compared to patients on a GFD. Although GP2A-IgA was not associated with the degree of villous atrophy, GP2A-IgA levels were able to distinguish RCD patients from GFD patients (ROC AUC=0.79, p=0.002). CONCLUSION: Follow-up of GP2A-IgA titres in CD patients on a GFD may help to identify patients at risk for developing RCD.

Serum autoantibodies directed against transglutaminase-2 have a low avidity compared with alloantibodies against gliadin in coeliac disease.

Coeliac disease is characterized by intolerance to gliadin and related gluten components present in wheat, barley and rye. Coeliac disease patients harbour antibodies directed against alloantigens such as gliadin, but also against the autoantigen transglutaminase-2 (TG2). The type and quality of antibody responses provides insight into the underlying immune activation processes. Therefore, in this study we have analysed the avidity of the antibody response directed against the autoantigen TG2 and compared this with antibody responses against the alloantigens gliadin and Escherichia coli. We observed that the immunoglobulin (Ig)A autoantibody response directed against TG2 is of low avidity compared with the IgA response against the alloantigens gliadin and E. coli in the same patients; the same was true for IgG, both in IgA-deficient and in -sufficient coeliac patients. The observed avidities appear not to be related to disease stage, antibody levels, age or duration of exposure to gluten. In conclusion, in coeliac disease there is a clear difference in avidity of the antibody responses directed against the auto- and alloantigens, indicating different regulation or site of initiation of these responses.

Consumption of gluten with gluten-degrading enzyme by celiac patients: a pilot-study.

AIM: To assesses the safety and efficacy of Aspergillus niger prolyl endoprotease (AN-PEP) to mitigate the immunogenic effects of gluten in celiac patients. METHODS: Patients with initial diagnosis of celiac disease as confirmed by positive serology with subtotal or total villous atrophy on duodenal biopsies who adhere to a strict gluten-free diet (GFD) resulting in normalised antibodies and mucosal healing classified as Marsh 0 or I were included. In a randomised double-blind placebo-controlled pilot study, patients consumed toast (approximately 7 g/d gluten) with AN-PEP for 2 wk (safety phase). After a 2-wk washout period with adherence of the usual GFD, 14 patients were randomised to gluten intake with either AN-PEP or placebo for 2 wk (efficacy phase). Measurements at baseline included complaints, quality-of-life, serum antibodies, immunophenotyping of T-cells and duodenal mucosa immunohistology. Furthermore, serum and quality of life questionnaires were collected during and after the safety, washout and efficacy phase. Duodenal biopsies were collected after the safety phase and after the efficacy phase. A change in histological evaluation according to the modified Marsh classification was the primary endpoint. RESULTS: In total, 16 adults were enrolled in the study. No serious adverse events occurred during the trial and no patients withdrew during the trial. The mean score for the gastrointestinal subcategory of the celiac disease quality (CDQ) was relatively high throughout the study, indicating that AN-PEP was well tolerated. In the efficacy phase, the CDQ scores of patients consuming gluten with placebo or gluten with AN-PEP did not significantly deteriorate and moreover no differences between the groups were observed. During the efficacy phase, neither the placebo nor the AN-PEP group developed significant antibody titers. The IgA-EM concentrations remained negative in both groups. Two patients were excluded from entering the efficacy phase as their mucosa showed an increase of two Marsh steps after the safety phase, yet with undetectable serum antibodies, while 14 patients were considered histologically stable on gluten with AN-PEP. Also after the efficacy phase, no significant deterioration was observed regarding immunohistological and flow cytometric evaluation in the group consuming placebo compared to the group receiving AN-PEP. Furthermore, IgA-tTG deposit staining increased after 2 wk of gluten compared to baseline in four out of seven patients on placebo. In the seven patients receiving AN-PEP, one patient showed increased and one showed decreased IgA-tTG deposits. CONCLUSION: AN-PEP appears to be well tolerated. However, the primary endpoint was not met due to lack of clinical deterioration upon placebo, impeding an effect of AN-PEP.

Complete versus partial fundoplication in children with gastroesophageal reflux disease: results of a systematic review and meta-analysis.

Complete fundoplication (Nissen) has long been accepted as the gold standard surgical procedure in children with therapy-resistant gastroesophageal reflux disease (GERD); however, increasingly more evidence has become available for partial fundoplication as an alternative. The aim of this study was to perform a systematic review and meta-analysis comparing complete versus partial fundoplication in children with therapy-resistant GERD. PubMed (1960 to 2011), EMBASE (from 1980 to 2011), and the Cochrane Library (issue 3, 2011) were systematically searched according to the PRISMA statement. Results were pooled in meta-analyses and expressed as risk ratios (RRs). In total, eight original trials comparing complete to partial fundoplication were identified. Seven of these studies had a retrospective study design. Short-term (RR 0.64; p = 0.28) and long-term (RR 0.85; p = 0.42) postoperative reflux control was similar for complete and partial fundoplication. Complete fundoplication required significantly more endoscopic dilatations for severe dysphagia (RR 7.26; p = 0.007) than partial fundoplication. This systematic review and meta-analysis showed that reflux control is similar after both complete and partial fundoplication, while partial fundoplication significantly reduces the number of dilatations to treat severe dysphagia. However, because of the lack of a well-designed study, we have to be cautious in making definitive conclusions. To decide which type of fundoplication is the best practice in pediatric GERD patients, more randomized controlled trials comparing complete to partial fundoplication in children with GERD are warranted.

Transition metal sensing by Toll-like receptor-4: next to nickel, cobalt and palladium are potent human dendritic cell stimulators.

BACKGROUND: Nickel was recently identified as a potent activator of dendritic cells through ligating with human Toll-like receptor (TLR)-4. OBJECTIVES: Here, we studied an extended panel of transition metals neighbouring nickel in the periodic table of elements, for their capacity to activate human monocyte-derived dendritic cells (MoDCs). METHODS: The panel included chromium, cobalt, and palladium, all of which are known to be frequent clinical sensitizers. MoDC activation was monitored by assessment of release of the pro-inflammatory mediator interleukin (IL)-8, a major downstream result of TLR ligation. Results The data obtained in the present study show that cobalt and palladium also have potent MoDC-activating capacities, whereas copper and zinc, but not iron and chromium, have low but distinct MoDC-activating potential. Involvement of endotoxin contamination in MoDC activation was excluded by Limulus assays and consistent stimulation in the presence of polymyxin B. The critical role of TLR4 in nickel-induced, cobalt-induced and palladium-induced activation was confirmed by essentially similar stimulatory patterns obtained in an HEK293 TLR4/MD2 transfectant cell line. CONCLUSIONS: Given the adjuvant role of costimulatory danger signals, the development of contact allergies to the stimulatory metals may be facilitated by signals from direct TLR4 ligation, whereas other metal sensitizers, such as chromium, may rather depend on microbial or tissue-derived cofactors to induce clinical sensitization.

Differential IL-13 production by small intestinal leukocytes in active coeliac disease versus refractory coeliac disease.

A small fraction of coeliac disease (CD) patients have persistent villous atrophy despite strict adherence to a gluten-free diet. Some of these refractory CD (RCD) patients develop a clonal expansion of lymphocytes with an aberrant phenotype, referred to as RCD type II (RCDII). Pathogenesis of active CD (ACD) has been shown to be related to gluten-specific immunity whereas the disease is no longer gluten driven in RCD. We therefore hypothesized that the immune response is differentially regulated by cytokines in ACD versus RCDII and investigated mucosal cytokine release after polyclonal stimulation of isolated mucosal lymphocytes. Secretion of the T(H)2 cytokine IL-13 was significantly higher in lamina propria leukocytes (LPLs) isolated from RCDII patients as compared to LPL from ACD patients (P = 0.05). In patients successfully treated with a gluten-free diet LPL-derived IL-13 production was also higher as compared to ACD patients (P = 0.02). IL-13 secretion correlated with other T(H)2 as well as T(H)1 cytokines but not with IL-10 secretion. Overall, the cytokine production pattern of LPL in RCDII showed more similarities with LPL isolated from GFD patients than from ACD patients. Our data suggest that different immunological processes are involved in RCDII and ACD with a potential role for IL-13.

A prospective longitudinal study on endocrine dysfunction following treatment of laryngeal or hypopharyngeal carcinoma.

OBJECTIVES: The incidences of hypo(para)thyroidism were assessed prospectively in 137 consecutive patients with laryngeal (84.7%) or hypopharyngeal (15.3%) carcinoma who were treated with surgery and/or radiotherapy between 2004 and 2006. MATERIAL AND METHODS: Laboratory studies were performed in patients before primary or salvage treatment of a laryngeal or hypopharyngeal carcinoma and were repeated 6, 12, 18 and 24months after treatment. All patients were evaluated for the development of hypo(para)thyroidism, and the presence of autoantibodies. The association of hypothyroidism was analyzed against several patient parameters including tumor and treatment characteristics. RESULTS: The incidence of hypothyroidism following treatment of laryngeal and hypopharyngeal carcinoma was 47.4%: 27.7% subclinical hypothyroidism and 19.7% clinical hypothyroidism. The median time to develop hypothyroidism was 10months. The incidence of hypoparathyroidism was 7.3%. Univariate analysis showed that patients with laryngectomy, hemithyroidectomy, neck dissection, paratracheal lymph node dissection and radiotherapy had a higher risk of developing hypothyroidism. Multivariate analysis showed laryngectomy, hemithyroidectomy, neck dissection and age to be predictive factors for the development of hypothyroidism. The combination of surgery and radiotherapy increased this risk. Hemithyroidectomy was the most important risk factor. CONCLUSION: The incidence rate of hypothyroidism after treatment for laryngeal or hypopharyngeal cancer in this largest prospective study is high (47.4%), especially after combination treatment. Based on the intervals between treatment and the development of hypothyroidism, thyroid testing before treatment, every 3months during the first year, every 6months the second year and annually thereafter is recommended as screening procedure.